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

Synaptic fatigue is due to

  1. Repeated release of acetylcholine

  2. Repeated release of adrenaline

  3. Exhaustion of neurotransmitter

  4. Exhaustion of acetyl cholinesterase
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Synaptic fatigue occurs when the rate of neurotransmitter release exceeds the rate of synthesis and transport, leading to the depletion of neurotransmitters in the synaptic knob.

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

The following are the parts of a neuron:
a) Axon b) Terminal branches c) Cyton d) Dendrites. 
The correct pathway of a nerve impulse through these parts are ________.

  1. badc

  2. dcab

  3. bdac

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

A nerve impulse travels from the dendrites to the cyton (cell body), then down the axon to the terminal branches.

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

Opening of which of the following type of channels is responsible for repolarisation of an axonal membrane?

  1. $Na^+$ leaky channels
  2. $K^+$ leaky channels
  3. Voltage gates $Na^+$ channels
  4. Voltage gated $K^+$ channels
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

During an action potential, depolarization is caused by the influx of sodium ions through voltage-gated Na+ channels, whereas repolarization is achieved by the efflux of potassium ions through the opening of voltage-gated K+ channels.

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

State of complete inexcitability between polarisation and repolarisation is

  1. Refractory period

  2. Synaptic delay

  3. Action potential

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

The refractory period is the time during which a neuron is incapable of generating another action potential, occurring after depolarization and during repolarization.

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

Cell bodies of motor nerve fibres occur in

  1. Dorsal root of spinal nerve

  2. Dorsal horn of spinal cord

  3. Ventro-lateral horn of spinal cord

  4. Ventral root of spinal cord
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The cell bodies of motor neurons (somatic efferent neurons) are located in the ventral (anterior) horn of the spinal cord gray matter.

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

In resting nerve what is true

  1. 3N$a^+$ are pumped in and 2 $K^+$ pumped out
  2. 3N$a^+$ are pumped out for every 2$K^+$ pumped in

  3. There is no Na-K pump

  4. Na-K pump stops working
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The Na+/K+ pump maintains the resting potential by actively transporting 3 Na+ ions out of the cell and 2 K+ ions into the cell for every ATP molecule hydrolyzed.