State whether the following statements are true (T) or false (F).

(a) The main component of the white matter of the brain is perikaryon. (T/F)

(b) The arachnoid layer fits closely inside the pia mater. (T/F)

(c) A double chain of ganglia, one on each side of the nerve cord belongs to the spinal cord. (T/F)

(d) Dura mater is the outermost layer of the meninges. (T/F)

(a) False – The main component of the white matter of the brain are axons.

Explanation: The white matter is composed of bundles of myelinated axons, that connect various gray matter areas (the locations of nerve cell bodies) of the brain to each other, and carry nerve impulses between the neurons.

(b) False – The arachnoid layer fits closely inside the dura mater.

Explanation: The three membranes that cover the brain and spinal cord are called meninges. The outside meninx is called the dura mater. The center layer is the arachnoid membrane and the thin innermost layer is the pia mater.

(c) True – A double chain of ganglia, one on each side of the nerve cord belongs to the spinal cord.

Explanation: Sympathetic ganglia are the ganglia of the sympathetic nervous system. They deliver information to the body about stress and impending danger and are responsible for the familiar fight-or-flight response.

(d) True – Dura mater is the outermost layer of the meninges.

Explanation: The dura mater is a membrane that envelops the arachnoid mater. It surrounds and supports the dural sinuses and carries blood from the brain toward the heart.