Exam 4 Flashcards
Neuron vs nerve
Neuron: Single nervous system cell
Nerve: Bundle of axons (neurons)
Nervous tissue is excitable
Generates AP from RMP
Excitable: Allow signals to transmit fast, immediate response to stimuli, etc.
Forebrain
Prosencephalon;
Cerebrum;
Diencephalon: Thalamus, hypothalamus, epithalamus;
Telencephalon: Cerebral hemispheres (cortex), basal nuclei, limbic system; Responsible for higher cognitive functions
Midbrain
Mesencephalon;
Reticular activating centers; Alert/awake/consciousness (caffeine blocks adenosine receptors)
Hindbrain
Rhombencephalon; Cerebellum; Medulla oblongata; Pons; Controls basic-life sustaining functions and motor coordination
Spinal cord components
Medulla oblongata and pons
Dienecephalon
Thalamus, hypothalamus, epithalamus
Main parts of the brain
Cerebrum, Cerebellum, Diencephalon, Brainstem
Reticular activating centers
A network of neurons that regulate sleep-wake transition and arousal; Located in the brainstem (above the spinal cord) in the midbrain; Secretes acetylcholine, serotonin, dopamine, histamine
Medulla oblongata
Located in brainstem; Sits beneath the pons and above the spinal cord; Heart rate, breathing rate, blood pressure, blood flow, vomiting, swallowing
Pons
Located in brainstem; Beneath the midbrain and above the medulla oblongata; Balance and posture
Sulcus
A depression; Increase surface area; Greater number of neurons that can be packed in the cerebral cortex; Central sulcus
Central sulcus
AKA central fissure; Separates frontal and parietal lobes; Separates primary motor and primary somatic sensory cortex
https://www.imaios.com/en/e-anatomy/anatomical-structure/central-sulcus-1553797948
Fissure
Deeper and more prominent than a sulcus; Longitudinal fissure
Longitudinal fissure
Separates left and right halves of brain; Creates cerebral hemispheres; Connected by corpus callosum
Brainstem
Composed of medulla oblongata, pons, and midbrain; Connects the brain to the spinal cord
Cerebellum
Coordination, muscle tone, intricate movements, spatial equilibrium
Female vs male brain
Female brain is better at multitasking; increase in corpus callosum, leading to an increase in synapse connections
Substantia nigra
Located in midbrain; Part of the brainstem; Primary function is to produce dopamine (dopaminergic); A modulator for pyramidal tracts
Relationship between Parkinson’s and substantia nigra
In patients with Parkinson’s, dopamine producing neurons degenerate in the Substantia nigra which means pyramidal tracts cant send out signals properly, resulting in impaired motor control (tremors)
Pyramidal tracts
Main motor pathways that directly control voluntary movement by transmitting signals from the motor cortex to the spinal cord;
Limbic system
Paleomammalian cortex (old); Above the brainstem and within the temporal lobe; Made pf amygdala, mammillary bodies, stria medullaris, ventral nuclei of Gudden; interacts with basal ganglia (when see something scary); emotional nervous system; emotions, memory, behaviour
Amygdala
A small, almond-shaped cluster of nuclei located deep within the temporal lobe of the brain; Plays a role in memory, decision making, and processing emotional responses (fear, anxiety, anger, pleasure)
Why is it important that we have an emotional response and brain re-wiring when
experiencing something scary?
