Spinal Nerves

Question 1

What type of information carries each spinal nerve ?

Answer 1

• somatic sensory information
• somatic motor information
• visceral sensory information
• visceral motor information

Question 2

List the sensory afferent spinal nerves and the info they transport

Answer 2

• sympathetic nerve : carries sensory info from the viscera
• ventral ramus : carries sensory info from the anterolateral body surface, structures in body wall and limbs
• dorsal ramus : carries sensory info from the skin and skeletal muscles from the back
  (-dorsal root carries the sensory info to spinal cord)

Question 3

Where does the spinal nerve form ?

Answer 3

Just lateral to the intervertebral foramen where the dorsal and ventral roots unite.

Question 4

List the motor efferent nerves and their functions

Answer 4

• dorsal ramus : contains somatic motor and visceral motor fibers innervating the skin and back skeletal muscles
• ventral ramus : supply the ventrolateral body surface, structures in the body wall and limbs
• white ramus : first branch from spinal nerve carrying visceral motor information to sympathetic ganglion (myelinated fibers)
• gray ramus : post ganglionic fibers that innervate glands and smooth muscles in the body wall or limbs (unmyelinated fibers)
• sympathetic nerve : thoracic cavity

Question 5

How many spinal nerves are there ?

Answer 5

31 pairs
- 8 cervical
- 12 thoracic
- 5 lumbar
- 5 sacral
- 1 coccygeal

Question 6

From where does spinal nerves C1 merge ?

Answer 6

Between occipital bone and C1

Question 7

From where does spinal nerve C8 emerge ?

Answer 7

Between C7 and T1