Arm, forearm and hand I week 3 Flashcards
What is the group function of muscles in the anterior compartment of the arm? What nerve are they innervated by?
group function: flexion of the arm at the glenohumeral joint and/or flexion of the forearm at the elbow joint
innervation: musculocutaneous nerve (C5, C6)
What is the origin, insertion, function, and innervation of the biceps brachii?
origin:
long head: supraglenoid tubercle (on glenoid fossa of scapula) (passes through the bicipital/intertubercular groove which is covered by transverse humeral ligament)
short head: coracoid process of the scapula
insertion: radial tuberosity; fascia of the forearm
function: flexes the elbow and supinates forearm at proximal radio-ulnar joint. the long head can flex the arm at the glenohumeral joint
innervation: musculocutaneous nerve (C5, C6)
What is the origin, insertion, function, and innervation of the coracobrachialis?
origin: coracoid process of scapula
insertion: medial surface of the humerus
function: adducts and flexes the arm at the glenohumeral joint (is a weak flexor)
innervation: musculocutaneous nerve (C5, C6)
What is the origin, insertion, function, and innervation of the brachialis?
origin: anterior surface of the humerus
insertion: anterior surface of the ulna
function: flexes the elbow
innervation: musculocutaneous nerve (C5, C6)
What is the origin, insertion, function, and innervation of the triceps brachii?
origin:
long head: infraglenoid tubercle of glenoid fossa
lateral and medial heads: posterior surface of the humerus
insertion: olecranon process of the ulna
function: all heads can extend the forearm at the elbow joint. only the long head can extend the arm at the glenohumeral joint
innervation: radial nerve
Identify the branches of the axillary and brachial arteries.
Identify these veins.
Identify these nerves.
lateral epicondylitis
inflammation of the common tendinous origin of extensor muscles that originate at lateral epicondyle of humerus. is associated with overuse that not only affects tennis players but is associated with occupational overuse of extensor muscles in the forearm
carpal tunnel syndrome
caused by entrapment of median nerve as it passes under the flexor retinaculum (through the carpal tunnel) with the long flexor tendons of the hand
What is significant about scaphoid bone fractures?
one of the most frequently broken bones in a fall onto an outstretched hand-its location and shape make it susceptible to fracture. can go undiagnosed as sx can be mild. may need surgery. the scaphoid can easily disconnected from its blood supply and avascular necrosis can result
mallet finger
finger that does not straighten at the tip (DIP joint) due to trauma that results in overstretching or tearing of the extensor tendon
trigger finger
results when inflammation develops in the flexor tendons or their associated digital sheaths. the sheath or tendon may thicken or nodules may form resulting in decreased ability of the tendon to glide through the sheath during finger movement
What are the boundaries of the cubital fossa? What structures are contained in the cubital fossa?
The cubital fossa is the area of transition btwn the arm and forearm. It lies btwn the brachioradialis and the pronator teres muscle. The floor is formed mainly by the brachialis muscle and the roof is formed by superficial fascia and skin.
Major contents from lateral to medial: TAN
tendon of biceps brachii
brachial artery
median nerve
note: the radial nerve also passes through the cubital fossa
the brachial artery and median nerve are covered by the bicipital aponeurosis. contained within the roof the cubital fossa is the median cubital vein which connects the cephalic vein (lateral) and the basilic vein (medial)
What is the bicipital aponeurosis? What structures does it provide protection to?
the bicipital aponeurosis is a flattened extension of the biceps brachii tendon. is superficial to the brachial artery and median nerve and provides some protection to these structures during blood draws
Where do the cephalic and basilic veins terminate? What vein are they connected by?
cephalic (more lateral superficial vein): terminates in subclavian vein
basilic (more medial vein): terminates in axillary vein
are connected by the median cubital vein
Where does the radial nerve travel in the forearm and generally, what structures does it innervate?
The radial nerve lies just deep to the brachioradialis and gives off superficial and deep branches. The superficial branch continues into the forearm on the deep surface of the brachioradialis and is entirely cutaneous. It innervates the dorsal surface of the hand and digits
the deep branch pierces the supinator msucle and supplies the muscles of the posterior forearm and contributes to innervation of the elbow
Where does the ulnar nerve travel in the forearm?
It does not pass through the cubital fossa! It passes posterior to the medial epicondyle (funny bone). It is held down tightly by connective tissue which serves as a potential site of entrapment.
The gateway for structures passing between the arm and forearm is the ____ ____. The gateway for structures passing between the foreamr and hand is the ____ ____.
- cubital fossa
- carpal tunnel
Muscles in the anterior (flexor) compartment of the forearm are generally divided into what 3 layers? What are their general functions?
- superficial, intermediate, and deep
- movements of wrist joint, flexions of fingers including the thumb, and pronation of the forearm
What are the muscles of the superficial layer of the forearm? What is their common origin?
- from lateral to medial: pronator teres, flexor carpi radialis, palmaris longus, and flexor carpi ulnaris
- all originate on the medial epicondyle of the humerus
The muscles of the anterior compartment of the forearm are innervated by the ____ nerve with the exception of what muscles? What are those muscles innervated by?
