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

Which of the following is correct about distribution and function of glossopharyngeal nerve?

The 9th and 10th cranial nerves have their origins similar, i.e. side of medulla oblongata, but are distributed in different areas, hence have different functions. They actually control the voluntary and involuntary movements of pharynx, larynx and many visceral organs.

  1. Taste buds and phonation

  2. Pharynx and second half of tongue, and bitter taste of posterior tongue

  3. Oesophagus and swallowing

  4. Blood vessels and tongue movement

  5. Visceral receptors and larynx elevation
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Glossopharyngeal nerve is distributed in taste buds, pharynx, posterior tongue, parotid gland and pharyngeal muscle. Its function is larynx elevation, salivation and perception of bitter taste.

Multiple choice

Which one of the following is not the function of vagus nerve?

The 9th and 10th cranial nerves have their origins similar, i.e. side of medulla oblongata, but are distributed in different areas, hence have different functions. They actually control the voluntary and involuntary movements of pharynx, larynx and many visceral organs.

  1. Intestinal and gastric movement of food

  2. Cutaneous sensibility

  3. Phonation

  4. Saliva secretion

  5. Swallowing
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Saliva secretion is not the function of vagus. Vagus is the 10th cranial nerve, which is branched and the longest of all cranial nerves. It is mainly responsible for swallowing, phonation, intestinal and gastric movement, general taste, gastric and pancreatic sensation, breathing and cutaneous sensibility. Saliva secretion from the salivary gland is the function of 9th cranial nerve namely glossopharyngeal nerve. This nerve is also responsible for larynx elevation and taste sensation of posterior tongue.

Multiple choice

Which of the following statements is/are false?

a. The shorter fibres on the body of a neuron are called axon. b. The axon passes the nerve impulses to another neuron through a junction called synapse. c. Muscles and glands are the main effectors of the human body.

  1. Only a

  2. Only a and b

  3. Only b

  4. Only b and c

  5. Only c
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

This is the correct option as this statement is false. The shorter fibres on the body of a neuron are called dendrites.

Multiple choice

In myasthenia gravis blocking antibody binds to ______.

  1. acetylcholine

  2. dopamine

  3. acetylcholine receptor

  4. axons

  5. TSH receptors
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Acetylcholine receptor. In myasthenia gravis auto antibody binds to the acetylcholine receptors on the motor end plate of the muscle blocking the normal binding of acetylcholine also induced compliment mediated lysis of cells.

Multiple choice

Paresthesia eliciting during an inferior alveolar nerve block is due to ____________.

  1. poor technique

  2. acidic ph of the local anesthetic solution

  3. contact of the needle with the nerve trunk

  4. sodium conductance through the nerve membrane
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Reasons for persistent paresthesia (persistent anaesthesia) are as follows: a. Injection of a local anaesthetic solution contaminated by alcohol or sterilizing solution as these are irritant (alcohol is neurolytic) b. Trauma to the nerve sheath produced by the needle during injection c. Hemorrhage into or around the neural sheath can also cause paresthesia due to pressure over the nerve

Multiple choice

Which of the following statements is/are correct?

a. Cranial nerves connect all parts of the head to the brain. b. A spinal nerve is a mixed nerve, which carries motor, sensory and autonomic signals between the spinal cord and the body. c. Visceral nerves connect the internal organs of the body to the brain.

  1. a only

  2. b only

  3. c only

  4. a and b

  5. a, b and c
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

This is the correct answer as both statements are correct. 

Multiple choice

Which of the following statements is incorrect?

  1. Spinal cord helps in maintaining posture and balance of body.

  2. 31 pairs of nerves arise from the spinal cord.

  3. Spinal cord begins in continuation with medulla and extends downwards.

  4. Spinal cord is enclosed in a bony cage called vertebral column.

  5. Spinal cord conducts nerve impulses to and from the brain.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

This is the correct answer choice as this statement is incorrect.