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

Name the part of neuron through which information travels as an electrical impulses.

  1. Dendrites

  2. Axon

  3. Schwann cells

  4. Sypase
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
An axon is a long, slender projection of a neuron, that typically conducts electrical impulses away from the neuron's cell body in form of a wave of depolarization. The function of the axon is to transmit information to different neurons, muscles and glands.
So, the correct option is 'Axon'.
Multiple choice biology plant and animal tissues nervous system in animals structure of neuron structure and function of neuron

Neurilemma is name for :

  1. Plasmamembrane of axon

  2. Coating formed by myelin sheath

  3. Covering of schwann cells

  4. Connective tissue covering of nerve fasciculus
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Neurilemma is the outermost covering of Schwann cells that surrounds the axon of the neuron. It is also known as neurolemma.

Thus, the correct answer is 'Covering formed by Schwann cells.'

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 structures distinguishes a nerve cell from other cell types?

  1. Vacuoles and fibres

  2. Flagellum and medullary sheath

  3. Nucleus and mitochondria

  4. Perikaryon and dendrites
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The vacuole is membrane bound organelle present in all plant and fungal cells and some protist, animal and bacterial cells. The flagellum is an appendage, that protrudes from the cell body of certain prokaryotic and some eukaryotic cells. Nucleus and mitochondria are membrane bound organelles present in almost all cells. Perikaryon, also called cyton is the bulbous end of a neuron containing cell nucleus. Dendrites are the short cytoplasmic processes of the cell body of the neuron, which receives stimulus from other neurons. 
So, the correct answer is option D.

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

In peripheral nervous system, the nerves are made up exclusively from the

  1. Dendrons

  2. Axons

  3. Nodes of Ranvier

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

Nerves are made up of bundles of the axons of nerve cells. A nerve is an enclosed, cable-like bundle of axons (long, slender projections of neurons) in the peripheral nervous system.

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

'Nodes of Ranvier' are found in 

  1. Brain

  2. Heart

  3. Axon

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

Nodes of Ranvier are periodic gaps in the insulating sheath (myelin) on the axon of certain neurons, that serves to facilitate the rapid conduction of nerve impulses. 

The action potential propagated by one node of Ranvier jumps to and is regenerated at the next node along the axon, thereby enabling the action potential to travel rapidly along the fiber.

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

The function of an axon is 

  1. Transformation of nerve impulse

  2. Reception of stimuli from neurons

  3. Reception of external stimuli

  4. Conduction of nerve impulse
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

An axon is also known as a nerve fiber. It is a long, slender projection of a nerve cell, or neuron, that conducts electrical impulses away from the neuron's cell body. The function of the axon is to transmit information to different neurons, muscles and glands.

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

Dendrites are associated with which system?

  1. Nervous system

  2. Digestive system

  3. Muscular system

  4. Blood vascular system
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Dendrites are the branched projections of a neuron, that act to propagate the electrochemical stimulation received from other neural cells to the cell body, or soma, of the neuron from which the dendrites project.

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

"Nodes of Ranvier" are found in 

  1. Brain

  2. Heart

  3. Axon

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

The node of Ranvier is a periodic gap in the insulating sheath on the axon of certain neurons that serves to facilitate the rapid conduction of nerve impulses. These interruptions in the myelin covering were first discovered in 1878 by French histologist and pathologist Louis Antoine Ranvier, who describes the nodes as constrictions. They are present in myelinated nerves.

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

All information from our environment is detected by the specialized .................. cells.

  1. Nerve

  2. Nephron

  3. Glial

  4. Companion
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The two main types of cells of the nervous system are neurons/nerve cells and neuroglia. The main function of neurons is to receive sensory inputs from the internal and external environment by sensory nerves and transmit it to CNS (brain and spinal cord) for processing and finally transmit the nerve impulses from CNS to effectors (muscles and glands).

Neuroglia/glial cells support and nourish the nerve cells, destroy pathogen and modulate the impulse transmission.  
The nephron is the anatomical and functional unit of kidney and thus is the part of the excretory system. 
Companion cells are the component of phloem in flowering plants and regulate loading and unloading of sugars into sieve tube elements for translocation. 
Therefore, the correct answer is option A.

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

Main parts of a neuron are ............... and 

  1. Cell body, axon

  2. Axon hillock, synaptic knob

  3. Cell body, synaptic knob

  4. Myelin seath, axon
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The basic parts of a neuron are the dendrites, the cell body and the axon. However, all neurons vary somewhat in size, shape and characteristics depending on the function and role of the neuron. Some neurons have few dendritic branches, while others are highly branched in order to receive a great deal of information. Some neurons have short axons, while others can be quite long. The longest axon in the human body extends from the bottom of the spine to the big toe and averages a length of approximately three feet.

Therefore, the correct answer is option A.

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

................... is the functional and structural unit of the nervous system.

  1. Neuron

  2. Nephron

  3. Cerebrum

  4. Cerebellum
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

A neuron is an electrically excitable cell. It is the functional and structural unit of the nervous system. It processes and transmits information through electrical and chemical signals. These signals between neurons occur via synapses, specialized connections with other cells. Neurons can connect to each other to form neural networks. Neurons are the core components of the nervous system.

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

Which of the following is not a function of neuron?

  1. Receive information

  2. Conduct a signal

  3. Form the myelin sheath

  4. Co-ordinate metabolic activities
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Sensory neurons receive sensory inputs from the internal and external environment by sensory nerves and transmit it to CNS (brain and spinal cord) for processing. This makes option A incorrect. 

Motor neurons transmit the nerve impulses from CNS to effectors (muscles and glands). 
According to the signal, carried by motor nerves to effector organs, the muscles and glands perform their actions (contraction and secretion respectively) and thereby coordinating the metabolic activities. Thus, option D is incorrect. 
The two main types of cells of the nervous system are neurons and neuroglia. The myelinated axon fibres are covered with white myelin sheath formed from the membranes of tightly spiraled neuroglia cells. Thus, option C is the correct answer. 

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

A nerve is composed of

  1. Muscular tissue

  2. Nerve fibre bundles

  3. Bundle sheaths

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

A nerve is composed of nerve fiber bundles. A nerve fiber is a threadlike extension of a nerve cell and consists of an axon and myelin sheath (if present) in the nervous system. There are nerve fibers in the central nervous system and peripheral nervous system. A nerve fiber may be myelinated and/or unmyelinated. In the central nervous system (CNS), myelin is produced by oligodendroglia cells.
Muscle tissue is a soft tissue that composes muscles in animal bodies and gives rise to muscles ability to contract. This is opposed to other components or tissues in muscle such as tendons or perimysium.
Bundle sheath cells is a layer of cells in plant leaves and stem that forms a sheath surrounding the vascular bundles.

Therefore, the correct answer is option B.

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

The speed at which impulses are conducted increase with  

  1. Increasing diameter of the soma

  2. Increasing diameter of the axon

  3. Increasing number of dendrites

  4. Increasing branching of the dendrites
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Dendrites are the small extension of nerve cells that receive signals from sensory receptors or other neurons. The nerve impulse is not conducted by them. The long extension of the cell body of the nerve cell is called as axon that serves to conduct the nerve impulse away from the cell body. The increased diameter of axon results in reduced resistance to local current flow which in turn causes the action potential at its one site to activate the adjacent site. Soma is the metabolic center of the nerve cell where the metabolic contents are manufactured. It is not involved in nerve impulse conduction. Thus, the correct answer is option B.