BSI EXAM 4 Flashcards
Which hormone is secreted from bone?
- Parathyroid
- Calcitonin
- Vitamin D
- Ostercalin
- 1,2,3
- All
4
What is the major organic component of the matrix?
- Hydroxyapaptide
- Magnesium hydroxide
- Collagen
- 1,2
- All
3
What is the major inorganic component of matrix?
- Hydroxyapaptide
- Magnesium hydroxide
- Collagen
- 1,2
- All
4
How do osteoblasts arise?
- Division of osteoclasts
- Fusion of monocytes
- Differentiation of osteogenic cells
3
How do osteocytes arise?
- Mutation of osteoclasts
- Fusion of monocytes
- Differentiation of osteogenic cells
- Maturation of osteoblasts
4
What is the function of osteoclasts?
- Bone formation
- Bone resorption
2
How do osteoclasts arise?
- Mutation of osteoblasts
- Fusion of monocytes
- From division and differentiation of osteocytes
- Differentiation of osteogenic cells
3
Compact bone and spongy bone are both organized into osteons
T or F
False
Bone muticellular unit (BMU) consists of:
- osteocytes
- osteoblasts
- osteoclasts
- 1 and 2
- 2 and 3
- all
5
What do osteoclasts secret to resorb bone?
- collagen
- alkaine phosphotase
- lysosomal enzymes
- acids
- 3 and 4 only
- all
5
where does collagen come from?
- secrete from osteocytes
- secreted from osteoblasts
- secreted from osteoclasts
- synthesized by collagenases with in the bone matrix
2
what is the function of alkaine phostase?
1, to initial calcification of mineral salt units
- plays role in the secretion of collagen
- to activate osteoclasts
- 1 and 2
- all
1
what effect does PTH have on RANKL and OPG expression?
- increase both
- decrease both
- increase RANKL and decrease OPG
- decrease RANKL and incerase OPG
3
What effect does estrogen have on RANKL and OPG expresion?
- increase both
- decrease both
- increase RANKL and decrease OPG
- decrease RANKL and incerase OPG
4
what effect does glucocorticortal have on RANKL and OPG expression?
- increase both
- decrease both
- increase RANKL and decrease OPG
- decrease RANKL and incerase OPG
3
Calcium is only biologically active when:
- ionized
- bound to albumin
- bound to anions
- 2 of the above
- all
1
what effect does PTH have on the kidney?
- increase reabsortion of both Ca and P
- decrease reabsorption of both Ca and P
- decrease rebsorption of Ca and increase reabsorption of P
- increase reabsorption of Ca and decrease reabsorption of P
4
what is the effect of calcitonin on the kidney?
- increase reabsortion of both Ca and P
- decrease reabsorption of both Ca and P
- decrease rebsorption of Ca and increase reabsorption of P
- increase reabsorption of Ca and decrease reabsorption of P
2
if the PTh gene was deleted, what would happento the calcium level?
- it would cause hypocalcimia
- it would cause hypercalcimia
1
which is the biologically active form of vitamin D?
- vitamin D2
- vitamin D3
- 25- hydroxyvitamin D3
- 1,25 hydroxyvitamin D3
- all
4
which enzyme is regulated by PTH?
- vitamin D 25 hydroxylase
- 1 and hydroxylase
- both
- hydroxylase where? kidney
osteoclasts do not express receptor accept PTH but they are still bone reabsorption. How PTH still stimulate in reabsorption?
RANKL osteblast expresses PTH
increase RANKL and decrease OPG stimulate RANK receptor
Glucocrticoid induced osteporosis is
- primary osteoporosis
- secondary osteoporosis
2
why would enzyme 1 and alpha hydroxylate vitamin D decrease?
what is the function?
what organ?
kidney ( 1 and alpha hydroxylate)
absorp ca and p
a T score of -2.0 would be considered:
- normal
- osteopenia
- osteoporosis
2
what is primary determinant of peak bone mass?
- calcium and vitamin D consumption
- exercise
- genetics
3
what is the mechanism of action of denosumab?