- median nerve
- the flexor carpi ulnaris and the medial half of the flexor digitorum profundus are innervated by the ulnar nerve
What is the origin, insertion, function, and innervation of the pronator teres?
origin: medial epicondyle of humerus, ulna
insertion: lateral surface of radius
function: pronates forearm at distal radioulnar joint
innervation: median nerve
What is the origin, insertion, function, and innervation of the flexor carpi radialis?
origin: medial epicondyle of humerus
insertion: base of 2nd or 3rd metacarpal
function: flexes and abducts the wrist
innervation: median nerve
What is the origin, insertion, function, and innervation of the palmaris longus?
origin: medial epicondyle of humerus
insertion: palmar aponeurosis
function: flexes wrist
innervation: median nerve
What is the origin, insertion, function, and innervation of the flexor carpi ulnaris?
origin: medial epicondyle of humerus, olecranon process of ulna
insertion: 5th metacarpal, pisiform, and hamate
function: flexes and adducts the wrist
innervation: ulnar nerve
Identify these muscles of the anterior forearm. What group of muscles of the anterior forearm are they in?
superficial layer
What is contained in the intermediate layer of the anterior forearm? What structures pass in this pass.
- flexor digitorum superficialis
- the median nerve and the ulnar artery pass deep to the flexor digitorum superficialis btwn the two heads
What is the origin, insertion, function, and innervation of the flexor digitorum superficialis?
note: the flexor digitorum superficialis has a radial and humero-ulnar head
origin: medial epicondyle of humerus, proximal ulna and radius
insertion: shafts of the middle phalynx of digits 2-5
function: flexes MCP and PIP joints of digits 2-4, flexes the wrist
note: it does not go up to DIP
innervation: median nerve
What muscles comprise the deep layer of the anterior compartment of the forearm?
flexor pollicis longus
flexor digitorum profundus
pronator quadratus
What is the origin, insertion, function, and innervation of the flexor pollicis longus?
origin: radius, interosseous mebrane
insertion: base of the distal phlaynx of the thumb
function: flexes thumb at carpometacarpal, MCP, and IP joints (PIP)
innervation: median nerve
What is the origin, insertion, function, and innervation of the flexor digitorum profundus?
origin: medial and anterior surfaces of the ulna, interosseus membrane
insertion: bases of the distal phalynx of digits 2-5
function: flexes MCP, PIP, and DIP joints, flexes wrist
note: causes flexion of fingers at all joints
innervation: lateral half (index and middle fingers): median nerve
medial half (ring and pinky fingers): ulnar nerve
What is the origin, insertion, function, and innervation of the pronator quadratus?
origin: ulna
insertion: radius
function: pronates forearm at distal radio-ulnar joint
innervation: median nerve
Identify these muscles. What layer of the anterior portion of the forearm are they a part of?
deep layer
In the anterior forearm, what branches does the brachial artery give off? What do those arteries supply and what branches do they give off?
- radial artery (laterally) and ulnar artery (medially)
- the radial artery passes distally with the superficial branch of the radial nerve and contributes blood supply to the hand. the ulnar artery also contributes to blood supply of the hand but first gives off a common interosseus artery that divides into anterior and posterior interosseus arteries. the ulnar artery travels with the median nerve passes deep btwn the two heads of the flexor digitorum superficialis
Identify the structures in this picture of the anterior forearm.
Both the ___ nerve and the ____ nerve course through the cubital fossa. The ____ nerve courses posterior to the medial epicondyle and thus does not course through the cubital fossa.
- median nerve and radial nerve
- ulnar nerve
What are the boundaries of the carpal tunnel?
it is bound anteriorly by the flexor retinaculum and posteriorly by the carpal bones (specifically the hamate and pisiform postero-medially and the trapezium and scaphoid postero-laterally).
What structures do and do not pass through the carpal tunnel?
Structures that pass through the carpal tunnel: Median nerve (including its recurrent branch), tendons of the flexor digitorum superficialis and produndus, tendon of the flexor pollicis longus.
Structures that do not pass through: ulnar nerve and artery and palmar cutaneous branch of the median nerve
What does it mean for muscles of the hand to be intrinsic?
They have origins and insertions on the hand itself.
What muscles are considered to be in the thenar compartment of the hand? What are they innervated by?
flexor pollicis brevis
abductor policis brevis
opponens pollicis
innervated by the recurrent branch of the median nerve
What muscles are considered to be in the hypothenar compartment of the hand? What are they innervated by?
flexor digiti minimi
abductor digiti minimi
opponens digit minimi
innervated by the deep branch of the ulnar nerve
What is the origin, insertion, function, and innervation of the abductor pollicis brevis?
origin: flexor retinaculum, scaphoid, trapezium
insertion: proximal phalynx of the thumb
function: abducts thumb at MCP joint
innervation: recurrent branch of the median nerve
What is the origin, insertion, function, and innervation of the flexor pollicis brevis?
