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 plant and animal tissues nervous system in animals structure of neuron structure and function of neuron

Which one of the following pairs of structure distinguishes a nerve cell from other types of cell?

  1. Flagellum and medullary sheath

  2. Nucleus and mitochondria

  3. Perikaryon and dendrites

  4. Vacuoles and fibres
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
  • The structural difference between a neuron and other kinds of cell include the perikaryon and dendrites.
  • The cell body of a neuron, known as perikaryon, has a large and round nucleus. Nissil granules are present in its cytoplasm forming the characteristic feature.
  • While dendrites are branched thread like structure arising from cyton which functions to receive impulses from sensory system and transfer it in form of electrical impulses to other neurons via the Axon.
So, the correct option is 'Perikaryon and Dendrites'.
Multiple choice biology plant and animal tissues nervous system in animals structure of neuron structure and function of neuron

Select the correct statement regarding the Schwann cells.

  1. Surround axon of myelinated nerve fibre

  2. Support muscle fibres

  3. Found in Haversian system of bones

  4. Form basement membrane of epithelium.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
Schwann cell, also called neurilemma cell, any of the cells in the peripheral nervous system that produce the myelin sheath around neuronal axons. Myelin, which is a fatty layer that insulates the axon, helps to increase the saltatory conduction of the neuron. 
So, the correct answer is option A.
Multiple choice biology animal behaviour ethology natural selection coordination in human beings- chemical control endocrine system in humans

A frog has its brain crushed, but when pinched on the leg, the leg draws away. It is an example  of 

  1. neurotransmitter induced response

  2. simple reflex

  3. condition reflex

  4. automated motor response.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The action does not involve the brain and is an example of a simple reflex. When the leg of the frog is pinched, the stimulus is received by receptors on the skin that set up a sensory impulse. This impulse is carried to the spinal cord through the dorsal sensory root of a spinal nerve. The spinal cord then transforms the sensory impulse into a motor impulse. This impulse is then transmitted to the leg muscles. The muscles on receiving the impulse contract and the leg is withdrawn to avoid the stimulus. So, the correct option is 'simple reflex'.

Multiple choice

The axon terminal changes impulses from ____ signals to _____ signals.

  1. sensory to motor

  2. involuntary to voluntary

  3. chemical to electrical

  4. electrical to chemical
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

When an electrical impulse reaches the axon terminal, it triggers the release of neurotransmitters, effectively converting the electrical signal into a chemical signal.

Multiple choice

In what order do sensory neurons transport impulses?

  1. from the brain to the body

  2. from the body to the brain

  3. from the spinal cord to the organs

  4. from the muscles to the spinal cord
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Sensory neurons (afferent neurons) carry impulses from sensory receptors in the body toward the central nervous system (brain and spinal cord).

Multiple choice

What are the 2 main types of neurons in the human body?

  1. sensory & motor

  2. voluntary & involuntary

  3. automatic & scheduled

  4. efficient & inefficient
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

While there are interneurons, the two primary functional categories often taught in basic biology regarding signal direction are sensory and motor neurons.