L14 - PNS, nerve plexuses

nerves that supply motor function to the diaphragm and make it contracts and relax? (ex: breathing)

phrenic nerves (C3, C4, C5 KEEP THE DIAPHRAGM ALIVE)

if a patient has spinal cord injury above the C3 nerve root, what will they need and why?

The patient will require a respirator to help them breathe because the nerve roots that supply the phrenic nerves are no longer connected to the brainstem and brain

If a patient has a spinal cord injury below the C5 nerve root, what will happen and why?

the patient would be able to breathe independently because the injury is below the phrenic nerves so connection with the brain ad brainstem is sustained.

nerve roots combine to make these

nerve plexuses

the phrenic nerves have both _____ and _____ fibers

sensory, motor

what nerve roots are part of brachial plexus?

C5-T1

How many roots, trunks, divisions, cords, and nerves are part of the brachial plexus?

roots - 5 (C5, C6, C7, C8, T1)

trunks - 3 (superior, middle, inferior)

divisions - 6 (anterior and posterior divisions of ST, MT & IT)

cords - 3 (lateral, posterior, medial)

nerves - 5 (musculocutaneous, median, ulnar, axillary, radial)

What nerve root(s) innervate the radial nerve?

C5-C8, T1 (loosely)

What nerve root(s) innervate the axillary nerve?

C5 & C6

what are the only muscles that the axillary nerve supplies?

teres minor and deltoid

What nerve root(s) innervate the musculocutaneous nerve?

C5, C6 & C7

what are the only muscles that the musculocutaneous nerve supplies?

coracobrachialis, biceps brachii, and brachialis

What nerve root(s) innervate the median nerve?

C5 (loosely) C6-T1

What nerve root(s) innervate the ulnar nerve?

C8 & T1

what are the muscles and muscle groups does the radial nerve supplies?

• ALL EXTENSOR MUSCLES

• triceps

• anconeus

• supinator

• brachioradialis

• abductor pollicis longus

what are the muscles and muscle groups does the median nerve supplies?

• all flexors (EXCEPT FLEXOR CARPI ULNARIS)

• pronators

• palmaris longus

• 3 thenars and lumbrical 2,3

what are the muscles and muscle groups does the ulnar nerve supplies?

• flexor carpi ulnaris

• flexor digitorum profundus

• adductor pollicis

• interosseis, 3 hypothenars, and lumbricals 4,5

the median nerve enters the hand through the ______ ______ to supply motor to the thumb

carpal tunnel

what pathology occurs when there is a radial nerve lesion and why?

Wrist drop, happens because the radial nerve supply motor function in the extensor muscles, so the flexors have no active antagonists.

what nerve roots are part of lumbar plexus?

L1-L4

Which lumbar plexus nerve(s) ONLY originate from L1?

(“2 from 1, 2 from 2, and 2 from 3”)

iliohypogastric and ilioinguinal

Which lumbar plexus nerve(s) originate from BOTH L1 & L2?

(“2 from 1, 2 from 2, and 2 from 3”)

genitofemoral

Which lumbar plexus nerve(s) originate from BOTH L2 & L3?

(“2 from 1, 2 from 2, and 2 from 3”)

lateral femoral cutaneous

Which lumbar plexus nerve(s) originate from L2, L3 & L4? (ALL THREE)

(“2 from 1, 2 from 2, and 2 from 3”)

obturator, femoral

what are the muscles and muscle groups does the femoral nerve supplies?

HIP FLEXORS anteiror thigh)

• quadriceps (rectus femoris, and vastuses)

• sartorius

• pectineus

• iliacus

what are the muscles and muscle groups does the obturator nerve supplies?

HIP ADDUCTORS (medial thigh)

• pectineus

• obturator externus

• gracilis

what nerve roots are part of sacral plexus?

L4-S4

what are the 5 sacral plexus nerves?

S - superior gluteal nerve

I - inferior gluteal nerve

P - posterior femoral cutaneous nerve’

P - pudendal nerve

S - sciatic nerve

Which sacral plexus nerve originates from BOTH L4, L5, & S1; and innervates gluteus medius, minimus, and tensor fasciae latte?

superior gluteal

Which sacral plexus nerve originates from L5-S2; and innervates gluteus maximus?

inferior gluteal

Which sacral plexus nerve originates from S1-S3; and innervates posterior thigh, inferior buttock, and popliteal

posterior femoral cutaneous

Which sacral plexus nerve originates from S2-S4; and innervates genital muscles

pudendal

what muscle is use as a landmark of the superior and inferior gluteal nerve?

piriformis

The pudendal nerve exits through the _____________________________ and enters through the ________________________ and goes through the ______________________________

greater sciatic foramen, lesser sciatic foramen, pudendal canal

what are the muscles and muscle groups does the tibial nerve supplies?

• hamstrings (except biceps femoris short head) + adductor magnus

• flexors of the leg

• triceps surae

• tibialis posterior + deep posterior

• abductor hallucis

what are the muscles and muscle groups does the common fibular nerve supplies?

• ALL EXTENSORS OF THE LEG

• Biceps femoris short head

• fibularis, tibialis anterior

What are some of the symptoms of sciatica?

weakness of muscles around nerve, burning, numbness tingling of back, leg, and butt?

what are some causes of sciatica?

herniated discs, hypertonicity of piriformis, physical trauma, etc.