E1D Flashcards
Anterior compartment of the forearm
forearm cutaneous innervation
lateral antebrachial cutaneous
medial antebrachial cutaneous
posterior antebrachial cutaneous
lateral antebrachial cutaneous
branch of musculocutanous
medial antebrachial cutaneous
branch of medial cord
posterior antebrachial cutaneous
branch of radial nerve
superficial veins of forearm
cephalic vein (lateral)
basilic vein (medial)
median cubital vein
median antebrachial vein
median cubital vein
- lies superficial to cubital fossa (in superficial fascia)
- runs superiorly and medially from cephalic vein to basilic vein
- frequently used for venipuncture
median antebrachial vein
ascends along anterior midline of forearm and drains into median cubital vein
forearm compartments
divided by interosseous membrane
anterior (flexor and pronator mm.)
posterior (extensor and supinator mm.)
flexor retinaculum
(transverse carpal ligament
- strong fibrous band on anterior aspect of wrist
- transforms anterior, concave surface of carpus into an osteofibrous tunnel (carpal tunnel/canal); holds median nerve and tendons of long flexor muscles of thumb and fingers (surrounded by their synovial sheaths)
- laterally, it splits into two laminae (superficial and deep) that create a separate tunnel for tendon of flexor carpi radialis (with its synovial sheath)
flexor retinaculum attachments
medially to pisiform and hook of hamate
laterally to scaphoid and trapezium
superficial layer
of the anterior compartment
of the forearm
pronator teres
flexor carpi radialis
palmaris longus
flexor carpi ulnaris
intermediate layer
of the anterior compartment
of the forearm
flexor digitorum superficialis
deep layer
of the anterior compartment
of the forearm
flexor pollicis longus
flexor digitorum profundus
pronator quadratus
innervation of the muscles of the anterior compartment of the forearm
all muscles are supplied by median nerve, except flexor carpi ulnaris and medial half of flexor digitorum profundus, which are supplied by ulnar nerve
pronator teres origin
humeral head: common flexor tendon (attached to medial epicondyle of humerus)
ulnar head: medial aspect of coronoid process
pronator teres insertion
middle part of lateral surface of shaft of radius (pronator tuberosity)
pronator teres innervation
median nerve passes between two heads as it leaves cubital fossa (possible site of compression)
pronator teres action
pronation and flexion of forearm
flexor carpi radialis origin
common flexor tendon (attached to medial epicondyle of humerus)
flexor carpi radialis insertion
tendon passes through its own tunnel in lateral part of flexor retinaculum inserts into bases of 2nd and 3rd metacarpals
flexor carpi radialis innervation
median nerve
flexor carpi radialis action
flexion and abduction of hand at wrist joint
palmaris longus origin
common flexor tendon (attached to medial epicondyle of humerus)
palmaris longus insertion
tendon passes superficial to flexor retinaculum inserts into distal part of flexor retinaculum and palmar aponeurosis
palmaris longus innervation
median nerve
palmaris longus action
flexion of hand at wrist joint
opposes shearing forces on the skin of the palm during gripping
absent in about 14% of individuals
flexor carpi ulnaris origin
humeral head: common flexor tendon (attached to medial epicondyle of humerus)
ulnar head: medial aspect of olecranon and posterior border of ulnar shaft
flexor carpi ulnaris insertion
pisiform, hook of hamate and base of 5th metacarpal
flexor carpi ulnaris innervation
ulnar nerve passes between two heads as it enters anterior compartment of forearm (cubital tunnel)
flexor carpi ulnaris action
flexion and adduction of hand at wrist joint
flexor digitorum superficialis origin
humeroulnar head: common flexor tendon (attached to medial epicondyle of humerus) and medial aspect of coronoid process
radial head: anterior aspect of shaft of radius (linear attachment that extends from radial tuberosity to insertion of pronator teres to oblique line of radius)
flexor digitorum superficialis insertion
