Biology

Nervous System and Neurons

1,164 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 biology nervous system of man divisions of nervous system autonomic nervous system the human brain

Passage of action potential from one node of Ranvier to the next is

  1. Nodal conduction

  2. Saltatory conduction

  3. Threshold stimulus

  4. Mechanical conduction
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Saltatory conduction is the propagation of action potentials along myelinated axons from one node of Ranvier to the next, which increases the speed of transmission.

Multiple choice biology nervous system of man divisions of nervous system autonomic nervous system the human brain

The functions of our visceral organs are controlled by

  1. Sympathetic and somatic nervous system

  2. Sympathetic and parasympathetic nervous system

  3. Central and somatic nervous system

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

The autonomic nervous system, consisting of the sympathetic and parasympathetic divisions, regulates the involuntary functions of visceral organs.

Multiple choice biology nervous system of man divisions of nervous system autonomic nervous system the human brain

Which is not the effect of sympathetic nervous system

  1. Dilation of pupil

  2. Inhibition of peristalsis

  3. Elevation of blood pressure

  4. Stimulation of saliva secretion
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Stimulation of saliva secretion is a parasympathetic effect. The sympathetic nervous system typically inhibits salivary secretion, resulting in a dry mouth.

Multiple choice biology nervous system of man divisions of nervous system autonomic nervous system the human brain

An interneuron consists of the following

  1. Long dendrites and short axon

  2. Short dendrites and long and short axon

  3. Short dendrites and a long axon

  4. Long dendrites and a long axon
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Interneurons (also called association neurons) typically have short dendrites and axons that can vary in length, often acting as bridges between sensory and motor neurons.

Multiple choice biology nervous system of man divisions of nervous system autonomic nervous system the human brain

Which of the following pairs correctly identifies function of parasympathetic nervous system?

  1. Slows heart beat, promotes pancreatic secretion

  2. Increases secretion of sweat gland and intestinal gland

  3. Accelerates heart beat, dilates arteries

  4. Raises blood pressure, increases peristaltic activity.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
Parasympathetic Nervous system: It is active during relaxing times, restoring normal activity after stress.
Sympathetic Nervous system: Active during stressful conditions, preparing the body to face them.
A. It is the function of parasympathetic nervous system.
B. Increase secretion of sweat gland by sympathetic nervous system and promote secretion of intestinal juice by parasympathetic nervous system.
C. Accelerates heart beat by sympathetic nervous system and dilates arteries by parasympathetic nervous system.
D. Raises blood pressure by sympathetic nervous system and increases peristaltic activity by parasympathetic nervous system.
So, the correct answer is 'Slows heart beat, promotes pancreatic secretion'.
Multiple choice biology nervous system of man divisions of nervous system autonomic nervous system the human brain

What are the sympathetic and parasympathetic nervous systems the part of?

  1. Brain

  2. Spinal cord

  3. Central nervous system

  4. Autonomous nervous system
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The sympathetic nervous system (SNS) is part of the autonomic nervous system (ANS), which also includes the parasympathetic nervous system (PNS).

So both sympathetic and parasympathetic nervous systems are the part of autonomous nervous system.
So the answer is 'Autonomous nervous system'. 

Multiple choice biology nervous system of man divisions of nervous system autonomic nervous system the human brain

Parasympathetic nervous system on stimulation bring about the functions, like

  1. Dilation of blood vessels

  2. Contraction of pupil and muscles of urinary bladder

  3. Contraction of walls of digestive tract

  4. All of the above
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Parasympathetic stimulation causes: slowing down of the heartbeat; lowering of blood pressure; constriction of the pupils; increased blood flow to the skin and viscera; salivation increase; peristalsis of the GI tract.

Multiple choice biology nervous system of man divisions of nervous system autonomic nervous system the human brain

Parasympathetic nervous system has its origin from

  1. The brain

  2. The spinal cord

  3. Both of the above

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

Parasympathetic nerve fibres arise from the central nervous system with the $S _2$, $S _3$, and $S _4$ spinal nerves and from the third, seventh, ninth, and tenth cranial nerves. 

Because of its location, the parasympathetic system is commonly referred to as having craniosacral outflow.

Multiple choice biology nervous system of man divisions of nervous system autonomic nervous system the human brain

Which one of the following is not an effect of sympathetic nervous system? 

  1. Dilation of pupil

  2. Inhibition of peristalsis

  3. Elevation of blood pressure

  4. Stimulation for saliva secretion during digestion or eating
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The sympathetic nervous system is involved in the stimulation of activities that prepare the body for action, such as increasing the heart rate, increasing the release of sugar from the liver into the blood, and other generally considered as fight-or-flight responses (responses that serve to fight off or retreat from danger). 

The parasympathetic nervous system activates tranquil functions, such as stimulating the secretion of saliva or digestive enzymes into the stomach.

Multiple choice biology nervous system of man divisions of nervous system autonomic nervous system the human brain

Sympathetic fibres are generally stimulatory except that they

  1. Inhibit the contraction of urinary bladder

  2. Inhibit peristalsis

  3. Inhibit the secretion of saliva

  4. Inhibit the rate of heart beat

  5. Both B and C
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

The autonomic nervous system is made up of sympathetic nervous system and para-sympathetic nervous system. The sympathetic nervous system made up of sympathetic fibers is responsible for the body's flight or fight response The sympathetic nerves or fibers increases heart rate and helps enhancing the blood flow, while inhibiting digestion and peristalsis.

So, the correct answer is 'Both B and C'