Unsolved Questions

[impaction]

hey guys these are few questions that i cannot understand or the reason behind the answer is hard to find,
plz help with the explanations for answersbreathing


Q1 . breathing a gas mixture with 5% co2 ultimately leads to .......
a.hypoventilation
b.a decrease in heart rate
c.stimulation of central receptors
d inhibtion of peripheral receptors
e decrease in CSF H+ concenttation

Q2. which of the following has high affinity for binding Ca & collagen in calcifying matrix?
a calcitonin
b osteogenin
c osteonectin
d amelogenin
e fibronectin

Q3 temp. regulating mechanism that increase heat production?
a. increase voluntary activity............. how?
b. increased epinepherine secretion.............how?
c.cutaneaous vasoconstriction.......................why this is not the answer along with a & B

Q4 what is chronotropy?
Q5 what is intropy?

Q6 does stimulation of carotid sinus effects change in heart rate, arterial blood pressure or venous return?


Q7wht is after potential?

Q8 the action potential depends on which ion
Na or K

Q9 by what the H ion is liberated from kidney <most amount>
NH4, HCO3,

Q10 is Ca present in saliva? or is it a primary electrolyte of saliva?

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[impaction]

117 ppl went over this thread but no body explained the options???
are they tough???

 

[cornerstones]

hey guys these are few questions that i cannot understand or the reason behind the answer is hard to find,
plz help with the explanations for answersbreathing


Q1 . breathing a gas mixture with 5% co2 ultimately leads to .......
a.hypoventilation
b.a decrease in heart rate
c.stimulation of central receptors
d inhibtion of peripheral receptors
e decrease in CSF H+ concenttation
ans:-its hyponentilation ???? ...as HR must be increase....no stimulation of central receptors with high co2....not sure let me knw ans if u find out..

Q2. which of the following has high affinity for binding Ca & collagen in calcifying matrix?
a calcitonin
b osteogenin
c osteonectin
d amelogenin
e fibronectin
ans:- i thnk its osteonectin as it is the one which binds with both.

Q3 temp. regulating mechanism that increase heat production?
a. increase voluntary activity............. how?...
b. increased epinepherine secretion.............how?
c.cutaneaous vasoconstriction.......................why this is not the answer along with a & B

????

Q4 what is chronotropy?
ans:-substance which effect the rate of heart beat is chronotrpic..it can be negative or positive depending on inc or dec in HR..not sure??

Q5 what is intropy?

ans:-its ventricular contractility...

Q6 does stimulation of carotid sinus effects change in heart rate, arterial blood pressure or venous return?

yah ..as carotid sinus changes th blood pressure which can change all three...


Q7wht is after potential?

???


Q8 the action potential depends on which ion
Na or K
ans:-its Na...

Q9 by what the H ion is liberated from kidney <most amount>
NH4, HCO3,

its HCO3 mostly> NH4>H2PO4

Q10 is Ca present in saliva? or is it a primary electrolyte of saliva?

yes Ca is in saliva..

please correct me if i am wrong ...​

 

[impaction]

temp regulatory mechanism that increase heat production.......
the answer is increase in voluntry activity+increased epinepherine secretion...
why not vasoconstriction

and for Q9 answer is NH4 or hco3
i am confused between these two & this is very very important question

 

[cornerstones]

temp regulatory mechanism that increase heat production.......
the answer is increase in voluntry activity+increased epinepherine secretion...
why not vasoconstriction

because epinephrine vasodilates the arterioles in the skeletal muscle and increase the flow of blood to increase heat to the periphery ...

dont knw much ..

and for Q9 answer is NH4 or hco3
i am confused between these two & this is very very important question[/QUOte
ITS HCO3 .....mostly ..then 9% with NH4 and 7% as HPO4

 

[fairy123]

inotropy is heart rate
positive inotrope increase the heart rate like epinephrine,while negative decrease it,check weikipedia.
n chronotropy is contractility.

 

[dental material]

vasoconstriction occurs in AV shunts which are located primarily in fingers and toes.
Shivering is involuntary muscle acitvity that increase metabolic rate 2-3 times. so best option is shivering.
2 H+ r produce in kidney from HCO3- and kidney get rid of this H+ by primarily monobasic H2PO4 and 2nd is NH4+ [ when there is extra load ]

temp regulatory mechanism that increase heat production.......
the answer is increase in voluntry activity+increased epinepherine secretion...
why not vasoconstriction

because epinephrine vasodilates the arterioles in the skeletal muscle and increase the flow of blood to increase heat to the periphery ...

dont knw much ..

and for Q9 answer is NH4 or hco3
i am confused between these two & this is very very important question[/QUOte
ITS HCO3 .....mostly ..then 9% with NH4 and 7% as HPO4

 

[Ibanez]

hey guys these are few questions that i cannot understand or the reason behind the answer is hard to find,
plz help with the explanations for answersbreathing


Q1 . breathing a gas mixture with 5% co2 ultimately leads to .......
a.hypoventilation
b.a decrease in heart rate
c.stimulation of central receptors
d inhibtion of peripheral receptors
e decrease in CSF H+ concenttation

​

I'll answer one Q from these daily (I don't have much time... Damn biochemistry is taking a toll on me )

Firstly, the options should say CENTRAL "CHEMORECEPTORS" and not central receptors... (CO2 has diverse action on different areas of brain, like for example it is inhibitory at hippocampus and excitatory for Chemoreceptors at Medulla Oblongata)

1. Well 5% CO2 is too much CO2, it will cause Hypercapnia and therefore Acidosis.
2. To this increase in H+, the peripheral chemoreceptors are stimulated (Carotid and Aortic Bodies).
3. The stimulation of peripheral chemoreceptors causes INCREASE IN SYMPATHETIC OUTFLOW.
4. INCREASED H+ in CSF (filtered from the blood; Acidosis) will STIMULATE CENTRAL RECEPTORS (medulla oblongata).
5. Stimulation of central receptors will result in INCREASED SYMPATHETIC OUTFLOW.
6. Increased sympathetic outflow is perceived by beta1 receptors and heart rate is increased.
7. Both central and peripheral receptors, through sympathetic outflow, induce increase in breathing rate; HYPERVENTILATION. To say, respiratory compensation for metabolic acidosis. (Central receptors are more effective)

Now, the options...

a. Hypoventilation; Look at point 7 (Hyperventilation).

b. Decrease in HR; Look at point 6 (Increase in HR).

c. Stimulation of Central receptors; YOU'VE THE ANSWER. Look at point 4.

d. Inhibition of Peripheral receptors; Look at point 3 (Stimulation!)

e. decrease in H+ conc; Look at point 4, again. (Increase in H+ conc.)






Mayank.

PS And more than 10% CO2, and you're dead meat. (Higher conc. depresses all centers of brain)