nerves June 7 Flashcards
What do Platelets do?
Platelets are stem cell fragments made in your bone marrow. These cells bind together to help repair damaged blood vessels and stop bleeding. If you have a cut or a scrape, for example, platelets will stick together causing the blood to clot and stop the bleeding.
Is ACH always excitatory? Is this the same as stimulatory?
The neurotransmitter acetylcholine is excitatory at the neuromuscular junction in skeletal muscle, causing the muscle to contract. In contrast, it is inhibitory in the heart, where it slows heart rate.
My notes say parasympathetic is always stimulatory. Even though it is “stimulatory”, that stimulation may mean calming down. Does this mean ACH always stiumulates? or ? only in the Parasympathetic, and why? is it about the receptors?
Cells of cajal - where do they come from? and where do they live?
Interstitial cells of Cajal (ICC) are mesenchymal cells located within the muscle layers of the alimentary tract that mediate communication between the autonomic nervous system and smooth muscle and may underlie dysrhythmias, gastroparesis, and slow intestinal transit comprising diabetic gastroenteropathy
How does arachnoid villi work?
The arachnoid granulations act as one-way valves. Normally the pressure of the CSF is higher than that of the venous system, so CSF flows through the villi and granulations into the blood. If the pressure is reversed for some reason, fluid will not pass back into the subarachnoid space.
Are ependymal cells special?
Ependymal cells are a specialized type of epithelial cells that line the ventricular system of the brain and play a key role in the production of cerebrospinal fluid.
They line the internal cavities of the CNS - part of the blood-brain barrier and they can absorb and secrete cerebrospinal fluid.
What is the purpose of the nodes of ranvier?
The myelin sheath is regularly interrupted along the length of the axon by specialized regions called the nodes of Ranvier, which are necessary for the propagation of an action potential along the axon.[1] The nodes of Ranvier are essential in the speed and timing of delivery of impulses from one neuron to another,
Slow vs fast anterograde flow down axons?
Neurofilaments and other cytoskeletal polymers are transported down the axon at a rate of 0.2–8 mm day−1, in a process known as ‘slow’ axonal transport. This transport is orders of magnitude slower than the transport of vesicular cargos in ‘fast’ axonal transport
What is the speed of retrograde flow re axons and what is the danger?
Speed is about 200 (half between fast and slow antero - and danger is toxins - tetanus, herpes, rabies - toxins and viruses.
DYNEin powers retrograde flow
What are the two types of synapses?
Chemical and electrical. neurotransmitters vs. gap junctions, CAN BE EXCITATORY OR Iinhibitory
How many synapses can occur in one nuero
10 or a zillion. Purkinje in cerebellum 100,000
What are NSF and how does it relate to vesicles?
NSF is on the membrane of synaptic vesicles and is required for formation, targeting and fusion w/ membrane
synapses are morpholically classified how?
type 1 - asymmetrical, type ROUNDED / excitatory suggestion 2, symectrical FLATTENED - suggested to be INHIBITORY
Does release of nerotrasnmitter create excitation or inhibition?
Both - depending upon… Parasympathetic only excitation.
ACH bindings
M1, M2, M3 (muscarinic - G protein linked) - NICOtinic is Gated ION channel
What are catecholamines?
Norepinephrise, epinephrine, dopanmine - all G protein linked - NE and E bind with alpha 1,2 and beta 1,2,3
Dopamine binds w/ D1,2
NE - roles in anxiety, panic attacks, depression, mania
E - secreted by chromaffin cells in adrenal medulla
DOPA - role in parkinsons
What is required to restore the vesicle fro the membrane edge back into the bulb?
Clathrin, dynamine and syapsin are used to effect this, protein kinase is also involved -
four types of neuerglia?
astrocytes (BBB, etc), oligodendrocytes (made and wrap myelin), ependyma (line w/ cuboidal, / link w/ desmosomes - and CSF) and microglia - police (mesodremal v. neuroectodermal)
CNS has no CT - it’s mushy - so these help support. Pathologically, create 40% of tumors.
What protein do astorcytes have?
GFAP - glial fibrillary acidic protein. = these are prominent bundes of intermediate filament
What do astrocyte feet line?
external limiting membrane (pia) and internal limiting membrane (epedympa - lining ventricles)
they COVER the vare areas of nodes of ranvier in myelinated fibers - they lie on cell body or axolemma
They form gap junctions w/ each other -
have adrenergic receptors, GABA and peptide receptors
Can astrocytes remove excess neurotransmitters at synapses?
yes. They can also form scar tissue called gliosis. Huge roll in BBB
What are Tanycytes?
specialized Ependymal glial-like cells that line the third ventricle, are emerging as components of the hypothalamic networks that control body weight and energy balance. They contact the cerebrospinal fluid (CSF) and send processes that come into close contact with neurons in the arcuate and ventromedial hypothalamic nuclei.
Where do microglia come from?
Bone marrow.
What disease injures Schwann cells?
Guillian barre
A rare disorder in which your body’s immune system attacks your nerves. Weakness and tingling in your extremities are usually the first symptoms. These sensations can quickly spread, eventually paralyzing your whole body
What disease injures oligodendrocytes?
MS.
What causes Wallerian degeneration?
Any lesion of the axons that leads to an interruption and any lesion of the nerve cell bodies that leads to the cell death is followed by Wallerian degeneration. In the CNS common causes are infarction, hemorrhage, tumors, and head injury with shearing of nerve fibers.
four parts of cerebrum
frontal (reasoning)
parietal (movement, (TOP) perception of stiumli)
Occiptal (behind - visual)
temporral ( memory speech, auditory stimuli - on the SIDE)
Cerebellum is called the ?
Little brain - associated with regulation and coordination of movement, posture and balance, fine motor skills (ice skating
Brain stem
basic vital life functions - breathing, heartbeat BP
Midbrain (vision, hearing, eye and body movement);
Pons (motor control) consciouness, sleep
Medulla oblongata - breathing, heart rate
Alcohol effect?
forebrain - motor coord
midbrain - lose control of emotion and chance of blackout
brainstem - heart rate, body empt, appetite, consciousness
White matter in brain - not on the edge - and what’s it consists of?
myelinated axons and oligodendrocytes and microglia - no neural cell bodies
Where do synapses occur, grey or white area?
GREY. on the edges - with nucli (islands of grey) in the white
Where is the cortex of the brain?
On the outside - with GREY matter. White matter organizes in tracts
How many layers does the cerebral cortex have?
six - lots of pyramidal BETZ cells on 5th level.
What’s the function of the cerebral cortex?
integration of sensory info and initiation of voluntary motor responses.
First layer of cerebral cortex?
Lots of fibers, microglial and few cells - a few horizontal cells of cajal -
Cerebellum, how many layers
3 - purkenji with lots of dendrites in center layer. -
What are the granule layers made of in both cerebral and cerebellum?
small neruons
In the spinal cord, where does the lumen develop from ?
neural tube
Grey matter in spinal cord - anterior and posterior horns do what?
Posterior - receive sensory fibers info - anterior contain motor neurons that are the axon roots of motor neurons. spinal cord neurons are large and multipolar, especially in motor neurons..
what are the neuroglial processes in the brain?
Thin layer between pia mater and the nerve layer - BBB
Dilated ventricles in brain might signify?
Hydrocephalus. Failure of absorption of obstruction of CFS. Main absorption is by… archnoid villi - there is no lymph to absorb fluid in brain.
In PNS - do schwann cell wrap unmylienated axons?
YES - and schwann can wrap many - not just one (which is the case when mylinated)
What are neurilemma cells?
Schwann cells
What is the signal protein re how thick myelin should be?
Nrg1 - neuregulin - in axoleema
Spaces between nodes of Ranvier?
Each space, an internode, is covered by one Schwann -
deep cleft on where tight schwann wrapping has loosened are called?
Schmidt-Lantermann clefts or incisures - thought perhaps have to do with nutrition.
What proteins do Schwann cells make?
zero (MPZ) and PMP22. In the CNS is PLP - proteolipid protein
What types of axons are the thickest and have the most mylination - which will cause faster speed?
Motor and Skeletal muscles. Fiber type A alpha.
What are the different types of neural diseases?
Ones that affect mylination (MS, Guillian Barre - Schwann) and neural degeneration (Alz, huntington, Parkinson, ALS?)
Are there various demylination disease beyond the two mentioned above - that are IMMUNE Mediated?
Yes - In MS and Guillain Barre - the immune system attacks mylination - but mylination can also be attacked by:
Inherited - adrenoleukodystrophy (peroxisomal fatty acid beta oxidation disorder)
Metabolic - adverse effect from medical treatment - too quick rise in body sodium, vitamin B deficienty
Virus inducted - JC virus - almost exclusive where have severe immune deficiency
What characterizes these mylinating attacking diseases?
they leave the axons alone - and go after the fatty mylenations - clinical defects come from loss of transmission of electrical impulses.
Lose sensory (often eye sight), limbs fall asleep, muscles weakened, shake -
Autonomic system breaks down with incontinence, impotence
What are some nuerodegenerative diseases - Dementias? and what characterizes them?
Loss of grey matter (neurons) - progressive loss - typically affects groups of neurons located near one another - often associated with accumulation of abnormal proteins resistant to degrdation and which manifest inclusions (ALZ)
What is the sulcus of the brian
The furrows - the GYRI is the other part.
What are tangles caused by?
Tau protein - correlates w/ degree of dementia
IS ALZ missing ACH?
Yes - and narrowing of Gyri and widening of sulci - and cortical atrophy, especially hippocampus
What is parkinson’s disease about?
gene mutations - loss of dopaminergic neuron and lewy bodies causes Pallor of substantia nigra.
What does Parkinson’s do to your body?
TRAPS it - tremor, rigidity, akinesia )or bradykinesia), postural instability and shuffling gait.
What are lewy bodies?
Lewy body dementia (LBD) is a disease associated with abnormal deposits of a protein called alpha-synuclein in the brain. These deposits, called Lewy bodies, affect chemicals in the brain whose changes, in turn, can lead to problems with thinking, movement, behavior, and mood.
What causes parkinson’s?
Unknown - heroin production methods, possible envionmental
What causes huntington disease?
autosomal dominant - appears when 30 - 50 years old. Can be confused with substance abuse re aggressive, depressed, dementia -
Caudate loses Ach and GABA`
can cause ventricular enlargement
sensitive to glutamate
What is ALS?
Lou Gehrig - mostly autosomal dominant, various genetic mutations -
degenerative upper and lower motor neurons, weak hands, arms and legs - and respiratory muscles - deaht in 2 - 3 years for most.
degenerates anterior horn cells and in the brain
Tell me about the perineurium??
It is made of actin filaments and attaches to other cells by tight junctions -
Two functions:
Elastic (so nerves can stretch) and forms a Blood nerve barrier.
What are functions of epineurium (EPIC)
protective when nerves cross joints - acts as a cushion. disppears as nerve branches out - dense fibrous irreg CT, merging with loose CT and adipose surrounding nerve contains mast cells and fibroblasts and collagen bundles
What is chromatolysis?
nerve degeneration when Nissi substances disappear - during degeneration - whole cell size increases due to water entering cell, nucleus moves to edge, golgi shrinks, etc
What is Wallerian degeneration?
myelin sheath breaks down into fat droplets, axoplams disintegrates with 24 hours, endo tube collapes (if can stay together - better regeneration chances) Macrophages move in
how do schwann cells aid in regeneration?
They proliferate at both ends of axon and form bridge from which axon can start to sprout and crawl along.
What does sympathetic nervous system INHIBIT, Stimulate and Dilate?
saliva, GI actions are inhibited, bladder relaxed, pupils, bronchia are dilated, excites - heart rate, adrenal medulla (to release adenaline and NE, and orgasm
What does parasympathetic excite vs. inhibit?
