Hand Flashcards
What are the three bone types in the hand? How many are there?
- Carpals (SLTPTTCH) = 8
- Metacarpals (one for each finger/thumb) = 5
- Phalanges (three for each finger, two for thumb) = 14
Name the joints
Caropmetacarpal joint - location and function
between the carpal and metacarpal bones, saddle shape at the thumb joint increases flexibility
Metacarpophalangeal (MP) joint: location and function(s)
- Between metacarpal and phalanges
- Flexion/extension/abduction: All digits
- Oppose/Repose: Digits 1 and 5
- Adduction: All digits, except digit 3 (middle finger)
Proximal interphalangeal (PIP) joint: function
flexion and extension only
Distal interphalangeal joint (DIP): function
flexion and extension only
Carpal tunnel
- Nerves
- Muscles
- Arteries
- Median nerve only
- Flexor digitorum superficialis (FDS), Flexor digitorum profundus (FDP), Flexor pollicis longus (FPL), Flexor carpi radialis (FCR) –> 4 tendons
- NONE
Movements of the fingers
Movements of the thumb
What are the groups of intrinsic hand muscles?
4 groups
- Thumb muscles
- Little Finger Muscles
- Interosseous muscles
- Lumbrical muscles
What are the thumb muscles? What is the innervation of each?
Mnemonic: :FABO”
- flexor pollicis brevis (thenar muscle = recurrent branch of medial nerve)
- abductor pollicis brevis (thenar muscle = recurrent branch of medial nerve)
- opponens pollicis brevis (thenar muscle = recurrent branch of medial nerve)
- adductor pollicis (deep branch of ulnar nerve)
What are the little finger muscles? Innervations of each?
“FABO”
- Flexor digiti minimi brevis (hypothenar muscle = deep branch of ulnar nerve)
- Abductor digiti minimi (hypothenar muscle = deep branch of ulnar nerve)
- Opponens digiti minimi (hypothenar muscle = deep branch of ulnar nerve)
Interosseous muscles: where are they, functon, and two types
- between metacarpals
- abduction and adduction of the fingers (in reference to the middle finger)
- Palmar interossei and dorsal interossei
Palmar interossei
What does it do, where is it, what innervates it.
- Adducts the digits (“PAD”)
- Present in all fingers, except middle (No adduction for middle) = three total
- Deep branch of the ulnar nerve
Dorsal interossei
What does it do, where is it, what innervates it.
- Abducts the digits (DAB)
- 2 in the middle, 1 in index and ring fingers (4 total)
- Deep branch of the ulnar nerve
Lumbricals: OINA
- Origin: Flexor digitorum profundas (FDP)
- Insertion: Extensor expansion
- Innervation: Lateral 2 lumbricals= median nerve, Medial 2 lumbricals= deep ulnar nerve
- Action: Flex the MP joints + Extend the IP joints (Form the L-shape for writing, “L-shape for lumbrical”)
Draw the pathway of the MC nerve.
Draw the pathway of the radial nerve.
Draw the pathway of the median nerve.
Draw the pathway of the ulnar nerve.
Draw the pathway of the brachial artery (major artery of the arm).
Draw the pathway of the superficial veins.
What are the dermatomes of the hand?
C6: Thumb
C7: index and middle finger
C8: ring and little finger
Define terms:
- Palmar metacarpal arteries
- Vena comitantes
- Perforating veins
- Connect the deep arch to the common digital arteries (of the superficial arch)
- Deep veins that follow arteries (brachial vein with brachial artery)
- Deep vein that connects deep and superficial veins
Synovial sheathes - function, types, where is it continuous?
- Allow tendons to move freely
- Common flexor sheath - tendons in the carpal tunnel
- Fibrous digital sheath - surround each digits to prevent bowstringing (tendons coming off bones)
- Digital sheath of the pinky continuous with the common flexor sheath => infections can spread
Extensor Expansion/Hood: Function, Bands, and what inserts on it
- dorsal aponeurosis holds tendons in place
- Central band inserts on middle phalanx, Lateral bands converge on distal phalanx
- Extensor digitorum insert on the central band, Lumbricals and Interosseous muscles insert on the lateral band
Which bone moves during supination and pronation?
The radius (all muscles that cause supination/pronation MUST insert on the radius)
Supination: biceps brachii and supinator
Pronater; Pronater Teres
Which nerves have no branches in the arm?
Median and ulnar
What is innervated by the deep ulnar nerve?
- Hypothenar muscles
- Interosseus muscles
- Medial two lumbricals
- Adductor pollicis (Non-thenar muscle)
What is innervated by the MC nerve?
Only three muscles
- Coracobrachialis (pierces)
- Biceps brachii (passes under)
- Brachialis (passes over)
What are the lumbricals innervated by?
Deep ulnar nerve (medial two digits)
AND proper palmar digital branch of the median nerve (lateral two digits)
- Major arterial blood supply to the thumb?
- Major blood supply to the digits 2-5?
- Where does the superficial arch receive blood?
- Princeps pollicis artery (end of radial artery)
- Superficial palmar arch (from ulnar artery)
- Both ulnar and radial arteries
