Neural Control and Coordination

Choose the correct statement.

1. Nociceptors respond to changes in pressure.
2. Meissner's corpuscles are thermoreceptors.
3. Photoreceptors in the human eye are depolarised during darkness and become hyperpolarised in response to the light stimulus.
4. Receptors do not produce graded potentials.

Destruction of the anterior horn cells of the spinal cord would result in loss of

1. commissural impulses
2. integrating impulses
3. sensory impulses
4. voluntary motor impulses.

In mammalian eye, the 'fovea' is the center of the visual field, where

1. only rods are present
2. more rods than cones are found
3. high density of cones occur, but has no rods
4. the optic nerve leaves the eye.

Which of the following regions of the brain is incorrectly paired with its function?

1. Corpus callosum - communication between the left and right cerebral cortices
2. Cerebrum - calculation and contemplation
3. Medulla oblongata - homeostatic control
4. Cerebellum - language comprehension

A gymnast is able to balance his body upside down even in the total darkness because of

1. tectorial membrane
2. organ of corti
3. cochlea
4. vestibular apparatus.

Injury localized to the hypothalamus would most likely disrupt

1. short-term memory
2. co-ordination during locomotion
3. executive functions, such as decision making
4. regulation of body temperature.

Which one of the following statements is not correct?

1. Retinal is the light absorbing portion of visual photo pigments.
2. In retina the rods have the photopigment rhodopsin while cones have three different photopigments.
3. Retinal is a derivative of vitamin C.
4. Rhodopsin is the purplish red protein present in rods only.

The most abundant intracellular cation is

1. H+
2. K+
3. Na+
4. Ca++.

A diagram showing axon terminal and synapse is given. Identify correctly at least two of A - D. [Figure]

1. A - Receptor, C - Synaptic vesicles
2. A - Neurotransmitter, B - Synaptic cleft
3. C - Neurotransmitter, D - Ca++
4. B - Synaptic connection, D - K+

Parts A, B, C and D of the human eye are shown in the diagram. Select the option which gives correct identification along with its functions/characteristics. [Figure]

1. B - Blind spot - Has only a few rods and cones.
2. A - Retina - Contains photoreceptors, i.e., rods and cones.
3. C - Aqueous chamber - Reflects the light which does not pass through the lens.
4. D - Choroid - Its anterior part forms ciliary body.