AP Inter 2nd Year Zoology Important Questions Chapter 3(b) Neural Control and Coordination

Students get through AP Inter 2nd Year Zoology Important Questions Lesson 3(b) Neural Control and Coordination which are most likely to be asked in the exam.

AP Inter 2nd Year Zoology Important Questions Lesson 3(b) Neural Control and Coordination

Very Short Answer Questions

Question 1.
Name the cranial meninges covering the brain of man. [AP, TS MAY-22]
Answer:
The brain of man is covered & protected by three cranial meninges. They are

1. Duramater: It is an outer thick double layered membrane.
2. Arachnoid membrane: It is a thin net like, membrane.
3. Piamatcr: It is a thin membrane closely attached to brain.

Question 2.
What is corpus callosum? [TS MAR-15] [AP MAR-17] [TS MAY-17]
Answer:

1. Corpus callosum:It is a transverse internal connection between two cerebral hemispheres, beneath the cerebral cortex.
2. It is made up of a wide, flat bundle of myelinated fibres.
3. It coordinates the functions of the two cerebral hemispheres.

Question 3.
What do you know about arbor vitae?
Answer:
Arbor vitae: Arbor vitae is characteristic arrangment of white matter in the form of a tree in cerebellum of human brain. It is surrounded by grey matter (cerebellar cortex).

Question 4.
Why the sympathetic division is called thoraeo-lumbar division? [AP MAR-16] [TS MAR-17]
Answer:
In the sympathetic division of autonoamic neural system, the preganglionic nerves arise from thoracic and lumbar regions of spinal cord. Hence it is called thoraeo-lumbar division.

Question 5.
Why the parasympathetic division is called cranio-sacral division?
Answer:
In Cranio sacral division of ANS the pregranglionic nerves arise from brain and sacral region of spinal cord. Hence it is called cranio-sacral division.

Question 6.
Distinguish between the absolute and relative refractory periods.
Answer:
The period between two successive normal threshold stimuli is called refractory (resting) period.

Absolute refractory period	Relative refractory period
1)  Absolute refractory period is the time in which even a very strong threshold stimulus cannot initiate a second action potential. 2)  It coincides with depolarisation and repolarisation.	1)   Relative refractory period is the time during which a second action potential can be initiated by a larger than normal stimulus. 2)   It coincides with the period ofhyperpolarisation.

Question 7.
What is all-or-none principle?
Answer:

1. All or none principle: The action potential occurs in response to a threshold or super threshold stimulus but not to a subthreshold stimulus.
2. When an action potential is generated it cannot be stopped in the middle. It travels completely to its destination.
3. The nerve impulse is either conducted totally or not conducted at all. So it is called ‘all or none’ principle.

Question 8.
How do rods and cones of human eye differ from each other chemically and functionally? [TS MAR-19]
Answer:
Rods and cones are photoreceptor cells.
1) Rods contain a purplish-red protein called Rhodopsin or visual purple. Rhodopsin needs Vitamin A and opsin for its formation. Rods are necessary for vision in dimlight(scotopic vision)

2) Cones contain iodopsin. It is important for day light vision and colour vision.
There are three types of cones for the red, blue and green colours. Equal stimulus produce white colours. Different levels of stimuli produce different colours.

Question 9.
Distinguish between the blind spot and the yellow spot.
Answer:

Blind spot	Yellow spot
1)  The site of retina where optic nerve exits in the eye ball is called blind spot. 2)   It does not contain photoreceptor cells. So no image is formed at that point.	1)       The posterior portion of retina is called yellow spot. 2)         This regions contains only cones. So it forms sharp central vision.

Question 10.
What is organ of Corti? [AP MAR-15,17,19]
Answer:

1. The sensory ridge formed by the cochlear epithelium, on the basilar membrane of inner ear is called organ of Corti’.
2. It contains hair cells, which act as auditory receptors.

Short Answer Questions

Question 1.
Draw a labelled diagram of the T.S of the spinal cord of man. [TS MAY-22]
Answer:

Question 2.
Distinguish between somatic and autonomic neural systems.
Answer:

Somatic neural system	Autonomic neural system
1)    Somatic neural system includes both sensory and motor neurons. 2)     Sensory neurons carry impulses from different somatic receptors to CNS. 3)     These sensations are consciously perceived. 4)     Somatic motor neurons innervate skeletal muscles to produce voluntary movements. The effect is excitation.	1)    Autonomic neural system includes sympathetic and parasympathetic divisions. 2)     Autonomic neurons are associated with interoceptors such as chemoreceptors. 3)     These sensory signals are unconsciously perceived. 4)     The motor neurons regulate the involuntary activities of cardiac muscles and glands.

