Gray's Chapter 1

Question 1

PNS

Answer 1

peripheral nervous system- cranial and spinal nerves.

Question 2

CNS

Answer 2

Central nervous system- brain and spinal cord

Question 3

31 pairs of spinal nerves

Answer 3

There are eight pairs of cervical nerves (C1 to C8),

twelve thoracic (T1 to T12)
, five lumbar (L1 to L5),
 five sacral (S1 to S5), and
 one coccygeal (Co). 

Each nerve is attached to the spinal cord by a posterior root and an anterior root

Question 4

somites

Answer 4

Precursor cells that give rise to the dermis of the skin and much of the skeletal muscle in the body are derived from groups of mesodermal cells

Question 5

dermatome & myotome

Answer 5

Clinically, a dermatome is that area of skin supplied by a single nerve or spinal cord level.

A myotome is that region of skeletal muscle innervated by a single nerve or spinal cord level.

Most individual muscles of the body are innervated by more than one spinal cord level so the evaluation of myotomes is usually accomplished by testing movements of joints or muscle groups.