Anterior Forearm Flashcards
WHat are the two bones of the forearm? Which is medial and which is lateral?
the ulna (medial - pinky)
the radius (lateral - the thumb)
IDentify the structures
Where does the head of the readius articulate? WHat holds it in place?
It articulates with the radial notch of the ulna AND with the capitulum of the humerus
it’s held in position by the annular ligament
What membrane connects the radius and the ulna?
the interosseous membrane
Which forearm bone has the olecranon process at the upper end?
the ulna
What does the olecranon process articulate with?
the trochlea of the humerus
Which styloid process projects more ditally, the ulna or radius?
the radius
How do the forearm bones connect to the hand bones?
- the radius articulates with the scaphoid and lunate carpal bones
- the ulna is separated from the carpal bones by an articular disc
WHere does the medial cutaneous nerve of the foreamr arise?
Where does the lateral cutaneous nerve of the forearm arise?
medial = comes off the posterior cord of the brachial plexus
lateral = continuation of the musculocutaneous nerve
what does the brachioradialis attache?
proximally = lateral supracondular ridges of the humerus
distally = proximal to the styloid process of the radius
Thus, it crosses over the elbow joint, so it’s a flexor muscle.
What nerve innervates the brachioradiualis?
the radial nerve
After the radial nerve pierces the lateral intermuscular septum, what does it do?
It divides into superifcial and deep branches
the superficial branch is sensory and continues distally beneath the brachioradialis muscle
the deep branch pierces the supinator muscle and supplies motor fibers to extensor muscles of the forearm
What is the deep fascia thickening that serves to hold the flexor muscles in the carpal tunnel?
the transverse carpel ligament
also called the flexor retinaculum
What are the five muscles that compose the superficial group of forearm flexors?
- Pronator teres
- flexor carpi radialis
- palmaris longus
- flexor digitorum superficialis
- flexor carpi ulnaris
Protector teres flexes the carp in a radical way in his long palm. then flexes his superior digits and flings the carp to ulna.
Which 4 superficial forearm flexors are innervated by the median nerve?
Which is the only one innervated by the ulnar nerve?
the flexor carpi ulnarix is the only one supplied by the ulnar nerve
otherwise the pronator teres, flexor carpi radialis, palmaris longus, and the flexor digitorum superficialis are all innervated by the median nerve
The five muscles of the superficial flexors all have an origina hwere?
the medial epicondyle
Besides the medial epichondyle, where does the pronator teres originate? Where does it attach distally? What does this mean for its function?
It also takes origin on the ulnar head.
It attaches distally on the radius.
Because it originate on the ulnar side and attaches on the radial side, it can act as a pronator and flexor of the forearm
Where does the flexor carpi radialis attach distally?
to the base of the 2nd metacarpal
What does the palmaris longus attach to distally?
the palmar aponeurosis
Where does the flexor carpi ulnaris attach distally?
to the base of the 5th metacarpal
Where is the flexor digitorum superficialis located relative to the other 4 superficial forearm flexors?
deeper to them all (even though it’s called the superficialis)
Besides the medial epicondyle, where does the flexor digitorum superficialis take origin?
Where does it insert?
It takes origin fom the coronoid process of the ulna and the radius
it inserts on the middle phalange of the medial four digits
Of the superficial group, which one is the only one whose tendons pass through the carpel tunnel?
the flexor digitorum superficialis
there are 4 of them