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

Match the following:

 
a. The cranial nerves 1. They mostly connect the internal organs of the body to spinal cord, though some also connect to brain.
b. The spinal nerves 2. They connect parts of the body like muscles, skin etc. to the spinal cord.
c. The visceral nerves 3. They connect all the parts in the head directly to the brain.

  1. a - 3, b - 2, c - 1

  2. a - 3, b - 1, c - 2

  3. a - 2, b - 3, c - 1

  4. a - 1, b - 3, c - 2

  5. a - 1, b - 2, c - 3
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

This is the correct option. The cranial nerves connect all the parts in the head directly to the brain. The spinal nerves connect parts of the body like muscles, skin etc. to the spinal cord. The visceral nerves mostly connect the internal organs of the body to spinal cord, though some also connect to brain.

Multiple choice

Match the following:

 
a. Sensory neurons 1. They transmit impulses from the receptors towards the central nervous system i.e. towards the spinal cord and the brain.
b. Motor neurons 2. They occur in the central nervous system i.e. the brain and the spinal cord, where they serve as a link between other neurons.
c. Relay neurons 3. They transmit impulses from the central nervous system i.e. the spinal cord and the brain, towards the muscle cells.

  1. a - 1, b - 2, c - 3

  2. a - 2, b - 1, c - 3

  3. a - 3, b - 1, c - 2

  4. a - 2, b - 3, c - 1

  5. a - 1, b - 3, c - 2
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

This is the correct option. Sensory neurons transmit impulses from the receptors towards the central nervous system, i.e. towards the spinal cord and the brain. Motor neurons transmit impulses from the central nervous system, i.e. the spinal cord and the brain, towards the muscle cells. Relay neurons occur in the central nervous system, i.e. the brain and the spinal cord, where they serve as a link between other neurons.

Multiple choice

Match the following: Parts|Functions| |a. The pons|1. They control various involuntary actions like heart beat, breathing, blood pressure and peristaltic movements of the alimentary canal. | |b. The cerebellum|2. They take part in regulating respiration.| |c. The medulla|3. They help in maintaining posture and balance of the body.|

  1. a - 1, b - 2, c - 3

  2. a - 2, b - 1, c - 3

  3. a - 2, b - 3, c - 1

  4. a - 3, b - 2, c - 1

  5. a - 1, b - 3, c - 2
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

This is the correct option. The pons take part in regulating respiration. The cerebellum helps in maintaining posture and balance of the body. The medulla controls various involuntary actions like heart beat, breathing, blood pressure and peristaltic movements of the alimentary canal.

Multiple choice

Hering-Breuer reflex occurs in

  1. walls of bronchi and bronchioles

  2. trachea and tracheoles

  3. striped muscles

  4. cyton and neurons
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The Hering-Breuer inflation reflex, named for Josef Breuer and Ewald Hering, is a reflex triggered to prevent over-inflation of the lung. Pulmonary stretch receptors, present in the smooth muscle of the airways, respond to excessive stretching of the lung during large inspirations.

Multiple choice

Schwann cell is a part of the

  1. muscle cell

  2. nerve cell

  3. nephron

  4. liver cell
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Schwann cells wrap nerve cell axons in the peripheral nervous system with layers of myelin (a type of plasma membrane that provides electrical insulation).

Multiple choice

Which of the following is a purely motor nerve?

  1. Vagus

  2. Facial

  3. Abducens

  4. Trigeminal
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Abducens is a purely motor nerve which  orginates form the ventral side of the medulla and supplies to the posterior rectus muscles of the eye ball. 

Multiple choice

Which of the following statements is not true for a reflex arc?

  1. Stimulus triggers impulse in sensory neuron.

  2. Message is always carried to brain.

  3. Impulse is passed from sensory to motor neuron via inter neuron.

  4. Motor neuron passes impulse to effectors.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

A reflex arc is a neural pathway that controls a reflex action. The key characteristic is that the impulse travels from sensory neuron to motor neuron via interneuron in the spinal cord, without necessarily going to the brain. This allows for rapid involuntary responses. Option B is false because reflex arcs can bypass the brain entirely.

Multiple choice

A nerve impulse leaves a neuron through __________.

  1. nucleus

  2. axon

  3. cyton

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

A nerve impulse (action potential) travels along the neuron and leaves through the axon, which is the long fiber-like extension that conducts electrical signals away from the cell body. The axon terminal is where neurotransmitters are released to pass the signal to the next neuron. Dendrites receive signals, and the cyton contains the nucleus.

Multiple choice

What is the structural and functional unit of nervous system?

  1. Nephron

  2. Brain

  3. Neuron

  4. Sarcomere

Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The neuron (nerve cell) is the fundamental structural and functional unit of the nervous system. Neurons are specialized cells that transmit electrical and chemical signals throughout the body. Nephrons are kidney units, sarcomeres are muscle units, and while the brain is an organ composed of neurons, it's not the basic unit itself.