Anatomy- Anterior Arm, Anterior Forearm and Cubital Fossa Flashcards
what muscles are in the anterior compartment of the arm
biceps brachii, brachialis, coracobrachialis
what is the innervation of the anterior compartment of the arm
musculocutaneous nerve
what are the actions of the anterior compartment of the arm
flexion of the arm and forarm
what is the extra role of the biceps brachii
also supinates the forearm
what muscles are in the superficial layer of the anterior compartment of the forearm
pronator teres,
flexor carpi radialis, palmaris longus, flexor carpi ulnaris
what muscles are in the intermediate layer of the anterior compartment of the forearm
flexor digitorum superficialis
what muscles are in the deep layer of the anterior compartment of the forearm
flexor digitorum profundus, flexor pollicis longus, pronator quadratus
what is the innervation of the anterior forearm
all median nerve expect:
-flexor carpi ulnaris
-medial half of flexor digitorum superficialis (digits 4 & 5)
which are ulnar nerve
what are the actions of the anterior forearm muscles
- flexion of the wrist and digits
- pronation
- abduction and adduction of the wrist
how can the superficial muscles of the anterior forearm attach more proximal than the deep layer
as split to allow deep layer to go through
what does the biceps brachii consist of
long and short head (plus tendon of long and short head),
two distal tendons- biceps tendon and bicipital aponeurosis
what are the proximal attachments of biceps brachii
long head= supraglenoid tubercle of the scapula
short head- coracoid process of the scapula
what three muscles attach to the coracoid process
pectoralis minor, coracobrachialis, short head of biceps
what is the path of the tendon of the long head of the biceps
passes superiorly in the intertubercular (bicipital) groove/ sulcus of the humerus
then becomes enclosed within the fibrous layer of the shoulder joint capsule
reaches the supraglenoid tubercle of the scapula
why might palpation of the tendon of the long head of biceps be painful
biceps tendinitis- causes shoulder pain, caused by movement of the ligament in the groove
what are the two distal attachments of the biceps brachii
the biceps tendon- attaches to the the radial tuberosity
the bicipital aponeurosis- blends with the deep (antebrachial) fascia on the medial side of the proximal forearm
what does the biceps deep tendon (myotactic) reflex test
- confirms the function of the muscle
- its peripheral nerve supply
- central connections at the spinal chord level (reflex arc) and above (descending controls)
what are the peripheral nerves supplying the biceps brachii (and its nerve roots)
musculocutaneous (C5 and C6)
how is the biceps deep tendon reflex tested
placing the examiners thumb on the biceps tendon (within the cubital fossa) and then striking briskly the examiners thumb with a tendon hammer
this conveys a sudden stretch of the biceps tendon and should elicit an involuntary (reflex) contraction of the muscles (patient will flex their forearm at the elbow)
where does the coracobrachilalis attach proximally and distally
coracoid process of the scapula
medial surface of the humerus
where is coracobrachialis in relation to the other muscles of the anterior arm
deep to biceps brachii and medial to brachialis
what separates the coracobrachialis from the triceps
medial intermuscular septae
what is the origin and insertion of the brachialis
humerus
coronoid process of ulnar
where is brachialis in relation to the other muscles of the anterior arm
deep to biceps brachii and lateral to coracobrachilis
what separates the brachialis from the triceps
lateral intermuscular septae
what do the muscles of the anterior compartment of the arm span
the shoulder and elbow joint
biceps brachii also spans the proximal radioulnar joint
what muscle is the most powerful supinator of the forearm
biceps brachii
what are the actions of the muscles of the anterior compartment of the forearm
flexion, abduction and adduction of the wrist (carpus)
flexion of the fingers (digits 2-5: index-little)
flexion of the thumb (muscles named pollicis)
pronation of the forearm at the proximal and distal radioulnar joints
where do the muscles in the superficial anterior forearm originate
to the medial epicondyle of the humerus via the common flexor tendon
where does pronator teres attach distally
lateral surface of the radius
where does the palmaris longus attach distally
to the palmar aponeurosis
where does the flexor carpi radialis attach distally
metacarpals on the radial side
where does the flexor carpi ulnaris attach distally
metacarpals on the ulnar side
where does the intermediate layer of the anterior forearm attach to proximally
medial epicondyle of humerus, coronoid process of ulna and radial head
where does flexor digitorum superficialis attach distally (intermediate compartment)
has four muscle bellies/ tendons for the medial four digits- attaches at middle phalanges
where do the deep muscles of the anterior forearm attach proximally
to the anterior surfaces of the radius or ulnar
where does the flexor digitorum profundus attach proximally and distally
ulnar
distal phalanges of digits 2-5
where does the flexor pollicis longus attach proximally and distally
radius
distal phalanx of the thumb
where does the pronantor quadratus attach proximally and distally
anterior surface of ulnar to anterior surface of radius
what holds the tendons of the muscles in the anterior compartment of the forearm in place as they pass into the wrist and hand
palmar carpal ligament - at wrist joint
flexor retinaculum - at carpus
where does the common flexor tendon attach proximally
medial epicondyle of the humerus
what is golfers elbow
medial epicondylitis
-pain felt in area of medial epicondyle as a result of tendonitis of the common flexor tendon
what is the superior boundary of the cubital fossa
a transverse line between the epicondyles of the humerus
what is the medial boundary of the cubital fossa
pronator teres
what is the lateral boundary of the cubital fossa
brachioradialis
what are the superficial contents of the cubital fossa
median cubital vein, cephalic vein, basilic vein distal tendon (deep and lateral) and aponeurosis (medial) of biceps brachii are palpable in the fossa
what are the deep contents of the cubital fossa
median nerve (medially), brachial artery, radial nerve (laterally)
where does the median nerve after the cubital fosa
continues into the anterior compartment of the forearm
what happens to the brachial artery at the cubital fossa
bifurcates into radial and ulnar arteries at the apex of the triangle
what happens to the radial nerve at the cubital fossa
radial nerve divides into its superficial and deep branches when deep to brachialis
deep branch pierces supinator to enter to to entrt the foresr
what is the cubital fossa
triangular space between skin and the anterior aspect of the capsule of the shoulder joint
what is the funny bone
where the ulnar crosses the posterior surface of the medial epicondyle of the humerus
how does the ulnar nerve reach the anterior compartment of the forearm
passes through flexor carpi ulnaris (in cubital tunnel)
