When we move from dark to light, we fail to see for some time but soon visibility becomes normal. It is:
The myelin sheath in the CNS is synthesized by:
3. Schwann cells
The brain stem does not include:
1. Mid brain
2. Medulla oblongata
3. Pons varolii
The resting membrane potential is established primarily due to:
1. Sodium-potassium pump
2. Efflux of potassium
3. Influx of sodium
4. Influx of chloride
Immediately after an action potential has peaked, which cellular gates open?
In a chemical synapse, when an impulse arrives at the axon terminal, it:
1. leads to opening of the calcium channels at the postsynaptic membrane
2. Stimulates the movement of synaptic vesicles towards the membrane
3. causes the binding of the neurotransmitter of its receptors on the postsynaptic neuron
4. activates the opening the potassium channels in the axon terminal
Good vision depends on adequate intake of carotene rich food.
Select the best option from the following statements.
I. Vitamin-A derivates are formed from carotene.
II.The photopigments 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 photopigments.
1. (I) and (II)
2. (I), (III) and (IV)
3. (I) and (III)
4. (II), (III) and (IV)
Destruction of the anterior horn cells of the spinal cord would result in loss of
1. sensory impulses
2. voluntary motor impulses
3. commissural impulses
4. integrating impulses
Which part of the human ear plays no role in hearing as such but is otherwise very much required?
1. Eustachian tube
2. Organ of Corti
3. Vestibular apparatus
4. Ear ossicles
A person entering an empty room suddenly finds a snake right in front of opening the door. Which one of the following is likely to happen in his neurohormonal control system?
1. Sympathetic nervous system is activated releasing epinephrine and norepinephrine from adrenal medulla
2. Neurotransmitters diffuse rapidly across the cleft and transmit a nerve impulse
3. Hypothalamus activates the parasympathetic division of brain
4. Sympathetic nervous system is activated releasing epinephrine and norepinephrine from adrenal cortex
Alzheimer disease in humans is associated with the deficiency of
2. glutamic acid
4. Gamma Amino Butyric Acid (GABA)
Given below is a diagrammatic cross section of a single loop of human cochlea.
Which one of the following options correctly represents the names of three different parts?
1. B : Tectorial membrane
C : Perilymph
D : Secretory cells
2. C : Endolymph
D : Sensory hair cells
A : Serum
3. D : Sensory hair cells
A : Endolymph
B : Tectorial membrane
4. A : Perilymph
B : Tectorial membrane
C : Endolymph
Bowman's glands are located in the :
1. proximal end of uriniferous tubules
2. anterior pituitary
3. female reproduction system of cockroach
4. olfactory epithelium of our nose
Which one of the following statements is correct?
1. Neurons regulate endocrine activity, but not vice versa
2. Endocrine glands regulate neural activity and nervous system regulates endocrine glands
3. Neither hormones control neural activity nor the neurons control endocrine activity
4. Endocrine glands regulate neural activity, but not vice versa
A person showing unpredictable moods, outbursts of emotion, quarrelsome behaviour and conflicts with others is suffering from:
2. borderline personality disorder (BPD)
3. mood disorders
4. addictive disorders
In a neuron the concentration of intracellular potassium and extracellular sodium is in a ratio of
1. 1 : 1
2. 30 : 1
3. 10 : 1
4. 3 : 1
Pick the odd-one out.
1. Nervous tissue : node of Ranvier
2. Ear : aqueduct of Sylvius
3. Bone : Volkman's canal
4. Eye : canal of Schlemm
Though sensitive to entire visible spectrum, the cones in the human eye show maximum sensitivity to
1. blue colour
2. green colour
3. red colour
4. all of these
Which of the following types of cells are found in retina?
1. Neuroglial cell
2. Schwann cell
3. Amacrine cell
4. Purkinje cell
Which of the following minerals reduces the excitability of nerves and muscles?
A frog has its brain crushed. But when pinched on the leg. The leg draws away. It is an example of
1. neurotransmitter induced response
2. simple reflex
3. conditioned reflex
4. automated motor response
Which of the following pesticides is an acetylcholinesterase inhibitor?
Identify the correct statement
1. In amniotes last nerve spinal accessory.
2. In non-amniotes last nerve is vagus.
3. Optic is shortest nerve.
4. Olfactory nerves has mixed fibres.
A person is wearing spectacles with concave lenses for correcting vision. While not using the glasses, the image of a distant object in his case will be formed.
1. on the blind spot
2. behind the retina
3. in front of the retina
4. on the yellow spot
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?
The black pigment in the eye which reduces the internal reflection is located in
Injury to vagus nerve in humans is not likely to affect
1. tongue movements
2. gastrointestinal movements
3. pancreatic secretion
4. cardiac movements
If medulla oblongata is destroyed then which of the following functions will be affected?
