Block 1: Lecture 5: Cubital Fossa and Forearm
If the muscle is in the center of the forearm, where is it getting its blood supply from?
"halfsies", both ulnar and radial artery
List the flexor muscles of the antebrachium by layers from superficial to deep
*Slide 16 has a really nice picture* Layer 1: brachioradialis, pronator teres, flexor carpi radialis, palmaris longus, flexor carpi ulnaris Layer 2: flexor digitorum superficialis Layer 3: flexor pollicic longus, flexor digitorum profundus Layer 4: (most deep) pronator quadratus
What are the spinal contributions of the median nerve?
C6, C7, C8 and T1
What are the spinal contributions of the ulnar nerve?
C8, T1
True or False? The flexor digitorum superficialis flexes the distal phalanx?
FALSE. it does not flex the distal phalanx, only the proximal and middle phalanges of the fingers
What are the general compartmental rules of the flexor compartment?
Nerves: median-anterior interosseous branch, and ulnar nerve Blood supply: radial and ulnar arteries/veins
What are the general compartmental rules of the extensor compartment?
Nerves: radial-deep branch and posterior interosseous branches (efferent and afferent) Blood supply: anterior interosseous and posterior interosseous arteries/veins
Which compartment does the anterior interossius artery/vein supply?
POSTERIOR
What is an acronym for the major contents of the cubital fossa?
Really Need: radial nerve Booze To: biceps brachii tendon Be At: brachial artery My Nicest: medial nerve
What is the difference between the flexor digitorum superficialis and the flexor digitorum profundus?
The flexor digitorum profundus also flexes the distal phalanx
True or False? The investing fascia of the antebrachium is thicker than the brachium.
True
What is the name of the deep investing fascia surrounding the antebrachium?
antebrachial fascia
What are the two compartments of the forearm?
anterior and posterior
What does the common interosseous artery divide into?
anterior interosseous artery and posterior interosseous artery
What supplies blood to the posterior compartment of the forearm?
anterior interosseous artery and posterior interosseous artery
What is the origin of the flexor pollicis longus?
anterior surface of radius and interosseous membrane
What is the insertion of the flexor digitorum profundus?
anterior surface of the base of the distal phalanx of fingers
What is the insertion flexor policis longus?
base of the distal phalanx of the thumb
What are the boundaries of the cubital fossa?
base: imaginary line through medial and lateral epicondyles of humerus lateral: brachioradialis medial: pronator teres
Where do the majority of the flexor muscles of the forearm insert?
become tendinous at the wrist and continue down into the hand under the flexor retinaculum
Which structure of the cubital fossa crosses the biceps brachii tendon, is deep to the bicipital aponeurosis, and that ends by bifurcating into the radial and ulnar arteries?
brachial artery
Which structures of the cubital fossa make up the floor?
brachialis and supinator muscles
What is the beer drinking muscle?
brachioradialis
Which muscle doesn't really belong in either compartment?
brachioradialis
Which structure of the cubital fossa forms the lateral border and when reflected exposes the radial nerve as it enters the flexor compartment of the forearm?
brachioradialis
Which muscle is referred to as the "orphan muscle" and why?
brachioradialis, its innervated by the radial nerve which means its in the posterior compartment, but it flexes the forearm in the semi-pronated position, doesn't really fit in a specific compartment based on rules
What branches off of the ulnar artery in the cubital fossa?
common interosseous artery
What is the inverted triangular fat-filled region anterior to the elbow joint?
cubital fossa
What is the insertion of the pronator quadratus?
distal 1/4 of anterior surface of radius
What is the origin of the pronator quadratus?
distal 1/4 of anterior surface of ulna
When does the brachial artery terminate?
distal end of the cubital fossa
What is the thick fascia with fibers that run transversely across the posterior radoiocarpal joint that helps hold the tendons down?
extensor retinaculum
What are the actions of the flexor carpi radialis?
flexes and abducts hand at wrist
What are the actions of the flexor carpi ulnaris?
flexes and adducts hand at wrist
What are the actions of the brachioradialis?
flexes the forearm when its semipronated, elbow stabilizer
What are the actions flexor policis longus?
flexes wrist, proximal & distal plahalnges of thumb
What are the actions of the flexor digitorum superficialis?
flexes wrist, proximal and middle phalanges of fingers
What are the actions of the palmaris longus?
flexes wrist, tenses palmar aponeurosis
What are the actions of the flexor digitorum profundus?
flexes wrist; proximal, middle and distal phalanges
All but which muscle of the superficial flexor group in the forearm is innervated by the median nerve?
flexor carpi ulnaris, innervated by the ulnar nerve
Which compartment of the forearm is larger and why?
flexor compartment, use more muscles for flexion than extension
What are the muscles included in the deep flexor group in the forearm?
flexor digitorum profundus, flexor pollicis longus, pronator quadratus
Which muscle is innervated by two nerves?
flexor digitorum profundus: anterior interosseous branch of median nerve and ulnar nerve
What is the insertion of the palmaris longus?
flexor retinaculum and palmar aponeurosis
What is the ligament that spans multiple carpal bones forming the carpal tunnel and the ulnar canal?
