Posterior forearm, Dorsum of hand, Joints of upper limb Session 30 Flashcards
what innervates the posterior forearm
radial nerve
what r the two layer of muscles in the posterior forearm
superficial and deep
what r the 6 superficial muscles in the posterior compartment
brachioradialis extensor carpi radialis longus and brevis extensor digitorum extensor digiti minimi extensor carpi ulnaris
where do the superficial layer of muscle in the posterior compartment attach to
lateral epicondyle of the humerus
where is brachioradialis located and where does it insert
boundary between posterior and anterior compartments
inserts onto distal radius
action of brachioradialis
weak flexor of elbow joint
what r the insertions of the extensor carpi radialis longus and brevis
longus= 2nd metacarpal (index) brevis= 3rd metacarpal (middle)
actions of extensor carpi radialis longus and brevis
extend and abduct wrist
where does extensor digitorum insert onto
onto dorsal aspects of all four fingers
why is it difficult to fully extend the middle or ring finger independantly
tendons of extensor digitorum r connected by fibrous bands
where is the insertion and what is the action of extensor digiti minimi
inserts onto dorsum of pinky
extends little finger
what is the insertion and action of extensor carpi ulnaris
5th metacarpal
extends and adducts the wrist
what travels under the extensor retinaculum and what is the retinaculums function
all muscle tendons
prevents tendons from bowing when wrist is extended
what r the 5 deep muscles of the posterior compartment
supinator abductor pollicis longus extensor pollicis brevis extensor pollicis longus extensor indicis
what is the origin of the deep muscles and what is the exception
forearm bones and interosseous membrane
exception: supinator
what is the attachment of supinator and its interaction with the radius
origin from lateral epicondyle of the humerus
wraps around upper part of radialis
what three posterior forearm muscles r not extensors
brachioradialis
supinator
abductor pollicis longus
what is the action of supinator
supinates forearm
action and insertion of abductor pollicis longus
abducts thumb
inserts onto 1st metacarpal
what two muscles extend the thumb
extensor pollicis brevis and longus
what is the insertion and movements of extensor pollicis brevis
proximal phalanx
extends the metacarpalphalangeal joint
what is the insertion and movements of extensor pollicis longus
inserts onto distal phalynx
extends the interphalangeal joint of thumb (only muscle that can do this)
what is the insertion and action of extensor indicis
inserts onto dorsum of index finger
independant extension of index finger
what is the only intrinsic muscle on the dorsal aspect of the hand (group of muscles)
dorsal interossei
where do the veins drain into 1) the hand 2) the forearm
1) into the dorsal venous network on the back of the hand
2) cephalic vein laterally and basilic vein medially
how do the tendons of the digits and the extensor hoods interact and what is the purpose of this
tendons of extensor digitorum, indicis and digiti minimi insert onto dorsal aspect of extensor hoods
keeps tendons fixed in midline
what is the insertion of lumbricals and interossei onto extensor hoods and what joint do they extend
insert into side of proximal parts of extensor hoods
extension of interphalangeal joints of fingers
where/what is the anatomical snuffbox and when can it be seen best
triangle shaped depression between thumb and wrist
seen when thumb is extended as much as possible
what r the boundaries of the anatomical snuffbox
medial: tendon of extensor policis longus
lateral: tendons of extensor pollicis brevis and abductor pollicis longus
what lies in the floor of the anatomical snuffbox (1)
what arises here (1)
what passes through (1)
what passes over (1)
scaphoid lies in floor
radial artery passes through it
superficial branch of radial nerve passes over it
cephalic vein arises here
what is the ulnar artery usually accompanied with (posterior compartment)
deep veins
what type of joint is the shoulder joint and what is it formed between
synovial ball and socket
glenoid fossa of scapula and head of humerus
what four things increase stability of the shoulder joint
ligaments
glenoid labrum (rim of fibrocartilage that deepens glenoid fossa)
rotator cuff muscles
tendon of long head of biceps (inserts onto supraglenoid tubercle of scapula)
what type of joint is the elbow joint
synovial hinge joint
what 2 pairs of structures form the elbow joint
trochlea of humerus and trochlear notch of ulnar
capitellum of humerus and radial head
what reinforces the elbow joint
ulnar and radial ligaments
what type of joint is the radioulnar joint
synovial pivot type joint
how does the radius rotate around the ulnar and what movement is this
radial head rotates in the annular ligament
pronation
what type of joint is a wrist joint
condyloid synovial joint
what structures form the wrist joint
distal radius and scaphoid and lunate
what capsule is the wrist joint and what is it reinforced by
joint capsule which is also reinforced by ligaments
what type of joints r interphalangeal joints and how r they reinforced
synovial hinge
by ligaments
what type of joints r interphalngeal joints
hinge joints
what type of joints r metacarophalangeal joints
condyloid joints
what type of joint is the first carpometacarpal joint (thumb) and between which bones is it located
saddle joint
between trapezium and 1st metacarpal
what structure reinforces the joints of the hand between bones (hint: same as everything else)
ligaments
what is the insertion of the tendon of long head of biceps
inserts onto supraglenoid tubercle of scapula
