A: In the nervous system generation of action potential depends upon influx of sodium ions into axoplasm.
R: Influx of sodium ions during nerve impulse generation is due to efflux of potassium ions.
A: Presence of myelin sheath increases the rate of conduction of nerve impulse.
R: Ionic channels are absent in the area covered by myelin sheath therefore, depolarization occurs only at the nodes of Ranvier, resulting in saltatory or jumping conduction.
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A: Receptors in the tendon, joints give information regarding the position and movements of different parts of the body.
R: These are termed as noci-receptors.
A: Sharpest vision is in fovea centralis.
R: The relationship of receptor to bipolar cells to ganglion cells is 1 : 1 : 1 within fovea centralis.
A: Postganglionic nerve fibre of parasympathetic nervous system have acetylcholine while sympathetic nervous system have adrenaline as the neurotransmitter.
R: Sympathetic nervous system inhibits the intestinal peristalsis while parasympathetic stimulates peristalsis.
A: Transmission of the nerve impulse across a synapse is accomplished by neurotransmitters.
R: Transmission across a synapse usually requires neuro-transmitters because there is small space, i.e., synaptic cleft, that separates one neuron from another.
A: Sense organs do not interpret the stimulus, it is done by the brain.
R: Sense organs are transducers. They transform the energy of a stimulus to the energy of nerve impulses.
A: The imbalance in the concentration of Na+, K+ and proteins generates the resting potential.
R: To maintain the unequal distribution of Na+ and K+, the neurons use electrical energy.
A: Retina is arranged anatomically in reverse order from what might be expected.
R: The receptor cells are, towards the outside and ganglionic cells towards the inside and light must pass through the nerve cells to reach them.
A: The brain reaches between 75 and 80 percent of adult size within the first two years, and its full size at the age of 6 years.
R: From an evolutionary point of view, human gestation period is belived to be shortening.