- it is a synthetic form of PTH
- it is in antibody that binds RANKL
- it is a selective estrogen receptor module
- it stimulates the expression of RANKL
2
Which is the “faster” system: endocrine or nervous?
nervous obviously although humoral adrenaline only requires seconds!
☻ What are the main functional/anatomical divisions of our nervous system?
Functionally; somatic and visceral which itself is divided into visceral sensory and the ANS which is itself divided into the ANS and PNS, Anatomically; CNS and PNS (peripheral not para-).
What is our “lizard brain?”
Answer: our innate behaviors driven by basic emotions and needs such as food, water, sex, etc. (no cerebral cortex/telencephalon or actual “thinking” required).
Where is the “program” for walking stored?
in the spinal cord; our brain just adjusts for obstacles, rate, balance, etc.
☻ Where would the program for a concert pianist to play be stored?
lots of the basic mechanical movements may well be stored in the cerebellum while the forebrain worries about higher issues such as interpretation.
What is the main function of our frontal lobes and do they always help us?
decision making and planning; for some responses they can actually get in the way (“thinking too much”).
Once a drug reaches our systemic circulation does it “access all areas” including our CNS?
: no, it has to cross the BBB (NOT the Better Business Bureau!) BUT once crossed, any drug will access all areas of the CNS (drugs do not have the anatomical specificity afforded by specific synapse release).
What is afferent and efferent information?
: incoming sensory information and outgoing motor commands respectively
What are the 2 antagonistic parts of the visceral nervous system and which part is in control the majority of the time?
CNS and PNS; PNS is the “housekeeping” system and is normally in control ~+99% of time
How many interneurons are involved in a monosynaptic reflex?
none
Is activation of just flexor or extensor muscles sufficient to remove a limb from a noxious stimulus?
no, need to inhibit antagonistic muscles via inhibitory interneurons
What is the cerebellum?
our “motor computer”
What is the outer connective tissue covering of a nerve (containing many axons and fascicles) called?
epineurium
“Axons always start as a single process”- true or false?
true
Which type of glial cell is involved in neuronal nutrition?
astrocyte
Which type of glial cell is involved in neurotransmitter removal/recycling?
astrocyte
Which type of glial cell is involved in the BBB?
astrocyte
Which type of glial cell is involved in myelination within the CNS?
oligodendrocyte
A patient with parathyroid deficiency 10 days after inadvertent damage to the parathyroid glands during thyroid surgery would probably have
A
low plasma phosphate and Ca2+ levels and tetany.
B
low plasma phosphate and Ca2+ levels and tetanus.
C
a low plasma Ca2+ level, increased muscular excitability, and spasm of the muscles of the upper extremity (Trousseau sign).
D
high plasma phosphate and Ca2+ levels and bone demineralization.
E
increased muscular excitability, a high plasma Ca2+ level, and bone demineralization.
a low plasma Ca2+ level, increased muscular excitability, and spasm of the muscles of the upper extremity (Trousseau sign).
A mouse is engineered to lack a transcription factor necessary for the normal development of osteoclasts. Compared to normal littermate mice, which of the following would be reduced in the knock-out animals?
A
Phosphate deposition in trabecular bone
B
Hydroxyapatite levels in bone
C
Osteoblast proliferation
D
Secretion of acid proteases
E
Bone collagen
D
Secretion of acid proteases
1,25-Dihydroxycholecalciferol affects intestinal Ca2+ absorption through a mechanism that
A
includes alterations in the activity of genes.
B
activates adenylyl cyclase.
C
decreases cell turnover.
D
changes gastric acid secretion.
E
involves degradation of apical calcium channels.
A
includes alterations in the activity of genes.
Which of the following would you expect to find in a patient whose diet has been low in calcium for 2 mo?
A
Increased formation of 24,25-dihydroxycholecalciferol
B
Decreased amounts of calcium-binding protein in intestinal epithelial cells
C
Increased parathyroid hormone secretion
D
A high plasma calcitonin concentration
E
Increased plasma phosphate
C
Increased parathyroid hormone secretion
The skeleton of a normal male college student would be expected to display which of the following features, relative to that of his 7-year-old brother?