Question 3.
Give an account of the retina of the human eye.
Answer:

1. Retina is third and inner layer (coat) of the eye ball.
2. It consists of a pigmented and neural portions.
3. The pigmented portion is an epithelial layer containing melanin.
4. It is between the choroid coat and neural layer Bipolar of retina.
5. The neural portion has three layers of neurons.
   (i) Outer photoreceptors
   (ii) Middle bipolar cells and
   (iii) Inner ganglion cell layer. Light (failing on retina)
6. The light rays pass through ganglion layer. The retina is called inverted retina.
7. Photo receptor layer: It has two types of cells.
   (i) Rods: They contain rhodopsin and are necessary for dim light vision. Vitamin A is necessary for rhodopsin.
   (ii) Cones: They contain iodopsin and are necessary for daylight vision and colour vision. The posterior part of retina is macula lutea or yellow spot.
8. At the centre of yellow spot cone cells are concentrated into a depression called fovea centralis. It is responsible for sharp, clear vision during walking, reading, driving etc.,
9. Optic nerve fibres extend from ganglionic cells and the optic nerve exits the eyeball at the optic disc or blindspot.
10. Blind spot does not contain photoreceptor cells and hence no image is formed.

Question 4.
Give an account of synaptic transmission. [AP MAY-22] [AP MAR-16, 18] [TS MAR-17]
Answer: Synaptic transmission:
Synapse is a junction between two successive neurons.
It transmits nerve impulses from one neuron to other neuron.
There are two types of synapses . They are Electrical synapse and Chemical synapse

1. In electrical synapses, the membranes of pre and post synaptic neurons are in very close proximity. These synapses are electrically conductive links between two neurons
2. In a chemical synapse, the membranes of the pre and post-synaptic neurons are separated by a fluid-filled space called synaptic cleft.
3. Chemical messengers called neurotransmitters are involved in the transmission of impulses at these synapses.
4. Neuro transmitters are released from’the synaptic vesicles of axon terminals.
5. When an impulse (action potential) arrives at the axon terminal, it gets depolarized.
6. Then voltage gated calcium channels are opened.
7. Calcium ions stimulate the movement of the synaptic vesicles towards the membrane. Here they fuse with the plasma membrane and release their neurotransmitters in the synaptic cleft by exocytosis.
8. The released neurotransmitters (mostly Acetyl choline) bind to their specific receptors, present on the post-synaptic membrane.
9. The post synaptic membrane has ligand gated channels.
10. The entry of ions generate a new potential in the post-synaptic neuron.

Question 5.
List out the differences between sympathetic and parasympathetic neural systems in man.
Answer:
Differences between sympathetic and parasymapthetic neural systems:
Sympathetic and parasympathetic system are two branches of autonomic neural system.
Each internal organ or its part is innervated by both the systems and balance the function of the organ.

1.  Sympathetic system (SNS) originates in thoracic and lumbar regions of the spinal cord. Parasympathetic system (PNS) originates in brain and sacral region of spinal cord.
2. SNS ganglia form a chain on either side of vertebral column.
   PNS ganglia donot form a chain.
3. Preganglionic fibres of SNS are short while that of PNA are long.
4. Norepinephrine is produced at terminal ends of SNS hence adrenergic Acetylcholine is produced at end plate of PNS and hence cholinergic.
5. SNS is active during stress conditions.
   PNS is active during relaxed period.
6. Overall effect of SNS is excitatory and that of PNS is inhibitary.

Organ wise effect:

1. Eye: SNS dilates the pupil of the eye. PNS constricts.
2. Heart: SNS increases rate and force of contraction. PNS slows down.
3. Blood vessels: SNS constricts. PNS dilates.
4. Ciut: SNS inhibits peristalsis – PNS increases peristalsis.
5. Salivary glands: SNS inhibits secretion. PNS Stimulates secretion.
6. Pancreas: SNS inhibits activity. PNS Stimulates activity.
7. Lungs: SNS relaxes bronchi. PNS constricts bronchi
8. Kidneys: SNS stimulates secretion of renin. PNS decreases secretion of renin.
9. Urinary bladder: SNS inhibits emptying bladder. PNS promotes emptiying the bladder.

