Question | Answer |
What are the muscles of the anterior compartment of the arm? | Biceps brachii, brachialis, and the coracobrachialis |
What nerve supplies the anterior compartment of the arm? | The musculocutaneous nerve |
What artery supplies the anterior compartment of the arm? | The brachial artery |
What is the innervation and action of the biceps brachii? | Musculocutaenous; flexes and supinates forearm (most powerful supinator) |
What is the innervation and action of the brachialis? | musculocutaneous; chief flexor of the forearm |
What is the innervation and action of the coracobrachialis? | Musculocutaneous; flexes and adducts the humerus |
What are the muscles of the posterior compartment of the arm? | Triceps brachii, anconeus |
What nerve supplies the posterior compartment of the arm? | The radial nerve |
What artery supplies the posterior compartment of the arm? | The profunda brachii and the ulnar collateral arteries |
What is the innervation and action of the triceps brachii? | Nerve: radial nerve; Action: CHIEF EXTENSOR of the arm |
What is the innervation and action of the anconeus? | Nerve: Radial; Action: Extensions of the forearm |
Describe the path of the brachial artery | Continuation of the axillary artery at the LOWER BORDER OF THE TERES MAJOR MUSCLE. Superficial throughout course, running along MEDIAL side of biceps with MEDIAN NERVE; divides in cubital fossa into radial + ulnar art's. |
What are the major branches of the brachial artery? | Profunda brachii (largest), superior ulnar collateral, inferior ulnar collateral |
Where does the profunda brachii run? | Runs with RADIAL NERVE in the RADIAL GROOVE |
What are the terminal branches of the profunda brachii? Where do they anastomose? | Radial collateral (anastomoses with radial recurrent artery in front of lateral), Middle collateral (anastomoses with interossus recurrent artery in back of lateral epycondyle) |
Where is the superior ulnar collateral? | Arises in mid arm from brachial artery; accompanies ULNAR NERVE behind medial epicondyle and anastomoses with posterior ulnar recurrent artery |
Where is the inferior ulnar collateral? | Arises ~5 cm. above elbow; anastomoses with anterior ulnar recurrent in front of the medial epicondyle |
The radial collateral artery anastomoses with the ____ ___ artery in front of the ___ epicondyle. | radial recurrent; lateral |
Where does the median nerve lie? | Runs with the brachial artery; no branches in the arm |
Where does the musculocutaneous nerve lie? | Pierces coracobrachialis muscle; runs in the plane between biceps and brachialis; emerges at the elbow lateral to the biceps tendon at the lateral antebrachial cutaneous nerve |
Where does the ulnar nerve lie? | Passes behind the medial epicondyle of the humerus with the superior ulnar collateral artery; no branches in the arm |
Where does the radial nerve lie? | Joins profunda brachii in the radial groove between medial and lateral head of the triceps; pierces the lateral intermuscular septum-->enters anterior compartment and continues between brachialis and brachioradialis muscles |
What are the two branches of the radial nerve? | The superficial (sensory) and deep branches (motor) |
What are the boundaries of the cubital fossa? (lateral, medial, floor, and roof) | Brachioradialis muscle; pronator teres muscle; supinator and brachialis; bicipital aponeurosis |
What are the contents of the cubital fossa medial to lateral? | Median nerve; brachial artery and terminal branches; biceps tendons; radial nerve and terminal branches |
What is the antebrachial fascia? | Deep fascia of the forearm, which is continuous above with the brachial fascia |
* * What is the interosseous membrane? | Thin but strong membrane uniting the radius and ulna; fibers run obliquely down and medially so that a force applied to lower end of radius is transmitted upwards; serves as attachment site for many muscles |
How is forced transmitted along interossus membrane? | Radius-->ulna-->humerus-->scapula |
What is the flexor retinaculum? | Thickening of deep fascia that holds long flexor tendons in position at the wrist; converts concave anterior surface of the hand into an osteofibrous tunnel (Carpal tunnel) for passage of the median nerve and the long flexor tendons |
