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

Anesthesia reduces pain by blocking nerve conduction due to

  1. blockage of neurotransmitter receptors

  2. blockage of Na+ channels

  3. blockage of K+ channels

  4. blockage of blood flow in the target organ

  5. increasing the blood flow in the target part
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Anesthesia reduces pain by blocking nerve conduction due to the blockage of Na+ channels.

Multiple choice

During development of action potential in a nerve fibre, why are the positive and negative charges on outer and inner sides of axon membranes reversed?

  1. Due to movement of K+ ions out of the axon.

  2. As more K+ ions enter the axon than Na+ ions leave the same.

  3. As more Na+ ions enter the axon than K+ ions leave the same.

  4. Due to all Na+ ions entering the axon.

  5. Due to high concentration of Cl- ions.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Positive and negative charges on outer and inner sides of axon membranes are reversed as more Na+ ions enter the axon than K+ ions leave the same.

Multiple choice

Inhibition of which of the following nerves helps the opening of external urethral sphincter to facilitate micturation?

  1. Pudendal nerve

  2. Phrenic nerve

  3. Urethral nerve

  4. Sciatica nerve

  5. Hypogastric nerve
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Pudendal nerve is the parasympathetic supply to the external urinary sphincter and continuously maintains its closure. Its inhibition thus causes the opening of external sphincter and facilitate voluntary micturation.

Multiple choice

Which of the following statements regarding the development of the nervous system in humans is not true?

  1. The neural crest gives rise to the dorsal root ganglia.

  2. The nervous system develops with the formation of the neural plate.

  3. The folding of the neural tube forms the mature central nervous system (CNS).

  4. The CSF is formed continuously by the choroid plexus.

  5. Neurogenesis stops after complete fetus development.
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

Neurogenesis continues throughout life at certain sites in the adult brain.

Multiple choice

What is Enteric nervous system?

  1. It is a complicated assimilate network of neurons in the wall of the gut.

  2. It is controlled by the CNS

  3. It is made up of Meissner's and Auerbach's plexuses.

  4. It regulates the local activity of the gut.

  5. The enteric nervous system develops from neural crest.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The enteric nervous system gets inputs from the parasympathetic and sympathetic parts of the ANS and the gastrointestinal tract also receives a plentiful supply of afferent nerve fibre via vagus nerves and spinal afferent pathways. 

Multiple choice

Which of the following statements regarding nerve conduction and synaptic integration is incorrect?

  1. The synaptic inputs are then associated with the postsynaptic cell.

  2. The action potential on entering the synapse causes the release of neurotransmitters.

  3. The binding of neurotransmitters with the pre and post synaptic membranes cause the change in membrane potential.

  4. In myelinated neurons, the action potential acts at node of Ranvier .

  5. Neurotransmitters gets activated at the synaptic junction.
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

Neurotransmitters gets inactivated at the synaptic junction by enzymatic degradation or selective uptake mechanisms.

Multiple choice

Select the incorrect statement regarding the spinal cord.

  1. Sensory information on pain and temperature is delivered by the spinothalamic system .

  2. Sensory information is transmitted up the dorsal column system.

  3. The corticospinal tract is mainly implicated with regular distal motor control.

  4. The cervical spinal cord stimulates the arms.

  5. The spinal cord is highly organized with decending sensory pathways.
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

The spinal cord is highly organised with ascending sensory pathways, descending motor tracts, motor neurones that strengthen, muscles and interneurones that commands both sensory and motor information.

Multiple choice

According to Cajal, which among the following does not comprise neuron doctrine?

  1. Cellularity

  2. Synaptic communication

  3. Connection specificity

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

Signals in a neural circuit travel in only one direction, i.e. information flows from dendrites of a given nerve cell to the cell body. Then, along the axon to the presynaptic terminals and then across the synaptic cleft to the dendrites of the next cell, and so on.

Multiple choice

Which of the following statements is/are false?

a. All neurons of the nervous tissue have originated from the same germinal layer called dendrites. b. Tissues become organised to form organs and organs are formed into an organ system. c. Workload of individual cells has decreased due to the origin of tissues.

  1. Only a

  2. Only a and b

  3. Only b

  4. Only b and c

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

This is the correct option as this statement is false. All neurons of the nervous tissue originated from the same germinal layer called ectoderm, not dendrites.