Myelin sheath around the axons in the PNS is secreted by:

1. oligodendrocytes	2. axons
3. Schwann cells	4. ependymal

The brain stem includes all the following except:

The auditory tube [also called as the Eustachian tube] functions in equalizing pressure between the middle ear and:

When one enters a dark room from a bright area:
1. retinol is converted to rhodopsin and eye sensitivity is decreased
2. rhodopsin is converted to retinol and eye sensitivity is decreased
3. rhodopsin is converted to retinol and eye sensitivity is increased
4. retinol is converted to rhodopsin and eye sensitivity is increased

The amount of light entering the human eye is regulated by:

The tympanic membrane:
1. is covered on both sides by skin
2. is covered on both sides by mucus membrane
3. is covered with skin on the outside and by mucus membrane on the inside
4. is covered with skin on the inside and by mucus membrane on the outside

The auditory receptors in the human ear will be:

The olfactory bulb can be regarded as the extension of:

Photopigments in the human eye are composed of:
1. a lipid and an ester of vitamin A
2. a protein and an ester of vitamin A
3. a lipid and an aldehyde of vitamin A
4. a protein and an aldehyde of vitamin A

Identify the correct statement regarding the sections of the spinal cord shown in the given diagram:

I. A and D are part of the grey mater
II. B is motor and C is sensory