What is the flexor retinaculum attached to? | Medially to the pisoform bone and hook of hamate and laterally to the scaphoid and trapezium bones; proximal border of the flexor retinaculum corresponds to the distal transverse skin crease in front of skin |
What is the extensor retinaculum? | Thickening of the deep fascia across the back of the wrist; holds the long extensor tendons in position; attached medially to the pisiform bone and hook of hamate and laterally to the distal end of the radius |
What is the blood supply to the anterior (flexor) compartment of the forearm? The nerve supply? | Blood: ulnar and radial arteries; Nerve: all muscles are innervated by the MEDIAN NERVE except the FLEXOR CARPI ULNARIS and MEDIAL 1/2 of FLEXOR DIGITORUM PROFUNDIS (ulnar nerve) |
What are the superficial muscles of the anterior compartment? | Pronator teres; flexor carpi radialis, palmaris longus, and flexor carpi ulnaris |
What are the intermediate muscles of the anterior compartment? | Flexor digitorum superficialis |
What are the deep muscles of the anterior compartment? | Flexor pollicus longus; flexor digitorum profundus, and the pronator quadratus |
Nerve supply and action of the pronator teres | Median nerve; pronation and flexion of the forearm |
Nerve supply and action flexor carpi radialis | Median nerve; flexes and abducts the wrist joint (inserts into bases of the second and third metacarpal) |
Nerve supply and action palmaris longus | Median nerve; flexes wrist (inserts into the flexor retinaculum and palmar aponeurosis) |
Nerve supply and action flexor carpi ulnaris | ULNAR NERVE; flexes and adducts the wrist (inserts into pisiform, hook of hamate, and base of fifth metacarpal) |
Nerve supply and action of the flexor digitorum superficialis | Median nerve; flexes fingers, knuckles, and wrists |
Nerve supply and action of the flexor pollicus longus | Anterior interosseous branch of the median nerve; flexes thumb |
* * Nerve supply and action of flexor digitorum profundus | Ulnar and median nerves (anterior interossesous branch); flexes the fingers, knuckles, and wrist (THE ONLY MUSCLE WHICH FLEXES THE DISTAL PHALANGES OF THE MEDIAL FOUR FINGERS) |
Nerve supply and action of the pronator quadratus | Anterior interosseous branch of median nerve; pronates the forearm |
With what structures does the ulnar artery run with as it descends into the forearm? | Descends deep to the pronator teres and runs through the forearm with the ulnar nerve; emerges at the wrist with the ulnar nerve lateral to the pisiform bone and superficial to the flexor retinaculum |
What are the important branches of the ulnar artery in the forearm? | The anterior ulnar recurrent, the posterior ulnar recurrent, and the common interosseous artery |
Describe the path of the radial artery | Runs along the lateral forearm under the cover of the brachioradialis muscle; approaches the wrist between the radius and the flexor carpi radialis muscle |
What are the important branches of the radial artery in the forearm? | Radial recurrent, superficial palmar branch |
What artery do you typically use to get a pulse on the wrist? | The superficial palmar branch of the radial artery |
What is the superficial palmar arch? | It is a joining of the superficial palmar branch and the ulnar arteries |
This nerve appears in the cubital fossa medial to the brachial artery and then passes between two heads of the pronator teres muscle | Median nerve |
Describe the course of the median nerve | Cubital fossa (medial to the brachial artery); between two heads of pronator teres; courses in plane between flexor digitorum superficialis and flexor digitorum profundus; enters palm of the hand deep to the flexor retinaculum |
Describe how the median nerve enters the wrist | Enters the palm of the hand DEEP to the flexor retinaculum |
Describe the course of the ulnar nerve | enters the front of the forearm passing between the two heads of the flexor carpi ulnaris; runs down forearm between flexor carpi ulnaris and flexor digitorum profundus muscles; enters palm SUPERFICIAL to flexor retinaculum and lateral to pisiform bone |