Arm and Flexor Forearm Flashcards
With which fascias is the brachial (Deep) fascia continuous with?
Pectoral, deltoid, and axillary fascias
To what is the brachial fascia attached to?
Attached to the humeral epicondyles and olecranon process of the ulna
The brachial fascia divides the arm into which two compartments?
Anterior - flexor compartment
Posterior - extensor compartment
What are the 3 muscles of the anterior compartment of the arm?
Biceps brachii
Brachialis
Coracobrachialis
What is the blood supply of the anterior compartment of the arm? What is the nerve supply?
Brachial artery
Musculocutaneous nerve
What is the nerve supply of the biceps brachii? What is its action?
Is supplied by the musculocutaneous nerve
Flexes and supinates forearm (most powerful supinator)
Weak flexor of the arm
What is the nerve supply of the brachialis, and what is its action?
Supplied by the musculocutaneous nerve
**Is the chief flexor of the forearm
What muscles are contained in the posterior compartment of the arm?
Triceps brachii
Anconeus (which is a partially detached part of triceps)
What is the nerve supply of the triceps brachii, and what is its action?
Supplied by the radial nerve
Is the chief extensor of the forearm
What is the nerve supply of the anconeus, and what is its action?
Supplied by the radial nerve
Extension of the forearm
(recall that radial nerve is great extensor nerve of the forearm)
At what point does the axillary artery become the brachial artery?
At the lower border of the teres major muscle
What nerve does the brachial artery run along with?
Runs on the medial side of biceps with median nerve
What are the 2 arteries that the brachial artery divides into, and where does it divide?
Divides into the radial and ulnar arteries
Divides in the cubital fossa
What are the 3 major branches of the brachial artery in the arm?
Deep brachial artery
Superior ulnar collateral
Inferior ulnar collateral
What is another name for the deep brachial artery, what is it a branch of, and what are its 2 terminal branches? What does each terminal branch anastomose with?
Deep brachial artery is also called the profunda brachii artery
Is a branch of the brachial artery in the arm
Terminal branches are radial collateral and middle collateral
-radial collateral anastomoses with with radial recurrent artery in front of lateral epicondyle
-middle collateral anastomoses with interosseous recurrent artery in the back of lateral epicondyle
What is the superior ulnar collateral a branch of, and what does it anastomose with? What nerve does it accompany?
The superior ulnar collateral is a branch of the brachial artery, and anastomoses with the posterior ulnar recurrent artery behind medial epicondyle**
Accompanies the ulnar nerve*
What is the inferior ulnar collateral a branch of, and what does it anastomose with?
Inferior ulnar is a collateral of the brachial artery, and anastomoses with the anterior ulnar recurrent artery in front of medial epicondyle
What are the 4 nerves of the arm?
Median nerve
Musculocutaneous nerve
Ulnar nerve
Radial nerve
With what artery does the median nerve run with?
Runs with the brachial artery
What muscle does the musculocutaneous nerve pierce, and between what 2 muscles does it run between after that? What does it finally emerge as?
Musculocutaneous pierces the coracobrachialis muscle
Runs in plane between biceps and brachialis (sends branches to both muscles)
Emerges at elbow lateral to biceps tendon as lateral antebrachial cutaneous nerve
Behind what does the ulnar nerve pass, and with what artery?**
Passes behind the medial epicondyle of the humerus with the superior ulnar collateral artery
With what artery does the radial nerve join with, and in what groove between what muscle?
Radial nerve joins the profunda brachii artery
In the radial groove between the medial and lateral heads of the triceps
After piercing the lateral intermuscular septum to enter the anterior compartment, what two muscles does the radial nerve continue between?
Continues between the brachialis and brachioradialis muscles
In front of what does the radial nerve divide, and into what 2 branches?
Radial nerve divides in front of the lateral epicondyle into:
- superficial branch (sensory)
- deep branch (motor)
What are the borders of the cubital fossa?
Lateral - brachioradialis muscle
Medial - pronator teres muscle
Floor - supinator (lateral) and brachialis (medial) muscles
Roof - bicipital aponeurosis
What are the 4 contents from medial to lateral of the cubital fossa?**
Median nerve
Brachial artery and terminal branches
Biceps tendon
Radial nerve and terminal branches
What is the “club sandwich” of the cubital fossa?**
Biceps brachii tendon Lateral antebrachial cutaneous nerve Brachialis Radial nerve Brachioradialis
What is the deep fascia of the forearm, and what is it continuous with?
The deep fascia of the forearm is the antebrachial fascia
Continuous with brachial fascia above
What is the name of the membrane between the radius and ulna, and what are 2 primary purposes?
Interosseous membrane
- Transmits the force (e.g. falling on outstretched hand) from radius to ulna to humerus to scapula
- Attachment site for many muscles
What is the thickening of deep fascia that holds the long flexor tendons in position at the wrist?
Flexor retinaculum
What does the flexor retinaculum convert the concave anterior surface of the hand into, and what is this more commonly known as?
