Tag: generation and conduction of nerve impulse

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Questions Related to generation and conduction of nerve impulse

Multiple choice biology coordination generation and conduction of nerve impulse generation of nerve impulse neurons and synapses

Which of the following statements are correct regarding Na+ - K+ pump?


(i) Needs energy (ATP) to work.
(ii) Expels 3 Na+ for every 2K+ ions imported
(iii) Works against a concentration gradient
(iv) Maintains resting potential

  1. (i) and (iv)

  2. (ii) and (iii)

  3. (i) and (iii)

  4. All of these
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The Na-K pump is an active transport mechanism that uses ATP to move 3 Na+ ions out and 2 K+ ions in, working against concentration gradients to maintain the resting membrane potential.

Multiple choice biology coordination generation and conduction of nerve impulse generation of nerve impulse neurons and synapses

Which 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. Resting potential is the electrical potential difference across the resting membrane

  4. A neuron is polarised only when the outer surface of axonal membrane possesses a negative charge and inner surface is positively charged
  5. Ionic gradients are maintained by Na-K pumps across the resting membrane which transports 3 N$a^+$ ions outwards for 2$K^+$ ions into the cell
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

A polarized neuron has a positive charge on the outer surface and a negative charge on the inner surface. Option D incorrectly states the reverse.

Multiple choice biology coordination generation and conduction of nerve impulse generation of nerve impulse neurons and synapses


In the resting state, the axonal membrane is (i)_ with more (ii) charged ions outside than inside. This unequal distribution of ions is due to (1) the selective permeability of the membrane, which forms an almost impenetrable barrier to (iii) and (2) the action of the _(iv), which pumps (v) Na$^+$ out of the neuron for every _(vi) K$^+$ brought in.
Select the option that correctly fills the blanks in the paragraph.

  1. (i) - depolarised, (ii) - positively, (iii) - Na$^+$, (iv) - sodium - potassium pump, (v) - three, (vi) - two
  2. (i) - depolarised, (ii) - negatively, (iii) - Na$^+$, (iv) - sodium - potassium pump, (v) - three, (vi) - two
  3. (i) - polarised, (ii) - negatively, (iii) - Na$^+$, (iv) - sodium - potassium pump, (v) - three, (vi) - two
  4. (i) - polarised, (ii) - positively, (iii) - Na$^+$, (iv) - sodium - potassium pump, (v) - three, (vi) - two
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

In the resting state, the axonal membrane is polarised with more positively charged ions outside than inside, unequal distribution of ions is due to the selective permeability of the membrane, which forms impermeable barrier to sodium ion and the action of the sodium which pumps three sodium ions out of the neuron for every two potassium ions brought in.

Thus, the correct option is '(i) - polarised, (ii) - positively, (iii) - Na$^+$, (iv) - sodium - potassium pump, (v) - three, (vi) - two.'

Multiple choice biology coordination generation and conduction of nerve impulse generation of nerve impulse neurons and synapses

Sodium potassium pump transports

  1. Na+ and K+ out of the neuron

  2. Na+ and K+ into the neuron

  3. Na+ into the neuron and K+ out of the neuron

  4. K+ into the neuron and Na+ out of the neuron
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The sodium-potassium pump actively transports 3 Na+ ions out of the neuron and 2 K+ ions into the neuron, maintaining the electrochemical gradient.

Multiple choice biology coordination generation and conduction of nerve impulse generation of nerve impulse neurons and synapses

Diencephalon is the centre for the following except

  1. Sweating

  2. Sneezing

  3. Thirst

  4. Hunger
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The diencephalon acts as a relay station and control center for autonomic functions like hunger, thirst, and body temperature regulation. Sneezing is a reflex action controlled primarily by the medulla oblongata in the brainstem, not the diencephalon.

Multiple choice biology coordination generation and conduction of nerve impulse generation of nerve impulse neurons and synapses

A touch on the right hand stimulates neurons in the

  1. Left somatic sensory area

  2. Left occipital lobe

  3. Right somatic sensory area

  4. Right occipital lobe
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Sensory information from the right side of the body is processed in the contralateral (opposite) hemisphere of the brain. Therefore, touch on the right hand is processed in the left somatic sensory area.

Multiple choice biology coordination generation and conduction of nerve impulse generation of nerve impulse neurons and synapses

The release of chemical messenger from synaptic vesicles is under the influence of which of these ion(s)?

  1. Cl-

  2. Fe++ and s++

  3. Ca ++

  4. Mg++ and Sr++
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

When an action potential reaches the axon terminal, voltage-gated calcium channels open. The influx of Ca++ ions triggers the fusion of synaptic vesicles with the presynaptic membrane, releasing neurotransmitters into the synaptic cleft.