What is the venous supply of the posterior forearm similar to?
Click to see answer
The anterior forearm.
Click to see question
What is the venous supply of the posterior forearm similar to?
The anterior forearm.
What do deep veins in the posterior forearm do?
They accompany and are named the same as the major arteries.
Name a superficial vein in the posterior forearm.
Cephalic vein.
What is another superficial vein found in the posterior forearm?
Basilic vein.
What causes Mallet Finger?
Trauma that causes avulsion of the extensor tendon from the distal phalanx.
What is the mechanism of injury for Mallet Finger?
The distal interphalangeal joint is forced into hyperflexion.
What is another name for Mallet Finger?
A 'jammed' finger.
What is a common cause of Mallet Finger?
Sports injuries.
What is a key sign of Mallet Finger?
The injured joint is forced into a flexed position due to the torn extensor tendon.
What are the main muscles in the deep layer of the posterior forearm?
Supinator, Abductor pollicis longus, Extensor pollicis brevis, Extensor pollicis longus, Extensor indicis.
What are the three functional units of the posterior forearm muscles?
Movements at the wrist, movements of the fingers, movements of the thumb.
Which muscles are responsible for wrist movements?
Extensor carpi radialis longus, Extensor carpi radialis brevis, Extensor carpi ulnaris.
Which muscles extend the four medial fingers?
Extensor digitorum, Extensor indices, Extensor digiti minimi.
How many dorsal interossei muscles are there in the hand?
Four.
Which nerve innervates all muscles of the posterior forearm?
Radial nerve (C8 - T1).
What muscles are involved in thumb movements?
Abductor pollicis longus, Extensor pollicis longus, Extensor pollicis brevis.
What are the eight carpal bones of the hand?
Scaphoid, Lunate, Triquetrum, Pisiform, Hamate, Capitate, Trapezium, Trapezoid.
What is unique about the dorsal interossei muscles?
They are the only intrinsic muscles on the dorsum of the hand.
Where does the radial nerve travel along the arm?
Along the posterior/lateral side of the humerus.
What is another name for lateral epicondylitis?
Tennis elbow.
How many metacarpals are there in the hand?
Five in total.
What is the function of the dorsal interossei muscles?
They aid in adduction of the digits.
At what point does the radial nerve divide?
At the lateral epicondyle of the humerus.
What causes lateral epicondylitis?
Repetitive use of superficial forearm extensors that attach at the lateral epicondyle.
Which metacarpal corresponds to the thumb?
The first metacarpal.
What does the deep radial nerve turn into after passing through the supinator muscle?
Posterior interosseous nerve.
How many synovial sheaths do the extensor tendons pass under?
Six.
What are potential injuries associated with lateral epicondylitis?
Tearing of muscles or avulsion of the lateral epicondyle of the humerus.
Which metacarpal corresponds to the pinky?
The fifth metacarpal.
What is the function of the posterior interosseous nerve?
Motor innervation to posterior compartment muscles.
What are the first two extensor tendons that pass under the extensor retinaculum?
Abductor pollicis longus and extensor pollicis brevis.
What are common signs and symptoms of lateral epicondylitis?
Inflammation at the lateral epicondyle, pain over the lateral epicondyle, and radiating pain down the posterior forearm and hand.
Where does the superficial radial nerve travel?
Beneath the brachioradialis muscle.
What are the three parts of each metacarpal?
Head, Shaft, Base.
Which extensor tendons are associated with the radial side of the wrist?
Extensor carpi radialis longus and brevis.
What are synovial cysts also known as?
Ganglion cysts.
What is the sensory function of the superficial radial nerve?
Sensory nerve only to the lateral dorsum of the hand.
How many proximal phalanges are there in the hand?
Five proximal phalanges.
What is the function of the extensor digitorum?
It extends the digits.
Where do synovial cysts typically form?
On the synovial tendon sheaths of the extensor tendons.
Where does the superficial radial nerve exit?
Superficial between the brachioradialis and extensor carpi radialis longus tendons.
How many medial phalanges are there in the hand?
Four medial phalanges.