Long Answer Questions

Question 1.
Give a brief account of the structure and functions of the brain of man. [ TS MAY-22J
Answer:
Brain is located inside the cranium. Brain is protected by bony cranium and three meninges namely Dura mater, Arachnoid membrane and pia mater.
Cerebrospinal fluid is present between arachnoid membrane and pia mater.
Brain is divided into three major parts : (A) Fore brain (B) Mid brain (C) Hind brain.

A) Fore brain (Prosencephalon): Forebrain consists of Olfactory bulb, cerebrum and diencephalon.
Olfactory bulb receives smell impulses from Olfactory epithelium of nose.

Cerebrum is the largest part of the brain. It is divided into right and left halves by a deep longitudinal fissure.

Corpus callosum connectes the two cerebral hemispheres and coordinates functions of two hemispheres. The surface is formed of gray mater called cerebral cortex.

The cortex has many flods called gyri. In between folds there are deep grooves called fissures and shallow grooves called sulci.

Cerebral cortex interprets sensory impulses, control voluntary movements and many integrative functions such as memory and communication.

Cerebral hemispheres has four lobes called frontal, parietal, temporal and occipital lobes.

Diencephalon (Thalamencephalon): It has epithalamus, thalamus and hypothalamus.

Epithalamus: It is the roof of diencephalon. It is non nervous and forms anterior choroid plexus in union with piamater. Behind choroid plexus there is pineal stalk and pineal body.

Thalamus: It is above mid brain and coordinates sensory and motor signals.

Hypothalamus: It has a funnel shaped infundibulum connected to the pituitary body. It secretes hormones. It controls and integrates the activities of Autonomic nervous system. It has osmoregulatory, thermoregulatory, thirst and hunger centres.

Limbic system: The inner parts of cerebral hemispheres, amygdala, hippocampus etc. together form limbic system. It regulates sexual behaviour and expression of emotional reactions.

B) Midbrain( Mesencephalon): The dorsal part of mid brain has four round optic lobes called corpora quadrigemina. The anterior two lobes are large and concerned with visual function., The posterior smaller lobes deal with auditory functions.

The ventral part is formed by two longitudinal nerve tracts called cruracerebri which connect cerebral hemispheres with pons.

C) Hind brain (Rhombencephalon): It consists of two cerebellar hemispheres, pons varolii and medulla oblongata. Cerebellum is the second largest part of brain. Cerebellum has white matter distributed in the form of a tree. It is called arbor vitae. It is surrounded by gray matter. Cerebellum controls and coordinates locomotor movements. It maintains equilibrium.

Pons varolii: Present below the cerebellum. It-connects the two cerebellar parts. It is a relay station between cerebellum and spinal cord.

It has the pneumotaxic centre, which controls the respiratory muscles.

Medulla oblongata: It is posterior part of the brain. It has posterior choroid plexus dorsally. It has centres for all the involuntary actions like, cardiovascular, respiration, swallowing, digestion, cough, sneezing etc.

Brain stem: The mid brain, pons and medulla together called brain stem.

Ventricles: The cavities of brain are Ventricles. The first ventricle is present in right cerebral hemisphere. The second vertricle is present in left cerebral hemisphere. The first and second ventricle are called paracoels. The third ventricle is diocoel present in diencephalon.

The paracoels are connected to the diocoel by independent foramina of monro. The fourth ventricle myocoel present in medulla. The third and fourth ventricles are connected by iter or aqueduct of sylvius. The fourth ventricle is continued into central canal of spinal cord. The ventricles and subarachnoid space contain cerebro spinal fluid.

Question 2.
Explain the transmission of nerve impulse through a nerve fibre with the help of suitable diagrams.
Answer:
Transmission of nerve impulse: Nerve cells are electrically exitable. The message that pass through a nerve fibre is in the form of electrical impulse. There are Na⁺ and K⁺ ions on either side of axolemma and they move in both directions, i.e., from extra cellular fluid to axoplasm and vice versa.

