Question

Comment on the main cell types and their functions within the nervous system

Answer 1

There are two broad classes of cells in the nervous system: neurons and glia.

1.Neurons- their main function is to transmit nerve impulses. Neurons fall into 3 classes -

sensory neurons- these carry sensory information to the brain or spinal cord.

Interneurons-These cells receive signals from and send signals to other nerve cells. Interneurons serve to process information in many different ways and constitute the bulk of the human nervous system

Motor neurons- These carry orders from brian or spinal cord to the effector organs.

2.Glial cells -maintain homeostasis, form myelin, and provide support and protection for neurons. Glial cells are of following types-

Microglia- These serve to protect against injury and disease of the brain.Thus microglia are the brain’s protectors.

Macroglia- These are of following types-

Astrocytes- These are star-shaped cells that maintain a neuron’s working environment by controlling the levels of neurotransmitter around synapses, controlling the concentrations of important ions like potassium, and providing metabolic support.

Oligodendrocytes-provide support to axons of neurons in the central nervous system.. They produce a fatty substance called myelin, which is wrapped around axons as a layer of insulation.

Ependymal cells- line the spinal cord and ventricles of the brain. They form cerebrospinal fluid too.

Schwann cells- They have a function very similar to oligodendrocytes i.e help in myelin formation.

Satellite cells- help regulate the chemical environment in the ganglia.

Enteric glial cells - found in the nerves in the digestive system.