Week 10 Wrist and flexors (anterior compartment of the forearm) Flashcards
distal carpal bones from lateral to medial
tripezium: most irregular bone in the carpus, four sided, tubercle
tripezoid: wedge shaped
capitate: largest bone in the carpus
hamate: wedge shaped, hook of hamate
flexor retinaculum
laterally, medially
laterally: scaphoid tubercle, tubercle of trapezium
medially: pisiform, hook of hamate
Flexor retinaculum is a strong fibrous band which bridges the anterior concavity of the carpal bones thus converts it into a tunnel, the carpal tunnel.
joint classification of proximal row and distal row of carpal bones
synovial plane joint
bone and articular surfaces of proximal row and distal row of carpal bones (individual joints between)
scaphoid, lunate, triquetrum, pisiform
tripezium, tripezoid, capitate, hamate
ligaments and movements of proximal row and distal row of carpal bones
ligaments:
- interosseous intercarpal
–> proximal row: scapholunate ligament, lunotriquetral ligament
- palmar intercarpal
- dorsal intercarpal
movements:
minimal
joint classification of mid carpal joint
- synovial plane joint
- acts as functional unit
- slightly convex (laterally), slightly concave (medially)
- anatomically separate from the wrist (radiocarpal) joint
bones and articular surfaces, fibrous capsule of midcarpal joint
bones and articular surfaces:
proximally: scaphoid, lunate, triquetrum
distally: trapezium, trapezoid, capitate, hamate
fibrous capsule: continuous synovial lining
ligaments of midcarpal joint
palmar intercarpal
dorsal intercarpal
interosseous intercarpal
radial collateral
ulnar collateral
movements of midcarpal joint
flexion/ extension
abduction/ adduction (radial/ ulnar deviation)
proximal and distal attachment of pronator teres (PT)
ulnar and humeral head
proximal:
ulnar head: coronoid process
humeral head: medial epicondyle of humerus (common flexor origin)
distal:
middle of convexity of lateral surface of radius
innervation of PT
median nerve (C6, C7)
main action of PT
pronates and flexes forearm (at elbow)
proximal and distal attachment of flexor carpal radialis (FCR)
proximal:
medial epicondyle of humerus (common flexor origin)
distal:
base of 2nd metacarpal
innervation of FCR
median nerve (C6, C7)
main action of FCR
flexes and abducts hand (at wrist)
proximal and distal attachment of palmaris longus (PL)
proximal:
medial epicondyle of humerus (common flexor origin)
distal:
distal half of flexor retinaculum and apex of palmar aponeurosis
innervation of PL
median nerve (C7, C8)
main action of PL
flexes hand (at wrist) and tenses 拉緊 palmar aponeurosis
proximal and distal attachment of flexor carpi ulnaris (FCU)
proximal:
ulnar head: olecranon and posterior border of ulna (via aponeurosis)
humeral head: medial epicondyle of humerus (common flexors origin)
distal:
pisiform, hook of hamate, 5th metacarpal
innervation of FCU
ulnar nerve (C7, C8)
main action of FCU
flexes and adducts hand (at wrist)
proximal and distal attachment of flexor digitorum superficialis (FDS)
proximal:
humero-ulnar head: medial epicondyle (common flexor origin and coronoid process)
radial head:
superior half of anterior border
distal: shafts of middle phalanges of medial 4 digits
innervation of FDS
medial nerve (C7, C8, T1)
main action of FDS
- flexes middle phalanges at proximal IP joint of middle four digits
- acting more strongly
- flexes proximal phalanges at MCP joints
proximal and distal attachment of flexor digitorum profundus (FDP)
proximal:
proximal 3/4 of medial and anterior surfaces of ulna and interosseous membrane
distal:
medial part: bases of distal phalanges of 4th and 5th digits
lateral part: bases of distal phalanges of 2nd and 3rd digits
innervation of FDP
medial part: ulnar nerve (C8, T1)
lateral part: anterior interosseous nerve, from median nerve (C8, T1)
main action of FDP
medial part: flexes distal phalanges 4 and 5 at distal IP joints
lateral part: flexes distal phalanges 2 and 3 at distal IP joints
proximal and distal attachment of flexor pollicis longus (FPL)
proximal:
anterior surface of radius and adjacent interosseous membrane
distal:
base of distal phalanx of thumb
innervation of FPL
anterior interosseous nerve, from median nerve (C8, T1)
main action of FPL
flexes phalanges of 1st digit (thumb)
proximal and distal attachment of pronator quadratus (PQ)
proximal:
distal 1/4 of anterior surface of ulna
distal:
distal 1/4 of anterior surface of radius
innervation of PQ
anterior interosseous nerve, from median nerve (C8, T1)
main action of PQ
- pronates forearm
- deep fibers bind radius and ulna together
which muscles attach to medial epicondyle of humerus (common flexor origin)
PT (humeral head),
FCR
PL
FCU (humeral head)
FDS (humero-ulnar head)
muscles in 1st-4th layer (from lateral to medial) (from superficial to deep)
1st layer: PT, FCR, PL, RCU
2nd layer: FDS
3rd layer: FPL, FDP
4th layer: PQ
which muscles are in ulnar nerve in anterior compartment of forearm
FCU
FDP (medial part)
courses and branches of the median nerve in the flexor compartment of the forearm
- medial to brachial artery (cubital fossa)
- leaves cubital fossa through pronator teres
- passes deep to FDS
- at wrist – becomes superficial
- gives off anterior interosseous in distal part of cubital fossa
courses and branches of ulnar nerve in the flexor compartment of the forearm
- enters forearm through FCU
- continues between FCU and FDP
- runs on medial side of ulnar artery
- at wrist – becomes superficial
- enters the hand via Guyon’s canal (between pisiform and hook of hamate)
course and extent of the radial and ulnar arteries, anterior interosseous artery
radial artery:
- over to pronator teres
- runs deep to brachioradialis
- superficial near the wrist
- passes through the anatomical snuffbox
ulnar artery
- deep to pronator teres
- deep to arch of FDS
- branches: common interosseous, recurrent and muscular
anterior interosseous artery
- from common interosseous artery
borders, roof, floor, contents of carpal tunnel
borders: scaphoid, trapezium, hook of hamate, pisiform
roof: flexor retinaculum
floor: carpal bones, anterior ligament of wrist
contents:
- median nerve
- 9 tendons and their synovial sheaths:
tendon of FDS x4, FDP x4, FPL x1
- tendon of FCR (separate in the roof)
synovial sheaths: highly vascularized, easy to swelling
