MSK - Intrinsic Hand Muscles Flashcards
What are the thenor and hypothenor muscles?
The thenor muscles - thumb side
Hypothenor - little finger side
What are the intrinsic hand muscles?
These are muscles that originate in the hand and are responsible for precision grip.
What lies between the thenor and hypothenor muscles?
The flexor retinaculum
What are the three muscles on the palmar side that control the movement of the thumb? And what nerve innervates these
Opponens pollicis
Abductor pollicis brevis
Flexor pollicis brevis
Median nerve
What are the three hypothenor muscles that act on the little finger?
Abductor digiti minimi
Flexor digiti minimi brevis
Opponens digiti minimi
What does the Palmaris brevis do?
Tenses ulnar side of Palm
Creating a hollow in the palm
What does the adductor pollicis do?
Adducts the thumb
Where are the lumbricals found?
Inbetween the FDP tendons
Look like ‘worms’
What is the action of the lumbrical muscles?
Flex at the MCP joint
Extend at the IP joint
They originate on the FDP tendon
YES BOYS!
What do the palmar interosseous muscles do?
Adduct the fingers
What do the dorsal interosseous muscles do?
Abduct the fingers (index middle and ring)
How would you test for palmar IO muscle function?
Stop me pulling this ruler out of your adducted fingers
How would you test for dorsal IO muscle function?
Stop me closing your fingers together
Where does the median nerve supply?
The first 3.5 fingers palmar surface and the nail beds
This means it supplies the first 2 lumbicles and the hypothenor muscles.
Where does the ulnar nerve run in the hand?
Last 1.5 fingers
Supplies the rest of the hand muscles
Where does the radial nerve run in the hand?
To the cutaneous areas of the dorsal hand surface (skin sensation)
Which two arteries from the forearm run distally into the hand?
The ulnar and the radial artery
What are the arches of the hand arteries?
The superficial palmar arch is the main termination of the ulnar artery
The deep palmar arch formed from the radial artery and the deep branch of the ulnar artery
What is the digital artery supply?
The common palmar digital arteries
Palmar digital artery (little finger)
What is the venous drainage of the hand?
The superficial and deep venous arches drain into the deep vein of forearm.
Dorsal venous network drains into the cephalic from lateral side, basillic arises from the medial side.
What structures are in the carpal tunnel?
9 tendons - 4 from the flexor digitorum profundus 4 flexor digitorum superficialis 1 flexor pollicus longus Median nerve
What is carpal tunnel syndrome?
This is when one of the nine structures enlarges and compresses the median nerve.
What are the symptoms of CT syndrome?
Individuals with this cannot
Oppose their thumbs
Difficulty with grip
They have a weakened thumb