A
Merging of cortical bone and trabecular bone.
B
Differentiation of osteoclasts and osteoblasts.
C
An extended amount of proliferating cartilage that contributes to bone elongation.
D
A meeting of the lacunae with the trabecular bone.
E
Ephyses that are united with the bone shaft.
E
Ephyses that are united with the bone shaft.
Which of the following is produced only by large amounts of glucocorticoids?
A
Normal responsiveness of fat depots to norepinephrine
B
Maintenance of normal vascular reactivity
C
Increased excretion of a water load
D
Inhibition of the inflammatory response
E
Inhibition of ACTH secretio
D
Inhibition of the inflammatory response
Which of the following is not involved in regulating plasma Ca2+ levels?
A
Kidneys
B
Skin
C
Liver
D
Lungs
E
Intestine
D
Lungs
Thirst is stimulated by
A
increases in plasma osmolality and volume.
B
an increase in plasma osmolality and a decrease in plasma volume.
C
a decrease in plasma osmolality and an increase in plasma volume.
D
decreases in plasma osmolality and volume.
E
injection of vasopressin into the hypothalamus.
B
an increase in plasma osmolality and a decrease in plasma volume.
The electrogenic Na, K ATPase plays a critical role in cellular physiology by
A
using the energy in ATP to extrude 3 Na+ out of the cell in exchange for taking two K+ into the cell.
B
using the energy in ATP to extrude 3 K+ out of the cell in exchange for taking two Na+ into the cell.
C
using the energy in moving Na+ into the cell or K+ outside the cell to make ATP.
D
using the energy in moving Na+ outside of the cell or K+ inside the cell to make ATP.
A
using the energy in ATP to extrude 3 Na+ out of the cell in exchange for taking two K+ into the cell.
Which of the following statements about glia is true?
A
Microglia arise from macrophages outside of the nervous system and are physiologically and embryologically similar to other neural cell types.
B
Glia do not undergo proliferation.
C
Protoplasmic astrocytes produce substances that are tropic to neurons to help maintain the appropriate concentration of ions and neurotransmitters by taking up K+ and the neurotransmitters glutamate and GABA.
D
Oligodendrocytes and Schwann cells are involved in myelin formation around axons in the peripheral and central nervous systems, respectively.
E
Macroglia are scavenger cells that resemble tissue macrophages and remove debris resulting from injury, infection, and disease.
C
Protoplasmic astrocytes produce substances that are tropic to neurons to help maintain the appropriate concentration of ions and neurotransmitters by taking up K+ and the neurotransmitters glutamate and GABA.
The action potential of skeletal muscle
A
has a prolonged plateau phase.
B
spreads inward to all parts of the muscle via the T tubules.
C
causes the immediate uptake of Ca2+ into the lateral sacs of the sarcoplasmic reticulum.
D
is longer than the action potential of cardiac muscle.
E
is not essential for contraction.
B
spreads inward to all parts of the muscle via the T tubules.
Which of the following ionic changes is correctly matched with a component of the action potential?
A
Opening of voltage-gated K+ channels: After-hyperpolarization
B
A decrease in extracellular Ca2+: Repolarization
C
Opening of voltage-gated Na+ channels: Depolarization
D
Rapid closure of voltage-gated Na+ channels: Resting membrane potential
E
Rapid closure of voltage-gated K+ channels: Relative refractory period
C
Opening of voltage-gated Na+ channels: Depolarization
The membrane potential of a particular cell is at the K+ equilibrium. The intracellular concentration for K+ is at 150 mmol/L and the extracellular concentration for K+ is at 5.5 mmol/L. What is the resting potential?
A
–70 mV
B
–90 mV
C
+70 mV
D
+90 mV
B
–90 mV
Which of the following statements about neurotransmitters is true?
A
All neurotransmitters are derived from amino acid precursors.
