Nerve Impulse Conduction

Q.

What are the 5 steps of an Action Potential?

Q. Threshold potential is a state of depolarisation at which

1. An action potential is sure to fire
2. Voltage gated Na+ channels open
3. Membrane potential is near -55mV
4. Ca+ ion leakage channels open.

Q.

Which of the following has non myelinated nerve fiber?

1. Optic nerves

2. Cranial nerves

3. Spinal nerves

4. Autonomic nerves

Q. Which of the following statements is wrong regarding conduction of nerve impulse?

1. In a resting neuron, the axonal membrane is more permeable to $K^{+}$ ions and nearly impermeable to $N{a}^{+}ions$.
2. Fluid outside the axon has a high concentration of $N{a}^{+}$ and low concentration of $K^{+}$ in a resting neuron.
3. Ionic gradients are maintained by Na - K pumps across the resting membrane which transport $3N{a}^{+}$ ions outwards for $2K^{+}$ ions into the cell.
4. Resting potential is the electrical potential difference across the resting membrane.
5. A neuron is polarised only when the outer surface of the axonal membrane possess a negative charge and its inner surface is positively charged.

Q.

Which statement correctly describes the smooth muscles?

1. Unstriated involuntary with spindle shape cells

2. Unstriated involuntary with multinucleate cells

3. Unstriated voluntary with uninucleate cells

4. Striated involuntary with spindle shape cell

Q.

Juxtaglomerular cells stimulated to secrete renin when there is:

1. fall in GFR

2. both 1 and 3

3. more GFR

4. normal GFR

Q. What is the function of ion channels in conduction of nerve impulse?

1. Maintenance and change in electric potential
2. Maintenance of concentration gradient of ions
3. Transport of Na ion to the inner side of the membrane
4. All of the above

Q. Arrange th steps in nerve impulse conduction in the correct order.

1. $\mathrm{Na}\mathrm{ions}\mathrm{flow\; in}$
2. Action potential
3. $\mathrm{Stimulus}$
4. $\mathrm{Hyperpolarization};\mathrm{RMP}$
5. $\mathrm{Repolarisation}$

Q.

Is GLUT4 active transport?

Q. Out of 12 cranial nerves; how many are sensory nerves?

1. 3
2. 5
3. 4
4. 7

Q. Neurons receive signals through their ________ and send signals to other neurons through their _________.

1. Dendrites, receptors
2. End feet, cell bodies and dendrites
3. Cell bodies and dendrites, axons
4. Transmitter vesicles, axons

Q.

Why are amphibolic pathway important?

Q.

Complete the statement by chossing appropriate match among the following.

$\begin{array}{cc}ColumnI& ColumnII\\ A.Restingpotential& 1.Chemicalsinvolvedinthetransmissionof\\ & impulsesatsynapses.\\ B.Synapticcleft& 2.Gapbetweenthepresynapticandpostsynaptic\\ & neurons.\\ C.Synapticcleft& 3.Electricalpotentialdifferenceacrosstheresting\\ & neuralmembrane.\\ D.Neurotransmitters& 4.Anelectricalwavelikeresponseofaneurontoa\\ & stimulation.\end{array}$

Q. Reflex action is a vertebrate is an essential display exhibited by

1. Autonomic response
2. Sympathetic nerve
3. Motor sense
4. Sensory nerve

Q.

What is meant by receptors and effectors? Give two examples of each.

Q. Immediately after the peak of action potential which cellular channel opens.

1. Sodium
2. Potassium
3. Both sodium and potassium
4. Calcium

Q. can phenol show the tautomerism ?

Q. Which cellular channels open immediately after the peak of action potential?

1. Potassium
2. Both sodium and potassium
3. Calcium
4. Sodium

Q.

Unidirectional transmission of a nerve impulse through nerve fibre is due to the fact that

1. Neurotransmitters are released by dendrites and not by axon endings

2. Sodium pump starts operating only at the cyton and then continues into the nerve fibre

3. Neurotransmitters are released by the axon endings and not by dendrites

4. Nerve fibre is insulated by a medullary sheath

Q.

Nerve impulse through synapse is

1. unidirectional

2. bidirectional

3. multidirectional

4. none of the above

Q. Match the following column I and column II:

$\begin{array}{cc}\text{Column I}& \text{Column II}\\ \text{A. Resting potential}& \text{i. Na ions are more on the inside of the membrane at the site}\\ \text{B. Depolarization}& \text{ii. Potassium channels gets opened}\\ \text{C. Repolarization}& \text{iii. More K ions inside of the cell and more Na ions outside of the cell}\end{array}$

1. A-iii, B-i, C-ii
2. A-ii, B-iii, C-i
3. A-iii, B-ii, C-i
4. A-i, B-iii, C-ii

Q. If a frog’s brain is crushed, even then its leg moves on pinpointing. This is called as

1. Conditional reflex
2. Simple reflex
3. Neurotransmitter function
4. Autonomous nerve conditions

Q. Immediately after the peak of action potential which cellular channel opens.

1. Sodium
2. Potassium
3. Both sodium and potassium
4. Calcium

Q. In excitable cells, repolarization is closely associated with one of the following events

1. $N{a}^{+}$efflux
2. $N{a}^{+}$influx
3. $K^{+}$efflux
4. $K^{+}$influx

Q. Which of the following option is correct for statement 'X' and 'Y'?
Statement X: Immediately after repolarisation, ionic imbalance is created on both the sides of nerve fibre.
Statement Y: During repolarisation $K^{+}$ ion channel open up and $K^{+}$ ion moves on inner side of plasma membrane.

1. Statements X and Y are correct and Y is correct for X
2. Statement X is incorrect and statement Y is correct.
3. Statements X is correct and statement Y incorrect
4. Statements X and Y are correct and Y is not correct for X

Q. The resting membrane potential is maintained by

1. Ion leaks
2. Ion pumps
3. Both (a) and (c)
4. Neurotransmitters

Q. Short / Long answer type questions
How do nerve impulses on a neuron travel only in one direction?

Q.

Name one type of cell which is excitable in nature.

Q. Which structure is pure sensory?

1. Ramus dorsalis
2. Dorsal root
3. Spinal nerve
4. Ventral root

Q. Assertion : Na and K ions are necessary for muscle contraction
Reason : Na and K concentration changes across the muscle cell membrane resulting in development of potential difference

1. Both assertion and reason are true and reason is the correct explanation of assertion
2. Both assertion and reason are true but reason is not the correct explanation of assertion
3. Assertion is true but reason is false
4. Both assertion and reason are false