It only excites, except that excitement for PSNS means reducing heart rate and constricting pupils and urinary bladder - stimulates also erection
Autonomic vs somatic receptors?
Somatic - only nicotinic - Autonomic - Nicotinic, alpha 1,2, beta 1,2 M 1 - 5, D 1,2
what post ganglionic axons are mylinated?
NONE. The most heavily mylinated axons are ?? skeletal muscles that have no postganglionic feature.
Where does ganglia come from?
Neural crest cells. ?? all?
What are the collateral ganglia of the Sympathetic nervous system?
Greater, Lesser and Least Splanchnic, and Lumbar - maybe more other places.
What are the two types of sympathetic ganglia?
Chain and collateral - (celiac, aorticorenal, superior and inferior mesenteric)
What do sympathetic and parasympathetic ganglia syntheize?
Symp: catecholamines - PARA - ACH.
What is each ganglion surrounded by?
A layer of small cuboidal cells - satellite cells
Explain the organization of the Ganglionic neurons in the Sympathetic NS?
Lateral grey horns T1 - L2,
chain ganglia (paired), collateral (unpaired) Adrenal medulla (paired)
Chain ganglia effects most of body - including pila, blood vessels, sweat glands -
Collateral in abdominopelvic area
Adrenal by the use of hormones affects throughout body.
Does parasympathetic have a chain ganglia?
No - long preganglionic flow from Cranial 3, 7, 9, 10 (vagus - intramural ganglia), and S2 - 4 -intramural) - named intramural because they are near the organs they innervate
Does sympathetic relax or contract smooth muscles and inhibit glandular secretions?
Relaxes smooth, inhibits glandular secretion - while contracting cardia and vascular.
What does prevertebral and paravertebral mean?
Pre - (in the spinal cord), Para adjaced to spinal cord - hence the sympathetic nervous system and chain ganglia
in the parasympathetic, are there organs not controlled by the vagus in the abdominal cavity?
only the hindgut organs - supplies up to the splenic flexure.
What does peristalsis mean?
the involuntary constriction and relaxation of the muscles of the intestine or another canal, creating wave-like movements that push the contents of the canal forward.
What are the exceptions to the rule that post ganglionic receptors receive NE/E in the SNS?
sweat glands receive ACH,
renal vasculature receive dopamine
chomaffin cells of adrenal medulla - they release epinephrine
Adrenergic receptors - what a1 about?
located on vascular smooth muscle of skin and GI, bladder sphincters - generally produce excitation (constriction) -
GQ protein, Phopholipade C, and IP3, Ca2) intracellular
IN GI - produce RELAXATION
a2 receptors?
Often produce inhibition (relax or dilation) ,
LOCATION - platelets, fast cells, walls of GI tract
Pancreas - less insulin released, Platelets less aggregation,
via GI protein, inhibition of ACH and decrease in cyclic adenosine monophosphate (Camp)
B1 receptor?
produce excitation - located SA and AV node - and ventricular muscle of heart -
Kidney - renin release
Adipose - lipolysis
GS protein, stim of adenylate cyclas and increase in camp
B2 receptors?
blood vessels supplying skeletal, liver, heart; smooth muscles - eye, bronchial and walls of GI and bladder, and blood vessels
RELAXATION - dilation
methods same as B1
ACH and muscarinic - all excitory?? however… some inhibit
M2 and M3 - in heart inhibits Gi protein)
In smooth muscle and glans (excites) (Gq protein, stim phospholipase C, and increase in IP3 and intracellular ca2+.
Are nerves only sensory or motor, or can they be mixed and contain both?
Mixed - most common.
Neural crest cells give rise to which of the following?
dorsal horn,
adrenal cortex,
sympathetic ganglia, preganglion autonomic nerves,
somatic motor neurons?
Sympathetic ganglia
Does NE increase or decrease cardiac output?
Increase.
Are dopamin and GABA inhibitors or excitors?
inhibitors
What’s the most excitatory neurotrasnmitter of the CNS?
Glutamate.
Does seritonin help deal with pain?
Yes, it inhibits pain in mood control and sleep.
What roll does potassium K+ play in cell polarization?
Repolarization of the membrane, which follows membrane depolarization by sodium, and in some cases calcium, channels during the action potential; this is necessary for returning the membrane to a negative resting potential to terminate the action potential signal.
What do Nissi bodies contain?
polysomes and RER
What structure do axon hillocks contain?
microtubules
Rapid onset of fever, stiff neck headache and altered state of consciousness are associated with what neural disease?
meningitis
A patient has a lesion affecting the intermediate lateral horn of the spinal cord. What is the function of this region?
The intermediate horn carries sympathetic cell bodies from the brain and preganglionic neurons
Which form of dementia results from depigmentation of the substantia nigra pars compacta?
Parkinson’s
Patients with Parkinson disease have a loss of which neurons?
Dopaminergic. Dopaminergic neuron loss and excess cholinergic activity
What is the sodium potassium pump?
mechanism where Na+ is pumped out of the membrane and K+ is pumped back in to restore the original configuration within the membrane
What protects cell bodies of neurons?
Satellite cells
What connects sensory and motor neurons?
Interneurons
long axon and short process leaving cell body
unipolar
one axon and one dendrite
bipolar
where about would you find a unipolar neuron?
in the peripheral autonomic regions
Unipolar neurons are typically sensory neurons with receptors located within the skin, joints, muscles, and internal organs. The axons of such neurons are usually long, terminating in the spinal cord.
where would you find a pseudounipolar neurone
dorsal route ganglia
What symptoms of amyotrophic lateral sclerosis (ALS) result from lower motor neuron (LMN) deficits due to anterior horn cell involvement?
Dysarthria, dysphagia, fasciculation, asymmetric limb weakness, atrophy of muscles
Which brain cells respond to infection, such as in bacterial meningitis?
microglia
Which areas of the brain are most commonly affected in a patient with secondary reactivation of latent JC virus?
Parietal and occipital areas; visual symptoms are common
What are the 3 histologic hallmarks of chromatolysis in a peripheral nerve?
Swelling of the cell body, peripheral nuclear displacement, and Nissl substance dispersion throughout the cytoplasm
What parts of a neuron are seen with Nissl staining and why?
Cell bodies and dendrites are stained because they contain rough endoplasmic reticulum (Nissl substance) unlike axons, which do not appear on staining
Which cranial nerve (CN) innervates the muscles of mastication?
3, receptor musc?
What is the difference between Lewy body dementia and dementia secondary to Parkinson disease?
If cognitive and motor symptom onset are <1 year apart, it is called Lewy body dementia; otherwise, it is considered dementia secondary to Parkinson disease
Acute inflammatory demyelinating polyradiculopathy results in destruction of what cell type?
Schwann
How do oligodendrocytes appear histologically?
fried eggs - small nuclei, dark chromatin, and scant cytoplasm)
Which nerve roots are needed for the cremaster reflex?
L1 and l2 (“tesicle move”
What are the embryologic derivatives of each of the 3 meningeal layers?
Dura mater is derived from mesoderm; pia mater and arachnoid mater (leptomeninges) are derived from the neural crest
What is the name of the cranial nerve (CN) that carries parasympathetic efferent fibers from the Edinger-Westphal nucleus?
CN3
What pathology usually results in cauda equina syndrome?
Intervertebral disc herniation or tumor
What brain stem and cerebellar syndromes does multiple sclerosis present with?
Diplopia, ataxia, intention tremor, scanning speech, nystagmus/internuclear ophthalmoplegia (bilateral > unilateral)
Which sinus is the primary site of CSF return?
The superior sagittal sinus
What protein makes up ALZ Disease?
Amyloid-β (cleaved from APP), which forms neuritic plaques in gray matter (diagnosis: Alzheimer disease)
A patient from a nursing home presents with altered mental status after several falls. Likely cause of altered mental status?
Subdural hematoma (or several) as a result of shearing injury from the falls
Which nerve roots cause referred shoulder pain in patients with peritoneal injuries?
C3-C5 (phrenic nerve, which allows for pain referral from the diaphragm and gallbladder)
A patient has a lesion affecting the intermediate lateral horn of the spinal cord. What is the function of this region?
The intermediate horn carries sympathetic cell bodies from the brain and preganglionic neurons
What see in person with Alzheimer’s
Widespread cortical atrophy, especially in the hippocampus with narrowing of gyri and widening of sulci
What phenomenon causes successive generations to manifest features of Huntington disease earlier in their lives?
Anticipation - !!!!
Dopamine from which area binds D1 receptors? Does this stimulate or inhibit movement?
Stimulates
Substantia nigra pars compacta (SNc); this stimulates movement (via the direct pathway)
What markers are associated with neurons?
Synaptophysin and neurofilament protein
Which 2 cranial nerves (CNs) innervate the salivary glands?
CN VII (submandibular and sublingual glands) and CN IX (parotid gland)
Through which layers of the meninges does the venous system of the brain run?
Through the periosteal and meningeal layers of the dura mater
Which neurotransmitter decreases in a patient with Alzheimer disease?
ACH
What organellar activity is increased in this neuron?
Increased activity of the Nissl substance, which allows for increased protein synthesis necessary for axonal repair (this is chromatolysis, image: round cellular swelling)
What is the only type of cutaneous sensory receptor associated with unmyelinated nerve fibers?
free nerve endings
A patient cannot feel pressure, vibration, or touch, and proprioceptive sensation is absent. Which pathway in the spinal cord is impaired?
The dorsal column pathway
What is the purpose of chromatolysis in neuronal cells?
Axonal repair
A biopsy specimen of a brain tumor stains positive for glial fibrillary acid protein (GFAP). From what germinal layer did it arise?
Neuroectoderm (GFAP is an astrocyte marker)
man has an infection. What 3 structures of the blood-brain barrier prevent the infection from spreading into the brain?
Astrocyte foot processes, basement membrane, and tight junctions of nonfenestrated capillary endothelial cells
What brain changes result in a patient with Huntington disease?
Atrophy of caudate and putamen with ex vacuo ventriculomegaly
Which 2 meningeal layers form the subarachnoid space?
Pia mater and arachnoid mater
What 2 structures are present on the apical surfaces of ependymal cells, and what are each of their core functions?
Cilia (circulate cerebrospinal fluid [CSF]) and microvilli (help with CSF absorption)
In which space is cerebral spinal fluid (CSF) collected?
Subarachnoid space
how does a hot bath affect someone with MS?
Symptoms worsen as a result of increased body temperature
Which neural functions are not affected by amyotrophic lateral sclerosis (Lou Gehrig disease)?
Sensory and bladder/bowel functions
What features does Huntington disease usually present with?
Chorea, athetosis, depression, aggression, dementia (sometimes mistaken for substance abuse)
What disease would present in a patient with AIDS experiencing rapidly progressive memory loss and aphasia and who tests positive for active JC virus infection?
Progressive multifocal leukoencephalopathy (reactivation of latent JC virus infection)
What is the usual disease course of amyotrophic lateral sclerosis?
fatal
Describe the pathogenesis of multiple sclerosis.
Autoimmune inflammation and demyelination in the CNS (ie, the brain and spinal cord) with subsequent axonal damage
What demographic group (race, sex, and age) is most likely to be affected by multiple sclerosis?
White women in their 20s and 30s; risk of MS increases with distance from the equator and with low serum vitamin D levels
What does the epineurium surround?
An entire nerve, including both the fascicles and blood supply
What other axonal process is likely occurring at the same time as chromatolysis?
Wallerian degeneration (distal axonal degeneration and proximal retraction) occurs concurrently in response to axonal injury
What symptoms are commonly seen in a patient with Charcot-Marie-Tooth disease?
Foot deformities (eg, pes cavus, hammer toe), sensory deficits, and lower extremity weakness (eg, foot drop)
Charcot-Marie-Tooth disease (CMT) is a group of inherited conditions that damage the peripheral nerves. It’s also known as hereditary motor and sensory neuropathy (HMSN) or peroneal muscular atrophy (PMA). The peripheral nerves are found outside the main central nervous system (brain and spinal cord).