Converts the anterior surface of hand into the osteofibrous tunnel
AKA Carpal tunnel
What does the proximal border of flexor retinaculum correspond with in front of the wrist?
Corresponds with the distal transverse skin crease in front of wrist
What is the name of the thickening of the deep fascia on the back of the wrist which holds the long extensor tendons in position?
Extensor retinaculum
What is the extensor retinaculum attached to, medially and laterally?
Medially to the pisiform bone and hook of hamate
Laterally to distal end of radius
What is the blood supply of the anterior (flexor) compartment of the forearm?
What is the nerve supply?***
Blood supply is the radial and ulnar arteries
Nerve supply - all muscles are innervated by median nerve EXCEPT the flexor carpi ulnaris and medial 1/2 of flexor digitorum profundus which are supplied by ulnar nerve
(so median supply 6 1/2 muscles, ulnar supply 1 1/2 muscles)
What are the 4 superficial muscles of the anterior compartment?
Pronator teres
Flexor carpi radialis
Palmaris longus
Flexor carpi ulnaris
What part of the anterior compartment is the pronator teres, what is its nerve supply, and what is its action?
Is part of the superficial muscles of the anterior compartment
Supplied by median nerve
Pronates and flexes the forearm
What part of the anterior compartment is the flexor carpi radialis, what is its nerve supply, and what is its action?
Is part of the superficial muscles of the anterior compartment
Supplied by median nerve
Flexes and abducts the wrist joint (fan the hands OUT when in anatomical position)
(remember anything with radialis in name is abduction)
What part of the anterior compartment is the palmaris longus, what is its nerve supply, and what is its action?
Is part of the superficial muscles of the anterior compartment
Supplied by median nerve
Flexes wrist
What part of the anterior compartment is the flexor carpi ulnaris, what is its nerve supply, and what is its action?
Is part of the superficial muscles of the anterior compartment
Supplied by the ulnar nerve
Flexes and adducts the wrist
(remember anything with ‘ulnaris’ in name adducts)
What is the one intermediate muscle of the anterior compartment, what is its nerve supply, and what is its action?
Flexor digitorum superficialis
Supplied by the median nerve
Flexes fingers, knuckles, and wrist
(if a tendon runs over 3 joints, then the tendon moves all of them**)
What are the deep muscles of the anterior compartment?
Flexor pollicus longus
Flexor digitorum profundus
Pronator quadratus
What part of the anterior compartment is the flexor pollicus longus, what is its nerve supply, and what is its action?
Is part of the deep muscles of anterior compartment
Supplied by the anterior interosseous branch of median nerve
flexes thumb
What part of the anterior compartment is the flexor digitorum profundus, what is its nerve supply, and what is its action?***
Is part of the deep muscles of anterior compartment
Supplied by the ulnar and median nerve (the anterior interosseous branch)
Flexes the fingers, knuckles, and the wrist
What is the only muscle that flexes the distal phalanges of the medial four fingers?***
Flexor digitorum profundus
What part of the anterior compartment is the pronator quadratus, what is its nerve supply, and what is its action?
Is part of the deep muscles of anterior compartment
Supplied by the anterior interosseous branch of median nerve
Pronates the forearm
What are the 2 main arteries of the flexor compartment of the forearm?
Ulnar artery
Radial artery
What muscle does the ulnar artery descend deep to, and what nerve does it run with in the forearm?
Descends deep to pronator teres muscle and runs with ulnar nerve
With respect to the pisiform bone in the hand, does the ulnar artery run medial or lateral to it, and is it superficial or deep to the flexor retinaculum?** What is a consequence?
The ulnar artery runs lateral to the pisiform bone
Runs superficial to the flexor retinaculum
Therefore, it is not affected in carpal tunnel syndrome
What are the 3 main branches of the ulnar artery in the forearm, and what two branches does one of those subdivide into?
Anterior ulnar recurrent
Posterior ulnar recurrent
Common interosseous artery
-divides into anterior interosseous artery an posterior interosseous artery (which gives off interosseous recurrent)
Under what muscle does the radial artery travel?
Under the brachioradialis muscle
Where would someone take the radial pulse? It is between a bone and a muscle.
It would be between the radius and the flexor carpi radialis muscle
What are the 2 important branches of the radial artery in the forearm?
Radial recurrent
Superficial palmar branch (unites with terminal part of ulnar artery to make superficial palmar arch)
What two arteries unite to form the superficial palmar arch?
Superficial palmar branch (of the radial artery)
Terminal part of the ulnar artery
What are the 2 main nerves of the flexor compartment? Between what two muscles do each of these nerves run?**
Median nerve - runs between the flexor digitorum superficialis and the flexor digitorum profundus
Ulnar nerve - runs between the flexor carpi ulnaris and the flexor digitorum profundus muscles
How does the median enter the palm of the hand with respect to the flexor retinaculum? The ulnar nerve?
Median nerve enters deep to the flexor retinaculum
Ulnar nerve enters superficial to the flexor retinaculum
Behind what tendon does the median nerve lie in the palm?
Behind the tendon of the palmaris longus
