ANAT 5010 - unit 6

cubital fossa

a transition area between the arm and the forearm; a triangular depression on the anterior aspect of the elbow

- base: line between epicondyles of the humerus

- medial: pronator teres muscle

- lateral: brachioradialis muscle

- floor: brachialis muscle

- roof: deep fascia

what are the boundaries of the cubital fossa?

- tendons of biceps brachii

- arteries (brachial, radial, and ulnar)

- median nerve

what are the contents of the cubital fossa?

superficial branch of the radial nerve

descends under the brachioradialis muscle; innervates the dorsal-radial aspect of the hand and first 3.5 digits EXCEPT the DIP joints; sensory innervation

deep branch of the radial nerve

runs between the two heads of the supinator muscle to innervate the muscles in the posterior compartment of the forearm; motor innervation

styloid processes of radius and ulan

two palpable bony projections at the wrist; stabilize the carpal bones and anchor ligaments

distal skin crease

proximal border of flexor retinaculum

- proximal row: scaphoid, lunate, triangular, pisiform

- distal: trapezium, trapezoid, capitate, hamate (has a hook)

what are the carpal bones?

antebrachial fascia

dense connective tissue sheath enveloping the forearm muscles

palmar carpal ligament

thickening of antebrachial fascia on the anterior wrist

retinaculum

a thickened band of deep fascia that serves to hold tendons in place where they cross joints

flexor retinaculum (transverse carpal ligament)

connects the tubercles of scaphoid and trapezium and pisiform and the hook of the hamate; forms the roof of the carpal tunnel

thenar fascia

a thin layer of connective tissue covering the thenar muscle

hypothenar fascia

a thin layer of connective tissue covering the hypothenar muscle

palmar aponeurosis

a thick, triangular sheet of deep fascia in the center of the palm, stretching from the wrist to the base of the fingers

- flex the wrist

- flex the digits

- pronate the hand

what are the actions of the muscles in the anterior forearm?

origin: medial epicondyle (superficial head); coronoid process of ulna (deep head)

insertion: midway of later surface of radius

what is the origin and insertion of the pronator teres muscle?

- pronator teres

- flexor carpi radialis

- palmaris longus

- flexor carpi ulnaris

what muscles are in the first layer of the anterior forearm?

action: pronates hand

innervation: median nerve (passes between the two heads)

what is the action and innervation of the pronator teres muscle?

origin: medial epicondyle

insertion: on the bases of the 2nd and 3rd metacarpal bones on the palmar surface

what is the origin and insertion of the flexor carpi radialis muscle?

action: flex and abduct the wrist

innervation: median nerve

what is the action and innervation of the flexor carpi radialis?

origin: medial epicondyle

insertion: flexor retinaculum and palmar aponeurosis

what is the origin and insertion of the palmaris longus muscle?

action: flex the hand

innervation: median nerve

what is the action and innervation of the palmaris longus?

origin: medial epicondyle, olecranon and posterior border of ulna

insertion: pisiform (goes through the pisohamate and pisometacarpal ligament) and also inserts on the hamate and base of the fifth metacarpal bone

what is the origin and insertion of the flexor carpi ulnaris muscle?

action: flexes and adducts the wrist

innervation: ulnar nerve

what is the action and innervation of the flexor carpi ulnaris?

flexor digitorum superficialis muscle

what muscle is in the second layer of the anterior muscles of the forearm?

origin: humero-ulnar head (medial epicondyle and coronoid process of ulna), radial head (oblique line of radius)

insertion: bases of middle phalanges of medial four fingers

what is the origin and insertion of the flexor digitorum superficialis muscle?

action: flexes the wrist joint, the metacarpophalangeal joints, and the proximal interphalangeal joints

innervation: median nerve

what is the action and innervation of the flexor digitorum superficialis muscle?

- flexor digitorum profundus muscle

- flexor pollicis longus muscle

what muscles make up the third layer of the anterior muscles of the forearm?

origin: medial and anterior surfaces of the ulna, interosseous membrane

insertion: bases of distal phalanges of medial four fingers

what is the origin and insertion of the flexor digitorum profundus muscle?

action: flexes wrist, flexes MP, and flexes PIP and DIP

innervation: medial 2 tendons -> ulnar nerve; lateral 2 tendons -> anterior interosseous nerve

what is the action and innervation of the flexor digitorum profundus muscle?

origin: anterior surface of radius, interosseous membrane

insertion: base of distal phalanx of thumb

what is the origin and insertion of the flexor pollicis longus muscle?

action: flexes MP joint of first digit, flexes interphalangeal joint of first digit, flexes the wrist

innervation: anterior interosseous nerve

what is the action and innervation of the flexor pollicis longus muscle?

pronator quadratus muscle

what muscle is in the fourth layer of the anterior forearm muscles?

origin: distal anterior surface of ulna

insertion: distal anterior surface of radius

what is the origin and insertion of the pronator quadratus muscle?

action: pronation

innervation: anterior interosseous nerve

what is the action and innervation of the pronator quadratus muscle?

brachial artery

ends at the neck of the radius and divides into the radial and ulnar arteries

- radial recurrent artery

- muscular branches

- palmar carpal branch

- superficial palmar branch

- deep palmar arch

what does the radial artery split into?