What are Lewy bodies?
Intracellular eosinophilic inclusions composed of α-synuclein; seen in Parkinson disease and Lewy body dementia
What does the epidural space contain?
Fat and blood vessels
receptors that inhibit and excite?
the M’s (1-3) excite, M’s (2,4) inhibit. A1,B1 excite, A2,B2 inhibit. Thats what I remember off the top of my head
In Parkinson disease, due to less dopamine binding D1 receptors in the striatum, what happens within the direct pathway to decrease movement?
Striatum releases less γ-amino butyric acid (GABA); this disinhibits the globus pallidus interna (GPi), leading to inhibition of the thalamus and cortex to decrease movement
What 2 anatomic structures surround the epidural space?
The dura mater and skull
What are the steps in smooth muscle contraction that follow calmodulin binding to Ca2+?
Myosin–light-chain kinase (MLCK) is activated, phosphorylating myosin and leading to contraction
Patients with myasthenia gravis and Lambert-Eaton syndrome develop muscle weakness. Would patients with Lambert-Eaton syndrome display autonomic symptoms?
Yes; autoantibodies to presynaptic Ca2+ channel are produced, so the autonomic system (eg, dry mouth, constipation, impotence) and muscular junctions are affected
Describe the sequence of skin color changes that occur in Raynaud phenomenon.
White (ischemia), then blue (hypoxia), then red (reperfusion)
A weight trainer benches on a daily basis. He is inducing hypertrophy of which type of muscle fiber?
white fast - this is what sprinting and weight lifting build
A patient who had abdominal surgery reports burning at the incision site that radiates to the inguinal region. Which nerve is affected?
Iliohypogastric nerve (T12–L1)
How does estrogen exert its effects on bone?
Stops bone growth in puberty, promotes oclast activity throughout life - so when older women don’t have it - their bones may get weak.
It inhibits apoptosis in osteoblasts and induces apoptosis in osteoclasts
Osteoblasts keep living, and osteoclasts die
What is the function of the Golgi tendon organ, a muscle proprioceptor?
It senses tension via the dorsal root ganglion and facilitates inhibition of muscle activation, which reduces tension in the muscle and tendon
Name the 2 ophthalmic manifestations that can present in a patient diagnosed with myasthenia gravis.
eye droop Ptosis and double vision. Diplopia,
What is the fundamental mechanism of osteoarthritis?
Mechanical; wear and tear causes destruction of articular cartilage, leading to inflammation with inadequate repair (chondrocyte mediated)
Where is the Golgi tendon organ located and what type of sensory axons does it innervate?
It is located in the tendons; it innervates type Ib sensory axons
Patients can reduce their risk of osteoporosis by taking what 2 supplements?
Calcium and vitamin D (should be taken throughout adulthood)
Osteopetrosis leads to thickened, dense bones. How likely are these bones to fracture?
Brittle bone disease,
Very likely, because the normal process of remodeling and resorption is disrupted
A patient has an L3–L4 disc herniation. Which nerve roots are impaired by this lesion?
The L4 nerve roots (in the lumbar spine, the nerve roots are found inferior to the associated vertebral body)
Lambert-Eaton myasthenic syndrome predominantly leads to weakness in which muscle groups?
Proximal muscle groups
In membranous ossification, what is the role of cartilage in the formation of woven bone?
Woven bone is formed directly without cartilage (ie, there is no role for cartilage); woven bone is later remodeled to lamellar bone
A patient is told that an x-ray image shows diffuse symmetric sclerosis. What other phrase is used to describe this observation?
Bone-in-bone or “stone bone” seen in osteopetrosis
Are osteoclastomas (giant cell tumors) benign?
Yes, but they are locally aggressive
A patient with osteitis deformans has increased osteoblastic and osteoclastic activity with normal Ca2+, PO43-, and PTH levels. What disease stage is this?
The mixed stage of osteitis deformans (also known as Paget disease of bone) in which increases in both osteoblast and osteoclast activity occur
Which muscles are innervated by the obturator nerve?
Obturator externus, gracilis, pectineus, adductor longus, adductor brevis, adductor magnus
Rheumatoid arthritis is more prevalent in what population?
females
During the power stroke, what happens to myosin?
Myosin releases ADP and Pi and becomes displaced on the actin filament
Osteitis deformans has high-yield oncologic and non-oncologic complications. What cancerous outcome can you see in a patient with osteitis deformans?
Osteogenic sarcoma; increased activity of osteoblasts can create mutations, resulting in osteosarcoma
Achondroplasia is inherited in what fashion?
Autosomal dominant (with full penetrance); associated with increased paternal age
In achondroplasia, what type of bone ossification is impaired?
long bone growth - due to impaired endochondral ossification (due to a mutation in FGFR3)
What is the term for chronic joint degeneration caused by calcium pyrophosphate deposition disease?
Pseudo-osteoarthritis
Achondroplasia is inherited in an autosomal dominant manner. Are most cases of achondroplasia inherited?
No; most cases result from sporadic mutation
An osteoma affects what age group?
Middle-aged adults
Surface of facial bones
Associated with Gardner syndrome
How does estrogen deficiency (eg, due to surgery or menopause) lead to osteoporosis?
Excess remodeling cycles and bone resorption occur without the protective effects of estrogen
From which metabolic process do type II muscle fibers derive their energy?
Anaerobic glycolysis
Osteochondromas rarely transform into which type of malignancy?
Chondrasarcoma
A 2-year-old boy has bowing of the legs. His labs show elevated parathyroid hormone levels but decreased Ca2+ levels. What is the primary deficiency?
Rickets - Vitamin D - C is scurvy
What are the common extraarticular manifestations of rheumatoid arthritis?
Rheumatoid nodules; interstitial lung disease; pleuritis; pericarditis; anemia of chronic disease; Felty, carpal tunnel, and Sjögren syndromes; AA amyloidosis; scleritis
Inflammation and exuberant proliferation of the synovium leads to formation of pannus and destruction of cartilage, bone, tendons, ligaments, and blood vessels. Basically, the hypertrophied synovium is called pannus.
What secretions of osteoclasts effectively dissolve bone?
H+ and collagenases
Osteoporosis is most often diagnosed because of what finding in which procedure?
T-score of ≤ -2.5 on DEXA scan (at the lumbar spine, total hip, and femoral neck)
A new drug inhibits the ryanodine receptor. What ion will not be released from the sarcoplasmic reticulum as a result?
Calcium
What part of bone will be affected by osteosarcoma?
Metaphysis of long bone, especially the knee region
A sprinter would have a higher proportion of which type of muscle fibers?
White type II.
What nerve roots make up the pudendal nerve?
L2 - 4
What is the underlying pathophysiology of Paget disease of bone (osteitis deformans)?
Increases in both osteoblastic and osteoclastic activity, resulting in localized, pathologic bone remodeling
What happens when ATP binds to a myosin head that is attached to the actin filament?
Release of the myosin head; hydrolysis of ATP to ADP puts myosin in a cocked position for the next contraction cycle; Ca2+ is resequestered
How do osteoblasts build bone?
They secrete collagen and catalyze mineralization via alkaline phosphatase (osteoblasts build bone)
What x-ray findings are associated with vitamin D deficiency?
Osteopenia and Looser zones in osteomalacia; epiphyseal widening and metaphyseal cupping/fraying in rickets
What neurologic lesions may result from osteopetrosis?
Cranial nerve palsies due to narrowed foramina in the skull, which impinges the nerve
At what age is a 1-time screening for osteoporosis recommended for women?
65 years or older
Which benign bone tumors are more common in boys?
Osteochondroma, Osteoma, Osteoid osteoma, Osteoblastoma; benign bone tumors that start with O are more common in boys
What are some causes of primary hyperparathyroidism?
Parathyroid hyperplasia, a parathyroid adenoma or carcinoma, or idiopathic
Parathyroid hormone is increased in osteomalacia (rickets in children). What effect does this have on osteoblasts? Hence Vitamin D is needed to avoid to control parthyroid?
Osteoblasts are stimulated to make alkaline phosphatase because they require an alkaline environment to function properly
When calcium levels are low, parathyroid hormones are released by the body to help counteract this deficiency. … As vitamin D deficiency and elevated parathyroid hormone levels are extremely common in older adults, it is important that adults get enough calcium and vitamin D to promote cardiovascular health
Explain how type I slow-twitch muscle fibers utilize oxidative phosphorylation.
They have a relative increase in oxidative phosphorylation, which leads to sustained muscle contractions (think “1 slow red ox”)
What is oxidative phosphorylation?
the synthesis of ATP by phosphorylation of ADP for which energy is obtained by electron transport and which takes place in the mitochondria during aerobic respiration.
Why are type II muscle fibers white?
Lower myoglobin and lower mitochondria
What is the fundamental mechanism of rheumatoid arthritis?
Autoimmune; inflammation causes proliferation of granulation tissue (pannus formation), which erodes articular cartilage and bone
How is the synovial fluid in rheumatoid arthritis (RA) different from that in osteoarthritis (OA)?
In RA, the fluid is inflammatory (WBC >2000 mm3); in OA, the fluid is noninflammatory (WBC <2000 mm3)
Which hormone is likely chronically elevated in a patient with osteitis fibrosa cystica?
Parathyroid hormone, leading to excess bone catabolism (patient may have primary hyperparathyroidism)
How are osteoclasts activated?
RANKL (RANK ligand expressed on osteoblasts) stimulates RANK receptors on osteoclasts
You believe a patient has myasthenia gravis. What class of drugs would you prescribe to treat this disease?
Acetylcholinesterase inhibitors (such as pyridostigmine)
What are the classic physical exam findings in a patient with fibromyalgia?
Tender points and stiffness
Most common in women 20–50 years old. Chronic, widespread musculoskeletal pain associated with “tender points,” stiffness, paresthesias, poor sleep, fatigue, cognitive disturbance(“fibro fog”). Treatment: regular exercise, antidepressants(TCAs, SNRIs), neuropathic pain agents (eg, gabapentin
Osteitis deformans (Paget disease of bone) represents disordered activity of osteoclasts and osteoblasts. Which is disrupted first?
Osteoclasts (4 stages of Paget disease: lytic, mixed, sclerotic, quiescent)
Which malignant bone tumor presents as an enlarging mass that produces pain or occurrence of pathologic fractures?
Osteosarcoma
An x-ray obtained from a 12-year-old boy who has frequent fractures has a bone-in-bone appearance (image). What enzyme is likely deficient?
Carbonic anhydrase II, which is defective in osteopetrosis
Mutations (eg, carbonic anhydrase II) impair ability of osteoclast to generate acidic environment necessary for bone resorption. Overgrowth of cortical bone fills marrow space pancytopenia, extramedullary hematopoiesis. Can result in cranial nerve impingement andpalsies due to narrowed foramina.
X-rays show diffuse symmetric sclerosis(bone-in-bone, “stone bone” ). Bonemarrow transplant is potentially curative as osteoclasts are derived from monocytes
What is the most common cause of short-limbed dwarfism?
Achondroplasia
What are muscle proprioceptors?
Specialized sensory receptors that transmit information regarding muscle dynamics
Why might you expect to see abnormal red and white cells in the peripheral smear of a patient with osteopetrosis?
The marrow-filling process squeezes out normal cell lines (eg, one might see dacryocytes)
How does smooth muscle respond to intracellular Ca2+ vs nitric oxide?
Ca2+ = Contraction, nitric oXide = relaXation
Will see myosin light chain kinase /and MLC phospholate
Steps involved in smooth muscle cell contraction:
Depolarization of membrane or hormone/neurotransmitter activation.
L-type voltage-gated calcium channels open.
Calcium-induced calcium release from the SR.
