The ear ossicle, stapes, transmits vibrations from incus to the:
1. malleus
2. tympanic membrane
3. oval window
4. round window
In the internal ear, the membranous labyrinth is filled with:
1. cerebrospinal fluid
2. plasma
3. endolymph
4. perilymph
Reissner's membrane is a thin membrane that separates the scala media from the:
1. oval window
2. scalavestibuli
3. scala tympani
4. round window
The primary auditory area is located in:
1. medial geniculate body of thalamus
2. midbrain
3. temporal lobe
4. medulla oblongata
The maculae are the sensory organs in the:
1. cochlear duct
2. saccule
3. semicircular canals
4. semicircular ducts
The process by which the vertebrate eye changes optical power to maintain a clear image or focus on an object as its distance varies is known as:
1. adaptation
2. accommodation
3. amblyopia
4. visual acquity
The pigment that gets oxidized/bleached/decomposed when exposed to light is:
1. retinol
2. retinoyl ester
3. rhodopsin
4. iodopsin
Receptor sites for neurotransmitters are present on
1.membranes of synaptic vesicles
2. pre-synaptic membrane
3. tips of axons
4. post-synaptic membrane
Good vision depends on adequate intake of carotene rich food.
Select the best option from the following statements:
I. Vitamin-A derivatives are formed from carotene.
I. The photo pigments are embedded in the membrane discs of the inner segment.
III. Retinal is a derivative of vitamin-A.
IV. Retinal is a light absorbing part of all the visual photo pigments.
1. (I) and (II)
2. (I), (III) and (IV)
3. (I) and (III)
4. (II), (III) and (IV)
Myelin sheath is produced by
1. Schwann cells and Oligodendrocytes
2. Astrocytes and Schwann cells
3. Oligodendrocytes and Osteoclasts
4. Osteoclasts and Astrocytes