Biology

Nervous System and Neurons

1,224 Questions

The nervous system and neurons section covers the structural and functional aspects of the human nervous system. Topics include nerve fibers, the myelin sheath, and sympathetic nervous system functions. This material is crucial for general science preparation in various competitive exams.

Neuron structureMyelin sheath productionSympathetic nervous systemCranial and spinal nervesParasympathetic functions

Nervous System and Neurons Questions

Multiple choice zoology nervous system nervous systems involved in emotions types of nervous system components of nervous system

Sympathetic and parasympathetic nervous systems are often synergistic in their functions.

  1. True

  2. False
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
  • The autonomic nervous system is divided into two subdivisions. They are the sympathetic and parasympathetic nervous system.
  • The sympathetic nervous system (SNS) controls the body's responses to a perceived threat and is responsible for the "fight or flight" response while The parasympathetic nervous system (PNS) controls homeostasis and the body at rest and is responsible for the body's "rest and digest" function.
  • Hence Sympathetic and parasympathetic nervous systems are often antagonistic(opposing) in their functions.
  • So, the given statement is false.
Multiple choice zoology nervous system nervous systems involved in emotions types of nervous system components of nervous system

The autonomous nervous system is completely independent of the central nervous system.

  1. True

  2. False
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

  • The nervous system is divided into two major subdivisions. They are the Central nervous system(brain and spinal cord) and peripheral nervous system.
  • The peripheral nervous system is in turn divided into two divisions. They are a somatic and autonomic nervous system.
  • The main function of the PNS is to connect the CNS to the limbs and organs, essentially serving as a relay between the brain and spinal cord and the rest of the body.
  • The autonomous nervous system is completely independent of the central nervous system is a false statement because, within the brain, the autonomic nervous system is regulated by the hypothalamus(part of CNS).

Multiple choice zoology nervous system nervous systems involved in emotions types of nervous system components of nervous system

Consider the following statements and state true or false.
1. Synaptic cleft of neurons secrete adrenaline.
2. Myelinated nerve fibres and enveloped with Schwann cells, which form a myelin sheath around the axon.
3. Non-myelinated nerve fibre is enclosed by a Schwann cell that does not form a myelin sheath.
4. Spinal cord and cranial nerves are made up of non-myelinated nerve fibres.

  1. 1, 2 are correct but 3 and 4 are wrong.

  2. 1, 2 and 3 are correct but 4 is wrong.

  3. 3 and 4 are correct while 2 and 3 are wrong.

  4. 1 and 4 are correct while 2 and 3 are wrong.

  5. 2 and 3 are correct while 1 and 4 are wrong.
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

Myelin sheath is the insulating envelope of myelin, that surrounds the core of a nerve fiber or axon and that facilitates the transmission of nerve impulses, formed from the cell membrane of the Schwann cell in the peripheral nervous system and from oligodendroglia cells. Nonmyelinated nerve fiber lacks the fatty myelin insulating sheath. Such fibers form the gray matter of the nervous system, as distinguished from the white matter of myelinated fibers. 

Multiple choice zoology nervous system nervous systems involved in emotions types of nervous system components of nervous system

Parasympathetic system causes

  1. Inhibition of sweat glands

  2. Constriction of pupil in bright light

  3. Increase in rate of respiration

  4. Increase in heart beat
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The pupillary light reflex is a reflex that controls the diameter of the pupil, in response to the intensity of light that falls on the retina of the pupil and the eye. Parasympathetic nerve fibres from the third (oculomotor) cranial nerve innervate the muscle that causes constriction of the pupil, whereas sympathetic nerve fibres control dilation. 

Multiple choice zoology nervous system nervous systems involved in emotions types of nervous system components of nervous system

Which of the following two systems are opposite in action to each other?

  1. Nervous - Sensory

  2. Nervous - Endocrine

  3. Sensory - Endocrine

  4. Parasympathetic - Sympathetic
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Sympathetic and parasympathetic divisions function in opposition to each other. 

This opposition is better termed complementary in nature rather than antagonistic. The sympathetic division functions in actions requiring quick responses. The parasympathetic division functions with actions that do not require immediate reaction. The sympathetic system is often considered the "fight or flight" system, while the parasympathetic system is often considered the "rest and digest" or "feed and breed" system.