Increased intracellular calcium.
Calmodulin binds calcium.
Myosin light chain kinase activation.
Smooth muscle contraction is dependent on calcium influx. Calcium is increased within the smooth muscle cell through two different processes. First, depolarization, hormones, or neurotransmitters cause calcium to enter the cell through L-type channels located in the caveolae of the membrane
Intracellular calcium then stimulates the release of calcium from the sarcoplasmic reticulum (SR) by way of ryanodine receptors and IP3; this process is referred to as calcium-induced calcium release.[7] Unlike skeletal muscle, smooth muscle calcium release from the sarcoplasmic reticulum is not physically coupled to the ryanodine receptor. Once calcium has entered the cell it is free to bind calmodulin, which transforms into activated calmodulin. Calmodulin then activates the enzyme myosin light chain kinase (MLCK), MLCK then phosphorylates a regulatory light chain on myosin. Once phosphorylation has occurred, a conformational change takes place in the myosin head; this increases myosin ATPase activity which promotes interaction between the myosin head and actin. Cross-bridge cycling then occurs, and tension is generated.
The tension generated is relative to the amount of calcium concentration within the cell. ATPase activity is much lower in smooth muscle than it is in skeletal muscle.
What are the two types of smooth muscle?
Visceral smooth muscle - All cells work together at the same time as one unit.
Multi-unit smooth muscle - Cells can act and function independently of the others.
Which bones are formed by membranous ossification?
Bones of the calvarium, face, and clavicle
In what demographic does the incidence of primary osteosarcoma peak?
Boys and men <20 years old; osteosarcomas constitute 20% of primary bone cancers
Which tumor arises from the medulla of the pelvis, proximal femur, and humerus?
Chondrosarcoma
A drug is synthesized to prevent calcium binding to NO synthase. What effect would this have on smooth muscle function?
It would prevent relaxation of smooth muscle
Which type of muscle fiber is found in fast-twitch muscles?
Type II - white
Osteomalacia and rickets are the same disease, but rickets is the term for the childhood form
Adults vs. Children
What bone type will be seen in a biopsy specimen of a pathologic lesion from a patient with Paget disease?
Woven bone (as opposed to lamellar bone)
What is the pathophysiology of osteomalacia?
Low vitamin D leads to low serum Ca2+ levels, increasing secretion of PTH and secondarily lowering PO43- levels
During skeletal muscle contraction (power stroke), which bands of the sarcomere decrease in length?
H band and I band between the Z lines (HIZ shrinkage); ADP is released at end of power stroke. ATP still needed to release the head.
What is the curative treatment for osteopetrosis?
Bone marrow transplant - which provides normal monocytic precursors that differentiate into osteoclasts
What demographic group is most affected by osteochondroma?
Boys and men <25 years old
After presynaptic neuron neurotransmitter release, postsynaptic acetylcholine binding leads to the depolarization of which membrane?
The motor end plate of the muscle cell (postsynaptic membrane)
How does a genitofemoral nerve injury affect female patients?
Sensation is lost in the labia majora and medial thigh
The dorsal nerve of the clitoris is a nerve in females that branches off the pudendal nerve to innervate the clitoris.
A 77-year-old woman has pain in her hands at the end of the day. By what mechanism has her arthritis developed?
Mechanical wear and tear on articular cartilage (she has osteoarthritis, a degenerative joint disease)
Which bones are formed by endochondral ossification?
Bones of the axial and appendicular skeleton, as well as the base of the skull
How does repetitive muscle activity affect patients with myasthenia gravis vs those with Lambert-Eaton myasthenic syndrome?
MG - strength decreases with muscle use
In patients with myasthenia gravis, strength decreases with muscle use; in those with Lambert-Eaton syndrome, strength improves with muscle use
What protein can decrease osteoclast activity by binding RANKL, and what is the protein’s mechanism of action?
OPG - decoy, takes RANKL’s place
People of what age are predisposed to calcium pyrophosphate deposition disease?
Usually those older than 50 years
A patient has dry mouth and proximal muscle weakness that improves with muscle use. What is the root cause of her symptoms?
Autoantibodies to presynaptic Ca2+ channels, causing decreased acetylcholine release (patient has Lambert-Eaton myasthenic syndrome)
How would you differentiate between osteomalacia and osteoporosis?
Levels of vitamin D, PTH, Ca2+, and PO43- are altered in osteomalacia but normal in osteoporosis
What is the primary change in osteitis fibrosis cystica due to primary hyperparathyroidism?
Increase in PTH
What is the most common malignancy of the bone?
Mestastic Disease
Constitutive activation of what pathway is responsible for the pathophysiology behind achondroplasia?
Fibroblast growth factor receptor 3 (FGFR3), which inhibits chondrocyte proliferation
A poison affects the release of certain molecules (breakdown products), such that myosin cannot be displaced on the actin filament. What molecules are these?
ADP and inorganic phosphate
A man has autoantibodies against presynaptic Ca2+ channels, causing weakness. With what malignancy is his disease classically associated?
Small cell lung cancer (he has Lambert-Eaton myasthenic syndrome)
Would myasthenia gravis and Lambert-Eaton syndrome both improve with acetylcholinesterase inhibitor use?
No; only symptoms of myasthenia gravis are reversed with the use of AChE inhibitors
What is the role of troponin C in muscle contraction?
Calcium binds here - and that causes opening of active sites where myosin heads can bind.
What type of bone is formed by healed fractures?
woven at first… which then turns into lamellar
At what time of day is the stiffness of rheumatoid arthritis most intense and how long does it usually last?
morning - after one hour better, improves w/ use
Arthritis caused by the crystals shown in the image tends to predominantly affect which joints?
Large joints, usually the knee (these are the positively birefringent crystals of calcium pyrophosphate deposition disease)
Osteoporosis may present as a fracture following minimal trauma. What 3 fractures are classicly seen in osteoporosis?
Fractures of the femoral neck, the vertebrae (compression fractures), and the distal radius (Colles fractures)
As an action potential travels along a muscle cell, it goes down into invaginations in the membrane called what?
T-tubules
A patient has been told he has dense bones as shown (image), yet he is frequently fracturing them. Likely diagnosis?
osteopetronis - oclast problem - bone marrow transplant
What are T-tubules, and what is their relation to the muscle?
Extensions of muscle plasma membrane in contact with sarcoplasmic reticulum; this enables coordinated contraction of striated muscles
Membrane depolarization induces conformational changes in the voltage-sensitive dihydropyridine receptor (DHPR) and its mechanically coupled ryanodine receptor (RR) Ca2+release from the sarcoplasmic reticulum into the cytoplasm
What is the source of osteoblasts?
Mesenchymal stem cells in the periosteum
Osteoblast
Builds bone by secreting collagen and catalyzing mineralization in alkaline environment via ALP. Differentiates from mesenchymal stem cells in periosteum. Osteoblastic activity measured by bone ALP, osteocalcin, propeptides of type I procollagen.
Osteoclast
Dissolves (“crushes”) bone by secreting H+and collagenases. Differentiates from a fusion of monocyte/macrophage lineage precursors. RANK receptors on osteoclasts are stimulated by RANKL (RANK ligand, expressed on osteoblasts). OPG (osteoprotegerin, a RANKL decoy receptor) binds RANKL to prevent RANK-RANKL interaction osteoclast activity.
Parathyroid hormone
At low, intermittent levels, exerts anabolic effects (building bone) on osteoblasts and osteoclasts (indirect). Chronically PTH levels (1° hyperparathyroidism) cause catabolic effects (osteitis fibrosa cystica).
Estrogen
Inhibits apoptosis in bone-forming osteoblasts and induces apoptosis in bone-resorbing osteoclasts. Causes closure ofepiphyseal plate during puberty. Estrogen deficiency (surgical or postmenopausal) cycles of remodeling and bone resorption risk of osteoporosis
Why are type I muscle fibers red?
They have high concentrations of mitochondria and myoglobin for sustained contraction
Nitric oxide (NO) in smooth muscle cells is derived from which amino acid generated in the endothelial cells?
L-arginine (via L-arginine’s conversion to NO via NO synthase)
A patient who recently gave birth reports fecal and urinary incontinence. Exam shows loss of sensation in the perineum. What is the cause?
Injury to the pudendal nerve during childbirth
In smooth muscle, Ca2+ binds to which molecule after entering the cell to initiate contraction?
Calmodulin
How does a genitofemoral nerve injury affect male patients
Sensation is lost in the scrotum and medial thigh, and the cremasteric reflex is absent
A 40-year-old woman has diffuse musculoskeletal pain/stiffness, paresthesias, poor sleep, and fatigue. How do you treat her?
Fibromyalgia - Recommend regular exercise and prescribe antidepressants (SNRIs, TCAs) and/or a drug that targets neuropathic pain, such as gabapentin
A young athlete is increasing his endurance training. Which type of muscle fibers would increase in proportion as a result?
type 1
What factors activate muscle proprioceptors?
Muscle spindle gets activated by ↑ muscle stretch; Golgi tendon gets activated by ↑ muscle force
What disorder is caused by defective mineralization, leading to soft bones?
Osteomalacia/rickets
An experimental drug prevents the human body from breaking down old bone cells. Which enzyme does this drug most likely inhibit?
Collagenase, as osteoclasts release H+ and collagenases to dissolve old bone
What 3 markers can you use to measure the activity of osteoblasts?
Osteocalcin, bone ALP, and type 1 procollagen propeptides
A young woman has ptosis, diplopia, dyspnea, and weakness that worsens with muscle use. What is the root cause of her symptoms?
Autoantibodies to postsynaptic acetylcholine receptors (she likely has myasthenia gravis)
Myasthenia gravis: spared reflexes; Lambert-Eaton syndrome: hyporeflexia
What is the difference in function of myosin–light-chain kinase (MLCK) vs myosin–light-chain phosphatase (MLCP)?
phosphotase goes w/ NO to RELAX? which is correct??
Where is the muscle spindle located and what type of sensory axons does it innervate?
It is located in the body of the muscle; it innervates type Ia and II sensory axons
A scientist cultures osteoblasts and notes active mineralization. What will pH measurements of this cell culture show?
An alkaline environment (osteoblasts secrete ALP to create this environment and catalyze mineralization)
What bone density disease has no laboratory abnormalities?
Osteoporosis, which has a decrease in bone mass
With which artery does the long thoracic nerve travel?
Lateral thoracic artery
A child who is unable to have sunlight exposure (eg, one with xeroderma pigmentosum) should receive a supplement with which fat-soluble vitamin to prevent which bone disease?
Vit d - to prevent rickets
What opens the presynaptic voltage-gated Ca2+ channels, inducing the release of acetylcholine into the synaptic space?
Action potential
A 60-year-old woman has pain and stiffness in her hips and shoulders and a fever. She has no associated muscular weakness. Diagnosis?
Polymyalgia rheumatica
Describe the appearance of an osteoclastoma on an x-ray.
An osteoclastoma/giant cell tumor looks like a soap bubble on an x-ray
Name some predisposing factors for osteosarcoma.
Paget disease of bone, radiation, bone infarcts, familial retinoblastoma, Li-Fraumeni syndrome (germline p53 mutation)
I am switching over to just using usmle - https://usmle-rx.scholarrx.com/play-deck/724900?contentKey=FF109812.2
A few of the slides were pretty well laid out… the M’s (1-3) excite, M’s (2,4) inhibit. A1,B1 excite, A2,B2 inhibit. Thats what I remember off the top of my head
what is acellular cementum?
Acellular cementum is the thin, mineralized tissue covering the cervical portion of the tooth root, important for attachment of the periodontal ligament (PDL) to the root surface
which cells produce enamel
ameloblasts
What does the odontoblast do?
The odontoblast is a highly specialized cell with a high secretory function. It is a cell of neural crest origin and is found on the outer layer or periphery of the pulp adjacent to the peridentin layer. It is a post-mitotic cell and its primary function is secretion of dentin during dentinogenesis.