in lower forearm, muscle belly gives rise to 4 tendons (for medial 4 digits), which enter hand through carpal tunnel (in distal forearm and carpal tunnel tendons for ring and middle fingers are superficial to tendons for index and little fingers) at the level of proximal phalanges, tendons divide into 2 slips to allow passage of corresponding tendons of flexor digitorum profundus and two slips then attach to sides of middle phalanges of medial 4 digits
flexor digitorum superficialis innervation
median nerve
flexor digitorum superficialis action
flexion of middle phalanges of medial 4 digits; helps with flexion of proximal phalanges of medial 4 digits and with flexion of hand at wrist joint
flexor pollicis longus origin
anterior surface of shaft of radius and interosseous membrane
flexor pollicis longus insertion
tendon passes through carpal tunnel and inserts into base of distal phalanx of thumb
flexor pollicis longus innervation
anterior interosseous nerve (branch of median nerve)
flexor pollicis longus action
flexion of distal phalanx of thumb
helps with flexion of proximal phalanx of thumb, flexion of 1st metacarpal and flexion of hand at wrist joint
flexor digitorum profundus origin
anterior and medial surfaces of shaft of ulna and interosseous membrane
flexor digitorum profundus insertion
in lower forearm, muscle belly gives rise to 4 tendons (for medial 4 digits), which enter hand through carpal tunnel
tendons of flexor digitorum profundus pass between 2 slips of corresponding tendons of flexor digitorum superficialis and insert into bases of distal phalanges of medial 4 digits
flexor digitorum profundus innervation
medial half (for little and ring fingers): ulnar nerve ateral half (for index and middle fingers): anterior interosseous nerve (branch of median nerve)
flexor digitorum profundus action
flexion of distal phalanges of medial 4 digits
helps with flexion of middle and proximal phalanges of medial 4 digits and with flexion of hand at wrist joint
pronator quadratus origin
lower part of anterior surface of shaft of ulna
pronator quadratus insertion
lower part of anterior surface of shaft of radius
pronator quadratus innervation
anterior interosseous nerve (branch of median nerve)
pronator quadratus action
pronation of the forearm
contents of the carpal tunnel
4 tendons of flexor digitorum superficialis
4 tendons of flexor digitorum profundus
tendon of flexor pollicis longus
median nerve
carpal tunnel synovial sheaths
radial bursa: tendon of flexor pollicis longus ulnar bursa (common flexor sheath): 4 tendons of FDS and 4 tendons of FDP
ulnar artery
begins in cubital fossa (terminal branch of brachial artery) and leaves cubital fossa by passing deep to ulnar head of pronator teres, which separates it from median nerve
in upper forearm, it passes deep to superficial and intermediate muscles of anterior compartment
in lower forearm it is more superficial: tendon of flexor carpi ulnaris and ulnar nerve are medial to ulnar artery and tendons of flexor digitorum superficialis are lateral to ulnar artery
enters palm of hand anterior (superficial) to flexor retinaculum with ulnar nerve and ends in hand by forming superficial palmar arch
along most of its course, it is accompanied by ulnar nerve (nerve lies medial to artery)
ulnar artery branches
muscular (along its course)
anterior and posterior ulnar recurrent arteries (elbow joint anastomosis)
common interosseous artery (2 branches)
palmar and dorsal carpal branches
common interosseous artery
branch of ulnar artery
short branch that originates from proximal part of ulnar artery and divides into anterior and posterior interosseous arteries
anterior interosseous artery
branch of common interosseous artery
runs inferiorly, on anterior aspect of interosseous membrane, with anterior interosseous nerve
at proximal border of pronator quadratus, pierces interosseous membrane and enters posterior compartment of forearm
anastomoses with terminal part of posterior interosseous artery
posterior interosseous artery
branch of common interosseous artery
passes posteriorly, between ulna and radius, and above superior border of interosseous membrane, to enter posterior compartment of forearm
palmar and dorsal carpal branches of the ulnar artery
anastomose with corresponding branches of radial artery to form palmar and dorsal carpal arches
radial artery
