Tag: nervous system

Questions Related to nervous system

Conservation of energy take place by 

  1. Sympathetic autonomic nervous system

  2. Parasympathetic autonomic nervous system

  3. Reflex action

  4. None of the above


Correct Option: B
Explanation:

Parasympathetic autonomic nervous system (PNS) responses are highly specific, as supported by the direct innervation of target organs. The PNS is inhibitory, and promotes energy conservation. The primary defense strategies supported by the PNS involve energy conservation. PNS activation promotes passive coping strategies, such as withdrawal or disengagement, dissociation and the immobility response. Examples of passive coping styles include physical or emotional withdrawal.

Autonomic nervous system controls

  1. Conditioned reflexes

  2. Functioning of spinal cord

  3. Functioning of visceral organs

  4. Reflex actions


Correct Option: C
Explanation:

The autonomic nervous system is the part of the nervous system, that supplies the internal organs, like blood vessels, stomach, intestine, liver, kidneys, bladder, genitals, lungs, pupils, heart, and sweat, salivary, and digestive glands. 

This system works automatically (autonomously), without a person's conscious effort. The autonomic nervous system controls blood pressure, heart and breathing rates, body temperature, digestion, metabolism (thus affecting body weight), the balance of water and electrolytes (such as sodium and calcium), the production of body fluids (saliva, sweat, and tears), urination, defecation, sexual response, and other processes.

After sympathetic stimulation, which type of activities are not present in a human being?

  1. Tachycardia

  2. Bronchodilation

  3. Micturition

  4. Semen ejaculation


Correct Option: C
Explanation:

Urinary storage is a function of the sympathetic nervous system, whereas micturition is a function of the parasympathetic nervous system.

Given below is a table comparing the effects of sympathetic and parasympathetic nervous system for four features. which one feature is correctly matched?


Feature Sympathetic Parasympathetic
1. Salivary gland stimulates   inhibits
2. Pupil of the eye dilates  constricts
3. Heart rate decreases increases
4. Intestinal peristalsis stimulates inhibits

  1. 1

  2. 2

  3. 3

  4. 4


Correct Option: B
Explanation:

Parasympathetic innervation leads to pupillary constriction. A circular muscle called as the sphincter pupillae accomplishes this task. Sympathetic innervation leads to pupillary dilation. Dilation is controlled by the dilator pupillae, a group of muscles in the peripheral 2/3 of the iris.

The inhibitory effect of vagus nerve on the heart is due to the secretion of

  1. Acetylcholine

  2. Norepinephrine

  3. Glycine

  4. Dopamine


Correct Option: A
Explanation:

Acetylcholine is the main vagal neurotransmitter. The vagus nerve controls the heart rate by electrical impulses to the SA node of the heart in which acetylcholine release slows down the pulse rate and decreases the blood pressure. Thus the correct answer is option A.

Given below are comparing the effects of sympathetic and parasympathetic nervous system for four features.
Which one feature is correctly described?

  1. Feature- Salivary glands, Sympathetic nervous system- Stimulates secretion, Parasympathetic nervous system- Inhibits secretion

  2. Feature- Pupil of the eye, Sympathetic nervous system- Dilates, Parasympathetic nervous system- Constricts

  3. Feature- Heart rate, Sympathetic nervous system- Decreases, Parasympathetic nervous system- Increases

  4. Feature- Intestinal peristalsis, Sympathetic nervous system- Stimulates, Parasympathetic nervous system- Inhibits


Correct Option: B
Explanation:

Sympathetic nervous system inhibits salivary gland secretion, accelerates the heart rate, decreases intestinal peristalsis and dilate the pupil of the eye. Whereas parasympathetic nervous system stimulates salivary gland secretion, slows heart rate, stimulates intestinal peristalsis and constricts pupil of the eye. The sympathetic and the parasympathetic nervous system are parts of the autonomic nervous system. These systems work in balance with each other and directly or indirectly affect almost every structure in the body. The sympathetic nervous system has an active "pushing" function, the parasympathetic has mainly a relaxing function.