There are channels for the movement of these ions.

1. Leakage channels: They are Na⁺ and K⁺ leakage channels. K⁺ channels are more than Na⁺ channels. So Axolemma is more permiable to K⁺ channels.
2. Ligand gated channels: They are present in the post synaptic membrane and respond to chemical stimuli.
3. Voltage-gated channels: These channels open in response to change in membrane potential Na⁺ voltage gated channels have two types of gates. They are activation and inactivation gates. Where as K⁺ channels have only activation gates.

Resting membrane potential: In normal conditions there is small negative charge in axoplasm and equal positive buildup outside axolemma in extra cellular fluid. It is generally – 40 to -90 mv in axoplasm.

A typical resting potential is -70 mv At resting phase the axolemma is polarised.

During resting phase the activation gates of Sodium are closed and Inactivation gates are opened. Activation gates of Potassium are closed.

Sodium-Potassium pump: As the Na⁺ and K⁺ move in both directions, these movements disturb the resting potential. This flow is regulated by the Sodium-Potassium pump present in axolemma. These pumps expell 3 Na⁺ ion for each 2 K⁺ ions imported and maintain -70 mv resting potential.

Depolarisation (Rising phase): When a nerve fibre is stimulated, the axolemma becomes more permiable to Na⁺ ions than K⁺ ions, because both type of gates of Sodium are open and Potassium gates close. Axolemma becomes positively charged inside and negatively charged outside.

This reversal of electrical charge is called depolarization.

Action potential: The site, adjacent to the site of depolarisation remains positively charged outside. The electrical potential difference between these two areas is called action potential.

Threshold potential: Action potential occurs when depolarisation reaches threshold potential – 55 mv.

All or none principle: Action potential occurs in response to threshold or super threshold stimulus but not to subthreshold stimulus. It means a nerve impulse is either conducted totally or not conducted at all. This is ail or none principle.

Spike potential: Due to rapid inflow of Na⁺ ions the charge in axoplasm shoots up to +45 mv. It is spike potential.
Repolarisation (Falling phase): As the wave of depolarisation passes away from the site of its origin. In activation gates of Sodium are closed. Other two types of Sodium and Potassium gates are open. The influx of Na⁺ ions is checked. The K⁺ flow out and polarity reaches resting potential. It is called repolarisation.

Ilyper polarisation(llndershoot): The activation and inactivation gates of Na⁺ are closed. K⁺ gates remain open. With the movement of K⁺ ions to outside the polarity goes more negative upto -90 mV. It is hyper polarization. K⁺ gates close very slowly (lazy gates). The polarity gets back to resting potential when the K⁺ gates are closed.

Refractory period: The duration between two successive action potentials is refractory period. If is of two types.
1) Absolute refractory period in which action potential cannot be generated by any means. It coincides with depolarization and repolarization.

2) Relative refractory period in which an action potential can be generated by a stronger than normal stimulus. It coincides with hyperpolarization.

Conduction speed: It depends on the diameter of the axon. The greater the diameter the faster is the conduction. In myelinated nerves the voltage gates of Na⁺ and K⁺ channels are concentrated at the nodes of ranvier. Hence the impulse jumps from one node to the other. It is called saltatory conduction which is many times faster than normal conduction in nonmyelinated fibres. Synaptic transmission: A synapse is a junction between two adjacent neurons. It consists of presynaptic membrane of bouton, synaptic cleft and post synaptic membrane of dentrites.

Bouton has synaptic vesicles containing neurotransmitter when the impulse reach presynaptic membrane the neurotransmitter is released in synaptic cleft. The ligand gated channels of post synaptic membrane receive the chemical stimulus and transfer the electrical stimulus.

Acetyl choline, Epinephrine, norepinephrine, dopamine, serotonin, Glycine and GABA are neuro transmitters. In electrical synapses the synaptic cleft is very narrow and provided with gap junction. The speed of transmission is very high in such synapses and in some cases it is bidirectional conductions.