- begins in cubital fossa (terminal branch of brachial artery)
- in upper forearm is covered by brachioradialis and passes superficial to pronator teres close to its insertion
- in middle part of forearm it is accompanied by superficial branch of radial nerve (nerve lies lateral to artery)
- in lower forearm is superficial and lies between tendon of brachioradialis (lateral to artery) and tendon of flexor carpi radialis (medial to artery) site for taking radial pulse
- winds around lateral aspect of wrist to reach dorsum of hand
radial artery branches
muscular (along its course)
radial recurrent artery
superficial palmar branch
palmar and dorsal carpal branches
radial recurrent artery
participates in arterial anastomosis around elbow joint
superficial palmar branch of radial artery
originates just above wrist and enters palm of hand by passing through or superficial to thenar muscles and completes superficial palmar arch on lateral side
palmar and dorsal carpal branches of radial artery
anastomose with corresponding branches of ulnar artery to form palmar and dorsal carpal arches
deep veins of the forearm
- radial and ulnar arteries are accompanied by two veins each (radial and ulnar veins or venae comitantes [accompanying veins] of radial and ulnar arteries)
- there are numerous connections between two radial veins and between two ulnar veins
- radial and ulnar veins receive tributaries corresponding to branches of arteries and drain deep tissues of forearm
- in cubital fossa, radial and ulnar veins join to form two brachial veins (venae comitantes of brachial artery) and are connected to median cubital vein (superficial vein)
median nerve
- exits cubital fossa by passing between humeral and ulnar heads of pronator teres
- descends in forearm between flexor digitorum superficialis and flexor digitorum profundus
- just proximal to wrist emerges from underneath flexor digitorum superficialis and lies between tendon of palmaris longus (medial to nerve) and tendon of flexor carpi radialis (lateral to nerve)
- enters hand by passing through carpal tunnel
median nerve branches
muscular branches
articular branch at elbow joint
palmar branch
anterior interosseous nerve
muscular branches of median nerve
supply pronator teres, flexor carpi radialis, palmaris longus and flexor digitorum superficialis
palmar branch of median nerve
passes superficial to flexor retinaculum and supplies skin of central, depressed area of palm of hand
anterior interosseous nerve
originates from median nerve as it emerges from pronator teres (upper forearm)
runs inferiorly on anterior surface of interosseous membrane with anterior interosseous artery then passes deep to pronator quadratus and ends on anterior surface of carpus
supplies flexor pollicis longus, pronator quadratus and lateral half of flexor digitorum profundus and gives articular branches to distal radioulnar and wrist joints
ulnar nerve
- enters anterior forearm by passing between humeral and ulnar heads of flexor carpi ulnaris (cubital tunnel)
- along most of its course in forearm, it is accompanied by ulnar artery (artery lies lateral to nerve)
- in upper forearm is more deeply located (between flexor carpi ulnaris and flexor digitorum profundus)
- in lower forearm is more superficial and lies between tendon of flexor carpi ulnaris (medial to nerve) and ulnar artery (lateral to nerve)
- enters palm of hand by passing anterior (superficial) to flexor retinaculum
ulnar nerve branches
- muscular branches
- articular branch to elbow joint
- palmar branch
- dorsal branch (larger than palmar branch)
- anterior to flexor retinaculum, ulnar nerve ends by dividing into superficial and deep terminal branches
muscular branches of ulnar nerve
supply flexor carpi ulnaris and medial half of flexor digitorum profundus
palmar branch of ulnar nerve
passes superficial to flexor retinaculum and supplies skin on medial part of palm, at base of hypothenar eminence
dorsal branch of ulnar nerve (larger than palmar branch)
curves around ulna (deep to tendon of flexor carpi ulnaris) and supplies skin on medial part of dorsum of hand and dorsal surfaces of medial 2½ (or 1½) digits (digital branches do not extend far beyond proximal interphalangeal joints)