Question

7. Identify the layers of the meninges and describe their anatomical and functional relationships to the CNS (brain and spinal cord).

8. Identify and describe the major components of a typical neuron and indicate which parts receive input signals and which parts transmit output signals.

Answer 1

7-

Layers of meninges

There are three layers of meninges which cover the brain and spinal cord.

From external to internal the layers are

• Dura mater (outer layer)
• Arachinoid mater(middle layer)
• Pia mater(inner layer, closest to the CNS)

Meninges are the membranous covering of the brain and spinal cord which provide protection to the brain and spinal cord. Meninges encloses the blood vessels that supplies the brain and CSF which is present in between arachinoid and pia mater (sub arachinoid space) will act as a cushion and provide mechanical and immunological protection to the brain.

8- Major components of a neuron include dendrites, cell body and axons.

Dendrites are protoplasmic extensions which transmit impulses towards the cell body from another neuron.

Cell body transmits the impulse to the axon

Axon is an extension of the cell body that receive impulses from cell body and transmits the impulses to the adjacent neuron. Axon branches at the end forming axon terminals.

Dendrites receive input signals and axon transmit output signals.