Multiple Choice Questions

Question 1.
‘The tree of life’ is
1. Medulla oblongata
2. Arbor vitae
3. Pons varolii
4. Organ of Corti
Answer:
2. Arbor vitae

Question 2.
The second largest part of the brain is
1. Cerebrum
2. Medulla oblongata
3. Mesencephalon
4. Cerebellum
Answer:
4. Cerebellum

Question 3.
Brain stem does not include
1. Medulla oblongata
2. Mesencephalon
3. Hippocampus
4. Pons varolii
Answer:
3. Hippocampus

Question 4.
Third ventricle of brain occurs in
1. Cerebellum
2. Diencephalon
3. Medulla oblongata
4. Mesencephalon
Answer:
2. Diencephalon

Question 5.
Part of brain without ventricle is
1. Cerebellum
2. Diencephalon
3. Cerebrum
4. Medulla
Answer:
1. Cerebellum

Question 6.
Iter passes through
1. Medulla oblongata
2. Mid brain
3. Fore brain
4. Spinal cord
Answer:
2. Mid brain

Question 7.
Iter lies in between
1. Paracoel and diocoel
2. Metacoel and paracoel
3. paracoel and paracoel
4. Diocoel and Metacoel
Answer:
4. Diocoel and Metacoel

Question 8.
The -Medulla oblongata passes out through
1. Foramen of Monro
2. Foramen ovale
3. Occipital foramen
4. Foramen magnum
Answer:
4. Foramen magnum

Question 9.
Removal of which part of brain causes immediate death
1. Cerebrum
2. Optic lobes
3. Medulla oblongata
4. Olfactory lobes
Answer:
3. Medulla oblongata

Question 10.
The middle meninx is
1. Dura mater
2. Pia mater
3. Arachnoid mater
4. Grey matter
Answer:
3. Arachnoid mater

Question 11.
Human brain is considered evolutionarily advanced due to the development of
1. Diencephalon
2. Gyri and sulci
3. Optic lobes
4. Medulla oblongata
Answer:
2. Gyri and sulci

Question 12.
Frontal, parietal, temporal and occipital obes arc the parts of
1. Optic lobes
2. Cerebellum
3. Thalamencephalon
4. Cerebrum
Answer:
4. Cerebrum

Question 13.
The pituitary gland is connected to hypothalamus by
1. Aqueduct of Sylvius
2. Cerebral peduncles
3. Infundibulum
4. Colossal commissure
Answer:
3. Infundibulum

Question 14.
The part of corpora quadrigcmina that is concerned with hearing is
1. Posterior, inferior colliculi
2. Anterior, superior colliculi
3. Posterior, superior colliculi
4. Anterior, inferior colliculi
Answer:
1. Posterior, inferior colliculi

Question 15.
In adults spinal cord is extended upto
1. Coccyx
2. Sacral vertebrae
3. Second lumbar vertebra
4. Beginning of coccygeal vertebra
Answer:
3. Second lumbar vertebra

Question 16.
H-shaped part of the spinalcord is
1. Grey matter
2. White matter
3. Medulla
4. Cortex
Answer:
1. Grey matter

Question 17.
Opthalmic, maxillary and mandibular are the branch of
1. Vagus nerve
2. Glossopharyngeal nerve
3. Trigeminal nerve
4. Occulomotor nerve
Answer:
3. Trigeminal nerve

Question 18.
Vestibular nuclear complex is located ¡n
1. Pons and medulla
2. Metacoel
3. Diocoel
4. Midbrain
Answer:
2. Metacoel

Question 19.
Seventh cranial nerve is
1. Glossopharyngeal nerve
2. Auditory nerve
3. Facial nerve
4. Abducens nerve
Answer:
3. Facial nerve

Question 20.
The number of spinal nerves in man is
1. 10 pairs
2. 12 pairs
3. 37 pairs
4. 31 pairs
Answer:
4. 31 pairs

Question 21.
Terminal gandlia are the pari of
1. Sympathetic nervous system
2. Parasympathetic nervous system
3. Central nervous system
4. Somatic nervous system
Answer:
2. Parasympathetic nervous system

Question 22.
Parasympathetic nerve secretions cause
1. Increased heart beat
2. Dilation of iris of eye
3. Increased gut peristalsis
4. Dilation of bronchi
Answer:
3. Increased gut peristalsis

Question 23.
Crossing of optic nerves is called
1. Optic thalami
2. Infundibulum
3. Optic chiasma
4. Optic lobe
Answer:
3. Optic chiasma

