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

After successfully escaping by running from a fierce tiger that was running directly towards Raman, he paused to catch his breath and collect his wits. The physical symptoms he will be experiencing now are controlled by

  1. parasympathetic nervous system

  2. sympathetic nervous system

  3. central nervous system

  4. peripheral nervous system

  5. Enteric nervous system
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

When the stress subsides, the parasympathetic nervous system of the body produces opposite effects of sympathetic nervous system. It conserves energy as it calms an individual by decreasing heartbeat, lowering blood sugar and so forth.

Multiple choice

Regarding the innervation of the human heart, which among the following statements is false?

  1. Afferent fibres carrying pain sensation run to the spinal cord.

  2. During rest, the vagal tone is recessive.

  3. Postganglionic fibres descend to the heart and form two plexuses.

  4. The effect of autonomic nervous system on coronary artery and blood flow is a reciprocal.

  5. Preganglionic sympathetic fibres ascend from the upper five thoracic segments of the spinal cord.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

During rest, the vagal tone is dominant. There is continuous parasympathetic activity that has a negative chronotropic character.

Multiple choice

The acetylcholine receptor at the nerve-muscle junction is an example of

  1. intracellular receptor

  2. tyrosine kinase-linked receptor

  3. G protein-coupled receptor

  4. ion channel receptor

  5. receptors with intrinsic enzymatic activity
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The acetylcholine receptor at the nerve- muscle junction is an example of ion-channel receptors. The binding of ligand changes the conformation of the receptor that allows flow of specific ions through it. The ion movement thus alters the electric potential across the membrane.

Multiple choice

The conduction of electric impulse from a nerve cell to a muscle cell occurs via

  1. autocrine signaling

  2. endocrine signaling

  3. cell-to-cell signaling

  4. paracrine signaling

  5. signaling by plasma membrane-bound proteins
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The conduction of an electric impulse from one nerve cell to a muscle cell either to inhibit or induce the muscle contraction happens via paracrine signaling, where in the signaling molecules secreted by a cell affect the target cells that are in close proximity to the cell that secretes them.

Multiple choice

In which of the following disorders, the immune system of the body itself attacks the optic nerves and spinal cord of the body?

  1. Myositis

  2. Neuromyelitis optica

  3. Neuromyotonia

  4. Cicatricial pemphigoid

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

Neuromyelitis optica is an autoimmune, inflammatory disorder in which a person's own immune system attacks the optic nerves and spinal cord. This produces an inflammation of the optic nerve (optic neuritis) and the spinal cord (myelitis).

Multiple choice

Which of the following statements regarding sympathetic nervous system is incorrect?

  1. Sympathetic nervous system stimulates gut motility and urinary system output and function.

  2. Sympathetic nervous system stimulation causes vasodilation of most blood vessels in the body.

  3. Sympathetic nervous system mobilises the body in a fight-or-flight response.

  4. Sympathetic nervous system is responsible for up and down regulating of many homeostatic mechanisms of the body.

  5. Sympathetic nerves originate inside the vertebral column.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Sympathetic nervous system stimulation causes vasoconstriction of most blood vessels, including those of the skeletal muscles.

Multiple choice

Among the following biomolecules, ___________ is a neurotransmitter.

  1. Abamectin

  2. Abietic acid

  3. Acetic acid

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

The chemical compound acetylcholine is a neurotransmitter in both the peripheral nervous system (PNS) and central nervous system (CNS) in many organisms including humans. Acetylcholine is one of many neurotransmitters in the autonomic nervous system (ANS) and the only neurotransmitter used in the motor division of the somatic nervous system.

Multiple choice

Nerves are wires that are distributed all over the human body. Which of the following statements is/are correct about nerves?

a. There are mainly two types of nerves. b. Cranial nerves connect all parts of the body to the brain. c. Visceral nerves connect the internal organs of the body to the spinal cord, though some also connect to brain.

  1. Only a

  2. Both a and b

  3. Only b

  4. Both b and c

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

This is the correct option.

Multiple choice

Which of the following statements is correct about axon?

  1. Axon picks up the nerve impulses from receptors.

  2. Axon is the junction through which impulses are passed through to another neuron.

  3. Axon is made of fats and proteins.

  4. Axon is the shortest fibre on the cell body of a neuron.

  5. Axon is the longest fibre on the cell body of a neuron.
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

This is the correct option. Axon is the longest fibre on the cell body of a neuron.