Spinal Nerves, Plexuses, and Miscellaneous Functions

cervical nerves

The eight pairs of spinal nerves that emerge from the cervical region of the spinal cord, providing motor and sensory function to the neck, shoulders, arms, and diaphragm.

C1 - C8

what are the ventral rami in the cervical region?

C3 - C8

what are the ventral rami in the phrenic nerve?

phrenic nerve

which nerve mediates the diaphragm, and if damaged, could cause respiratory arrest?

thoracic nerves

The twelve pairs of spinal nerves originating from the thoracic region of the spinal cord, responsible for innervating the chest and upper abdominal muscles.

T1 - T12

what are the ventral rami in the thoracic region?

lumbar nerves

The five pairs of spinal nerves that arise from the lumbar region of the spinal cord, primarily responsible for innervating the lower back, legs, and feet.

L1 - L5

what are the ventral rami in the lumbar region?

sacral nerves

The five pairs of spinal nerves that originate from the sacral region of the spinal cord, responsible for innervating the pelvic organs, buttocks, and lower limbs.

S1 - S8

what are the ventral rami in the sacral region?

coccygeal nerves

The single pair of spinal nerves that emerge from the coccygeal region of the spinal cord, involved in innervating the skin over the coccyx.

C0

what are the ventral rami in the coccygeal region?

cervical plexus

which plexus innervates the skin of the neck, ear, back of the head, and shoulders?

phrenic nerve

which nerves arises from the cervical plexus?

C1 - C4

what are the ventral rami in the cervical plexus?

brachial plexus

which plexus innervates the upper limb?

C5 - C8, and T1

what are the ventral rami in the brachial plexus?

roots, trunks, divisions, cords

what are the major branches arising from the brachial plexus?

roots

which branch of the brachial plexus is made up of five ventral rami (C5–T1), which unite to form trunks?

trunks

which branch of the brachial plexus is made up of roots, which unite to form divisions?

divisions

which branch of the brachial plexus is made up of trunks, which unite to form cords?

cords

which branch of the brachial plexus is made up of divisions

axillary, median, musculocutaneous, radial, ulnar

what are the major nerves arising from the brachial plexus that innervate the upper limb?

axillary nerve

which brachial nerve innervates deltoid, teres minor, and skin and joint capsule of shoulder?

musculocutaneous nerve

which brachial nerve innervates biceps brachii and brachialis, coracobrachialis, and the skin of the lateral forearm?

median nerve

which brachial nerve innervates skin, most flexors, forearm pronators, wrist and finger flexors, and thumb opposition muscles?

ulnar nerve

which brachial nerve innervates the skin on the median aspect of the hand?

radial nerve

which brachial nerve innervates essentially all extensor muscles, supinators, and posterior skin of limbs?

brachial plexus

a shoulder dislocation injures which plexus?

median nerve

injuring which nerve makes it difficult to use pincer grasp and cause carpal tunnel syndrome?

ulnar nerve

injuring which nerve causes clawhand?

radial nerve

injuring which nerve causes wrist drop?

lumbar plexus

which plexus innervates the thigh, abdominal wall, and psoas muscle?

L1 - L4

what are the ventral rami in the lumbar plexus?

femoral and obturator

what as the major nerves in the lumbar plexus

femoral nerve

which lumbar plexus nerve innervates quadriceps and skin of anterior thigh and medial surface of leg

obturator nerve

which lumbar plexus nerve passes through obturator foramen to innervate adductor muscles

femoral nerve

a herniated disc damages what nerve?

obturator nerve

pain in the medial thigh is caused from damaging which nerve?

sacral plexus

which plexus serves the buttock, lower limb, pelvic structures, and perineum?

L4 - S4

what are the ventral rami in the sacral plexus?

sciatic nerve

what is the major nerve in the sacral plexus?

sciatic nerve

what sacral plexus nerve innervates hamstring muscles, adductor magnus, and most muscles in leg and foot?

sciatic nerve

what is the longest and thickest nerve of the body?

tibial and common fibular

what are the major nerves of the sciatic nerve?

common fibular nerve

which sciatic nerve mediates dorsal flexion?

tibial nerve

which sciatic nerve mediates plantar flexion?

sciatic nerve

paralyzed hamstrings and sciatica are caused from damaging which nerve?

common fibular nerve

footdrop is the inability to do dorsiflexion

it is caused by damaging the peroneal nerve; what is the other name of this nerve?

tibial nerve

shuffling gait, or foot dragging (cannot do plantar flexion), is caused by damaging what nerve?

back

what region of the body is innervated by dorsal rami via several branches?

cerebrum function

list the function: responsible for highest mental functions

frontal lobe function

list the function: personality; motor movement; expressive speech

occipital lobe function

list the function: vision; recognition of size, shape, color

parietal lobe function

list the function: gross sensation; touch/ pressure; fine sensation; determination of texture/ weight/ size/ shape; reading skills

temporal lobe function

list the function: center for behavior; hearing; language reception and understanding

thalamus function

list the function: relay center for sensory information - where pain is perceived

hypothalamus function

list the function: homeostasis, hormone function and behavior

basal ganglia function

list the function: coordination of motor movement & intensity of muscle movements

midbrain function

list the function: sensorimotor reflexes (visual reflexes)

medulla oblongata (medulla) function

list the function: center for automatic control of respiration and heart rate

cerebellum function

list the function: muscle coordination, tone, and posture

third ventricle

which ventricle encloses the thalamus, hypothalamus, and epithalamus

third ventricle

which ventricle lies in the diencephalon?

fourth ventricle

which ventricle lies in the hindbrain (pons, medulla, cerebellum)?