Arm, Forearm, Brachial Plexus Flashcards
Which is the biggest branch of the axillary artery?
Subscapular branch (can’t miss it)
What are the only 2 branches that originate from TRUNKS of the brachial plexus?
- Suprascapular nerve (easy to pick out)
2. Subclavius nerve
If your thumb goes numb…
you lost the c6 root somehow.
Erb’s palsy
upper root damage
“Waiter’s tip”
Klumpky’s palsy
lower root damage
“Claw” hand
Problems with flexors
Ulnar lesion in forearm
Ulnar claw (look's like saint's hands) Can't extend ring and 5th finger
Pope’s blessing
Looks like ulnar lesion but its a MEDIAN nerve lesion. It’s an active thing, not a passive thing. You can only flex ring and pinky. Thenar wasting.
Pushup trouble
Can’t protract scapula. Messed up Long thoracic n.
Wrist drop
Break anatomical head of humerus, break radial nerve.
Suprascapular nerve lesion
Neurofibromatosis disease
Destroy C5 and C6. Which nerve gets affected?
Axillary n. (assassinate)
If you hang from a branch, and rip part of the brachial plexus?
Klumpke’s palsy
Is the dorsal root ganglion part of the CNS or PNS?
PNS because it’s OUTSIDE of the dura mater.
What is the nerve root for the greater occipital nerve?
C2
Does C2 come off above or below the atlas?
BELOW the atlas.
T/F: The 8 cervical nerves come off ABOVE their respective vertebrae.
FALSE. Only C1-C7 come off above the vertebrae. C8 comes off below C7.
What are the two ways to tag the vertebral artery, so far?
- Via Sub-occipital triangle
2. Via Sub-clavian artery (VITC thing)
Which cervical vertebrae has the WIDEST transverse process?
C1 (atlas)
So that obliquus captitis inferior and superior muscles can attach for torsional movement…
What muscle does the greater occipital nerve innervate?
NONE! Greater occipital n. is only sensory!
What muscles do C1 innervate?
Sub-occipital triangle muscles.
Name the spinous processes attached to C1.
NONE.
Spiral groove
radial nerve runs there.
flexors
medial epicondyle
extensors
lateral epicondyle
Which dermatomes are on the hand?
C6 C7 C8
The long head of biceps attaches to the…
supraglenoid tubercle.
The short head of biceps attaches to the…
coracoid process…
What covers and protects the median nerve and brachial artery?
Bicipital aponeurosis
Primary function of biceps?
supination and flexion
Which enhances flexion of biceps?
Supination, not pronation
Ulnar tuberosity…
Brachialis
Does corachobrachialis help with flexion of the forearm?
No. Flexion of arm.
What pierces the coracobrachialis muscle?
Musculocutaneous nerve
What innervates the triceps?
Radial nerve
Which is the workhorse for active resistance - lateral, long, or medial head of triceps?
Lateral head
Which head of the triceps extends the arm?
Long head
What artery perfuses the posterior compartment of arm?
Profunda brachii a.
Superior ulnar collateral a
inferior ulnar collateral a.
Branching of radial a and ulnar occurs where usually?
Cubital fossa
Anterior compartment arm nerve?
musculocutaneous n.
Do ulnar and median n. innervate the arm?
No!
What’s in the medial epicondyle of the humerus?
Ulnar n.
Once the musculocutaneous n. finishes with muscles in anterior compartment, it becomes
lateral antebrachial cutaneous n.
Damage musculocutaneous n…
weak flexion of elbow
What nerve runs with the brachial artery?
Median nerve (rolls over top of brachial a)
What prevents bow-stringing of the tendons in the wrist when you extend the wrist?
Extensor retinaculum
What prevents bow-stringing of the tendons in the wrist when you flex the wrist?
Flexor retinaculum
How many structures run through carpel tunnel?
10 (median nerve + 9 tendons)
Canal of Guyon. What’s in it?
Ulnar artery and ulnar nerve
posterior compartment is smaller or bigger than anterior compartment of forearm?
smaller
Posterior interoseous n. is branch off
radial n.
Superficial flexor muscles of forearm originate on
medial epicondyle of humerus
Which forearm flexor muscle inserts on the thick aponeurosis on the palm?
Flexor carpi ulnaris m.
Thumb flexor
Flexor pollicis longus m.
Two pronators of forearm
pronator terres and pronator quadratus
can the ulna rotate?
no the radius rotates with respect to ulna
Extensors of the forearm are innervated by
radial n
Can the brachioradialis flex elbow?
Yes. It originates from humerus.
What extends the pinky?
Extensor digiti minimi m.
What two muscles supinate the forearm?
Biceps and supinator
What extends the index finger?
extensor carpi radialis longus m.
What three muscles go to thumb?
Extensor pollicus longus m
extensor pollicis brevis m.
Abductor policus longus m.
What runs through the anatomical snuff box?
radial artery
Common interosseous a divides into
anterior and posterior interosseous a; both run closely to the interosseous membrane
Most superficial tendon in forearm, that doesn’t go through carpel tunnel (it pops out)
palmaris longus tendon
Thenar muscles and 1st/2nd lumbrical will hurt if
compress median nerve (carpel tunnel)
What arteries anastomoses around the elbow?
Profunda brachii, superior ulnar collateral a., and inferior ulnar collateral a.
