Lecture 18. Muscles in the forearm+hand Flashcards
What divides the compartments of the forearm?
ulna, radius, interosseus membrane
What supplies muscles of the anterior compartment of the forearm
ulnar or median
What supplies muscles of the posterior compartment of the forearm
radial nerve
What are the layers of the anterior compartment of the forearm? How many muscles are there in the anterior part of the forearm?
superficial, intermediate, deep.
has 11 muscles
What is the common origin of most of the muscles of the anterior compartment of the forearm?
medial epicondyle of the humerus, has the common flexor of tendon
What is the O,I,F,I of the pronator teres
O: medial epicondyle, common flexor of tendon I: radius F: pronation of forearm I: median nerve - SUPERFICIAL MUSCLE
What is the tendon near the medial epicondyle where most of the muscle’s origin are located
common flexor tendon
What is the O,I,F,I of the flexor carpi radialis
O: medial epicondyle of humerus
I: base of first and second metacarpal bone
F: flexion and abduction of wrist ( abduction of wrist= radial deviation)
I: median nerve
- SUPERFICIAL MUSCLE
What is the flexor retinaculum
thick band of C.T. holds the tendons in place so muscles when working they don’t bow anteriorly, adds to efficiency of flexor muscles
What is the only muscle in the intermediate layer of the anterior compartment of the forearm
flexor digitorum superficialis
What is the O,I,F,I of the flexor digitorym superficialis
O: medial epicondyle of humerus
I: * Base of the middle phalanges of fingers 2 -5 ( don’t go to thumb)
F: flexion of wrist and fingers (joints: metacarpophalangeal, proximal interphalangeal joints) , can maybe flex the elbow a little
I: median nerve
What is the O,I,F,I of the flexor digitorum profundus
O: ulna I: distal phalanges of fingers 2 to 5 F: flexion of wrist PRIME MOVER: of wrist flexion and finger flexion ( both PIP, DIP,MCP): help with power grip not fine movement I: fingers 2,3: median nerve fingers 4,5 : ulnar nerve DEEP LAYER of forearm
What is the O,I,F,I of the brachioradialis
O: humerus
I: styloid process of radius
F: flexion of elbow
I: radial nerve
What is the only muscle found in the anterior part but is considered a muscle in the posterior compartment?
Brachioradialis
What is the O,I,F,I of the extensor digitorum
O: lateral epicondyle of humerus
I: middle and distal phalanges of fingers 2-5
F: PRIME MOVER: extension of wrist and fingers of MCP ,ICP ( metacarpophalangeal and interphalangeal joint) of fingers 2 to 5.
I: radial nerve
How many layers are present in the posterior compartment of the forearm?
2 layers: superficial and deep
What is the O,I,F,I of the extensor carp ulnaris
O: lateral epicondyle
I: fifth metacarpal
F: extension of wrist, ulnar deviator, adduction of wrist
I: radial nerve
-SUPERFICIAL layer of posterior compartment of forearm
What is the O,I,F,I of the supinator
O: ulna
I: radius
F: supination of forearm ( not prime mover,
I: radius
deep layer of posterior compartment of forearm
What is the O,I,F,I of the extensor pollicis longus
O: ulna
I: distal phalanx of thumb
F: prime mover of extension of thumb ( interphalangeal and metacarpophalangeal joints)
I: radial nerve
How many muscles are present in the hand
19
What are the intrinsic muscles of the hand for
fine movement of the hands
What are the 3 groups of intrinsic muscles of the hand
thenar, hypothenar, central groups
Describe the thenar muscles
found at the base of the thumb, cause flexion, abduction and opposition of thumb, innervated by median nerve
Describe the hypothenar muscles
found at the base of the 5th finger: flexion, opposition,
innervated by ulnar nerve
Describe the central muscles of the hand
- consists of lumbricals
- palmar and dorsal interossei
Describe the lumbricals
- have 4 of them in each hand O: tendon of flexor digitorum profundus I: proximal pharynx of fingers F: flex the MCP, IP-joints I: ulnar median nerves
Describe the dorsal interossei
will do adduction of fingers 2,4,5
-DAB : dorsal => abduction
O: metacarpal bone
I: proximal phalanges
Describe the palmar interossei
will do abduction of all four fingers
-PAD: palmar => adduction
O: metacarpal bone
I: proximal phalanges
EXAM: What is the most important nerve for the innervation of the hand
ulnar, out of 19 , 14 are innervated by ulnar
What is a transitional region
region of upper or lower limb which major blood vessels or nerves pass from one region to another
What are the 3 transitional areas of the upper limb
axilla
cubital fossa
carpal tunnel
What is the axilla
major blood vessels from aorta have to pass through axillary fossa
What is the cubital fossa
triangle space
major nerve: median nerve pass through fossa
brachial artery passes through it
What is the carpal tunnel
tunnel of the carpal bone, where the flexor retunaculum covers the bony tunnel , median nerve and flexor muscles passes through ut