The emotional response and brain re-wiring gets the body ready to either face the threat or escape from it (fight or flight); This comes from the sympathetic nervous system
Sympathetic Nervous system
Sympathetic: Emergency response and energy mobilization; Prepares for stress and action (fight or flight);
Increases heart rate, respiratory rate, blood pressure, and blood flow to the muscles; Slows down digestion;
Stronger than parasympathetic (uses hormone from adrenal medulla; sympathetic chain)
CNS soma cluster = nuclei;
Thoraco-lumbar nervous system;
Norepinephrine and epinephrine
Frontal lobe
Voluntary movements, voluntary thought, cognition, think, engage in reason/cause-effect, long-term memory
Parietal lobe
Taste (gustation), temperature, touch, pressure, vibration detection
Temporal lobe
Short-term memory, emotions, speech, smell (olfaction), auditory stimuli
Occipital lobe
Vision
Cerebellum
Balance, posture, muscle tone, coordination (spatial equilibrium)
Spinal cord
Reflexes, walking, urination, sex organ function
Primary motor cortex vs Primary somatic sensory cortex
Primary motor cortex: Anterior; controls voluntary muscle movements
Primary somatic sensory cortex: Posterior; receives and processes sensory information from the body
Central sulcus divides them
Hypothalamus
Located below the thalamus and above the brainstem; Located within the diencephalon; Helps to maintain homeostasis; Controls pituitary gland; Autonomic nervous system regulation; Regulates circadian rhythm; Satiety center
Thalamus
Located on top of the brainstem and below the cerebral cortex; Acts as a central relay station, processing and transmitting sensory and motor information between different regions of the brain, primarily to the cerebral cortex; Plays a role in sensory perception, motor control and the regulation of consciousness, sleep, and alertness
Epithalamus
Located above the thalamus and below the midbrain; Contains the pineal gland
Pineal gland
Located in the epithalamus; Endocrine gland responsible for producing melatonin; Helps to regulate sleep-wake cycle (circadian rhythm)
Cerebrospinal fluid
Found in/around the brain and spinal cord, within the ventricles of the brain, and the subarachnoid space; “Cushions” the brain, provide nutrients, circulates hormones. and contributes to waste removal and nutrient distribution; Produced by ependymal cells
Meninges
Dura mater (most superficial), arachnoid mater, and pia mater (deepest layer); 3 protective layers of tissue that surround and cover the brain and spinal cord; Protects the CNS and provides a cushioning effect
White blood cells in cerebrospinal fluid could signify…
White blood cells in cerebrospinal fluid could signify meningitis
Meningitis
Inflammation of the meninges; Typically caused by viral or bacterial infections
Epidural block
A type of regional anesthesia that involves the injection of local anesthetic into the epidural space (area surrounding spinal cord and its protective membranes; space between the dura mater and the walls of the vertebral canal); Injected between L3 and L4; Goal is to numb or block pain in a specific area of the body while the person remains conscious
Epidural block pharmacology
Caines: Mepivacaine, ropivacaine, levobupivacaine, chloroprocaine
Opioids: Fentanyl, morphine, hydromorphone, oxycodone, sufentanil
How to deal with pain
1) Local pain blockers (anesthetics): “-caine” blocks VG Na+ so there is no depolarization and no signal at the source of pain (signal never sent to brain)
2) Systemic pain blockers: “-opiates/narcotics”; leads to pleasure/reward pathways; influences the production and release of endorphins (flat pEg)
SSRI
Selective serotonin reuptake inhibitor; Selective = Only in brain (Ex: Brain feels better); Takes long time to be effective (2-4 weeks); Elevates serotonin levels in only the brain, but does not trigger an immediate or intense feeling of euphoria or pleasure; Antidepressant; Example drugs: Zoloft (generic: sertraline), Prozac (fluoxetine), Lexapro (escitalopram)
SRI
Serotonin reuptake inhibitor; Works very fast and is short term; Illegal; Decreases natural serotonin production because it increases serotonin production all over the body; Leads to feedback inhibition; Body stops the production of serotonin; Elevates serotonin and dopamine levels in brain which plays into addiction centers in the brain (fast dopamine hit = brain happy because brain wants to be happy in an easy way); Illegal; Example drug: Methamphetamine
Proprioception
Located in muscles, tendons, joints, and the skin; The body’s ability to sense the position, movement, and orientation of its parts in space without relying on visual input; Muscle spindles, Golgi tendon organs, joint receptors; Helps to detect the position and movement of your body and limbs to maintain overall balance
Relationship between inner ear fluid and CN VIII
Vestibulocochlear nerve VIII; Semicircular canals of the ear have fluid that play a role in balance in detection of acceleration/deceleration; Proprioception works together with the vestibular system in the inner ear to help maintain balance and coordination
Cranial nerves I-XII
Olfactory nerve I
Optic nerve II
Oculomotor III
Trochlear IV
Trigeminal nerve V
Abducens nerve VI
Facial nerve VII
Vestibulocochlear nerve VIII
Glossopharyngeal nerve XI
Vagus nerve X
Spinal accessory nerve XI
Hypoglossal XII
Cranial nerve I
Olfactory nerve I; Sensory; Larger in vertebrates with a better sense of smell; Proprioception is a sensory function; Smell and taste are linked and are both chemoreceptors; Smell is linked to memory
Cranial nerve II
Optic nerve II; Sensory; Vision; Optic chiasm (part of the brain where optic nerves cross); Vision centers are in occipital lobe
Cranial nerve III
Oculomotor nerve III; Motor; Double vision, blurred vision, and drooping eyelids (ptosis); Superior, inferior, medial rectus, and inferior oblique; Proprioceptive; Parasympathetic to the sphincter of the pupil (constriction) and ciliary muscles (accommodation)
Cranial nerve IV
Trochlear nerve IV; Motor; Superior oblique; Proprioceptive; Some of the smallest motor units are found within the muscle of the eye; Lens mineralize (cataract); Double vision
Cranial nerve V
Trigeminal nerve V; Both sensory and motor; Mastication = chewing (mainly V3); 3 branches
Cranial nerve VI
Abducens nerve VI; Motor; Double vision; Lateral rectus
Cranial nerve VII
Facial nerve VII; Both sensory and motor; Facial expressions; Facial palsy
Cranial nerve VIII
Vestibulocochlear nerve VIII; Sensory; Semicircular canals of ear have fluid that play a role in balance and detection of acceleration/deceleration; Cochlea play a role in hearing
Cranial nerve IX
Glossopharyngeal nerve IX; Both sensory and motor; Parasympathetic increases salivary gland secretion; Motor to pharyngeal muscle; Proprioceptive to pharyngeal
Cranial nerve X
Vagus nerve X; Both sensory and motor; “To wander”; Vagus nerve goes all over the body; Only nerve to extend beyond head and neck to visceral organs in thorax and abdomen; Parasympathetic to SA node of the heart (heart rate goes down by half)
Cranial nerve XI
Spinal accessory nerve XI; Motor; Most posterior; Sternocleidomastoid; Trapezius
Cranial nerve XII
Hypoglossal nerve XII; Motor; “Under tongue”; Intrinsic tongue muscles are entirely within the tongue; Extrinsic tongue muscle attach the tongue to other structures
Cranial nerves associated with vision or double vision
Vision: Optic nerve II
Double vision: Oculomotor nerve III, Trochlear nerve IV, Abducens nerve VI
Why are there smaller motor units in the eye?