B
Small-molecule neurotransmitters include dopamine, histamine, ATP, glycine, enkephalin, and norepinephrine.
C
Large-molecule transmitters include ATP, cannabinoids, substance P, and vasopressin.
D
Norepinephrine can act as a neurotransmitter in the periphery and a neuromodulator in the CNS.
E
Nitrous oxide is a neurotransmitter in the CNS.
D
Norepinephrine can act as a neurotransmitter in the periphery and a neuromodulator in the CNS.
What happens to the balance between bone formation and bone resorption as we age?
It’s getting imbalance, lost bone mass (low bone formation and higher bone resorption).
Define osteoporosis.
A medical condition where bone becomes brittle and fragile due to the loss of tissue (typically due to hormonal changes, deficiency of calcium and vitamin D).
What is the difference between primary and secondary osteoporosis
- Primary osteoporosis: results from cumulative bone loss as people age and undergo sex hormone changes
- Secondary osteoporosis: results from a variety of medical conditions, diseases, or the use of certain medications that adversely affect skeletal health.
What is the most common cause of secondary osteoporosis?
Glucocorticoid-induced osteoporosis is the most common cause of secondary cause.
How prevalent is osteoporosis and low bone mass?
It can cause severe reductions in bone formation and can, to a lesser extent, increase bone resorption.
Osteoporosis affects approximately 10 million Americans and an additional 34 million have low bone mass.
What are the consequences of vertebral fractures?
Substantial pain, height loss, and kyphosis, resulting in compression of internal organs.
What is the primary determinant of peak bone mass?
In women, the greatest determinant of peak bone mass is heredity.
Can people do anything to increase peak bone mass? What would you suggest?
Yes because bone mass accumulation can be affected by nutrition, physical activity, health during growth, and smoking. I would suggest individuals to maintain a healthy diet (as best as possible to maintain healthy weight), maintain a consistent exercise schedule, upkeep your health, and also avoid smoking or excessive alcohol consumption.
What is the importance of peak bone mass in risk for osteoporosis?
Maintaining an optimal peak bone mass is important for the prevention of osteoporosis and potential fractures. An increase in the peak bone mass could reduce fracture risk. 10% increase in PBM would decrease the risk of fracture by about 30%.
How does WHO define osteopenia and osteoporosis? What is a T-score?
WHO defines low bone mass (osteopenia) as a BMD between -1.0 and -2.5 SD below the norm for young healthy adults of the same sex and osteoporosis is indicated by a BMD of -2.5 SD or below. T score is the expected BMD from a sex-matched young adult healthy population.
What is DXA and what sites are typically measured?
DXA is dual energy x-ray absorptiometry. Sites are measured at both spine and the hip.
List three drugs that can cause secondary osteoporosis.
Glucocorticoids, aromatase inhibitors, and gonadotropin-releasing hormone antagonists.
Describe nonpharmacologic interventions to prevent osteoporosis.
A well balanced diet rich in Ca and Vitamin D, regular weight-bearing and muscle-strengthening exercise, smoking cessation, avoidance of excessive alcohol consumption, and prevention of falls.
Two main classes of medications are available for postmenopausal osteoporosis:
• Antiresorptive agents: decrease bone resportion.
• Anabolic agents; promote bone formation.
What is the mechanism of action for the following drugs for the treatment/prevention of osteoporosis: (Which are antiresorptive and which are anabolic? Do they affect activity of osteoclasts and/or osteoblasts?)
a. Bisphosphonates
b. Calcitonin
c. PTH (teriparatide)
d. Estrogen and selective estrogen receptor modulators
e. Denosumab:
a. Bisphosphonates: decrease the rate of bone breakdown. Antiresorptive. For postmenopausal women with osteoporosis, this is the first line of treatment.
b. Calcitonin: inhibits osteoclast activity Antiresorptive.
c. PTH (teriparatide): stimulates osteoblast activity. Anabolic.
d. Estrogen and selective estrogen receptor modulators: inhibit osteoclast formation by stimulating OPG synthesis and inhibiting RANKL expression in osteoblasts. Antiresorptive.
e. Denosumab: binds to RANKL and prevents it from activating its receptor RANK. Antiresorptive.
