Anatomy Unit II - Chapter 14

Brachial plexus

-innervates shoulder girdle and upper extremeties -is formed from the ventral rami of spinal nerves C5-T1 -is the source of musculocutaneous, radial, median, and ulnar nerves

What is the role of meninges in protecting the spinal cord?

Protection, stability, and space for the CSF

Axons crossing from one side of the spinal cord to the other within the gray matter are found in the

gray commissures.

The middle layer of connective tissue that surrounds each peripheral nerve is the

perineurium

involuntary motor response

reflex

Spinal nerves are called mixed nerves because

they contain both motor and sensory fibers

Sensory and motor innervation of the skin and lateral and ventral surfaces are provided by the ____ _____.

ventral ramus

The expanded area of the spinal cord that supplies nerves to the pectoral girdle and upper limbs is the

cervical enlargement

Tingling and numbness in the palmar region of the hand could be caused by:

comopression of the median nerve in the carpal tunnel

The paired structures that contain cell bodies of sensory neurons and are associated with each segment of the spinal cared are the

dorsal root ganglia

single bundle of axons

fasicles

The ___ ____ is a strand of fibrous tissue that provides longitudinal support as a component of the coccygeal ligament

filum terminale

The rectus abdominus is always cut laterally, never medially. Why?

It is innervated by nerves of T7-T12 vertebrae which run laterally. The incision must be cut the same way to avoid cutting the nerves and causing paralysis.

How does a reflex differ from a voluntary muscle movement?

Muscle movements use conscious control and are voluntary. Relfexes are automatic and immediate. They aren't under conscious control .

Why is response time in monosynaptic reflexes much faster than polysnaptic?

Polysynaptic totals several synapses which contribute to a delay. Mono synaptic are only one synapse, so it has a faster response time.

If the dorsal root of the spinal cord were damaged, what would be affected?

Sensory information coming in

Why are there 8 cervical spinal nerves but only 7 cervical vertebrae?

The first pair of spinal nerves are located above the atlas. This extra pair is why there are 8 instead of 7.

What nerve is likely to transmit pain when a person receives an IM injection into the deltoid region of the arm?

The upper lateral cutaneous nerve of the arm

The deep crease on the ventral surface of the spinal cord is the

anterior median fissure

The gray matter of the spinal cord is dominated by

cell bodies of neurons and glial cells

What prevents side to side movement of the spinal cord?

dentricular ligaments

specific region of body surface

dermatome