What are dentin tubules
Dentin tubules are microscopic channels that radiate from the underside of the enamel surface to the inside of the tooth, called the pulp. They get their name because they travel through the dentin. Dentin is the major structural component and middle layer of the tooth, supporting the brittle enamel on the exterior.
What do sharpies fibers do re teeth
Bind teeth to bone
Sharpey’s fibres are also used to attach muscle to the periosteum of bone by merging with the fibrous periosteum and underlying bone as well. … In the teeth, Sharpey’s fibres are the terminal ends of principal fibres (of the periodontal ligament) that insert into the cementum and into the periosteum of the alveolar bone.
hardest fiber in body?
enamal 95%
What is pulp cavity of teeth?
The pulp or pulp chamber is the soft area within the center of the tooth and contains the nerve, blood vessels, and connective tissue. The tooth’s nerve is in the “root” or “legs” of the tooth. The root canals travel from the tip of the tooth’s root into the pulp chamber.
What is enamel rod of teeth
An enamel rod is the basic unit of tooth enamel. Measuring 4 μm wide to 8 μm high, an enamel rod is a tightly packed, highly organized mass of hydroxyapatite crystals, which are hexagonal in shape and provide rigidity to the rods and strengthen the enamel.
What are interglobular dentin?
“Interglobular dentin (IGD) is mineralization defects (bubble-like spaces) that form in bands where dentine fails to mineralize properly along incremental lines due to low levels of vitamin D,”
Most of oral cavity - is it keratinized or non-keritznied squamous?
NON - 4 exceptions - gingiva (except inner part near tooth), outside lips to red zone; hard palate, filiform papillae
four types of lingual papillae
filiform (all over), fungiform (mushroom) has taste buds; circumvallate - lots of taste budy and VON EBNER Cells (serous) - fourth foliate (not count in humans)
Riley Day disorder
inability to detect taste - maybe lesion in nerve
Taste buds
taste pores - microvilla - synapse with Phospholypase lypase C, IP3, DAG - g protein procedure
what divides 1/3 and 2/3 anterior part of tongue?
Sulcus terminalis
Posterior 1/3 of tongue
The posterior one-third of the tongue is innervated by the glossopharyngeal nerve (CN IX) which carries both general sensory information from mucosa and special sensory information from the vallate papillae. The anterior two-thirds of the tongue have double sensory innervation.
Has crypts
TO DO MORE re oral cavity - use first aid and slides.
I am going to try to get anat lecture done in Qs
Re supradrenal glands, what is of interest in the veins?
right goes directly to IVC, left goes to left renal vein
a single vein draining each adrenal gland. Like the gonadal veins each side drains differently: left suprarenal vein drains into the left renal vein
right suprarenal vein drains directly into the inferior vena cava
Re supradrenal glands, what is of interest in the veins?
right goes directly to IVC, left goes to left renal vein
a single vein draining each adrenal gland. Like the gonadal veins each side drains differently: left suprarenal vein drains into the left renal vein
In parasympathetic - what muscaline are inhibitory vs. Excitatory
M2, 4 - inhibit, M135 excite
Nicotinic all excitory
IN sympathetic - NE stimulates?
B and a1
A1 is G protein with photolipase C, IP3, CA and other way DCG, protein Kinase all CAMP
a2 is inhibitory
What are blood supplies of suprarenal?
Three sources of arteries maintain blood supply to the suprarenal glands. The superior suprarenal arteries are multiple small branches from the inferior phrenic artery, whereas the middle suprarenal artery is a direct branch from the abdominal aorta
Arteries of ureters?
The blood supply to the ureter is segmental. The upper ureter closest to the kidneys receives blood directly from the renal arteries. The middle part is supplied by the common iliac arteries, branches from the abdominal aorta, and the gonadal arteries.
What type of cells make up ureters - that allow them to stretch?
transitional epithelium
kidney machine to help get rid of stones?
SWL - stones will cause HUGE pain - if <1 - can pass them, machine can take out small stones. - staghorn calculi can exist.
Why does an artery enter and leave the kidney?
Afferent and efferent artery - and efferent (carry now filtered yucky stuff) leaves, and eventually turns into a vein, which returns to the IVC via the renal vein.
Why does an artery enter and leave the kidney?
Afferent and efferent artery - and efferent (carry now filtered- with good (vit D? and bad) leaves, and eventually turns into a vein, which returns to the IVC via the renal vein.
What’s a horseshoe kidney?
It never divided during fetal life.
usually find, but causes lots of UTIs in kids.
What does a kidney absess often cause?
Pain in psoas muscle , can’t climb stairs.
Does kidney have several layers of covering?
Yes, Gerotas fascia (anchors kidney), adipose capsule and rental capsule - last prevents kidney infection
If you can palpate the kidney, what does that probably mean?
That it is swollen bec very hard to palpate. The LEFT one is really hard - maybe possible in children or skinny people.
Where is the kidney?
T12 - L3 - right lower
what nerves innervate the kidney?
Kidney innervation consists of both afferent and efferent nerves, of which the efferent is strictly sympathetic. These nerves make up the renal plexus, and receive inputs from the celiac and aorticorenal plexuses as well as the least splanchnic nerves.
What are the three muscles of the posterior abdomen?
There are five muscles in the posterior abdominal wall: the iliacus, psoas major, psoas minor, quadratus lumborum and the diaphragm.
Psoas major - can’t climb stairs if kidney inflamation
What are the 6 pairs of arteries in the abdomen that are not the main 3?
6 -
Inferior phrenic, middle suprarental, renal, gonadal, lumbar, median sacral.
The abdominal aorta has: 3 single anterior visceral branches (coeliac, superior mesenteric artery, inferior mesenteric artery) 3 paired lateral visceral branches (suprarenal, renal, gonadal) 5 paired lateral abdominal wall branches (inferior phrenic and four lumbar)
What are the enteric nerves?
Myenteric Auderback plexus and Submucusal
What are the enteric nerves?
Myenteric Auderback plexus and Submucusal
Auerbach’s plexus, also known by the name of myenteric plexus, is a group of ganglia that run throughout the entire gastrointestinal tract and innervate its multiple layers of smooth muscle. … The myenteric plexus is principally responsible for the peristaltic movement of the bowels
What organ activates Vitamin D
kidney
It is activated by two protein enzyme hydroxylation steps, the first in the liver and the second in the kidneys.
What does Rennin do?
Help regulate blood pressure
What type of parasym receptor is on the salivary glands
Musc -
What type of recepters does the kidney have
Dopamine for symp
Where does the kidney efferent artery turn into a vein?
Interlobular vein and arcuate vein
From what wall do the ureters enter the bladder?
Posterior
What is renal colic
Stones in the kidney/ureter system.
Renal colic is a type of pain you get when urinary stones block part of your urinary tract. Your urinary tract includes your kidneys, ureters, bladder, and urethra. You can get stones anywhere in your urinary tract.
Where is the nerve supply on the kidneys?
The renal, testicular (or ovarian), and hypogastric plexuses (in the pelvis)
Afferent fibers travel with the sympathetic nerves and enter the spinal cord in the 1st and 2nd lumbar segments
Where will pain be felt with kidney stones?
back to front flank and down into inner thigh
Tell me about the suprarenal glands - do they make cortisol?
Yes. Cortisol is a steroid hormone, in the glucocorticoid class of hormones. When used as a medication, it is known as hydrocortisone
How many areas does it have, do they do different things?
Yes,
the capsule, cortex and medulla (where chormmafin neural crest cells are - that make the CATACOLAMINES _ NE and EP
Vasculature of suprarenals?
The suprarenal glands are among the most extensively vascularized organs in the body.
Arteries:
Superior suprarenal arteries (multiple small branches from the inferior phrenic artery)
Middle suprarenal artery (a direct branch from the abdominal aorta)
Inferior suprarenal artery (arise from the renal artery on each side)
The blood drains through the suprarenal vein to the left renal vein or directly to the inferior vena cava on the right side
What posterior abdominal muscle assists with respiration?
Quadratus lumbarus. From iliac crest upward to rib 12 and lumbar fascia
if someone is having an Aortic Anyerism what might you see?
Syncope is a temporary loss of consciousness usually related to insufficient blood flow to the brain. It’s also called fainting or “passing out.” It most often occurs when blood pressure is too low (hypotension) and the heart doesn’t pump enough oxygen to the brain.
And raised abdomen - often no clue this is going to happen until explodes.
List the sympathetic nerve supplies -
Greater splanchnic nerve (T5-9/10) Lesser splanchnic nerve (T10-11) Lowest (least) splanchnic nerve (T12) Lumbar splanchnic nerves (L1-3) Sacral splanchnic nerves primarily preganglionic somatic nervous system fibers that come off the chain, synapse in inferior hypogastric plexus
What’s the celiac plexus, and does it join with the greater or lesser splanchic?
The largest of the three sympathetic plexuses
At the level of the upper part of the first lumbar vertebra
Composed of two large ganglia, the celiac ganglia
The upper part of each ganglion is joined by the greater splanchnic nerve, while the lower part, which is segmented off and named the aorticorenal ganglion, receives the lesser splanchnic nerve and gives off the greater part of the renal plexus
What’s the enteric nervous system about?
These ganglia and their neural networks include the following:
Myenteric (Auerbach’s) plexuses
Ganglia and nerves located between the circular and longitudinal smooth muscle layers of the muscularis externa of the bowel wall
Submucosal (Meissner’s) plexuses
Ganglia and nerves located in the submucosa of the bowel wall
What is renal agenisis?
Missing one kidney - not serious, more common in males asymptomatic
Potter syndrome?
No kidneys - can’t live - OLIGOhYdra problems - limbs harmed re no space, wrinkles, abnomal face
HOX genes need to develop what?
Kidneys
What is reciprocal inductions?
When forming kidneys and ureters communicate and help each other grow - with a variety of different genes
Where does kidney move from? Do they also rotate?
Has to ascend and rotate. Leaves arteries behind, gets new ones.
yes, the rotate - hilem from front to medially
sometimes problems here too
Horseshoe kidney
Two kidneys grow together. During ascension they may get stuck on the IMA
More UTIs - 1/600.
Left renal vein, how differ from right?
Left renal had the gonadal vein joining. Right gonadal goes straight to IVC. Left renal is LONGER as has to come from farther awa - maybe that’s why it joined
Where do gonads move?
From upper and lower, and due to gravity, take their arteries with them
What does allantois become?
Median umbilical Ligament
What develops from vesicle part of urogenital sinus?
Bladder and uppert part of postetic uretha above ejac duct
What does Indifferent mean in embyiology
Can’t tell sex yet - same
What is bladder extrophy?
when ventral wall of abdoment fail to close - can see variety of problems - including open ureters - epispodia
What causes urachus cysts and fistulas?
Failure of ventral wall of abdomen to close
Other bladder problems?
Septum divides in two, or bladder duplicates, hourglass bladder, heart shaped.
What are teniae coli?
on colon, gathers up the colon, help with digestion
What the Teres ligamentum?
The round ligament of the liver (or ligamentum teres, or ligamentum teres hepatis) is the remnant of the umbilical vein that exists in the free edge of the falciform ligament of the liver. The round ligament divides the left part of the liver into medial and lateral sections.
What’s the ductus venosa, and what does it connect/
The ligamentum venosum is the fibrous remnant of the ductus venosus of the fetal circulation.
In the fetus, shunts a portion of umbilical vein blood flow directly to the inferior vena cava. Thus, it allows oxygenated blood from the placenta to bypass the liver.
Bypass connection left branch of portal vein and IVC
Ductus venosus (DV) is a narrow, trumpet-shaped vessel which is seen in the fetal liver connecting the umbilical vein directly to the caudal inferior vena cava.
