wrist Flashcards
what does the wrist joint act as and allow?
- acts as pivot point that can move in almost any direction
- can grab and touch objects
what are the main bones around the wrist joint and where are they ?
- radius always on thumb side (lateral)
- ulnar always on pinkie side (medial)
what is the acronym for carpal bones?
- some lovers try positions that they cannot handle
- so long to thumb, hear comes pinky
what are the 8 carpal bones?
- scaphoid
- lunate
- triquetrum
- pisiform
- hamate
- capitate
- trapezoid
- trapezium
what bone won’t you see on a posterior diagram?
- pisiform bone
- more anterior
what is the carpal tunnel?
- path between hook of hamate, trapezoid and trapezium
what is the carpal tunnel formed by?
- transverse carpal ligament
- flexor retinaculum
what is the carpal tunnel between?
- pisiform/ hamate
- trapezium/ scaphoid
what is the flexor retinaculum?
- band of fibrous connective tissue that covers the anterior side of the carpal tunnel
what is the median nerve?
- forearm nerve
what does the median nerve cause when pinched?
- carpal tunnel syndrome
what do tendons help with?
- help move the finger
what are metacarpals?
- bones of the hand
what is the thumb called?
- pollex
what do some metacarpals articulate with? - give an example
- some articulate with multiple carpals
e.g., 4th metacarpal
what are phalanges?
- bones of the fingers
what do the 2nd to 5th metacarpals contain?
- proximal
- middle
- distal phalanges
what phalanges does the pollex contain?
-proximal and distal
what are the 5 joints of the wrist/ hand?
- radiocarpal (RC)
- carpometacarpal (CMC)
- metacarpophalangeal (MCP)
- proximal interphalangeal (PIP)
- distal interphalangeal (DIP)
what is the radiocarpal joint?
- between the radius and scaphoid & lunate and triquetrum
what type of joint is the radiocarpal joint?
- condyloid joint
- allows 2 degrees of motion
- flexion/ extension
- adduction/ abduction
what other type of joint is the radiocarpal joint?
- synovial joint contains articular cartilage and synovial fluid
- articular disc extends from articular cartilage of radius to cover some of the ulna
what is the carpometacarpal joint?
- joint between carpals and metacarpals
what is the 1st carpometacarpal joint?
- trapeziometacarpal joint
- between trapezium and 1st metacarpal
- saddle joint so it allows plenty of movement
what movement is allowed in the 1st carpometacarpal joint?
- flexion
- extension
- abduction
- adduction
- opposition
what is the carpometacarpal joint between 2nd to 5th?
- condyloid joint
- varying degrees of motion
how much motion is allows in 2-3 carpometacarpal joint compared to 4-5?
- 2 to 3 allows no motion whereas 4 to 5 allows little flexion and extension
what is the metacarpophalangeal joint?
- joints of the knuckles
- between metacarpals and phalanges
what type of joint is metacarpophalangeal joint and what does it allow?
- condyloid joint
- allows flexion and extension as well as spreading of the fingers
what type of joints are interphalangeal joints and what does it allow?
- hinge joints
- allows one degree of motion
- flexion/ extension
how many interphalangeal joints do the fingers contain?
- thumb only has one interphalangeal joint
- 2-5 contain both
what do ligaments provide?
- stability of radiocarpal joint
what are the 4 main ligaments?
- radial collateral ligament
- ulnar collateral ligament
- palmar radiocarpal ligament
- dorsal radiocarpal ligament
what is radial collateral ligament? what does it prevent?
- connects styloid process to tubercle of scaphoid bone
- prevents adduction
what is ulnar collateral ligament? what does it prevent?
- has two parts that connects the ends of the ulnar with the pisiform and triquetrum
- prevents over abduction
what is the palmar radiocarpal ligament? what does it prevent?
- series of 4 ligaments
- prevents over extension
what are the four ligaments of the palmar radiocarpal ligament?
- radioscaphocapitate
- radioscapholunate
- long radiolunate
- short radiolunate
what is the dorsal radiocarpal ligament? what does it prevent?