Smaller motor units create finer motions; Smallest motor units are used in eye muscles because they provide small movements and help with focusing sight
Relationship between “-caines” and CN V
Trigeminal Nerve V: Ophthalmic (V1), Maxillary branch (V2), Mandibular branch (V3)
“-caines” = local anesthesia: blocks voltage-gated sodium channels; No depolarization
Parasympathetic nervous system
Relaxation, energy conservation, and recovery; Promotes relaxation and energy conservation (rest and digest);
Decreases heart rate, respiratory rate, and blood pressure; Increased blood flow to digestive organs and enhances digestion;
Antagonistic effects on target organs and promotes calming and a return to “rest and digest” functions; Default but weaker system;
PNS soma = ganglia
Cranio-sacral nervous system; Enteric system
Acetylcholine
Both sympathetic and parasympathetic
Have pre and post ganglionic;
PNS: Acetylcholine = pre and post neurotransmitter
CNS: Acetylcholine = ONLY post ganglionic
Relationship between heart rate and CN X
Vagus nerve goes throughout the body; Parasympathetic to the SA node of the heart, causing heart rate to go down; SA would fire twice per second without “vagal tone”; Uses muscarinic receptor which dumps acetylcholine into SA node and Vagus nerve binds to; Results in hyperpolarization of SA node cells, making it more difficult for them to reach the threshold necessary for action potentials
Relationship between muscles and CN XI
Spinal accessory nerve XI connects to sternocleidomastoid and trapezius; Medical conditions that affect the CN XI will lead to difficulty elevating the scapula or rotating the neck
Graded potential vs action potential
Graded potential: Barrage of EPSPs; Determine if an action potential is generated; Na+, Cl-, K+; Summation; Usually occurs in dendrites and cell bodies; Ex: Non-myelinated multipolar neuron
Action potential:
Transmit signals over long distances; Na+, K+; No summation
Leak channel
Ion channel that is always open, allowing ions and substances to pass through; Aka passive channels or non-gated channels; Ex: Slow leak Na+ channel action potential in SA node (from RMP to threshold); Slow leak K+ channel maintains RMP in all action potentials
Carrier
Membrane protein that moves molecules across a cell membrane
Pump
Generate a membrane potential by creating an electrochemical gradient across the membrane (against the electrochemical concentration gradient); Ex: Na+/K+ ATPase pump maintains RMP in all action potentials; Ca+ ATPase pumps Ca+ out of somatic motor neuron when action potential is not happening
Ligand-gated receptor/channel
Protein embedded in a cell membrane that acts as a gate, allowing specific ions to pass through only when a signaling molecule (called a ligand) binds to it; Opening the channel by triggering a conformational change in the receptor protein; Ex: Nicotinic receptors found in neuromuscular junctions that turn into channels when Acetylcholine from neurons bind to it
Voltage gated channel
Transmembrane protein that opens and closes in response to changes in a cell’s electrical potential; Ex: VG Na+ opens and closes during depolarization (not SA node); VG K+ opens during beginning of plateau phase and opens and closes during repolarization; VG Ca+ opens and closes during depolarization of SA node and plateau phase
Pre-ganglionic
Neurons that originate in the central nervous system have its fibers (axons of neurons) extend and travel to a ganglion, where they synapse with post-ganglionic neuron
Post-ganglionic
Neurons that are located in a ganglion and have its fibers (axons of neurons) extend out to the target organ
Sympathetic fibers
Pre-ganglionic: Short; Releases acetylcholine
Post-ganglionic: Long; releases norepinephrine
Stronger due to release of Ach on adrenal medulla, which releases norepinephrine; Thoracic and lumbar
Parasympathetic fibers
Pre-ganglionic: Long; Releases acetylcholine
Post-ganglionic: Short; Releases acetylcholine
Weaker;
Sacrum and coccyx
APCV
Action potential conductance velocity; Refers to the speed at which an action potential travels along an axon from one end to another, ultimately reaching the target cells
What factors increase APCV
Larger axon diameter; Myelination; Higher temperatures; More efficient ion channel activation and faster ion movement
Relationship between APCV and myelination
Myelinated sheaths increase APCV; Length doesn’t matter because myelination causes saltatory conduction; However, diameter of axons matter
Release of neurotransmitters
Neurotransmitters are made in the soma of neurons; Dynein and kinesin are rotary proteins that move the vesicles from the soma to the pre-synaptic membrane; Action potential travel down axon to the pre-synaptic terminal, causing a depolarization of the membrane; Depolarization causes opening of VG Ca+ channels, allowing Ca+ in; Ca+ forces the vesicles to fuse with the synaptic terminal, further releasing acetylcholine into the synaptic cleft through exocytosis