Which of these drugs can potentially cause osteosarcoma?
Teriparatide: a recombinant form of PTH, is the only anabolic agent approved for the treatment of postmenopausal osteoporosis.
- *Osteonecrosis of the jaw: an area of exposed bone in the maxillofacial region that does not heal within 8 weeks after identification by a health care provider.
- Side effects of raloxifene are hot flashes and leg cramps, increase risks of DVT and PE, but reduce risk of invasive breast cancer.
- Calcitonin nasal spray: can cause nasal stuffiness, dry mouth, and nausea.
- Teriparatide: possible development of osteosarcoma limited to max of 2 years therapy. It also can cause leg cramps, dizziness, and nausea.
The source of intraceullar calcium triggered by AP’s in the pre-synaptic terminal is
of course via voltage gated calcium channels which open every time an ap ivades the terminal/reaches threshold for those channels so in effect counting aps
Axons unlike dentrites always start as a single process ( but they can divided)
True or False?
T
The increase in equilibrium potential for an ion ( and RMP if only ion involved) going from a x10 to a x1000 concerntration difference is x100 concentration difference which is 2 in long 10 so it is twice supplied factor
True or false
T
Spatial consideration ONLY (spatial summation) a synapse closest to AP initiation will have the greatest effect so the axo hillock
True or False
T
The metabotropic 5-HT family acts by increasing cAMP
True or False
T
Ion channels contain hydrophilic lipophobic channels
True or false
T
Botulinum and tetanus toxins affect vesicle exocytosis ( triggered by calcium)
True or False
T
The family of ionotropic receptors (excluding the glutamate ones) all have 5 subunits
True or false
T
Histamine is involved implicated in arousal, water intake and vomitting
True or False
T
All glutamate ionotropics (AMPA, NMDA and kainite) are NOT similar in structure to nicotinics ( different family infact) not all activated NMDA (AMPA and kainite) and some are permeable to calcium (NMDA to give LTP)
True or False
T
P2X purinergics are ionotropic
True or False
T
Adenosine is the preferred endogenous ligand for PA receptors
True or False
T
Glutamine is almost certainly NOT a neurotransmitter
True or False
T
The NMDA receptor is unique because it is ligand and voltage gated, requires glycine and has a high calcium coductance as well as sodium
True or False
T
A nicotinic ionotropic receptor will have no effect unless acetylcholine ( or nicotine) is added extracelluarly
True or False
T
Hyperkalemia means extracelluar potassium levels are higher than normal so the Eq.pot.is reduced; this results in depolarization relatively speaking less effect repolarization inhibitory synaptic transmission
True or False
T
Hypokalemia means the opposite; greater concentration gradient so increased/more negative potassium equilibrium potential
True or False
T
ONLY the AP does not decrease in size with distance
True or False
T
Artificially moving the RMP to +30 means that potassium rather than sodium will flow when both ions can now potassium is farther from its equilibrium potential
True or False
T
Depolarzing a cell will with a RMP of -60mV by -15mV does not reach the -40mV threshold
True or False
T
What color is sensory neuron? what color is motor neuron?
Sensory neuron- blue
motor neuron- red
Telenchephanlon
Cerebrum
Lateral ventricles
Diencephalon
Diencephalon
Third ventricules
Mesencephalon
- Brain stem: midbrain/ cerebral aqueduct
- Brain stem: pons/ fourth ventricles
- cerebellum/ fourth ventricles
Myelencephalon
Brain stem: medulla
fourth ventricles
Everything dies away within the distances except action potential
True or False
T
Mutipolar neuron
mutiple dendrites
common incerebral cortices and cerebellum
AP starts in cell bodies
ex) foot
bipolar neuron
both dentrites and axon join the cell body as single processes
ex) retina
Unipolar neuron
btoh dentrites and axon join the cell body as shared processes
ex) skin
major sensory afferent
spinal cord
Types of glia
Astrocytes
- BBB
- Metabolism
- nutrientions
Types of glia
microglial cell
immune cell
Ependymal cell
secret CSF
Oligodendrocyte
can monitor
insulating
myelination
Schwann cell
myelination axons outside the CNS
Fat myelins are faster than thin
True or False
T
Multiple Sclerosis MS
Unmyelinated diseases
autoimmune diseases
periods of remission
What is two ways to stop MS?