1. No thermoregulation
2. No vision
3. No memory
4. No response when picked with needle
Given is the diagrammatic representation of the sectional view of cochlea. Select the correct option regarding it.
1. A-organ of corti-responsible for maintenance of balance of the body and posture.
2. B-Scala vestibuli-filled with endolymph that ends at the round window.
3. C-Scala tympani-terminates at the round window which opens to the middle ear.
4. D-Basilar membrane nerve impulses are generated against it.
A small rise in the body temperature of humans is corrected by
(ii) dilating the skin arteries
(iii) constricting the skin arteries
(iv) increased tension of muscles in the skin.
1. (i) only
2. (ii) only
3. (i) and (ii)
4. (iii) and (iv)
Pacinian corpuscles occur in the skin of certain parts of body in mammals. These are
1. type of glands
2. pain receptors
3. naked tactile receptors
4. encapsulated pressure receptors
The cavity of diencephalon is known as
1. first ventricle
2. second ventricle
3. third ventricle
4. fourth ventricle
Which one is an incorrect match?
1. Glaucoma-Abnormal high pressure on liquid of eye
2. Eustachian tube-Connects middle ear cavity with pharynx
The cranial nerves which originate from the medulla oblongata are
1. IX, X, XI and XII
2. III, VII and IX
3. VII, VII, IX and X
4. VII, IX, X, XI and XII
The cornea is a very important component of the human eye. The main function of the cornea is to
1. bend the light before it reaches the lens
2. provide structural support to the eye
3. contain a concentrated amount of cone cells in the correct orientation
4. change the shape of the lens to enable the image to be focused on the retina
Assertion : All of the cranial nerves are said to be mixed nerves.
Reason : All cranial nerves carry both sensory and motor nerve fibres simultaneously.
Assertion : Nerve impulse can never be transmitted from dendrite or cell body of one neuron to the axon of the next neuron, across a synapse.
Reason : This happens because of the synaptic delay at each synapse.
Assertion : Motor neuron terminates on a motor endplates at the neuromuscular junction.
Reason : Motor end plate acts as receptor for detecting changes in the muscle fibres.
PNS does not belong to which of the following system?
1. Somatic Neural System
2. Autonomic Neural System
3. Central Neural System
4. Both 1 and 2
Which of the following is not associated with axon terminals?
1. Synaptic vesicles
3. Neurotransmitter release
4. Axon hillock
Which of the following is not associated with midbrain?
1. Located between thalamus of the forebrain and pons of the hindbrain
2. A canal called the cerebral aqueduct passes through the midbrain
3. The ventral portion of the midbrain made up of mainly of four round swellings (lobes) called Corpora Quadrigemina
4. Midbrain and hindbrain form the brain stem
Which of the following is not associated with sense organ nose?
1. Nose contains mucus coated receptors which are specialised for receiving the sense of smell
2. Olfactory epithelium with five kinds of cells
3. Brain's limbic system's extensions are olfactory bulb
4. Both 2 and 3
Which of the following is not associated with Iris?
1. Ciliary bodies form it
2. Pigmented and transparent
3. Visible colored part of the eye
4. Present in anterior part of eye
1. Is a derivative of vitamin A
2. Has a derivative of vitamin A
3. Has vitamin A
4. Is vitamin A
These are events of mechanism of vision. Arrange them in order.
a. Light rays are focussed on retina
b. Dissociation of the retinal and of opsin
c. Generation of impulses in rods and cones
d. Changes in the structure of the opsin
e. Generation of potential difference
f. Change in membrane permeability
g. Transmission of action potential by the optic nerves to the visual cortex area of the brain
h. Generation of action potential in photoreceptors
i. Image formation in retina and recognition based on earlier memory and experience
Eustachian tube does not perform
1. Connects middle ear to pharynx
2. Connects internal ear to external ear by means of pharynx
3. Equalises the pressure on either side of pharynx
4. Both 2 and 3
Find the incorrect match.
1. Bony labyrinth-series of channels
2. Inside of bony labyrinth-membranous labyrinth
3. Bony labyrinth-surrounding fluid is perilymph
4. Coiled portion of labyrinth-Cochlea
Which of the following will end at oval window (1) and terminate at round window (2) in human ear?
1. (1) Scala media
2. (1) Scala tympani
3. (2) Scala tympani
4. (2) Scala vestibuli
Which of the following is correct order for transmission of sound waves in human ear?
1. Ear drum- ear ossicles- round window
2. Ear meatus- ear ossicles- ear drum
3. Ear ossicles- oval window- cochlea
4. Ear drum- ear meatus- oval window