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 biology coordination generation and conduction of nerve impulse generation of nerve impulse neurons and synapses

An action potential travelling along an axon

  1. Moves rapidly in both direction

  2. Moves faster than a neurotransmitter

  3. Is slowed by myelin

  4. Travels through the blood
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

A neurotransmitter is a chemical messenger that carries, boosts and modulates signals between neurons and other cells in the body. In most cases, a neurotransmitter is released from the axon terminal after an action potential has reached the synapse. The neurotransmitter then crosses the synaptic gap to reach the receptor site of the other cell or neuron. 

An action potential is a short-lasting event in which the electrical membrane potential of a cell rapidly rises and falls, which follows a consistent trajectory. Action potentials occur in several types of animal cells, called excitable cells, which include neurons, muscle cells, and endocrine cells, as well as in some plant cells. So, the correct answer is option B.

Multiple choice muscle contraction locomotion and movements biology

Muscular and nervous excitability is reduced by

  1. $Na^+$
  2. $K^+$
  3. $Ca^{2+}$
  4. $Mg^{2+}$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

  • Potassium is an important mineral that functions as an electrolyte. 
  • It helps regulate fluid balance, nerve signals and muscle contractions and nervous excitability. 
  • Increased extracellular potassium levels result in depolarization of the membrane potentials of cells due to the increase in the equilibrium potential of potassium.
  •  This depolarization opens some voltage-gated sodium channels but also increases the inactivation at the same time. Hence, Muscular and nervous excitability is reduced by K+. 
So, the correct answer is 'K+'.

Multiple choice muscle contraction locomotion and movements biology

Muscle contraction is initiated by a signal by the central nervous system via

  1. Motor nerve

  2. Sensory nerve

  3. Mixed nerve

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

Most of the muscle actions of the body are voluntary except for the pumping of heart and the reflex action. These muscle receive a signal through the motor nerves , send by the brain or the CNS.

So the correct option is ' Motor nerve '.

Multiple choice biology endocrine glands different type of gland glands in humans coordination in human beings- chemical control

Integrative system in the body are 

  1. Endocrine system

  2. Nervous system

  3. Blood vascular system

  4. Both A and B
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The nervous system and the endocrine system are the two primary regulatory and integrative systems in the human body. They work together to coordinate bodily functions and maintain homeostasis.

Multiple choice biology endocrine glands different type of gland glands in humans coordination in human beings- chemical control

Proprioreceptors are found in

  1. Sole of feet

  2. Adrenal cortex

  3. Hypothalamus

  4. Medulla
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
Proprioreceptors are the receptors sensitive to internal stimuli. The stimulus is received within the body. These respond to position and movement. They are considered as sixth sense of body. Such receptors can be found in sole of feet as they respond to change in position of body.
So, the correct answer is 'Sole of feet'.
Multiple choice biology endocrine glands different type of gland glands in humans coordination in human beings- chemical control

Integration system in the body is 

  1. Nervous system

  2. Endocrine system

  3. Circulatory system

  4. Nervous and Endocrine system
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

  • Nervous system is a coordinated network of nerve cells and fibres by which nerve impulses are transmitted throughout the body.
  • Endocrine system consists of glands that produce hormones.
  • Circulatory system consists of heart and blood vessels which supply throughout the body.
In our body, nervous system and endocrine system jointly integrate all the activities as nervous system directs endocrine system to secrete hormones that act on the target organs.
So, the correct answer is 'Nervous system and Endocrine system'.

Multiple choice biology endocrine glands different type of gland glands in humans coordination in human beings- chemical control

The nervous system maintains homeostasis within the body by providing rapid responses to change. The other body system that responds more slowly, but just as importantly, is the 

  1. Integumentary system

  2. Endocrine system

  3. Cardiovascular system

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

The endocrine system is the collection of glands that produce hormones that produce hormones that regulate metabolism, growth and development, tissue function, sexual function, reproduction, sleep, and mood, among other things.

So, the correct option is 'Endocrine system'.

Multiple choice biology transport in animals cardiac cycle heart, blood vessels and cardiac cycle human heart

Which of the following can't be taken as an example of parasympathetic stimulation:

  1. Increase in the intestinal peristalsis

  2. Increased secretion of gastric juice

  3. Contraction of the detrusor muscles of urinary bladder.

  4. Increase in ventricular force of contraction.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
Increase in vertricular force of contraction is not an example of Parasympathetic stimulation because its function is to slow the heart rate of person.
Multiple choice biology transport in animals cardiac cycle heart, blood vessels and cardiac cycle human heart

In which the following has the ability to generate action potentials without any external stimuli? 

  1. Sino-atrial node(SAN)

  2. Atrio-ventricular node (AVN)

  3. Purkinje fibers

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

Sino-atrial node(SAN)  is known as a pacemaker and has the ability to generate action potentials without any external stimuli. 

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

Choose the incorrect statement for Autonomic nervous system.

  1. Acts on skeletal muscles

  2. Acts on smooth muscles

  3. Consists of ganglia formed by pre and post ganglionic neurons

  4. Consists of sympathetic and parasympathetic nervous system
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The autonomic nervous system is a division of the peripheral nervous system that supplies smooth muscle and glands, and thus influences the function of internal organs. 

  • The autonomic nervous system has three branches: the sympathetic nervous system, the parasympathetic nervous system and the enteric nervous system.
  • The autonomic nervous system is unique in that it requires a sequential two-neuron efferent pathway; the preganglionic neuron must first synapse onto a postganglionic neuron before innervating the target organ.
  • So, the correct answer is 'Acts on skeletal muscles'.

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

Sympathetic nerves in mammals arise from

  1. Sacral region

  2. Cervical region

  3. Thoraco-lumbar region
  4. $3^{rd}, 7^{th}$ and $9^{th}$ and $10^{th}$ cranial nerves
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The sympathetic system is the system which mainly controls the involuntary actins. There are two kinds of neurons involved in the transmission of any signal through the sympathetic system: pre-ganglionic and post-ganglionic. The shorter preganglionic neurons originate from the thoracolumbar region of the spinal cord (levels $T _1$-$L _2$). So, the correct answer is option C.

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

White matter is composed of 

  1. Ependyma

  2. Nerve cells

  3. Nerve fibres

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

The tissue of the brain and spinal cord, consisting mainly of nerve fibres with their myelin sheaths is the white matter, that transmit signals from one region of the cerebrum to another and between the cerebrum and lower brain centres. In contrast, the darker tissue of the brain and spinal cord, consisting mainly of nerve cell bodies and branching dendrites is the grey matter. The function of grey matter is to route sensory or motor stimuli to interneurons of the CNS in order to create a response to the stimulus through chemical synapse activity.
So, the correct answer is option C.

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

Sympathetic nerves in mammals arise from

  1. Sacral region

  2. Cervical region

  3. Thoracolumbar region
  4. 3$^{rd}$, 7$^{th}$, 9$^{th}$ and 10$^{th}$ cranial nerves
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
Sympathetic nerves are composed of efferent fibres derived from the thoracic and lumbar regions of the spinal cord. It activates the involuntary action. It is also known as fight or flight. The post ganglion which originates from the sympathetic chain innervates the effector organ and effect it. So, the correct answer is option C.