flexor retinaculum/transverse carpal ligament
What is a common injury of the medial epicondyle?
golfer's elbow/medial epicondylitis
When does the axillary artery become the brachial artery?
inferior border of the teres major muscle
What structure connects the radius and ulna and also separates the flexor and extensor compartments?
interosseous membrane
What is the purpose of the palmar aponeurosis?
it adheres to the skin to make the palm not flabby
What is the insertion of the brachioradialis?
lateral aspect of styloid process of radius
Which structure of the cubital fossa appears between the biceps brachii and brachialis muscle becoming superficial over the brachialis muscle?
lateral cutaneous nerve of the forearm (sensory continuation of musculocutaneous nerve)
What structures can be found when the "roof" (i.e. skin, superficial and deep fascia/bicipital aponeurosis) is removed from the cubital fossa?
lateral cutaneous nerve of the forearm, brachioradialis, radial nerve, tendon of biceps brachii muscle, median nerve, brachial artery, brachialis muscle, and supinator muscle
Where do the extensor muscles of the forearm originate?
lateral epicondyle of the humerus
What is the insertion of the pronator teres?
lateral mid shaft of radius
What is the origin of the brachioradialis?
lateral supracondylar ridge of humerus
What is the origin of the flexor carpi radialis?
medial epicondyle of humerus
What is the origin of the palmaris longus?
medial epicondyle of humerus
What is the origin of the pronator teres?
medial epicondyle of humerus and coronoid process of ulna
What is the origin of the flexor digitorum superficialis?
medial epicondyle of humerus and proximal half of anterior border of radius
What is the origin of the flexor carpi ulnaris?
medial epicondyle of humerus and proximal ulna
Where do the bulk of the flexor muscles of the forearm originate?
medial epicondyle of the humerus
What is the innervation of the flexor carpi radialis?
median nerve
What is the innervation of the flexor digitorum superficialis?
median nerve
What is the innervation of the palmaris longus?
median nerve
What is the innervation of the pronator teres?
median nerve
Which nerve runs with the brachial artery to the cubital fossa?
median nerve
What is the innervation flexor policis longus?
median nerve (anterior interosseous branch)
What are the major nerves that supply the flexor/anterior compartment of the forearm?
median nerve and ulnar nerve
What is the innervation of the flexor digitorum profundus?
median nerve-anterior interosseous branch (digits 2 & 3) AND ulnar nerve (digits 4 & 5)
What is the innervation of the pronator quadratus?
median nerve: anterior interosseous branch
What is the insertion of the flexor digitorum superficialis?
middle phalanx of fingers
Which muscle does about 15% of the population not have?
palmaris longus
Where does the anterior interosseous artery supply blood?
posterior compartment
What are the actions of the pronator teres?
pronates forearm and flexes forearm
What are the actions of the pronator quadratus?
pronation of forearm/hand
What are the muscles included in the superficial flexor group in the forearm?
pronator teres, flexor carpi radialis, palmaris longus, flexor digirorum superficialis, flexor carpi ulnaris
What muscles pronate the forearm?
pronator teres, pronator quadratus
What is the origin of the flexor digitorum profundus?
proximal 2/3 of the anterior/medial ulna and interosseous membrane
If the muscle is on the radial side, where is it getting its blood supply from?
radial artery
Where is the pulse most commonly taken from?
radial artery
Which artery extends from the neck of the radius to the medial side of the styloid process and lies deep to the brachioradialis muscle, but become superficial in the distal third of the arm?
radial artery
What does the brachial artery divide into?
radial artery and ulnar artery
What supplies blood to the anterior compartment of the forearm?
radial artery and ulnar artery proper
What is the innervation of the brachioradialis?
radial nerve
Which structure of the cubital fossa can only be seen if the brachioradialis muscle is reflected?
radial nerve
What is the insertion of the flexor carpi radialis?
radial side of wrist
What causes injuries of the medial/later epicondyles?
repetitive overuse
Why is it hard to abduct the hand?
styloid process of radius provides a mechanical stop point
What muscles supinate the forearm?
supinator, biceps brachii
What is the result of tennis elbow?
tendonitis of the common extensor tendon from the lateral epicondyle, causes damage to the muscles and tendons for extending your wrist and fingers
What is the result of golfer's elbow?
tendonitis of the common extensor tendon from the medial epicondyle, causes damage to the muscles and tendons responsible for flexing your wrist and fingers
What is a common injury of the lateral epicondyle?
tennis elbow/ lateral epicondylitis
What does pollicis mean?
thumb
True or False? The ulna does NOT articulate with the wrist.
true, it does not articulate with the wrist, only the radius does
Which two bones can be found in the antebrachium?
ulna and radius
If the muscle is on the ulnar side, where is it getting its blood supply from?
ulnar artery
Which artery extends from the neck of the radius to the flexor retinaculum on the medial edge of the wrist?
ulnar artery
What does the ulnar artery run with in the distal half of the forearm and enter the hand via ulnar canal with?
ulnar nerve
What is the innervation of the flexor carpi ulnaris?
ulnar nerve
What is the insertion of the flexor carpi ulnaris?
ulnar side of wrist