Fate of neurotransmitters
1) Can be enzymatically degraded; Ex: Acetylcholine: Can be inhibited by sarin nerve gas, ach levels go way up causing intense skeletal muscle contractions
2) Part or all of the neurotransmitter can be taken up by reuptake proteins on the presynaptic side; Ex: FE-SSRI: Serotonin levels go up in the brain slowly and only in the brain
3) Sometimes neurotransmitters escape from the synapse and are usually scavenged by astrocytes
Summation
Graded potentials between resting and threshold; Made up of EPSPs (excitatory postsynaptic potentials) and IPSPs (inhibitory postsynaptic potentials) until they reach threshold
Threshold
The level of membrane depolarization that must be reached for an action potential to be initiated; EPSP + IPSP = T
CNS glial cells
Astrocytes
Microglia
Oligodendrocytes
Ependymal cells
PNS glial cells
Schwann cells
Satellite cells
CNS
Central nervous system; Information processing, motor control, sensory processing, cognition and thought, emotional and behavioral regulation, autonomic functions, and homeostasis; Includes brain and spinal cord
PNS
Peripheral nervous system; Transmits information to and from the CNS and regulates movement and the internal environment; Afferent neurons transmits information to the CNS and efferent neurons transmit information away from CNS; Somatic and autonomic PNS; 31 pairs of spinal nerves and 12 nerves of cranial nerves
Autonomic vs Somatic PNS
Autonomic: Regulates smooth and cardiac muscles; Typically involuntary
Somatic: Carries signals to skeletal muscles; Voluntary
Aquaporin
Channel protein that transports water
Relationship between aquaporin and ADH
Dehydration causes an influx of aquaporins and ADH (vasopressin), which leads to a decrease in urine; Allows kidneys to absorb more water resulting in less waste/urine from exiting the kidneys
Peptide hormone
Binds to cell surface receptors (2nd messenger); Fast effects; Rough ER to Golgi apparatus to neurotransmitter vesicles; Vesicles release when needed; Hydrophilic; Ex: Epinephrine
Steroid hormone
Binds to intracytoplasmic receptors, which affects transcription (genes “on/off”); Slow effects; Smooth ER makes and releases when needed; Hydrophobic; Ex: Testosterone
Anterior pituitary hormones
All made and released within the anterior pituitary; Hypothalamic hypophyseal portal system;
FSH, LH, ACTH, TSH, Prolactin, Endorphins, GH
Posterior pituitary hormones
Made by hypothalamus and released within the posterior pituitary; Oxytocin and ADH (vasopressin)
GH
Growth hormone from anterior pituitary makes its way down the liver and upregulates Insulin-like Growth Factor 1 (IGF1); Stimulated systemic body growth; Growth promoting effects on almost cells of the body
RN: Growth promoting effects on almost cells of the body
Skeletal muscle, cartilage, bone, liver, kidney, nerve, skin, hematopoietic cells, lung, DNA synthesis
Baroreceptors
Detects changes in pressure; Found in aortic arch and carotid sinuses; Blood pressure is closely monitored by baroreceptors, and they communicate with multiple brain centers to regulate blood pressure
Hypothalamic hypophyseal portal system
Two capillary beds that plays a role in the communication between the hypothalamus and the pituitary gland; Allows for direct transport of hormones from the hypothalamus to the anterior pituitary; Hormones transported are hormones that regulate (release or inhibit) the hormones created in the anterior pituitary
Neuroendocrine neurons
Can both transmit electrical impulses and release hormones directly into the bloodstream; Release hormones into bloodstream in response to electrical signals; Acts as bridge cells that convert neural signals into hormonal signals; Located in areas of the brain that regulate homeostasis (hypothalamus, pineal gland, posterior pituitary)
Hormones associated with blood sugar
Blood sugar up: Glucagon, epinephrine, cortisol, growth hormone
Blood sugar down: Insulin
Hyperglycemia vs hypoglycemia
Hyperglycemia: High blood sugar
Hypoglycemia: Low blood sugar
Type I Diabetes vs Type II Diabetes
Type I: Congenital (born with it); Makes no insulin at all; Beta cells (that produce insulin) in pancreas are attacked by immune system
Type II: Mainly affects those in 40s, 50s, and 60s; Weight is high and activity is down; Insulin resistance
What happens when blood sugar is too high for too long
Crystallization: If untreated, sugars will crystalize and block blood flow;
Glycosylation: If untreated, it can stiffen blood vessels and block blood flow;
Extremities: Blockage of blood flow in extremities can lead to amputation of limbs
Pre-capillary sphincters