- anterior ulnar recurrent

- posterior ulnar recurrent

- common interosseous (then to anterior and posterior interosseous)(posterior becomes the interosseous recurrent)

- muscular branches

- palmar carpal branch

- superficial palmar arch

- deep palmar arch

what does the ulnar artery split into?

superior ulnar collateral artery and posterior ulnar recurrent artery

what anastomoses posterior to the medial epicondyle?

inferior ulnar collateral artery and anterior ulnar recurrent artery

what anastomoses anterior to the medial epicondyle?

radial collateral artery and radial recurrent artery

what anastomoses anterior to the lateral epicondyle?

middle collateral artery and interosseous recurrent artery

what anastomoses deep to the anconeus?

median nerve

runs between the two heads of the pronator teres, then deep to the FDS, is located between the palmaris longus and FCR at the wrist

median nerve

innervates all the anterior forearm muscles of the first and second layer besides the flexor carpi ulnaris

- anterior interosseous nerve (innervates the third and fourth layer muscles except for the medial half of the FDP)

- palmar branch (sensory innervation to the skin superficial to the flexor retinaculum

what does the median nerve give off in the anterior forearm?

ulnar nerve

travels behind the medial epicondyle of the humerus and runs between the two heads of the flexor carpi ulnaris, is on the FDP to the wrist and enters the hand through guyon's canal

ulnar nerve

innervates the flexor carpi ulnaris and the flexor digitorum profundus (4th and 5th digits)

- palmar branch (sensory innervation of the skin over the hypothenar eminence)

- dorsal branch (entire 5th and ulnar side of the 4th digit, ulnar side to the middle phalange of the 3rd digit, radial side to the middle phalange of the 4th digit)

what does the ulnar nerve give off?

- lateral side: tubercle of the scaphoid and tubercle of the trapezium

- medial side: pisiform and hook of hamate

what makes up the base of the carpal arch?

flexor retinaculum

connects the carpal arch

- flexor digitorum superficialis tendons (two layers)

- flexor digitorum profundus tendons (one layer)

- flexor pollicis longus tendon

- median nerve

what is in the carpal tunnel?

carpal tunnel syndrome

common condition that causes pain, numbness, and tingling in the hand and arm; occurs when the median nerve is squeezed or compressed as it travels through the wrist

- lateral: capitulum of humerus and head of radius

- medial: trochlea of humerus and trochlear notch of ulna

what are the articulations for the elbow joint?

ulnar collateral ligament

connects the medial epicondyle of the humerus and the ulna

anterior ulnar collateral ligament

connects the medial epicondyle of the humerus to the coronoid process of the ulna

posterior ulnar collateral ligament

connects the medial epicondyle of the humerus to the olecranon process of the ulna

intermediate ulnar collateral ligament

connects the olecranon process to the coronoid process

radial collateral ligament

connects the lateral epicondyle and the annular ligament

- head of the radius

- radial notch of the ulna

what is the articulation of the proximal radioulnar joint?

annular ligament

connects the radial notch of the ulna and the head and neck of the radius; provides stability

quadrate ligament

connects the inferior border of the radial notch of the ulna and the neck of the radius; closes the cavity between the radius and the ulna; allows rotation of the radius

interosseous membrane

connects the radius and ulna

head of ulna and ulnar notch of radius

what is the articulation of the distal radioulnar joint?

- palmar radioulnar ligament

- dorsal radioulnar ligament

what are the ligaments in the distal radioulnar joint?

colles' fracture

occurs to a fall on an outstretched hand with an extended wrist; fracture of the distal radius; dorsal displacement of the wrist and hand

flexion, extension, adduction, abduction, and circumduction

what does the wrist joint allow?

- radius and fibrocartilaginous disc

- proximal row of carpal bones (except pisiform)

what are the articulations of the wrist joint?

fibrocartilaginous disc

connects the radius and the styloid process of the ulna

palmar radiocarpal ligament

connects the distal end of the radius with the scaphoid, lunate, and triquetrum

dorsal radiocarpal ligament

connects the distal end of the radius with the scaphoid, lunate, and triquetrum on the dorsal side

radial carpal collateral ligament

connects the styloid process of the radius with the scaphoid and trapezium

ulnar carpal collateral ligament

connects the styloid process of the ulna with the pisiform and triquetrum