Heart Nerve Muscle Important Solved SEQs By Medical Study Center
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Heart + Nerve & Muscle Important Solved SEQs By Medical Study Center
Ref: Guyton
Q.1. a). What is saltatory conduction? Enlist its advantages? 1+1 marks
b). briefly mention the three determinants of resting membrane potential. 3 marks
Ans: Q.1.a.
SATTATORY CONDUCTION: 1 mark
Propagation of action potential along a myelinated nerve fiber from one node of Ranvier to other in jumping manner is called as saltatory conduction. r
Node to node conduction.
Also called saltatory / jumping conduction.
All ion channels are present at nodes of Ranvier.
Myelin sheath is absent & only neurilemma is there at the node.
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It increases velocity of conduction directly in proportion to the fiber diameter,
Conservation of energy- less energy expenditure.
No short circuiting
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ADVANTAGES OF SALTATORY CONDUCTION: 1 mark
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Q.1. b). briefly mention the three determinants of resting membrane potential. Any two= 2 marks
1. Contribution of the Potassium Diffusion Potential (-94 mVolts)
2. Net Contribution of Sodium Diffusion Through the Nerve Membrane (+8 mVolts)
3. Contribution of the Na+-K+ Pump (-4 mVolts)
Nernst Equation: (0.5 MARK)
•
EMF (mV) = +/- 61 log conc. inside / conc. Outside
•
Nernst Potential for K is -94 mV
•
Nernst Potential for Na is +61 mV (but net contribution is only 8 mV because Na is 100 TIMES less permeable thru leak channels than K)
Goldmann’s equation: 0.5 mark
Shared By: Ussama Maqbool(N61)
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https://www.facebook.com/Medicalstudycenter2012
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Q.2: a). Draw and label the neuromuscular junction. 2 marks
b). What is end plate potential? How is it produced? How is it affected in myasthenia gravis? (2004, 2008 UHS). 1+1+1 marks
M
END PLATE POTENTIAL:
It is a local potential of motor end plate, i-e., the thickened muscle membrane that is supplied by a motor-neuron, thus forming a component of neuro-muscular junction.
Production
Heart + Nerve & Muscle Important Solved SEQs By Medical Study Center
Ref: Guyton
Q.1. a). What is saltatory conduction? Enlist its advantages? 1+1 marks
b). briefly mention the three determinants of resting membrane potential. 3 marks
Ans: Q.1.a.
SATTATORY CONDUCTION: 1 mark
Propagation of action potential along a myelinated nerve fiber from one node of Ranvier to other in jumping manner is called as saltatory conduction. r
Node to node conduction.
Also called saltatory / jumping conduction.
All ion channels are present at nodes of Ranvier.
Myelin sheath is absent & only neurilemma is there at the node.
al
St
ud
y
C
en
te
It increases velocity of conduction directly in proportion to the fiber diameter,
Conservation of energy- less energy expenditure.
No short circuiting
ed
ic
ADVANTAGES OF SALTATORY CONDUCTION: 1 mark
M
Q.1. b). briefly mention the three determinants of resting membrane potential. Any two= 2 marks
1. Contribution of the Potassium Diffusion Potential (-94 mVolts)
2. Net Contribution of Sodium Diffusion Through the Nerve Membrane (+8 mVolts)
3. Contribution of the Na+-K+ Pump (-4 mVolts)
Nernst Equation: (0.5 MARK)
•
EMF (mV) = +/- 61 log conc. inside / conc. Outside
•
Nernst Potential for K is -94 mV
•
Nernst Potential for Na is +61 mV (but net contribution is only 8 mV because Na is 100 TIMES less permeable thru leak channels than K)
Goldmann’s equation: 0.5 mark
Shared By: Ussama Maqbool(N61)
en
te
r
https://www.facebook.com/Medicalstudycenter2012
ed
ic
al
St
ud
y
C
Q.2: a). Draw and label the neuromuscular junction. 2 marks
b). What is end plate potential? How is it produced? How is it affected in myasthenia gravis? (2004, 2008 UHS). 1+1+1 marks
M
END PLATE POTENTIAL:
It is a local potential of motor end plate, i-e., the thickened muscle membrane that is supplied by a motor-neuron, thus forming a component of neuro-muscular junction.
Production