- Block adhesion molecures
2. Sphingosine 1 inhibit lymphocyte thtat attacking myelin
Vesicle Exocytosis Calcium Domains
Presynaptic terminal
not changing membrane potential
ca+ is 2nd messenger
Accumulation of ca+—> lead to placity
Low affinity means it needs to increase ca+ to activate it —> many action potential—> activated by hgh ca+
high affinity means ca+ escapes = summnation
activated by low ca+—-> 1-2 action potential
Faciliatation
no enhancement
1-2 ap
Identical
depression
due to ca+
increased ca+ releases depression
2nd response is reduced; not identical
Excessive ca+ in neurons are toxix
True or false?
T
Glutamine is not a trasmitter, not active
True or False?
T
Ionotropic family
nAchR, 5HT, GABA and glycine
Which best describes an afferent neuron?
- the cell body is in the CNS and the peripheral axon terminal is in the skin.
- the cell body is in the dorsal root ganglion and the central axon terminal is in the spinla cord
- the cell body is in the vertral horn of the spinal cord and the axon ends on skeletal muscle.
- the dendrites are in the PNS and the axon terminal is in the dorsal
- all
2
Which incorrectly pain a glial cell type with an associated function?
- astrocytes: formation of BBB
- Microglia: performance of immune fucntion in the CNS
- Oligodendrocytes: formation of myelin sheaths on axons in the PNS
- Ependymal cells: regulation of production of CSF
- astrocytes: removal of potassiun ions and neurotransmitters from the brains extracellular fluid
3
If the extracellular cl- concertaion is 110mmol/L and a particular neuron maintains an intracellular cl- concentration of 4mmol/L at what memebrane potention would cl- be closer electrochemical equlibrium in the cell?
- +80mV
- +60mV
- 0mV
- -86mV
- -100mV
4
Which is a true statement about the resting membrane potential in a typical neuron?
- the RMP is closer to the NA+ equilibrium potential than to the K+ equilibrium potential
- The cl- permeability is higher than that for NA+ or K_
- The RMP is at the equilibrium potential for K+
- There is no ion movement at the steady RMP
- ion movement by the Na+/K+ ATPase pump equal and opposite to the leak of the ions thruogh Nat+ AND K+ channels
5
Catacholamine receptors are important in mediating the peripheral effects of the sympathetic division of ANS
True or False?
True
What type of NT inhibitory on forehead?
GABA
What type of NT most inhibit in spinal cord?
Glycine
What can cross BBB?
L-DOPA and TryOHASE
Sites of calcium sources
NMDA
AMPA
VGCa channels
mGluR
The effects on calcitriol active Vitamin D where?
GI and kidney
Signs of hypocalcemia
- Spontaneous AP due to increased Na
- Tingling
- Muscle spams
- Cardiac arrhythmias
- Seizure
Signs of hypercalrcimia
- Nervous system depression
- Sluggish reflex’s
- Muscle weakness
- Fatigue
- Constipation
- Deceased appetite
- Frequency urination
- Excessive thirst
- Nausea and vomiting
- Kidney stones
The form of vitamin D measure to access Vitamin D status is?
25(OH)D3
Which is major circulating form
1,25(OH)2D3- active form
Teraparatide is synthetic PTH and potential side effect is cancer
True or false
True
Endocrine function of osteocalcin is?
Prevent type 2 diabetes
Knock out PTH, animal will die why?
Hypocalcemia
What types of NT are Catacholamine?
DA, NE and Epi
PTH deficiency will lead to
Hypocalcemia
Normal osmolarity?
290mosm/L