origin: flexor retinaculum, capitate, trapezium
insertion: proximal phalynx of thumb
function: flexes thumb at MCP joint
innervation: recurrent branch of the median nerve
What is the origin, insertion, function, and innervation of the opponens pollicis?
origin: trapezium
insertion: lateral side of 1st metacarpal
function: opposes thumb
innervation: recurrent branch of the median nerve
What intrinsic hand muscle controls thumb movement but is not considered a thenar muscle and why is it not in this group? What is its origin, insertion, innervation, and function?
adductor pollicis. it is in the intermediate compartment of the hand is not in the thenar group bc it is innervated by the deep branch of the ulnar nerve
origin: capitate, base of metacarpals 2 and 3, shaft of 3rd metacarpal
insertion: base of proximal phalynx of thumb
function: adducts the thumb
What is the origin, insertion, function, and innervation of the abductor digiti minimi?
origin: pisiform
insertion: proximal phalynx of 5th digit
function: abducts little finger at MCP joint
innervation: deep branch of the ulnar nerve
What is the origin, insertion, function, and innervation of the flexor digiti minimi brevis?
origin: hamate and flexor retinaculum
insertion: proximal phalynx of 5th digit
function: flexes little finger at MCP joint
innervation: deep branch of the ulnar nerve
What is the origin, insertion, function, and innervation of the opponens digiti minimi?
origin: hamate and flexor retinaculum
insertion: medial border of 5th metacarpal
function: opposes little finger
innervation: deep branch of ulnar nerve
Identify these muscles of the hand. Are they anterior or posterior?
anterior
What are the origins, insertions, functions, and innervation of the lumbricals?
There are 4 lumbricals. note the 3rd and 4th lumbricals often have two heads.
origin: all have origins on the tendons of the flexor digitorum profundus
insertion: all insert on the extensor hood
function: flex MCP while simultaneously extending PIP and DIP joints
the 1st and 2nd lumbricals are innervated by the digital branch of the median nerve
the 3rd and 4th lumbricals are inervated by the deep branch of the ulnar nerve
What is the origin, insertion, function, and innervation of the dorsal interosseus muscles? How many of them are there?
There are four dorsal interosseus muscles which can also be called DABS (dorsal abductors). note that each one has 2 heads
origin: adjacent side of two metacarpal bones
insertion: extensor hood, base of proximal phalanges 2-4
function: abduct digits, flex MCP joints, extend PIP and DIP joints
innervation: deep branch of ulnar nerve
note: the middle finger can only abduct
What is the origin, insertion, function, and innervation of the palmar interosseus muscles? How many of them are there?
There are 3 palmar interosseus muscles which can also be called PADS (because the adduct fingers). they have 1 head as opposed to 2 heads like DABS
origin: palmar surfaces of metacarpals 2, 4, and 5
insertion: extensor hood, base of proximal phalanges 2, 4, and 5 (note the middle finger cannot adduct bc it is in midline of hand)
function: adduct digits, flex MCP joints, extend PIP and DIP joints
innervation: deep branch of ulnar nerve
Identify these muscles. What is their function? What are they innervated by?
DABS
abduct digits, flex MCP, extend DIP and PIP joints
innervated by deep branch of ulnar nerve
What are these muscles? What is their function and what are they innervated by?
PADS
adduct digits, flex MCP joint and extend PIP and DIP joints
innervated by deep branch of ulnar nerve
What arteries contribute to the superficial palmar arch? Where is the superficial palmar arch? What are the branches of the supericial palmar arch? What do those branches supply?
The ulnar artery courses laterally across the palm forming the superficial palmar arch. This arch is just deep to the palmar aponeurosis but superficial ot the long flexor tendons of the digits. One branch of the radial artery also contributes to the superficial palmar artery
The superficial palmar aretery gives off a palmar digital branch to the medial side of the little finger and common digital arteries
the common digital arteries are joined by branches deep palmar arch before biforcating into proper digital arteries
Identify the arteries of the superficial palm.
What arteries contribute to the deep palmar arch? Where is the deep palmar arch? What are the branches of the deep palmar arch? What do those branches supply?
The radial artery curves around the lateral side of the wrist through the anatomical snuff box into the deep plane of the palm. It passes btwn the 2 heads of the 1st dorsal interosseous mucle (DAB) and then btwn the 2 heads of the adductor pollicis to form the deep palmar arch. The deep palmar arch passes medially in the hand btwn metacarpals and long flexor tendons of digits where it is joint by the deep branch of the ulnar artery. A vessel to the thumb and index finger arise from the radial artery and serve as the primary blood supply to the thumb and lateral index finger.
The deep palmar arch gives rise to a) palmar metacarpal arteries which anastamose with common digitial arteries (that branched from the superficial palmar arch) to form proper digital arteries and **b) **perforating brances which pass to the dorsum of the hand
Identify the arteries of the deep palm.
What are the 3 branches of the ulnar nerve? What do they innervate?
- deep branch, superficial branch, and palmar branch
- the superpicial and palmar branches are cutaneous. the deep branch innervates the hypothenar muscles, the 3rd and 4th lumbricals, PADS, DABS, and adductor pollicis
What are the branches of the median nerve?