Multiple choice zoology nervous system nervous systems involved in emotions types of nervous system components of 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
Reveal answer Fill a bubble to check yourself
B Correct answer
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.

Multiple choice zoology nervous system nervous systems involved in emotions types of nervous system components of nervous system

Autonomic nervous system controls

  1. Conditioned reflexes

  2. Functioning of spinal cord

  3. Functioning of visceral organs

  4. Reflex actions
Reveal answer Fill a bubble to check yourself
C Correct answer
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.

Multiple choice zoology nervous system nervous systems involved in emotions types of nervous system components of 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
Reveal answer Fill a bubble to check yourself
B Correct answer
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.

Multiple choice zoology nervous system nervous systems involved in emotions types of nervous system components of nervous system

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
Reveal answer Fill a bubble to check yourself
B Correct answer
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.

Multiple choice zoology nervous system nervous systems involved in emotions types of nervous system components of nervous system

Constriction of the pupil is function of

  1. Parasympathetic system

  2. Hypothalamus

  3. Thalamus

  4. None of the above
Reveal answer Fill a bubble to check yourself
A Correct answer
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. 

Multiple choice zoology nervous system nervous systems involved in emotions types of nervous system components of nervous system

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
Reveal answer Fill a bubble to check yourself
D Correct answer
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.

Multiple choice zoology nervous system nervous systems involved in emotions types of nervous system components of nervous system

Which of the following is not a characteristic of the human sympathetic nervous system?

  1. Prepares the person for fight or flight

  2. Has ganglia near the spinal cord

  3. Increases heart beat

  4. Is a craniosacral division of the autonomic nervous system
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The human sympathetic nervous system controls the functions (for example accelerated heartbeat, reduced digestion rate etc) that help prepare the organism for the physical strain which is required to escape from a dangerous situation.

The preganglionic fibres of sympathetic nervous system arise from thoracic lumbar portion of spinal cord and immediately terminate in ganglia lying near the cord. 
Under stress conditions, preganglionic neurons of this system release acetylcholine which in turn makes postganglionic neurons to release norepinephrine causing increased heart beat.
Sympathetic nervous system is thoracic lumber division of autonomous nervous system. The parasympathetic system is its sacral division
So, the correct answer is 'Is a craniosacral division of the autonomic nervous system'

Multiple choice zoology nervous system nervous systems involved in emotions types of nervous system components of nervous system

Which of the following systems slows the heart rate, constricts the pupil and stimulates pancreatic activity during emergency conditions?

  1. Enteric nervous system

  2. Somatic nervous system

  3. Peripheral nervous system

  4. Parasympathetic division

  5. Sympathetic division
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
Parasympathetic nervous system slows the heart rate, constricts the pupil and stimulates pancreatic activity during emergency conditions.
The parasympathetic nervous system has almost the exact opposite effect and relaxes the body and inhibits or slows many high energy functions.
Heart rate is controlled by the two branches of the autonomic nervous system. The sympathetic nervous system (SNS) and the parasympathetic nervous system (PNS). The sympathetic nervous system (SNS) releases the hormones (catecholamines - epinephrine and norepinephrine) to accelerate the heart rate. The parasympathetic nervous system (PNS) releases the hormone acetylcholine to slow the heart rate. 
The reduced heart rate results from an increase in activity of the parasympathetic nervous system, and perhaps from a decrease in activity of the sympathetic nervous system.
Examples of body functions stimulated by the parasympathetic nervous system  include sexual arousal, salivation, lacrimation, urination, digestion, and defecation. 
The parasympathetic nervous system is also known as the rest and digest activation, is the segment that assists with normal, autonomic functions. Typically all are in the control of the parasympathetic nervous system. Since this is the normal state of the body, the parasympathetic system is more active than the sympathetic system in controlling body functions.

Multiple choice zoology nervous system nervous systems involved in emotions types of nervous system components of nervous system

Which of the following human parasympathetic function is not under the control of a cranial nerve?

  1. Contraction of bladder

  2. Constriction of pupil

  3. Increase of salivation

  4. Stimulation of gall bladder activity
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The parasympathetic nervous system decreases respiration and heart rate and increases digestion. Stimulation of the parasympathetic nervous systems results in the construction of pupils. Salivation, decrease heart rate and blood pressure.

So, the correct option is 'Contraction of bladder'.