The ligamentum venosum is the fibrous remnant of the ductus venosus of the fetal circulation. Usually, it is attached to the left branch of the portal vein within the porta hepatis (gateway to theliver). It may be continuous with the round ligament of liver (ligamentum teres hepatis).
What drains into the IVC from the liver?
The portal vein
Where is the quadrate vs. the caudate liver sections?
The q is below the C.
What is pyloris defined
Where the lesser curvature takes a turn - the pyloric notch
What’s the ductus venosa, and what does it connect/
In the fetus, shunts a portion of umbilical vein blood flow directly to the inferior vena cava. Thus, it allows oxygenated blood from the placenta to bypass the liver.
Bypass connection left branch of portal vein and IVC
Touches the ?vagin
Ductus venosus (DV) is a narrow, trumpet-shaped vessel which is seen in the fetal liver connecting the umbilical vein directly to the caudal inferior vena cava.
The ligamentum venosum is the fibrous remnant of the ductus venosus of the fetal circulation. Usually, it is attached to the left branch of the portal vein within the porta hepatis (gateway to theliver). It may be continuous with the round ligament of liver (ligamentum teres hepatis).
Calot’s triangle is between liver, cystic duct and common hepatic duct. - what’s in it?
Cystic Artery. How to be careful if operating.
INteresting structures on tongue
four types - first hard, 2nd and 3dr with taste buds
INteresting structures on tongue
four types of papillae - first hard (keritanized), 2nd and 3dr (von Ebner - serous) with taste buds
Tongue - back 1/3?
crypts, mucosal, glands
What secretes dentin?
odontoblasts - with processes (tomes dentinal fibers - running in dentinal tubules in canals, originally unmineralized - called predentis. then mineralizes with crystals
as dentin grows
Lines of Owen form - incremental - sensitive to heat, cold. Odontoblasts persist thrugh life.
How is enamal laid down?
rhythmically, concentric lines of Retzium. AMeloblasts lay it down - they blasts only live for a short while - when tooth eruprts, ameloblasts depart - no further enamel formation is possible
Epithelial attachment of Gottlieb - keritanized
gingiva linked to tooth enamel - gradually recedes with age.
Attachment area of gingiva to crown does not have what?
Keritanization. the crevice.
Where’s kidney
T12 - L 3, right lower
Is kidney retroperitoneal?
Definitely.
structure of kidney?
Cortex, medulla pyramida w/ major and minor calyces (branching ducts
Renal artery divides into how many segmental arteries?
5,
How is pain generated in kidney?
Mostly via dilation, stretch and spasm when abstruction due to stone.
adrenal cortex of suprarenal has how many zones, and what do they do?
They make different things - 3 zones -
All very vascularized
Drainage of suprarenal? and Arteries?
The blood drains through the suprarenal vein to the left renal vein or directly to the inferior vena cava on the right side
Arteries? from phrenis (superior suprarental), Middle suparrenal from AA, and inferior suprarenal from renal
Innervation and Lymph of suprarenal?
Innervation:
From the celiac plexus and abdominopelvic (greater, lesser, and least) splanchnic nerves
Lymphatics:
The lymph drains into the lateral aortic nodes
What is in the psoas major muscle and other muscles on posterior abdominnal wall?
? Iliacus, Psoas minor (some people don’t have), Quadd Lumbar
What are three terminal branches of AA? 3
Two common iliac (external, internal), median sacral
What is the only splanchnic nerve that carries parasymp fibers?
Pelvic splanchnic. S2 - 4
They proejct to paravertebral plexsus aterior to aorta and vert column
Where is the enteric NS?
Myenteric (Auerbach’s) plexuses
Ganglia and nerves located between the circular and longitudinal smooth muscle layers of the muscularis externa of the bowel wall
Submucosal (Meissner’s) plexuses
Ganglia and nerves located in the submucosa of the bowel wall
What is the urogenital ridge?
week 3, 4 intermediate mesoderm forms a longitudinal elevation along the dorsal body wall
Development of kidney?
has a primitive kidney, which becomes a middle kidney, and a final set of 2. moth 2 - 3, final is ready - and urine begins.
Development of kidney?
has a primitive kidney, which becomes a middle kidney, and a final set of 2. moth 2 - 3, final is ready - and urine begins.
Develops fro ureteric bud and metanephric mesoderm
Derivatives of the ureteric bud:
Collecting tubules and ducts, Minor and major calyces
Ureters
Derivatives of the metanephric blastema:
Podocytes covering glomerular capillaries; Epithelial cells lining Bowman’s capsule
Proximal convoluted tubules; Descending thick limbs of the loops of Henle
Thin limbs of the loops of Henle
Ascending thick limbs of the loop of Henle
Distal convoluted tubules
Reciprocal induction between kidney and ureter bud - may cause what?
Abnormalities, overproliferation of structures, etc
How are the urinary bladder and urethra formed?
The urogenital sinus and anorectal canal are formed during septation of the entodermal cloaca by the urorectal septum, during weeks 4 to 7
What’s the urogential sinus, and how many parts does it have?
Three -
A vesical part that forms most of the urinary bladder and is continuous with the allantois
A pelvic part that becomes the urethra in the neck of the bladder; the prostatic part of the urethra in males and the entire urethra in females
A phallic part that grows toward the genital tubercle (primordium of the penis or clitoris
What is the allantois?
As the bladder forms (from vesical part), the allantois is progressively obliterated and forms the urachus, a thick tube
It becomes the median umbilical ligament after birth
The allantois is an extension of the posterior wall of the yolk sac. Its exact role in development is unclear, though its blood vessels do become the umbilical blood vessels. It gives rise to a structure called the urachus which contributes to the superior wall of the urinary bladder.
Bladder exstrophy? Exstrophy means ‘turned inside out’.
Origins appear to occur not just by abnormal bladder development, but by a congenital malformation of the ventral wall of abdomen (between umbilicus and pubic symphysis).
There may also be other anomolies associated with failure of closure of abdominal wall and bladder (epispadias, pubic bone anomolies)
Bladder exstrophy is a congenital abnormality that occurs when the skin over the lower abdominal wall (bottom part of the tummy) does not form properly. The bladder is open and exposed on the outside of the abdomen. In epispadias, the urethra does not form properly. Exstrophy means ‘turned inside out’.
Epispadias is a rare birth defect located at the opening of the urethra. In this condition, the urethra does not develop into a full tube, and the urine exits the body from an abnormal location. The causes of epispadias are unknown.
How can the allantois/urachus have problems?
IT is supposed to be obliterated - however, it can misform, and become patent, partially patent, open externally, or create a cyst.
Bladder abnormalities
They happen, dividing into two with a septum or partial septum, hourglass, etc.
What is the mesonephric duct?
The Wolffian duct (also known as the mesonephric duct) is one of the paired embryogenic tubules that drain the primitive kidney (mesonephros) to the cloaca. … In both the male and the female the Wolffian duct develops into the trigone of the urinary bladder.
What’s the trigone?
Both sperm and urine pass through the trigone in males.
The trigone is longer in males than in females.The trigone (a.k.a. vesical trigone) is a smooth triangular region of the internal urinary bladder formed by the two ureteric orifices and the internal urethral orifice. The area is very sensitive to expansion and once stretched to a certain degree, the urinary bladder signals the brain of its need to empty.
What lines the bladder?
With time, the mesodermal lining of the trigone is replaced by endodermal epithelium, so that finally, the inside of the bladder is completely lined with endodermal epithelium
What happens to the mesonephric Duct? Is it different in females and males ?
In females, most of the mesonephric ducts regress except for that which was incorporated into the trigone of the bladder.
In males, the mesonephric ducts are retained as the ductus deferens and ejaculatory ducts that convey sperm from the testes ultimately to the prostatic urethra
How does the male urethra develop?
The vesicourethral canal of the urogenital sinus gives rise to the bladder (vesical) and the upper part of the prostatic urethra (proximal to the ejaculatory ducts)
All are derived from endoderm
The lamina propria, smooth muscle, and serosa (adventitia) develop from adjacent splanchnic mesenchyme
The lower potion of the prostatic urethra and the membranous urethra are derived from endoderm of the pelvic portion of the urogenital sinus
The penile urethra, except for its glandular part, comes from cells of the phallic or genital portion of the urogenital sinus
What develops from the
vesical part of the
urogenital sinus?
The upper part gives rise to the urinary bladder and the pelvic part gives rise to the prostatic and membranous parts of the urethra.
The phallic portion gives rise to the penile urethra.
How does the male urethra develop?
The epithelium of the glandular part of the penile urethra (terminal or navicular fossa) develops by canalization of an ectodermal cord of cells that extends into the glans from its tip
The connective tissue and smooth muscle develop from adjacent splanchnic mesenchyme
How does the female urethra develop?
The endodermal vesicourethral canal of the urogenital sinus gives rise to the bladder (vesical) and the entire urethra
The connective tissue and smooth muscle come from the adjacent splanchnic mesenchyme
How are the urethral glands developed?
At the end of the 3rd month the epithelium of the cranial part of the urethra proliferates and forms out-buddings that penetrate the surrounding mesenchyme. In the male, these buds form the prostate gland; in the female the urethral (Littre) and paraurethral (Skene’s) glands
How do the adrenal glands develop?
The suprarenal gland develops from two components:
A mesodermal portion, which forms the cortex
An ectodermal portion, which forms the medulla
What are chromaffin cells in the adrenal medulla and how do they develop?
While the fetal cortex is being formed, cells originating in the sympathetic system (neural crest cells) invade its medial aspect, where they are arranged in cords and clusters
These cells give rise to the medulla of the suprarenal gland.
They make NE and E
They stain yellow-brown with chrome salts and hence are called chromaffin cells
What do Oclasts release at the ruffled border?
cathepsin K and collagenase, H+
What is interstitial growth?
lengthening of the bone resulting from the growth of cartilage and its replacement with bone tissue. A person grows taller because of interstitial growth. This growth occurs at the epiphyseal plate and continues until the person reaches the teenage years.
What triggers interstitial growth?
Interstitial growth occurs in hyaline cartilage of epiphyseal plate, increases length of growing bone. Appositional growth occurs at endosteal and periosteal surfaces, increases width of growing bones.
How does hyaline affect bone?
Endochondral ossification is the process of bone development from hyaline cartilage. Long bones lengthen as chondrocytes divide and secrete hyaline cartilage. Osteoblasts replace cartilage with bone. Appositional growth is the increase in the diameter of bones by the addition of bone tissue at the surface of bones.
What is endochondral ossification?
Endochondral ossification is the process of bone development from hyaline cartilage. All of the bones of the body, except for the flat bones of the skull, mandible, and clavicles, are formed through endochondral ossification. In long bones, chondrocytes form a template of the hyaline cartilage diaphysis.
In what ways do intramembranous and endochondral ossification differ?
In intramembranous ossification, bone develops directly from sheets of mesenchymal connective tissue, but in endochondral ossification, bone develops by replacing hyaline cartilage.
What is osteogenesis imperfecta? and why see it with blue sclera?
Genetic disorder Collagen 1
that causes increased bone fractures and collagen defects. The main causes for developing the disorder are a result of mutations in the COL1A1 and COL1A2 genes which are responsible for the production of collagen type 1.
Is Osteogenesis Imperfecta a type of dwarfism?
There are four different types of osteogenesis imperfecta and not all of them lead to dwarfism. This illness, commonly called “glass bone disease”, causes increased bone malleability and brittle bones. … Deformations from fractures or bone malleability can be extremely severe and lead to seriously deformed dwarfism.
Essential difference intramembrous and endochondral bone growth?
Intra - happen w/ only few bones - and mesenchymal cells go directly into osteoblasts - no cartilage involved.
what proteins stimulate intramembrous bone growth in fetus?
WNT, HH FGF, TGFbeta - web forms with proteoglycans, osteoblasts form that secrete OSTEOID
Once osteoid is formed, what happens?
