Lecture 14: Peripheral Nervous System Flashcards
1
Q
what is the cervical plexus?
A
contains nerve roots C1 - C5
2
Q
what the mnemoic for the cervical plexus?
A
C3, C4 and C5 keep the diaphragm alive
3
Q
what happens if a spinal cord injury occurs above C3?
A
- a person will require a respirator to help them breathe
- this is because the nerve roots that supply the phrenic nerve no longer have a connection to the brainstem and the brain
- if the injury is inferior to C5 nerve root, the person should be able to breathe independently
4
Q
what is the importance of the phrenic nerve?
A
- is the sole motor nerve supply for the diaphragm to help with breathing
- has sensory and motor fibres
5
Q
what is the brachial plexus?
A
contains nerve roots C5 - T1
6
Q
what are the major branches of the brachial plexus?
A
- median nerve
- ulnar nerve
- radial nerve
- musculocutaneous nerve
- axillary nerve
7
Q
how do brachial plexus divide?
A
roots –> trunks –> divisions –> cords –> branches
8
Q
mnemonic for the brachial plexus
A
Rugby Teams Drink Cold Beer
53635 (roots, trunks, divisions, cords, branches)
My Aunt Rescued my Uncle (nerves)
9
Q
nerve root origin of radial nerve
A
c5, c6, c7, c8, t1
10
Q
nerve root origin of axillary nerve
A
c5, c6
11
Q
nerve root origin of musculocutaneous nerve
A
c5, c6, c7
12
Q
nerve root origin of median nerve
A
c5, c6, c7, c8, t1
13
Q
nerve root origin of ulnar nerve
A
c8, t1
14
Q
function/supply of radial nerve
A
- entire posterior aspect of arm
- triceps brachii
- all extensors (elbow, forearm, wrist, fingers)
15
Q
function/supply of axillary nerve
A
- teres minor and deltoid
16
Q
function/ supply of musculocutaneous nerve
A
- coracobrachialis, biceps brachii, brachialis
- flexors of the elbow
17
Q
function/supply of median nerve
A
- flexors of forearm and hand
- NOTHING proximal to elbow
18
Q
function/supply of ulnar nerve
A
- NOTHING proximal to elbow
- medial epicondyle of humerus (funny bone = ulnar nerve)
19
Q
how does Carpal Tunnel Syndrome develop?
A
- when the bones and ligaments of wrist compress on the median nerve
- this is because the median nerve goes through the carpal tunnel and branches off to supply parts of the hand
20
Q
what is Claw Hand?
A
- a deformity caused by a lesion to the ulnar nerve
- occurs because the ulnar nerve is superficial
- numbness of the fourth and fifth fingers and hand muscle weakness.
21
Q
what is Wrist Drop?
A
- occurs if there is a lesion of radial nerve
- this is because the radial nerve supplies motor to the extensors of the elbow, wrist and hand
- if injured, wrist drop occurs when flexors do not have an active antagonist so flexors overtake extensors
22
Q
what is the lumbar plexus?
A
L1 - L4
23
Q
what are the major branches of the lumbar plexus?
A
- iliohypogastric
- ilioinguinal
- genitofemoral
- lateral femoral cutaneous
- obturator
- femoral
24
Q
mnemoics for lumbar plexus
A
I (twice) Get Lunch On Fridays
2 from 1, 2 from 2 and 2 from 3
25
nerve root origin of iliohypogastric nerve
L1
26
nerve root origin of ilioinguinal nerve
L1
27
nerve root origin of genitofemoral nerve
L1, L2
28
nerve root origin of lateral femoral cutaneous nerve
L2, L3
29
nerve root origin of femoral nerve
L2, L3, L4
30
nerve root origin of obturator nerve
L2, L3, L4
31
function/supply of iliohypogastric nerve
- side of buttock, pubis
- inferior internal oblique muscle
- transversus abdominal muscle
32
function/supply of ilioinguinal nerve
- skin of external genitalia
33
function/supply of the genitofemoral nerve
- skin of scrotum (male), labia (female)
34
function/supply of lateral femoral cutaneous nerve
- skin of lateral thigh
- some to peritoneum
35
function/supply of obturator nerve
- ADDUCTORS OF THIGH
- obturator externus
- shares supply of pectineus with femoral nerve
36
function/supply of femoral nerve
- QUADRICEPS
- iliacus, sartorius
- shares supply of pectineus with obturator nerve
37
what is the sacral plexus?
L4 - S4
38
what are the major branches of the sacral plexus?
- superior gluteal nerve
- inferior gluteal nerve
- posterior femoral cutaneous nerve
- pudendal nerve
- sciatic nerve
39
mnemonics for the sacral plexus
SIPPS
40
nerve root origin of superior gluteal nerve
L4, L5, S1
41
nerve root origin of inferior gluteal nerve
L5, S1, S2
42
nerve root origin of posterior femoral cutaneous nerve
S1, S2, S3
43
nerve root origin of pudendal nerve
S2, S3, S4
44
nerve root origin of sciatic nerve
L4, L5, S1, S2, S3
45
function/supply of superior gluteal nerve
- gluteus medius
- gluteus minimus
- tensor fasciae latae
46
function/supply of inferior gluteal nerve
- gluteus maximus
47
function/supply of posterior femoral cutaneous nerve
- inferior buttock
- posterior thigh
- popliteal region
- sometimes skin of calf and heal
48
function/supply of pudendal nerve
- most of skin and muscle of perineum
- external anal sphincter
49
function/supply of sciatic nerve
- major parts of the skin and muscles in the thigh, leg, and foot
50
what are the branches of the sciatic nerve?
- tibial nerve
- common fibular nerve
51
what is the sciatic nerve?
- a large bundled nerve (2), usually wrapped in sheath
- about the size of a thumb
- branches off below the knee
52
what is the mnemonic for the pudendal nerve?
S2, 3 and 4 keeps the P's off the floor (poo, pee)
53
what is the greater sciatic foramen?
a hole formed by ligaments combining with bones
54
what forms the greater sciatic foramen?
- greater sciatic notch
- sacrotuberous ligament
- sacrospinous ligament
- anterior sacroiliac ligament
- ischial spine
55
what is the importance of piriformis?
- piriformis is the landmark for the superior and inferior gluteal nerve
- origin = anterolateral surface of sacrum
- insertion = greater trochanter of femur
56
what is Sciatica?
- burning, numbness or tingling of back, butt leg or foot
- pressure on sciatic nerve
- caused by herniated disc, hypertonicity of piriformis, trauma etc.
57
pudendal canal
the anatomical structure in the pelvis in which the internal pudendal artery, internal pudendal veins, and the pudendal nerve pass through
58
what is spinal stenosis
the narrowing of the spinal canal in your lower back that may cause pain or numbness in your legs