Smooth muscles structures that regulate blood flow into capillary beds; Role in hemodynamics: When they constrict, blood flow into capillaries decreases, shunting blood to other areas or larger vessels; When they relax, blood flows freely into capillary beds, enhancing tissue perfusion; Adrenergic influence
Adrenergic influence
Constriction of pre-capillary sphincters are primarily mediated by α-adrenergic receptors
Adrenergic tone
Refers to the baseline level of sympathetic nervous system activity, which heavily influences vascular tone;
The balance between vasoconstriction (α1-adrenergic) and vasodilation (β2-adrenergic) receptors determines blood vessel diameter
Epinephrine based on adrenergic receptor affinities
Acts on both α-adrenergic and β-adrenergic receptors; At low concentrations, it primarily stimulates β2 receptors, causing vasodilation (especially in skeletal muscle); At high concentrations, it binds more strongly to α1 receptors, leading to vasoconstriction; Increases systolic BP (β1 receptors in the heart increase cardiac output); May decrease diastolic BP (β2-mediated vasodilation)
Catecholamine
A group of neurotransmitters and hormones that are essential in regulating several physiological processes; Includes norepinephrine, epinephrine, and dopamine
Adrenergic receptors
Proteins on cell membranes that respond to norepinephrine and epinephrine
Adrenergic alpha receptors
α1 receptors are mostly involved in vasoconstriction, increased blood pressure, and contraction of smooth muscles;
α2 receptors are mostly inhibitory, reducing the release of norepinephrine in a negative feedback mechanism, and they are involved in reducing sympathetic nervous system activity
Adrenergic beta receptors
β1 receptors are primarily located in the heart, where their activation increases heart rate, force of contraction, and conduction velocity in the heart;
β2 receptors are found in smooth muscle; Activation of β2 receptors causes vasodilation, bronchodilation, and muscle relaxation in various organs;
β3 receptors are involved in lipolysis (breakdown of fat) and thermogenesis (heat production) in adipose tissue
Nonrepinephrine based on adrenergic receptor affinities
Prefers α1 receptors (vasoconstriction) and β1 receptors (cardiac stimulation) but has weak effects on β2 receptors;
Effect on Blood Pressure:
Increases both systolic and diastolic BP due to widespread vasoconstriction
Relationship between cortisol and immune system function
Long time periods of stress leads to cortisol levels to increase and white blood cells to decrease causing immune system function to decrease and the ability to get sick to increase
Broken bones
Transverse: Perpendicular to the medullary cavity;
Linear: Parallel to the medullary cavity;
Oblique, nondisplaced: Broken at an angle;
Oblique, displaced: Broken at an angle all the way through;
Spiral: Corkscrew bone;
Greenstick: Bone bends before it breaks;
Comminuted: Bone breaks into fragments;
Compound: Bone breaks through skin
Palsy vs Neuralgia
Palsy: Paralysis
Neuralgia: Pain that is distributed to one or more nerves; Pain occurs along the path of a nerve
5 Epidermis layers
1) Stratum corneum (superficial)
2) Stratum lucidum
3) Stratum granulosum
4) Stratum spinosum
5) Stratum basale (deep; Contains melanocytes)
5 Regions of the bone growth plate
1) Cartilage (chondroblasts) (towards epiphysis or end of bone)
2) Proliferation (Cell number increases)
3) Hypertrophy (cell size increases)
4) Calcification (Cell with hydroxyapatite will apoptose, leading to cell being gone but hydroxyapatite stays)
5) Ossification (new diaphysis) (towards diaphysis or shaft of bone)
Outer layers of brain cortex in mammals
Process sensory input; Rapid gamma waves often originate in outer layers; Has higher frequency brain waves
Inner layers of brain cortex in mammals
Controls what the brain does with resulting information gathered by outer layers; Slower alpha and beta waves arise from deeper layers; Has lower frequency brain waves
High vs low frequency brain waves
High frequency: Encode sensory information; If higher frequencies dominate, this can cause attention problems or sensory overload;
Low frequency: Controls signals; If lower frequencies dominate, this can cause psychosis (like schizophrenia) by reducing information from the outside world and increasing the brains reliance on internally generated signals
Bone remodeling hormones
1) Calcitonin (thyroid c cells): Inhibits osteoclast activity
2) Parathyroid hormone (PTH): Activates osteoclasts to release calcium into the blood
3) Calcitriol: Activated vitamin D5; Promotes reabsorption of calcium
4) Estrogen: Inhibits apoptosis of osteoblast, so number of osteoblast increases
Hemodynamic formulas
Cardiac output = Stroke Volume x Heart Rate
C.O. = S.V x H.R.