It is immature bone- which can be replaced by spongy (trabeculated) or compact. both are lamellated.
How does bone mineralize?
Bone mineralization occurs in a specific, highly ordered process. The process is mediated by osteoblasts and confined to the organic osteoid matrix produced by osteoblasts.
What is hyaline cartridge made of?
type II collagen and chondroitin sulphate, both of which are also found in elastic cartilage. Hyaline cartilage exists on the ventral ends of ribs, in the larynx, trachea, and bronchi, and on the articulating surfaces of bones.
How is hyaline cartrdge different than elastic or and fibrocartilage?
Hyaline cartilage is easily distinguished from elastic and fibrocartilage because of the homogeneous (no fibers are visible) extracellular matrix (ECM) . … Elastic cartilage (like hyaline cartilage) has chondrocytes located in lacunae and the tissue is surrounded by a perichondrium .
In endochondrial ossif - how are blood vessels formed?
in primary growth centers, endothelial cell growth factor induces sprouting from perichondrium.
What is the growth process in endoch ossif?
resting , then chondro prolif - > hypertroph - vessels sprout via GF -> calcification -> apoptosis of hypertropich chondrocytes
What part of endoc ossif is not eventually mineralized?
articular surfaces.
Function of Indian HH in epiphyseal bone growth?
regulated formation of bone via RUNX2 (differentiation); stimulated PTHrp secretion by perchondrial cells.
What does mutation in RUNX2 do?
About 200 mutations in the RUNX2 gene have been identified in individuals with cleidocranial dysplasia, a condition that primarily affects development of the bones and teeth. Some mutations change one protein building block (amino acid) in the RUNX2 protein.
What causes achondroplasia?
gene alteration (mutation) in the FGFR3 gene. The FGFR3 gene makes a protein called fibroblast growth factor receptor 3 that is involved in converting cartilage to bone. FGFR3 is the only gene known to be associated with achondroplasia.
It’s about decrease in chondrocytes
Short limbed - because effecting growth plates
What is periostium?
covering over bone- two layers - tough fibrous, inner osteogenic layer that nourish and heal-
What is cretinism caused by a thyroid deficiency - is this a factor affecting growth?
Cretinism: Congenital hypothyroidism (underactivity of the thyroid gland at birth), which results in growth retardation, developmental delay, and other abnormal features. Cretinism can be due to deficiency of iodine in the mother’s diet during pregnancy.
What if you have too much or not enough pituitary growth hormone?
giant/dwarf
How do bones harden?
Calcium is essential - rickets/osteomalacia if missing Vitamin D to help calcium work.
Vit D is essential in intestines to absorb Calcium. Growth plate affected bec can’t calcify - bones bendable and OSTEOID adjacent is deficient in Ca.
Why is vitamin c needed for bones - scurvy?
forms collagen in new bone. if no vit c, matrix lacks collagen fibers and disrupts growth place
What is achondroplasia?
genital - poorly formed epiphyseal growth plates - head trunk normal, limbs stunted
what causes osteitis fibrosa?
Hyperthyroidism, excessive bone resorption - bones fractures more easily
Where is calcitonin producted?
parafollicular cells in the thyroid. - LOWERS oclast activity.
What hormones affect bones?
PTH, Calcitonin, OPG -
gonadal (precocious - accelerated bone growth but closes early (stunted), testicular - bone growth closes late (long limbed), estrogen)
GH - stimulates IGF (insuline like GF) in liver. -
in utero - too much - giant, too little dward
as adult - Acromely - bones become very THICK.
How does Vit A affect bones?
Active in remodeling. lack of remodeling in skull spinal chord - can compress brain.
What causes osteogenesis imperfecta?
congenital - Collagen I deficient - brittle bones, blue sclera, seizures can confirm diag wtih DNA tests or collagen test - COL1A1 and 2 genes -
What does decrease in estrogen do in elderly?
increases OClast activity, decrease OBlast activity
Structure of articular cartilage?
4 zones - arched in zone 2 - in osteo-arthritis zones tend to disappear
Can bones grow via mitosis?
Only in the osteogenic cells. One of the key characteristics of osteoblasts, osteocytes, and osteoclasts is that they do not undergo mitosis. Also, remember that only germ cells undergo meiosis. … Osteogenic cells, however, can undergo mitosis. Osteogenic cells are cells that differentiate into osteoblasts.
Where do osteogenic cells live?
These osteogenic cells are undifferentiated with high mitotic activity; they are the only bone cells that divide. Immature osteogenic cells are found in the deep layers of the periosteum and the marrow. When they differentiate, they develop into osteoblasts.
Does periosteum cover articular cartilage?
No. it lines outer and Inner surfaces of bone - marrow cavity and trabeculae - called endosteum
where is woven (immature) bone found?
newly formed bone in embryo and children
healing fractures
tooth sockets
sutures of cranial bones
collagen not arranged in layers, less minerals -
What are haversian canals?
Haversian canals are microscopic tubes or tunnels in cortical bone that house nerve fibers and a few capillaries. … Haversian canals and osteons are part of the Haversian system, which allows nutrients to pass between the blood and bone.
What are volkmann canals?
Volkmann’s canals are inside osteons. … Volkmann’s canals are any of the small channels in the bone that transmit blood vessels from the periosteum into the bone and that communicate with the haversian canals.
What are in the lacunae of bones?
Between the rings of matrix, the bone cells (osteocytes) are located in spaces called lacunae. Small channels (canaliculi) radiate from the lacunae to the osteonic (haversian) canal to provide passageways through the hard matrix.
canaliculi? provide nutrition and communication to osteocyes
Small channels (canaliculi) radiate from the lacunae to the osteonic (haversian) canal to provide passageways through the hard matrix
Are osteocytes dead? No - but they will be as age.
Osteocytes get nutrients through their dendrites which are tentacle-like structures that extend through tiny structures called canaliculi.
What do osteogenic daughter cells do?
Osteogenic cells are stem cells - able to divide (the only ones able to divide in bone system) - when one divides - it leaves a daughter behind while the other differentiates into a osteoblast.
What is endosteum consist of?
Delicate latery, covers surfaces of spongy bone, osteoprogenitor cells, osteoblasts and bone lining cells.
Do osteoblasts becomes osteocytes?
yes, they can also return to be osteoprogenitor cells
What are bone-lining cells?
Osteoprogenitor cells - located in inner layer of periosteium, endosteal lining, bone marrow
do osteoblasts contact their neighbors
Yes - through gap junctions. they deposit osteoid (build bone) - which is nonmineralized
What happens when bone has been built?
osteoblasts become osteocytes - trapped, or return to osteoprogenitor cells
What do osteoblasts produce?
Tons of osteo type things - to create bone - and collage type 1, and alkaline phosphatase (need alkaline envionment?)
And RANKL via PTH stimulation
How do osteoblasts come to be - because they are derived from mesenchymal cells that also form muscle, adipocytes, fibroblasts, and chondroblasts?
Sox9 - determines if preosteoblast or chondroblast
Runx2, turns them from preosteoblasts to post mitotic osteoblasts
Osterix (OSX) - turns oblasts into octytes and functions of oblasts and chondroblasts
deficient Runx2? SOX9?
cleidocranial dysplasia _ hypoplastic clavicles, delayed ossification of sutures
mice have cartilage - without oblasts)
SOX9 -
deficient OSX?
Brittle bone disease - osteogenesis imperfecta - blue sclera
How are osteoclasts formed?
monocytes in the blood. These in turn are derived from the bone marrow.
What do osteoclasts secrete to degrade bone?
H+ and collagenases
What is achondroplasia?
FGFR3 - chondrocytes proliferation inhibited at growth plate, dwarfism with short limbs, normal head, paternal age affect. most common casue of short limbed dwards
Osteopetrosis?
oclasts defective - can’t generate acidic environment - , overgrowth fills marrow space STONE BONE _ marrow transplants
What causes osteogenesis imperfecta (OI)?
OI is caused by defects in or related to a protein called type 1 collagen.
What does cathepsin K do in bones?
bone resorption. The enzyme’s ability to catabolize elastin, collagen, and gelatin allows it to break down bone and cartilage.
What does the right common iliac artery often do?
Compresses left common iliac vein - DVT
four nerve plexus? 444
cervical 1-4,
branchiol,after 4 is C5 - T1
lumbar 1-4,
sacral L4 - S4
A nerve plexus is a plexus (branching network) of intersecting nerves. A nerve plexus is composed of afferent and efferent fibers that arise from the merging of the anterior rami of spinal nerves and blood vessels.
What are the main nerve plexuses of the body?
1 – Nerve Plexuses of the Body: There are four main nerve plexuses in the human body. The cervical plexus supplies nerves to the posterior head and neck, as well as to the diaphragm. The brachial plexus supplies nerves to the arm. The lumbar plexus supplies nerves to the anterior leg.
What’s inside of psoas?
Lumbar plexus
Which common iliac vein is longer?
left
What veins form the hepatic portal vein
SPlechic and SMA - Behind NECK of pancreas
four muscles behind kidney?
Psoas, DPH, qua, transverse abductor
In abdomen, where does IVC end?
T8, esoph 10, aa 12
What’s the ventral ramus?
The anterior division of a spinal nerve. The ventral rami supply the antero-lateral parts of the trunk and the limbs. They are mainly larger than the dorsal rami.
What does the lesser sac divide?
supra and infra colic compartments
Do females have rectovesical pouch?
No, they have a recto uterine pound that divides rectum from vagina. Pouch of Douglas
Where is morrison’s pouch?
below liver -
Where is the right paracolic gutter?
lateral to asc colon
of the MSMS of the GI tract, what level shows the most variation?
Mucosa - especially when change at junction where esop meets stomach. - gastroduodenal junction.
What are Meissner’s nerves?
Nerve plexus in submucosa
Where are glands present in MSMS?
submucosa?
2nd M level - muscularis externa/ what’s interesting?
internal circular layer, external longitudinal - and MYENTERIC (Auerbach’s) nerve plexus betw the two
Is it serosa or adventitia?
Serosa in GI - adventitia not have mesothelium.
What does Hirschsprung disase have to do with nerve?
supermegacolon - congential and acquired
- Chagas infection) nerve plexuses in GI tract are injured - disturbing digestive tract motility, w frequent idalations?
What does enteric system do?
REgulations peristaltic contraction and secretory activities -
Para increases GI activity, SNS decreases motility
why are esophagus varices seen?
Portal vein drainage - - rupture of vaices, or ulcerationof mucosa can produce hemorrhage into esop and stomach - often vomiting blood - hematemesis
What is hematemesis?
vomiting blood
What are cardiac esop glands and where are they found???
Mucosal tubular glands in lamina propria in esop - drained by single duct
Esop - 3 types of muscle
striated, mixed, smooth - what moves the food down - striated
esoph - 2 sphincters
upper CRICOpshangeal, and LES which is muscle only - bird beak problem if can’t relax -
What does LES prevent?
GERD - clinical? Heartburn, dysphagia (swallowing diff), regurg of sour brash, chest pain (rare) - adults over 40 -
sometimes: hematemesis and MELENA - blood in stool
What does chronic reflux create?
Barrett’s (neutrolphis, eosinophils, squiggly lymphocytes enter). fibrosis and/or restriction of LES
Treatment for GERD?
Proton pump inhibitor or H2 HISTAMINE receptor
What does chronic GERD lead to?
Intestinal metaplasia - lower 1/3 usually most effective - like the stomach lining cells move up into esop - normal squamous epithelium replaced by abnormal columnar epth and goblet
Does Gerd increase cancer risk?
