Question

Describe the 4 types of neuroglia in the CNS.

Describe the steps involved in the generation of an action potential.

Pick 6 brain regions and describe their function. Predict the deficits if a stroke were to occur.

Define synapses and neurotransmitters. Provide examples of neurotransmitters and describe their function.

Answer 1

ANSWER-1-

There are four types of neuroglia found within central nervous sytem-

Astrocytes- Maintain the blood brain barrier and preserve the chemical environment by recycling ions and neurotransmitters.

Oligodendrocytes - Myelinate axons in the central nervous sytem and provide an overall structural framework

Ependymal cells- Line ventrice ( brain ) and central canal ( spinal ) and are involved in the production of cerebrospinal fluid.

Microglia- Remove cell debris and pathogens waste via phagocytosis.

ANSWER- 2- Four step in generation of action potential-

1- Depolarization to threshold

- Stimulus initiates action potential large enough to open sodium channels ( threshold )

2- Activation of sodium channels and rapid depolarization

- Rapid depolaarization of sodium ions rush into cytoplasm .inner membrane changes from negative to positive.

3- Inactivation of sodium channels and activation of potassium channels

- inactivation gets close ( sodium channels inactivation ) . potassium channels opens repolarization begins.

4- Closing of potassium channels ( return to normal permeability )

- potassium channels begins to close. when membrane reaches normal resting potential potassium channels finish closing. Membrane is hyperpolarized to transmembrane potential return to resting level. Action potential is over.