- connects radius to triquetrum
- prevents over flexion
what is the interosseous membrane?
- made up of 5 ligaments that limit supination of forearm
- allows multiple forearm muscles to attach
where are flexors found?
- anteriorly
what are the 6 flexors?
- flexor pollicis longus
- flexor digitorum profondus
- flexor digitorum superficialis
- palmaris longus
- flexor carpi ulnaris
- flexor carpi radialis
where does flexor pollicis longus originate and insert?
- originates at anterior surface of radius
- inserts into distal phalanx of thumb
where does flexor digitorum profoundus originate and insert?
- originates at proximal 3/4 of ulna
- inserts into distal phalanx of digits 2-5
where does flexor digitorum superficialis originate and insert?
- originates at medial epicondyle of humerus
- inserts into middle phalanges of fingers
where does palmaris longus originate and insert?
- originates at medial epicondyle
- inserts into palmar aponeurosis
where does flexor carpi ulnaris originate and insert?
- originates at medial epicondyle of the humerus
- inserts into hook of hamate and anterior side of proximal 5th metacarpal base
where does flexor carpi radialis originate and insert?
- originates at the medial epicondyle of humerus
- inserts into anterior side of proximal 2nd and 3rd metacarpal
where are the extensors located?
- posterior aspect
what are the 10 extensors?
- extensor carpi ulnaris
- extensor carpi radialis longus
- extensor carpi radialis brevis
- extensor digitorum
- extensor digiti minimi
- extensor digiti ulnaris
- extensor indicis
- extensor pollicis longus
- extensor pollicis brevis
- abductor pollicis longus
where does extensor carpi ulnaris originate and insert?
- originates at lateral epicondyle of humerus
- inserts onto posterior side of the 5th metacarpal
where does the extensor carpi radialis brevis originate and insert?
- originates at the lateral epicondyle of humerus
- inserts onto posterior side of the 3rd metacarpal base
where does extensor carpi radialis longus originate and insert?
- originates superior to lateral epicondyle of humerus
- inserts into posterior 2nd metacarpal base
where does extensor digitorum originate and insert?
- originate at lateral epicondyle
- inserts into dorsal digital expansion
where does extensor digiti minimi originate and insert?
- originates at lateral epicondyle
- inserts into dorsal digital expansion to extend the little finger
where does extensor carpi ulnaris originate and insert?
- originates at lateral epicondyle
- inserts into base metacarpal V
where does extensor indices originate and insert?
- originates at the posterior surface of ulna & interossous membrane
- inserts into extensor expansion of 2nd digit
where does extensor pollicis longus originate and insert?
- originates at posterior surface of ulna
- inserts into posterior surface of base of distal phalanx of thumb
where does the extensor pollicus brevis originate and insert ?
- originates at posterior surface of lower middle radius
- inserts into base of proximal phalanx of thumb
where does the abductor pollicus longus originate and insert?
- contributes to extension of the wrist and abduction of the thumb
- goes from ulna and radius to the base of the 1st metacarpal
what are the two ulnar deviators?
- flexor carpi ulnaris
- extensor carpi ulnaris
what are the four radial deviators?
- flexor carpi radialis
- extensor carpi radialis longus
- extensor carpi radialis brevis
- abductor pollicis longus
what are the two pronators?
- pronator quadratus
- pronator teres
where does the pronator quadratus originate and insert?
- originates at anterior aspect of distal 1/4 of ulna
- inserts into distal 1/4 of radius
where does the pronator teres originate and insert?
- originates at medial super condyle of humerus
- coronoid process of ulna
- inserts into lateral surface of mid shaft radius
what are the two supinators ?
- biceps brachii
- supinator
where does the biceps brachii originate and insert?
- short head originates at tip of coracoid process
- long head originates at supraglenoid tuberosity
- inserts into tuberosity of radius
where does the supinator oirginate and insert?
- originates at the lateral epicondyle and supinator crest of humerus
- inserts into lateral proximal end of radius
what is the anatomical snuffbox created by?
- extensor pollicis longus, extensor pollicis brevis and abductor pollicis longus
