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Flashcards in 4.2 Nerves CTD Deck (23)
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1
Q

What is a nerve plexus? Why are they important?

A

– interlacing nerve networks grouped by body regions
Blending of nerve fibers from the ventral rami from adjacent spinal nerves
Purpose: areas receive nerve supply from more than one spinal nerve
limits the loss of complete region if a nerve is damaged

2
Q

What do nerve plexuses attach to?

A

Ventral rami of spinal nerves

3
Q

What are the nerve plexuses? Where are they?

A
Cervical Plexus (C1-C4) 
Brachial Plexus (C5 – T1) 
Lumbar Plexus (L1-L5) 
Sacral Plexus (L4-S4)
4
Q

What is the cervical plexus?

A

10+ nerves that innervate skin and muscles of the neck and shoulder

example:
Phrenic nerve – controls diaphragm
branches from C3,4,5 keeps the diaphragm “alive”
Fractures above the C3 level - respiratory arrest

5
Q

Where is the brachial plexus? What does it innervate? Major nerves?

A
C5-T1
Innervates pectoral girdle and arms
Convergences and divisions:
Trunks
Cords
Branches
major nerves:
Musculocutaneous
Median
Axillary
Radial
Ulnar
6
Q

What does the musculocutaneous nerve innervate?

A

supplies anterior arm - biceps brachii, coracobrachialis, brachialis muscles
skin of lateral forearm

7
Q

What does the ulnar nerve innervate?

A

supplies some flexors of the forearm, medial hand, ½ ring finger to pinky
skin of medial palm, ½ ring finger to pinky

8
Q

What does the median nerve innervate?

A

supplies most flexors of the forearm, lateral palm, thumb to ½ ring finger
skin of lateral palm, thumb to ½ ring finger

9
Q

What does the radial nerve innervate?

A

posterior arm, posterior extensors of forearm

skin of posterior arm

10
Q

What does the axillary nerve innervate?

A

supplies deltoid and teres minor muscles

skin of shoulder

11
Q

What is carpal tunnel? What nerve is involved?

A
occurs when the connective tissue between the carpal bones and the flexor retinaculum becomes inflamed and compresses tendons and a nearby nerve
Median nerve (brachial plexus)
12
Q

What does the lumbar plexus innervate, in general? What are it’s major nerves?

A

Innervates lower abdominal, medial and anterior portions of the thigh
Femoral nerve
Obturator nerve

13
Q

What does the femoral nerve innervate?

A

anterior, inferior, medial thigh skin sensation and anterior thigh muscles (quadriceps femoris, sartorius, iliopsoas)

14
Q

What does the obturator nerve innervate?

A

medial thigh skin sensation and medial thigh muscles (adductors)

15
Q

In general, what does the sacral plexus innervate?

A

skin and muscles of gluteal region, pelvis, perineum, posterior thigh, leg and foot

16
Q

What doe the superior and inferior gluteal nerves innervate?

A

Superior Gluteal Nerve: gluteus medius, minimus and tensor fascia latae
Inferior Gluteal Nerve: gluteus maximus

17
Q

What are the branches of the sciatic nerve?

A

Tibial Nerve: posterior thigh (all except biceps femoris short head), plantar and digital flexors of posterior leg and foot
Common Peroneal Nerve ( = Common Fibular Nerve): biceps femoris short head
Superficial Peroneal Nerve ( = Superficial Fibular Nerve): fibularis longus and brevis, skin of dorsum of foot
Deep Peroneal Nerve ( = Deep Fibular Nerve): anterior extensors (dorsiflexors) of leg and foot, skin between digit 1-2.

18
Q

What does the pudental nerve innervate?

A

perineum, external anal sphincter, external urethral sphincter, skin of external genitalia

19
Q

What is central cord syndrome?

A

compression of neurons within center of spinal cord
motor dysfunction, variable sensory loss, variable bladder function loss
common with cervical hyperextension

20
Q

What is anterior spinal artery syndrome?

A

loss of blood flow to anterior 2/3 of spinal cord, ischemia, infarction
intervertebral disc herniation, fracture, blocked aortic blood flow

21
Q

What is Brown-Sequard syndrome?

A

hemisection of the spinal cord, damage of ascending and descending tracts on one side of spinal cord
paralysis or loss of sensation, depending on specific pathways lesioned

22
Q

What is conus medullaris syndrome?

A

injury to lower spinal cord, fractured L1/L2
urinary retention, erectile dysfunction, constipation, relaxed anal sphincter, loss of anal and bulbocavernosus reflex, inguinal sensation loss, motor weakness

23
Q

What is cauda equina syndrome?

A

compression of bilateral nerve roots of lumbosacral region due to fracture of lumbar spine, sacrum, or acute herniated disc
motor and sensory loss variable, major sign is incontinence