Anatomy Flashcards
What innervates the flexor muscles of the forearm?
The median nerve
The deepest muscles of the forearm perform what motion?
Rotation (pronation/supination)
The brachial artery bifurcates into what two arteries?
Ulnar and radial arteries
Which artery provides most of the blow flow to the hand?
Ulnar
Which muscle allows the “hitch hiker” thumb?
Extensor pollicus longus
The extra tendons on the small and index fingers are always found where?
The ulnar side of their redundant tendons
What innervates the extensors of the forearm?
The radial nerve
Which carpals articulate with the radius?
Scaphoid and the lunate
Which carpals articulate with the thumb?
Trapezium
Which carpals articulate with the ulna?
None
What are you concerned about with a fall on an outstretched hand?
Scaphoid fracture
Which metacarpals are fixed?
first and second digits (index and middle finger)
Why are fingers mobile in extension and tight on flexion?
Collateral ligaments
- only true for joint between metacarpal and 1st phalynx
- ligament tension is equal in flexion and extension for proximal interphalangeal joint
What are the prime flexor of the hand (make a fist)
Interosseous muscles
What is the purpose of the palmar aponeurosis?
for non-slip power grip
What are the thenar muscles? (3)
Abductor pollicis brevis
Flexor pollicis brevis
Opponens pollicis
What are the hypothenar muscles? (3)
Abductor Digiti Minimi
Flexor Digiti Minimi Brevis
Opponents Digiti Minimi
Which muscle is key for pinching?
Adductor Pollicis (along with 1st dorsal interosseus muscle); both controlled by ulnar nerve
Which is the last muscle innervated by the median nerve?
Opponens pollicis
Which is the last muscle innervated by the ulnar nerve?
Middle finger (wiggle side to side)
Ulnar nerve palsy
- can’t pinch thumb and forefinger together (atrophy of interosseus muscles)
- last two digits are clawed (not first 2 because median nerve are still intact)
Carpal Tunnel
median nerve is compressed
- atrophy of thenar muscles over time
- nighttime splinting is classic treatment
What is a dermatome?
the area of skin supplied by a cutaneous branches from a single spinal nerve
What is a myotome?
all muscles derived from one somite and innervated by one segmental spinal nerve