Change in Pressure = Flow in System x Resistance
ΔP = Q (or C.O.) x R
Mean Arterial Pressure = Diastolic Blood Pressure + 1/3 x (Systolic Blood Pressure - Diastolic Blood Pressure)
MAP = D + ((S-D)/3)
Systolic vs. Diastolic in Blood Pressure
Systolic blood pressure is the top number
Diastolic blood pressure is the bottom number
Ex: 120 (Systolic)/80 (Diastolic)
Pressure units = mmHg
PG I2
Wound stage 2;
Causes vasodilation for increased blood flow/healing;
Demotes platelet aggregation
PG D2
Pain, sleep/wake cycles, pyretic (fever inducing);
Mediates inflammation
PG E2
Main inflammation prostaglandin;
Causes pain, redness, swelling, inflammation
PG F2 alpha
Corpus luteum (CL) regression, skeletal muscle;
End of menstrual
Estrogen and oxytocin stimulate the release of oxytocin, which aids in the stimulation of uterine contraction
PG H2
Wound stage 1;
Thromboxane (substance produced by platelets);
Vasoconstriction and increased clotting/platelet aggregation;
Don’t want to endure massive blood loss
Skeletal muscle cell/neuron AP graph
Na+ voltage-gated channel slowly opens until threshold; At threshold it opens all the way and Na+ ions enter cell during depolarization; Na+ closes at 35mvols, and K+ channel opens; K+ leave the cell during repolarization; When cell becomes more negative than RMP, hyperpolarization occurs; During hyperpolarization, K+ channels close; Another action potential cannot occur unless in hyperpolarization or RMP is reached; AP completely stops once the cell hits RMP; Na+/K+ ATPase pump and slow “leak” K+ channel work during RMP and AP to maintain RMP
Skeletal muscle cell/neuron AP graph (with summation)
During EPSP (towards threshold), Na+ and/or Ca+ goes into the cell; During IPSP (away from threshold), Cl- goes into the cell; Causes waves until the action potential is strong enough to reach threshold
Cardiac muscle cell AP graph
Na+ voltage-gated channel opens when depolarization occurs; Closes at peak; Simultaneously, VG K+ and VG Ca++ opens as VG Na+ channel closes; Causes plateau phase where two VG channels cancel each other out; VG Ca++ channel closes at beginning of repolarization; K+ continues leaving cell from VG K+ channel until RMP is reached;
Na+/K+ ATPase pump and slow “leak” K+ channel work during RMP and AP to maintain RMP
“Pacemaker” of heart (SA Node) AP graph
Before threshold is reached, slow leak Na+ channel lets Na+ into cell; When threshold is reached, VG Ca++ channel opens and depolarization occurs; Ca++ goes into cell until peak; During repolarization, VG K+ channel opens and lets K+ out until RMP is achieved; Na+/K+ ATPase pump and slow “leak” K+ channel work during RMP and AP to maintain RMP
Smooth muscle AP graph (GI tract and enteric nervous system)
Roll instead of spikes because very few fast VG Na+ channels within smooth muscle; Slow VG Na+ channel opens during depolarization letting Na+ into the cell; At peak, slow VG Na+ channel closes and VG K+ channel opens; During repolarization, K+ exits the cell; Spike potentials can occur on the top of the rolls, so the muscle can stay contracted for long periods of time; Na+/K+ ATPase pump and slow “leak” K+ channel work during RMP and AP to maintain RMP
Pancreas functions
Endocrine: Secretes hormones into blood; Islets of Langerhans;
Exocrine: Secretes into GI tract, usually enzymes;
Paracrine: Affects tissues nearby;
Autocrine: Self affecting
Islets of Langerhans
Clusters of specialized cells found within the pancreas that contribute to endocrine function;
Alpha cells produce glucagon (elevates blood sugar); Beta cells produce insulin (lowers blood sugar); Delta cells produce somatostatin (GI inhibitor)
Interferons
Type of cytokine (cell movement); 1st line of defense against viruses; Amplifies immune defense system against viruses; Produced by macrophages (which came from monocytes), T-cells (lymphocytes), fibroblasts, and virus-infected cells;
Guillain-Barre Syndrome
A fast/sudden and progressive autoimmune disorder that affects the nervous system, especially the PNS; Muscle weakness that can lead to paralysis; Unsure of cause, but usually a series of antecedent infections occurs prior of onset (viruses (mono), respiratory infections, bacterial infections)
Relationship between muscle soreness, testosterone, and satellite stem cell recruitment
Microtears (24-48 hours) occur; Stem cell recruitment is true muscle building because adding nuclei (more genes for actin and myosin; transcription and translation); Testosterone goes up and turns genes on to promote repair; Genetics play a role
Short-term memory vs long-term memory
Short term memory is stored within the temporal lobe; Long term memory is stored within the frontal lobe/prefrontal cortex
GLUT-4
Regulates glucose levels by transporting glucose into muscle and fat cells; GLUT-4 in cell membrane leads to blood sugar decreasing
Cranial nerve with the most posterior origin
Spinal Accessory Nerve XI
Why are cancers so deadly?