Constriction of the pupil is function of

  1. Parasympathetic system

  2. Hypothalamus

  3. Thalamus

  4. None of the above


Correct Option: A
Explanation:

Constriction of the pupil is the function of the parasympathetic system. The parasympathetic nervous system is one of the two divisions of the autonomic nervous system, the other is the sympathetic nervous system. The autonomic nervous system is responsible for regulating the body's unconscious actions. The parasympathetic system is responsible for stimulation of "rest and digest" or "feed and breed" activities that occur when the body is at rest, especially after eating, including sexual arousal, salivation, lacrimation (tears), urination, digestion and defecation. 

Select the wrong paired match from the following.

  1. CNS - Site of information processing and control

  2. PNS - Transmission of impulses to and from the CNS

  3. SNS - Relays impulses from the CNS to skeletal muscles

  4. ANS - Transmission of impulses from the CNS to voluntary organs


Correct Option: D
Explanation:

The central nervous system (CNS) includes brain and spinal cord. It integrates and stores the sensory information from external and internal sense organs and commands different organs to respond accordingly. 

Peripheral nervous system (PNS) lies outside the central nervous system and consists of somatic and autonomic nervous system. Somatic nervous system (SNS) serves to carry the sensory information from external sensory receptors to CNS and motor signals from CNS to skeletal muscles (the voluntary actions). 
The autonomic division (ANS) of peripheral nervous system consists of motor fibres that relay nerve impulses from CNS to cardiac and smooth muscles and glands, thereby controlling the functioning of internal organs, without our conscious control (the involuntary actions). 
PNS relays information to and from CNS via its somatic and autonomic divisions.
Therefore, the correct answer is option D.

If a man could learn to stop his heartbeat at will, he must have control over his 

  1. Central nervous system

  2. Peripheral nervous system

  3. Autonomic nervous system

  4. Cranial nerves


Correct Option: C
Explanation:

The central nervous system includes brain and spinal cord. It integrates and stores the sensory information from external and internal sense organs and commands different organs to respond accordingly.

Peripheral nervous system lies outside the central nervous system. It serves to carry the sensory information from external sensory receptors to CNS and motor signals from CNS to skeletal muscles via its somatic division (the voluntary actions). The autonomic division of peripheral nervous system controls the cardiac and smooth muscles and glands, thereby the functioning of internal organs, without our conscious control (the involuntary actions). The autonomic nervous system controls the heartbeat rate via cardioregulatory centre in the medulla oblongata. The emergency conditions activate the sympathetic motor nerve and make the adrenal medulla release epinephrine and norepinephrine which in turn increase the heartbeat rate. On the other hand, vagus nerve conducts the parasympathetic motor impulses which in turn slow down the heartbeat rate by the effect of acetylcholine. Thus, to control heartbeat, a man should have control over its autonomic nervous system. 
The 12 pairs of cranial nerves are part of the peripheral nervous system and are mostly concentrated in head, neck and facial region of the body (vagus nerve X being the part of autonomous division serves as an exception). 
Hence, the correct answer is option C.

The heart rate is increased by a nerve which belongs to the following division of nervous system.
I. Autonomic
II. Central
III. Peripheral
IV. Sympathetic

  1. I and IV only

  2. II and III only

  3. I, II, and III

  4. I, III, and IV

  5. II, III, and IV


Correct Option: A
Explanation:

The autonomous nervous system controls the heart beat rate via cardioregulatory centre in the medulla oblongata. The emergency conditions activate the sympathetic motor nerve and make the adrenal medulla release epinephrine and norepinephrine which in turn increase the heart beat rate. Hence, the nerve which increases heart beat is part of autonomic and sympathetic nervous system. The central nervous system includes brain and spinal cord only. The peripheral nervous system includes all cranial and spinal nerves; the 12 pairs of cranial nerves, except Vagus nerve, are part of the peripheral nervous system and are mostly concentrated in head, neck and facial region of the body. Vagus nerve conducts the parasympathetic motor impulses which in turn slow down the heart beat rate by the effect of acetylcholine; a neurotransmitter released by the parasympathetic nervous system. 

Therefore, the correct answer is option A.