Unidirectional transmission of a nerve impulse through nerve fibre is due to the fact that
1. nerve fibre is insulated by a medullary sheath
2. sodium pump starts operating only at the cyton and then continues into the nerve fibre
3. neurotransmitters are released by dendrites and not by axon endings
4. neurotransmitters are released by the axon endings and not by dendrites.
Given below is a table comparing the effects of sympathetic and parasympathetic nervous system for four feature (a-d). Which one feature is correctly described?
|
Features |
Sympathetic Nervous system |
Parasympathetic Nervous system |
1. |
Salivary Glands |
Stimulates secretion |
Inhibits Secretion |
2. |
Pupil of the Eye |
Dilate |
Constricts |
3. |
Heart rate |
Decreases |
Increases |
4. |
Intestinal peristalsis |
Stimulates |
Inhibits |
The black pigment in the eye which reduces the internal reflection is located in
1. retina
3. cornea
2. iris
4. sclerotic
Hearing impairment affects which part of the brain?
1. | Frontal lobe | 2. | Parietal lobe |
3. | Temporal lobe | 4. | Cerebellum |
One common example of simplex reflex is
1. tying your shoe laces while talking to another person and not looking at them
2. watering of mouth at the sight of a favourite food
3. climbing up a stairs in dark without stumbling
4. closing of eyes when strong light is flashed across them.
Injury to vagus nerve in humans is not likely to affect
1. tongue movements
2. gastrointestinal movements
3. pancreatic secretion
4. cardiac movements.
Consider the following statements:
I. Somatic neural system relays impulses from CNS to skeletal muscles.
II. Autonomic neural system transmits impulses from CNS to involuntary organs and smooth muscles.
III. Unmyelinated nerve fibres are commonly found in spinal and cranial nerves.
Which of the above statements are true?
1. I and II only 2. I and III only
3. II and III only 4. I, II, and III
Consider the following statements:
I. The resting axonal membrane is nearly impermeable to sodium ions.
II. Depolarization of the axonal membrane is due to influx of sodium ions.
III. The size of the action potential, if produced, does not depend on the strength of the stimulus.
Which of the above statements are true?
1. I and II only 2. I and III only
3. II and III only 4. I, II, and III
Consider the following statements:
I: | Acetylcholine is released at the electrical synapse. |
II: | Electrical synapses are faster. |
III: | It is more difficult to regulate an electrical synapse with respect to a chemical synapse. |
Which of the above statements are true?
1. I and II only
2. I and III only
3. II and III only
4. I, II, and III
Identify the correct statement regarding the following diagram:
1. B and F are filled with endolymph
2. C is filled with perilymph
3. Hair cells press against E to generate nerve impulses
4. D is the sensory organ of hearing and has auditory receptors