1) Steals nutrients from healthy cells
2) A cell changing in form causes it to change in function
3) Metastasize (non-muscle reference to actin): Cancer can move into blood vessels leading to blood vessels weakening causing internal bleeding and hemorrhaging (blood escaping vessels into surrounding organs and tissues)
A, B, C, D, E of moles
Asymmetrical; Border; Color; Diameter; Evolution
Motor unit size
Dependent on how many muscle fibers are innervated to a neuron; Size affects how fine the movements are for a group of muscle fibers; Smaller motor units have less muscle fibers innervated (down to one); Larger motor units have many more muscle fibers innervated (up to thousands)
Golgi tendon organ
Proprioceptors that are located in the tendon adjacent to the myotendinous junction; Detects stress
Cervical enlargement
Widening in cervical region of spinal cord due to increased number of nerve cells needed to innervate the upper limbs
Conus medullaris
Located at beginning of lumbar vertebrae and marks end of spinal cord proper; Below this point, spinal cord transitions into cauda equina
Cauda equina
A bundle of nerve roots that originate from the conus medullaris and descend within the vertebral canal; These nerve roots innervate the lower limbs, pelvic organs, and perineal area; Consists of lumbar, sacral, and coccygeal nerve roots
Filum terminale
A thread-like structure of connective tissue that extends from the tip of the conus medullaris and attaches to the coccyx; Serves to anchor the spinal cord in place within the vertebral canal and stabilize the spinal cords position
Phrenic nerve
Innervates diaphragm for respiration; Spinal nerve that originates from the cervical spinal cord
Gray matter vs white matter
Gray matter consists of neuron cell bodies, dendrites, and unmyelinated axons; White matter consists of bundles of myelinated axons; Gray matter is superficial (closer to skin) to white matter in the brain; White matter is superficial (closer to skin) to gray matter in the spinal cord
Optic chasm
Part of brain where optic nerves cross; Found in all vertebrates; Located at the bottom of the brain immediately inferior to the hypothalamus
Ventricles of brain
Fluid-filled cavities responsible for producing and circulating cerebrospinal fluid; 4 ventricles: 2 Lateral (1 in each hemisphere of brain), third ventricle (narrow cavity in midline of brain), fourth ventricle (between brainstem and cerebellum), and cerebral aqueduct (connects third and fourth ventricle)
5 senses found in which brain lobes?
Parietal: Taste and touch
Temporal: Hearing and smell
Occipital: Vision
Speech formation and speech comprehension found where?