Question 24.
Vermis represents
1. Median part of brain stem
2. A part of limbic system
3. Central part of cerebellum
4. White matter of medulla oblongata
Answer:
3. Central part of cerebellum

Question 25.
Post synaptic potentials are
1. Action potentialš in the postsynaptic membrane
2. Graded potentials in the presynaptic membrane
3. Action potentials in the presynaptic membrane
4. Graded potentials in the postsynaptic membrane
Answer:
4. Graded potentials in the postsynaptic membrane

Question 26.
Depolarization of an axon is associated with
1. Influx of Na⁺
2. Outflow of Na⁺
3. Influx of K⁺
4. Outflow of K⁺
Answer:
1. Influx of Na⁺

Question 27.
The summation of post synaptic potentials occurs at
1. Axonal terminal
2. Synaptic knobs
3. Axonal hillock
4. Post synaptic dendrites
Answer:
3. Axonal hillock

Question 28.
I PSP refers to
1. Depolarization of postsynaptic membrane
2. Hyper polarization of postsynaptic membrane
3. Depolarization of presynaptic membrane
4. Hyper polarization of presynaptic membrane
Answer:
2. Hyper polarization of postsynaptic membrane

Question 29.
During synaptic transmission, calcium ions diffuse into the synaptic terminal through
1. Ligand-gated channels
2. Leakage channels
3. Voltage gated channels
4. Ungated channels
Answer:
3. Voltage gated channels

Question 30.
The threshold potential of axolcmma for the generation of an action potential is
1. 70mV
2. -45mV
3. -90mV
4. -55mV
Answer:
4. -55mV

Question 31.
EPSP refers to
1. Depolarization of postsynaptic membrane
2. Hyperpolarization of postsynaptic membrane
3. Depolarization of presynaptic membrane
4. Hyperpolarization of presynaptic membrane
Answer:
1. Depolarization of postsynaptic membrane

Question 32.
In humans, colour vision is controlled bv
1. Rods
2. Rhabdome
3. Crystalline cone
4. Cones
Answer:
4. Cones

Question 33.
Lens and cornea arc nourished by
1. Vitreous humor
2. Aqueous humor
3. ScIera
4. CanaI of Schlemm
Answer:
2. Aqueous humor

Question 34.
Principle function of iris is
1. Filtering dust particles
2. Preventing entry of UV rays into eyes
3. Formation of tears
4. To regulate the amount of light that enter the eyes
Answer:
4. To regulate the amount of light that enter the eyes

Question 35.
Optic disc contains
1. Only rods
2. Only cones
3. Neither rod nor cones
4. Both rods and cones
Answer:
3. Neither rod nor cones

Question 36.
NissI’s granules are absent in
1. Dendrites
2. Cyton
3. Axon
4. Both (1) and (2)
Answer:
3. Axon

Question 37.
Most neurons in our cerebral cortex are .
1. Bipolar
2. Unipolar
3. Multipolar
4. Apolar
Answer:
3. Multipolar

Question 38.
The structure that is present only in mammalian brain Is
1. Corpus luteum
2. Corpus striatum
3. Corpus fibrosum
4. Corpus Callosum
Answer:
4. Corpus Callosum

Question 39.
Conduction velocity of neurons depends on
1. Presence of myelin
2. Diameter of nerve fibre
3. Both (1) and (2)
4. None of the above
Answer:
3. Both (1) and (2)

Question 40.
………… is an autoimmune disease where antibodies are formed against cholinergic receptor of neuromuscular junction
1. Parkinson’s disease
2. Myasthenia gravis
3. Poliomyelitis
4. Multiple sclerosis
Answer:
2. Myasthenia gravis

Question 41.
Receptors that respond to gravity and maintain balance are called
1. Algesireceptors
2. Statoreceptors
3. Photoreceptors
4. Phondreceptors
Answer:
2. Statoreceptors

Question 42.
Which of the following is released by parasympathetic nervous system
1. Serotonin
2. Acetylcholine
3. Epinephrine
4. Norepinephrine
Answer:
2. Acetylcholine

Question 43.
Choroid plexus is a network of
1. Nerves
2. Muscle fibres
3. Capillaries
4. Lymph vessels
Answer:
3. Capillaries

Question 44.
Organs of corti are examples of
1. Algesireceptors
2. Phonoreceptors
3. Propioreceptors
4. Rheoreceptors
Answer:
2. Phonoreceptors

Question 45.
Depolarization is caused by
1. Influx of K⁺
2. Efflux of K^–
3. Efflux of Na⁺
4. Influx of Na⁺.
Answer:
4. Influx of Na⁺.

