Forearm, Wrist, Hand (+muscles) Flashcards
what makes up the proximal and distal radioulnar joint
proximal = radial tuberosity (radius) + radial notch
distal = ulnar head(ulnar) + ulnar notch
both are synovial pivot joints
what attaches to radial styloid process
brachioradialis muscle
origin = lateral, distal supercondylar ridge of humerus
what type of joint is the interosseous membrane between radius and ulnar
Syndesmosis (fibrous joint)
colles’ fracture
complete transverse fracture within the distal 2cm of the radius
(most common fracture of forearm)
racture results from forced dorsiflexion of the hand, usually as the result of trying to ease a fall by outstretching the upper limb
why are forces (e.g Fall) on outstretched hand transmitted through the radius ?
wrist joint( =radio-carpal joint) involves only the articulation of the distal end of the RADIUS with the Scaphoid and Lunate bones.
Why is a fracture of the scaphoid commonly associated with avascular necrosis of the PROXIMAL fragment?
middle and distal part of scaphoid bone receives blood supply from dorsal and palmar branches of radial artery
but neglects the proximal portion - it relies on the retrograde flow (if fractured, no retrograde flow)
which carpal bone is a sesamoid bone
pisiform in the tendon flexor carpi ulnaris
which is deeper:
palmar carpal ligament or Flexor retinaculum (transverse carpal ligament)
Flexor retinaculum (transverse carpal ligament)
what nerve is within the carpal tunnel
median
what kind of joint is the 1st carpometacarpal joint (thumb)
saddle (synovial)
what muscles form the lateral and medial borders of antecubital fossa
medial border = pronator teres
lateral = brachioradialis
superficial venous system of arm
dorsal venous network of hand—> basilic and cephalic veins
basilic vein travels anterior, medial side of arm and then goes deep to join with brachial vein to form axillary vein
cephalic vein travels anterior, lateral, superficial —> delta-pectoral groove
between basilica and cephalic = median cubital vein
bicipital aponeurosis
found in cubital fossa
from bicep brachii tendon to antebrachial fascia (so travels inferior-medially)
used to be known as the “Grace à Dieu” fascia by the barber- surgeons
anterior superficial muscles forearm
- pronator teres
- flexor carpi radialis
- palmaris longus
- flexor carpi ulnaris
anterior intermediate muscles of forearm:
-flexor digitorum superficialis
anterior deep muscles forearm
- flexor pollicis longus
- flexor digitorum profundus
- pronator quadratus
borders of anatomical snuffbox
Medial border = extensor pollicis longus tendon
Lateral border = abductor pollicis longus tendon + extensor pollcis brevis
Proximal border = styloid process of radius
floor = triquetrium and scaphoid carpals
roof = skin
posterior deep forearm muscles
- supinator
- abductor pollicis longus
- extensor pollicis brevis
- extensor pollicis longus
- extensor indicis
posterior superficial forearm muscles
- brachia’s
- extensor carpi radialis longus
- extensor carpi radialis brevis
- extensor digitorum
- extensor digiti minimi
- extensor carpi ulnaris
- anconeus
what superficial vein and nerve run within anatomical snuffbox
superficial branch of radial nerve
cephalic vein
what is flexor retinaculum attached to
tubercle of trapezium —> hook of hamate/pisiform
Which structures pass superficial and deep to the flexor retinaculum?
Superficial Structures:
- Ulnar nerve
- Ulnar artery
- Palmar cutaneous branch of ulnar nerve
- Palmaris longus
- Palmar cutaneous branch of median nerve
Deep Structures:
- Flexor digitorum superficialis
- Flexor digitorum profundus
- Median nerve
- Flexor pollicis longus
- Flexor carpi radialis
blood supply in forearm and hand
posterolateral = radial artery
anteromedial = ulnar artery
ulnar artery also –>anterior and posterior interosseous arteries, which supply deeper structures in the forearm
radial artery travels dorsally—> superficial palmar arch—> deep palmar medially
ulnar travels anteriorly –> deep palmar –> superficially laterally
muscles of the thenar and hypothenar eminences
Thenar eminence:
○ Abductor pollicis brevis
○ Flexor pollicis brevis
○ Opponens pollicis
Hypothenar eminence (OFA):
○ Opponens digiti minimi
○ Flexor digiti minimi brevis
○ Abductor digiti minimi
lumbricals
interossei muscles of hand
Lumbricals – flexion at metacarpophalangeal joint + extension interphalangeal joint
- There are 4 (index = 1)
- 1&2 originate from their respective tendon of flexor digitorum profundus
- 3 - from tendons to middle and ring finger
- 4 - from tendons to ring and little finger
- They all insert on the lateral side of finger
interossei muscles are deeper:
Palmar interossei - ADDUCTION and flexion at metacarpophalangeal joint whilst simultaneously extending at interphalangeal joint
- There are 3 (index,ring and little finger)
- From palmar metacarpal to the medial base of proximal phalanx
Dorsal interossei - ABDUCTION and flexion at metacarpophalangeal joint whilst simultaneously extending
- There are 4 (index, 2 on middle and ring)
- They originate from 2 metacarpals and insert to lateral base of proximal phalanx (but for middle its on both sides)