Broca’s area (left brain): Speech formation/execution
Wernicke’s area (right brain): Speech/language comprehension and interpretation
Afferent vs efferent neurons
Afferent: Into spinal cord; Sensory; Bipolar neuron; Takes information to CNS
Efferent: Away from spinal cord; Motor; Affects skeletal muscles; Takes information given from CNS and responds to stimuli
Cranial nerve V branches
Trigeminal nerve V has 3 branches;
Ophthalmic branch (V1): Sensory input like touch, pain, and temperature from these regions; Eye, forehead and scalp, nose, and upper eyelid
Maxillary branch (V2): Sensory input from the midface and upper oral structures (upper jaw and teeth, cheeks, nose, palate, sinuses)
Mandibular branch
(V3): Sensory input from lower face and motor control of chewing muscles; Masseter, temporalis, medial and lateral pterygoids
Intrinsic vs extrinsic muscles
Intrinsic: Within the tongue
Extrinsic: Tongue muscles that attach the tongue to other structures
Dorsal root ganglia
Located along the dorsal roots of spinal nerves; Transmits sensory signals from the body to the CNS
Ganglia
A cluster of neuronal cell bodies located outside the CNS in the PNS
Relationship between snake bites and necrosis
Snake bites can lead to necrosis (tissue death); Venom, toxins, or poison keeps VG Ca++ channels open leading to progressive skeletal muscle weakness and potentially paralysis
Venoms, toxins, and poisons
Venom, toxins, or poison keeps VG Ca++ channels open (Ach is released into synaptic cleft causing constant muscle contraction) leading to progressive skeletal muscle weakness and potentially paralysis
Gap junctions
Cell-to-cell junction that allows for the direct communication between adjacent cells; Physical synapses
Neural circuits and pathways
Convergent neuronal circuits: Input from many sources/nerves to a single source;
Divergent neuronal circuits: Input to many sources/nerves originating from a single source;
Reverberating neuronal circuit: Sends signals in a loop between neurons; Repetitive;
Discharge neuronal circuit: Most complicated; Quick, temporary neuronal firing in response to a stimulus; Rapid responses to environmental stimuli; Different cognitive elements of brain; cause/effect, reasoning, answering questions, solving problems
What happens if valves give out?
Back flow can occur leading to reduced cardiac output
Absolute vs relative refactory periods
Absolute refactory periods: No new APs can be generated; Longer absolute refactory periods in cardiac muscle, so cardiac muscle cannot summate twitches; VG Na+ gates are resetting
Relative refactory periods: A new AP can be generated, but there would need to be a stronger stimulus to get back to threshold; Occurs during hyperpolarization
Plateau phase
Occurs during cardiac muscle AP; Ca++ goes into cell as K+ exits the cell, canceling each other out; Extends absolute refactory period of cardiac muscle to prohibit summation of twitches; Prevents cardiac tetany; Promotes ventricular emptying because of longer, sustained contraction of the heart
Muscular dystrophy
Refers to a groups of more than 30 genetic disease that cause progressive weakness and degeneration of skeletal muscles used during voluntary movement; All forms worsen as muscles progressively degenerate and weaken; Most prominently affects the integrity of muscle fibers
Myopathy
Muscular disease; Disease of muscle where the muscle fibers do not function properly resulting in muscle weakness; Primary defect is in muscles as opposed to nerves
Neuropathy
Nervous/nerve disease; Damage or dysfunction of the peripheral nerves
Huntington’s disease
Autosomal dominant; Short arm of chromosome #4; “Huntingtin” gene; Too many CAG repeats which causes issue with transcription of genes, issue with cell to cell communication, and issue with cell signaling; Disease causes cognitive and behavioral issues; Not visible until after the age of 30, which can lead to it having already been passed on
Rheumatoid arthritis
Long-term autoimmune disorder that affects joints; Self-attacking antibodies or immunoglobin; Dendritic cells sound alarm against own synovial tissues; Typically in wrist and hands
Osteoarthritis
Impingement (bone on bone); Thinning of hyaline cartilage; Formation of osteophytes; Can lead to bone spurs on heel
Gout arthritis
A type of inflammatory arthritis; Deposition of needle-like crystals of uric acid into joints; Factors include diet, genetics, and under excretion of uric acid by the kidney
Antihistamine
Swelling and inflammation of smooth muscle of respiratory tree; Inhaler blocks H1 and inhibits mast cells (Histamine decreases)
Muscle relaxants
Helps with tension and pain in skeletal muscle; Nicotinic AcR antagonists; GABA increases in brain leading to inhibition of cerebral pathways
Processing centers of the brain
Thalamus: Receives sensory information and sends it to regions of cerebral cortex; Handles all senses except smell;
Cerebral cortex: Involved in higher-order processing, including thinking, memory, and voluntary movements;
Brainstem: Responsible for basic, life-sustaining functions, such as breathing, heartbeat, and digestion;
Cerebellum: Involved in motor control and learning, coordination of voluntary movements, and maintaining balance and posture;
Limbic system: Responsible for emotion processing, memory, and behavior;
Hypothalamus: Maintains homeostasis within the body
Brain lobes
4 lobes make up the cerebrum:
1) Frontal lobe: Reasoning, motor control, speech production, personality and social behavior, cognitive function
2) Parietal lobe: Processes sensory information, spatial awareness, sensory integration
3) Temporal lobe: Auditory processing, language comprehension, memory formation, emotional responses
4) Occipital lobe: Visual processing and recognition
Brain segments
Brain is separated into 3 segments:
1) Forebrain (Prosencephalon): Cerebrum and diencephalon (thalamus, hypothalamus, epithalamus)
2) Midbrain (Mesencephalon): Reticular activating centers
3) Hindbrain (Rhombencephalon): Brainstem (minus the midbrain) and cerebellum