Question 46.
GABA (Gama Amino Butyric Acid) is a (an)
1. Inhibitory neurohormone
2. Transmittery neuro humor
3. Anti co-agulant
4. None
Answer:
1. Inhibitory neurohormone

Question 47.
The nerves leading to the central nervous system are called
1. Afferent
2. Efferent
3. Motor
4. central nerves
Answer:
1. Afferent

Question 48.
“Jumping of the action potential” at the nodes of ranvier is known as
1. Saltatory conduction
2. Neuro transmission
3. Recovery phase
4. Active phase
Answer:
1. Saltatory conduction

Question 49.
Brain stem includes
1. cerebrum, diencephalon and pons varolii
2. diencephalon, mid brain and cerebellum
3. medulla oblongata, pons varolii and mid brain
4. pons varolii, mid brain and diencephalon.
Answer:
3. medulla oblongata, pons varolii and mid brain

Question 50.
Coordination of voluntary muscle activity is connected with
1. cerebrum
2. cerebellum
3. medulla oblongata
4. crura cerebri
Answer:
2. cerebellum

Question 51.
Anamniotes and amniotes possess
1. 8 & 10 pairs of cranial nerves
2. 10 & 12 pairs of cranial nerves
3. 12 & 8 pairs of cranial nerves
4. 14 & 14 pairs of cranial nerves
Answer:
2. 10 & 12 pairs of cranial nerves

Question 52.
Oculomotor cranial nerve innervates the
1. inferior oblique, superior oblique, inferior recctus muscles
2. inferior oblique, superior, inferior and medial recti muscles
3. superior, inferior, medial recti muscles
4. superior oblique, inferior oblique and medial rectus muscles
Answer:
2. inferior oblique, superior, inferior and medial recti muscles

Question 53.
Parasympathetic neural system causes
1. decrease in heart beat
2. increase in heart beat
3. originates heart beat
4. no effect on heart beat
Answer:
1. decrease in heart beat

Question 54.
Thermoregulatory centre in brain of man is
1. pituitary
2. diencephalon
3. hypothalamus
4. medulla oblongata
Answer:
3. hypothalamus

Question 55.
The fluid filled space between lens and cornea is
1. vitreous humour
2. aqueous humour
3. synovial fluid
4. capillary fluid
Answer:
2. aqueous humour

Question 56.
Pigment iodopsin is contained in
1. rod cells
2. cone cells
3. amacrine cells
4. horizontal cells
Answer:
2. cone cells

Question 57.
Autonomic nervous system affects
1. reflex actions
2. sensory organs
3. internal organs
4. external organs
Answer:
3. internal organs

Question 58.
Which kind of waves are generated in brain during deep sleep?
1. Alpha wave
2. Beta wave
3. Delta wave
4. Theta wave
Answer:
3. Delta wave

Question 59.
Integrative system in the body are
1. Endocrine system
2. Nervous system
3. Blood vascular system
4. Both 1&2
Answer:
4. Both 1&2

Question 60.
Arbor vitae is present in
1. Cerebellum
2. Cerebrum
3. Diencephalon
4. Optocoel
Answer:
1. Cerebellum

Question 61.
The cavity of diocoei is known as
1. I-ventricle
2. II-ventricle
3. Ill-ventricle
4. Iter
Answer:
3. Ill-ventricle

Question 62.
Cavity in spinal cord is called
1. Enterocoel
2. Blastocoel
3. Schizocoel
4. Neurocoel
Answer:
4. Neurocoel

Question 63.
Which cranial nerves are sensory
1. 1,2,8
2. 3,4,6,11,12
3. 5,7,9,10
4. 1,4,3
Answer:
1. 1,2,8

Question 64.
Smallest cranial nerve is
1. Abducens
2. Optic
3. Olfactory
4. Auditory
Answer:
1. Abducens

Question 65.
Nissl’s bodies are mainly composed of
1. Proteins and lipids
2. DNA and RNA
3. nucleic acids and SER
4. free ribosomes and RER
Answer:
4. free ribosomes and RER