Yes - adinocarcinomas - part from Barretts
What is the cell transtion at Gastroesophgael junction?
stratified squamous to simple columnar. - where is it? where esop meets stomach
What is rugae?
mucosa and submucosa of undistended stomach lieing in longitudinal folds
What two things aid in stomach digestion?
muscle contractions and chemicals (acid and enzymes). once all mixed up and a thick fluid, goes to duodenum
Stomach divided into what regions?
ORAD and CAUDED areas - based upon motility patterns Cardis fundis body antrum py?
What is gastric microcirculation?
relevant to pathogenesis of PUD - peptic ulcer disease - and protection of gastric mucosa from Hydrocloric acid HCI - and pepsin
Mucosa of stomach?
invaginates into lamina propria forming gastric pits - glands empty into pits (cardiac, gastric and pyloric - regions of stomach)
What separates mucosa from Underlying submucosa?
Muscularis mucosa
What does surface mucosa of stomach secrete?
alkaline mucus BICARBONATE (1 - 7) - simple columnar - 95% water + lipids and glycoproteins - froms hydrophobic protective gel
Are tight junctions found in stomach?
Yes - surface epithelial use these and ionic trasnporters that maintain intracellular PH and bicarbonate production - key for gel alkalinations
Regions of stomach, and why do they matter?
cardia, fundus/body, pyloris - what cells secrete HCI and pepin - body and fundus
What is produced mainly in the cardia and pylorus?
Glands producing mucus
Glands in cardia are marked by?
COILS - simple tubular continuous opening with gastric pits - and few parietal cells.
COILED - results in cross and oblique sections
What’s the epithelial transformation zone?
abrupt transition from strqtified squamous of espp to simple columnar mucus secreting cells in cardiac zone
Gastric glands in fundus?
Gastric juice - 3 regions
Pit (foveola) lined by mucous cells
Neck - stem cell and parietal
Body - major area - upper and lower portion have different proportions of cells
5 areas of tubular gastric glands?
mucus neck stem parietal "oxyntic" chief "peptic" G CELLS _gastroenteroendocrine (enterochromaffic)
What’s up, what’s down in the tube? Where do the chief and G cells predominate?
upper lots of parietal
Lower - chief and G cells
Where are stem cells found?
in isthmus and neck - high mitosis rate - they move up and down - where needed, producing more of all the cells
What do mucus neck cells do?
produce different type of mucus - they are throughout stomach
Chief cells? Zymogenic
lower region of tubular, house pepsinogen and made lipase
They are not in charge - parietal are.
INACTIVE - enzyme pepsinogen - when released into acidic stomach - PEPSIN
Pepsin is a stomach enzyme that serves to digest proteins found in ingested food. Gastric chief cells secrete pepsin as an inactive zymogen called pepsinogen. Parietal cells within the stomach lining secrete hydrochloric acid that lowers the pH of the stomach. A low pH (1.5 to 2) activates pepsin.
What do parietal cells do?
In fundus - upper area -
When Resting - below plasmalemma - few microvilli
When stimulated, rise and fuse to surface forming canaliculus and more microvilli (more surface area) - and secrete H+ AND CL-
Also secrete GASTRIC INTRINSIC FACTOR (vit B12 connection)
What stimulates parietal cells (stomach) to produce Hydochloric acid?
ACH of PSNS, and peptide GASTRIN from enteroendycrine cells of pyloric antrum
Parietal cells secrete acid in response to three types of stimuli:
Histamine, stimulates H2 histamine receptors (most significant contribution).
Acetylcholine, from parasympathetic activity via the vagus nerve and enteric nervous system, stimulating M3 receptors.
Pepsin is a stomach enzyme that serves to digest proteins found in ingested food. Gastric chief cells secrete pepsin as an inactive zymogen called pepsinogen. Parietal cells within the stomach lining secrete hydrochloric acid that lowers the pH of the stomach. A low pH (1.5 to 2) activates pepsin.
Release of gastrin by Ach?
Histamines also affects ACh and gastrin - when bound w/ H2 receptor (Cimetidine is H2 receptor antagonist inhibiting histamine dependent acid secretion.
Atrophic gastritis?
Not enough parietal and chief cells - No/little Acid or pepsin activity -
What does atrophic gastritis often create?
Pernicious anemia - may be autoimmune disease (antibodies against parietal cells often detected in these patients?
What does atrophic gastritis have to do with B12?
parietal cells produce Intrinsic factor - binds avidly to b12. absorbed in ileum (pinocytosis) -
lack of intrinsic factor?
b12 deficiency - pernicious anemia - may be autoimmune disease.
What do G cells create?
Peptide hormone - largest endocrine organ in body! Found in mucosa from stomach to colon
Peptide hormones are secreted and function in an endocrine manner to regulate many physiological functions, including growth, appetite and energy metabolism, cardiac function, stress, and reproductive physiology. Many signal via G protein-coupled receptors (GPCRs).
GI regulated by peptide hormone and what else?
Neuroendocrine mediators - produced by neurons ??
What is GHRELIN?
produced in stomach - stimulates Growth hormone - levels increase during fasting triggering hunger - act on hypthalamic feeding center
Tumors called Carcinoids?
Gherlin creates tumors, Serotonin overproduction from Ghrelin- increases gut motility - but high level mucusal VASOconstriction and damage.
Zollinger Ellison syndrome?
gastrin secreting tumors (gastrinomas)
hyperplasia and hypertrophy of fundic region of stomach and HIGH ACID secretion
Stomach ulcers
condition in which a gastrin-secreting tumor or hyperplasia of the islet cells in the pancreas causes overproduction of gastric acid, resulting in recurrent peptic ulcers.
PUD
PUD? Peptic Ulcer Disease?
Most common ulcer of GI tract - defined - mucosal erosion > .5cm.
70-90% helicobacter pylori bacteria - loves acid
What drugs can cause ulcers?
aspirin, ibuprofen and other NSAIDs (disrupt mucus lining and digestive juice defenses)
What does H pylofi create?
ammonia NH3 - decreases acidity of gastric juice during ACTIVE cycle, then
attach to mucosal blanket - with adhesins where they are nourished,
Detach, replicate and re-enter active cycle
BLEEDING caused by?
Drugs to treat Peptic ulcer and GERD and Zollinger Ellison?
H2 antagonists (cimetidine, ranitidine, famotidine -
decreases (indirectly) proton pump activity to food stiumulation and nocturnal secretion
Also antagonize HCl secretion -
Other drugs effective on PUD, GERD, and Zollinger?
proton pump inhibitors -
Omedprazole and other PRAZOLES
direct inhibition
looks like more effective thatn H2 antagonists?
OTHER DRUGS?
Sucralfate
Bismuth subsalicylate
antacis (neutalize protons in gut)
What is eradication regime for h.pylori
PRAZOLES
Pepsin is inactive when?
PH greater than 4 - antacids can reduce pepsin
What are pyloric glands?
Differ from cardiac and gastric in two layers - gastric pits deeper and larger lumen
Three layers of stomach muscles?
inner oblique, middle circular, and outer longitudinal - at pyloric antrum, CIRCULAR muscle thickens to form annular pyloric sphincter
contraction under control of autonomic nerve plesuses between muscle leeyrs (auerbach
gastric secretions - inhibit or stimulate release of HCI?
Gastrin and histamine - released by enteroendocrine) STIMULATE HCI secretion
Inhibit:
Somatostain - Inhibit gastrin - inhibit HCI
Urogastrone HEGF - inhibit
vermillion zone of lip - what kind of cells?
stratified squamous KERITinized
Are chief or mucous neck cells found in gastric glands in pyloric stomach?
mucous neck in all parts of stumach
Parietal and chief - in fundus
Parietal cells are the epithelial cells that secrete HCl and intrinsic factor. They are located in the gastric glands found in lining of fundus and stomach. The gastric chief cells , are cells in the stomach that release pepsinogen and chymosin.
Secretin and cholecystokinin are secreted where/
small intestine - enteroendicrine cells
odontoblast malfunction?
dentin
where is the periodontal ligament?
is a soft connective tissue between the inner wall of the alveolar socket and the roots of the teeth. It consists of collagen bands (mostly type I collagen) connecting the cementum of teeth to the gingivae and alveolar bone.
passage of bolus into stomach from esop - how?
peristaltic activity of muscularis externa of esop
Small intestine - 3 histological regions?
Peyer in ileium, brunner submucosa duod, goblet cells throughout.
Can stomach directly absorb alcohol?
yes
Sores on corner of mouth?
20 year old, angular cheilitis
Are chief cells in charge?
No, Parietal - they decide when to produce hydrocho acid - pepsin inactive is produced by chief - but only activiate when Parietal releases HCL.
Since parietal are in charge, what stimulates them?
Parietal cells secrete acid in response to three types of stimuli: Histamine, stimulates H2 histamine receptors (most significant contribution). Acetylcholine, from parasympathetic activity via the vagus nerve and enteric nervous system, stimulating M3 receptors.
What organs are only innervated by the sympathetic nervous system?
Although most organs are innervated by both sympathetic and parasympathetic nerves, some-including the adrenal medulla, arrector pili muscles, sweat glands, and most blood vessels-receive only sympathetic innervation.
Glisson’s capsule?
Liver capsula, Intercostal nerves innervate!
Portal triad?
Hepatic artery, Portal venule, Bile duct - at each corner of liver lobule. Lymph is there too (portal tetrad)
Where do arterial and portal venous blood meet in the liver?
toward the central canal - sinusoidal capillary
When central veins meet up in liver, what do they form?
Interlobular vein -> hepatic veins -> IVC
What are the three types of capillaries?
sinusoid (most permeable - even large molecules can enter), fenestrated, continuous.
Kupffer cells are in the liver
What parts of body have sinusoid capillaries?
Liver, spleen, red bone marrow. Really good at trapping old aged RBCs.
What are Kupffer cells?
macrophages - in the sinusoids. Breaks down bacteria, paracites, old RBCs, toxins,
Hepatocytes?
liver cells, make up 80% of liver.
Where is bile secreted to?
biliary canaliculi
Space of Disse?
perisinusoidal space
What does space of Disse do? What does moll space do
The perisinusoidal space (or space of Disse) is a location in the liver between a hepatocyte and a sinusoid. It contains the blood plasma. Microvilli of hepatocytes extend into this space, allowing proteins and other plasma components from the sinusoids to be absorbed by the hepatocytes.
Moll drains lymph
Stellate cells in liver?
preferentailly store vit A, but if kupffer tell them to, can create fibroids - keratin.
Where does bilirubin come from?
Kupffer cells break down RBC into Hemoglobin, -> heme ._ bilirubin and iron
Where does bilirubin go ?
it goes into biliary canicula - as bile.
Where does bilirubin get conjugated?
in hemocytes, and then sent into bile caniculi
What do stellate cells do in liver?
Store vitamin A and fat. - quiescent - but if liver has consistent injury - over time (hepatitis, cyrohis, infection, etc) cells can be CONVERTED - and create FIBER - myofibrilblasts. Fibrosis of liver (creating portal hypertension_
3 main components of bile ?
salts, lecithin, bilirubin (causes pigmentation)
on hematocyte - what side has the microvilli?
basal lateral membrane. Apical membrane faces bile canincula - which actually are formed between the hematocytes - but easier on diagram to imagine them running in same line as sinusoids.
3 ways to classify liver lobules?
classic (blood flow of hepatic aterial and portal venule to central vein), portal (bile flow direction from various lobules), acinas (flow of arterial blood - oxygen rich) ZONES created
Zone 1 - closest to other lobule, 3 - closest to central vein - what does this mean?
Zone 1 - gets richest oxy blood, most resistant,
and does things needed with all this oxygen - cholesterol syntheses, uria genesis, etc.
Zone 3 - more necrosis, ischemia,
Glycolosis - fatty acid synthesis, Zenobiotic metabolism (drugs - ??) TOXICITY?
Vitamin A?
stored in liver called RETINOL ESTER, when needed, released as retinol
VIT A needed at growth plate, vision, reproduction,