What is the extensor expansion?
A triangular, tendinous aponeurosis that wraps over the metacarpals and phalanges.
Which extensor tendon is responsible for extending the little finger?
Extensor digiti minimi.
What is the etiology of synovial cysts?
Idiopathic; the etiology is unknown.
What is unique about the thumb's phalanges?
The thumb only has a proximal and distal phalange.
Which muscle's tendon does the extensor expansion attach to?
The tendon of the extensor digitorum muscle.
What is the last extensor tendon listed that passes under the extensor retinaculum?
Extensor carpi ulnaris.
What are the signs and symptoms of synovial cysts?
Small swelling on the posterior wrist, typically non-tender or painful, but can enlarge and cause pain when flexing the wrist.
What is the function of the median band of the extensor expansion?
It attaches from the proximal phalanx to the base of the middle phalanx.
How many distal phalanges are there in the hand?
Five distal phalanges.
What do the lateral bands of the extensor expansion attach to?
They attach to the base of the distal phalanx.
What are the three parts of each phalanx?
Head, Shaft, Base.
Which tendons join the lateral bands of the extensor expansion?
Interossei and lumbrical tendons.
What is the primary function of the extensor expansions?
They hold the extensor digitorum tendons in place and allow for full extension of the fingers.
What is the arterial supply to the dorsum of the hand derived from?
Palmar arterial arches.
What is the dorsal venous arch?
A network of superficial veins on the dorsal surface of the hand.
What is the attachment point for extensor muscles on the humerus?
Lateral epicondyle.
Where do the medial dorsal surface veins drain?
Into the basilic vein.
What is the attachment point for flexor muscles on the humerus?
Medial epicondyle.
Where do the lateral dorsal surface veins drain?
Into the cephalic vein.
Which part of the humerus articulates with the head of the radius?
Capitulum.
What are the three main cutaneous innervations of the dorsum of the hand?
Radial (lateral), Ulnar (medial), and Median (fingertips).
Which part of the humerus articulates with the olecranon process of the ulna?
Trochlea.
What is the function of the interosseous border of the radius?
Attachment for interosseous membrane.
What articulates with the capitulum of the humerus?
Head of the radius.
What is the function of the olecranon process of the ulna?
Slides into the olecranon fossa of the humerus.
Which notch of the ulna articulates with the trochlea of the humerus?
Trochlear notch.
What is a common attachment point for many muscles in the superficial layer of the posterior forearm?
Lateral epicondyle of the humerus.
Name a muscle in the superficial layer of the posterior forearm that extends the wrist.
Extensor carpi radialis longus.
Which muscle in the superficial layer is responsible for extending the digits?
Extensor digitorum.
What is the anatomical snuffbox?
A hollow gap in the posterior/lateral wrist that appears when the thumb is extended.
What are the lateral borders of the anatomical snuffbox?
Extensor pollicis brevis and abductor pollicis longus muscles.
What forms the medial border of the anatomical snuffbox?
Extensor pollicis longus muscle.
What structures form the floor of the anatomical snuffbox?
Scaphoid and trapezium bones.
Why is the anatomical snuffbox an important landmark?
It is where the radial artery travels through to reach the hand, allowing for radial pulse measurement.
What is the arterial supply of the posterior forearm similar to?
The anterior forearm.
What is the radial artery a terminal branch of?
The brachial artery.
Where does the radial artery travel in relation to the brachioradialis muscle?
Just deep to the brachioradialis muscle.
What anatomical feature does the radial artery cross through at the wrist?
The anatomical snuff box.
What artery does the radial artery give off in the forearm?
Radial recurrent artery.
What is the ulnar artery a terminal branch of?
The brachial artery.
Where does the ulnar artery initially accompany in the forearm?
The median nerve between the heads of the flexor digitorum superficialis muscle.
What are the branches given off by the ulnar artery in the forearm?
Anterior ulnar recurrent artery, posterior ulnar recurrent artery, and common interosseous artery.
What are the branches of the common interosseous artery?
Anterior interosseous artery, posterior interosseous artery, and interosseous recurrent artery.
