The fascial compartments of arm refers to the specific anatomical term of the compartments within the upper segment of the upper limb (the arm) of the body. The upper limb is divided into two segments, the

arm In human anatomy, the arm refers to the upper limb in common usage, although academically the term specifically means the upper arm between the glenohumeral joint (shoulder joint) and the elbow joint. The distal part of the upper limb between th ...

and the forearm. Each of these segments is further divided into two compartments which are formed by deep fascia – tough connective tissue septa (walls). Each compartment encloses specific muscles and nerves. The compartments of the arm are the anterior compartment of the arm and the posterior compartment of the arm, divided by the lateral and the medial intermuscular septa. The compartments of the forearm are the anterior compartment of the forearm and

posterior compartment of the forearm The posterior compartment of the forearm (or extensor compartment) contains twelve muscles which primarily extend the wrist and digits. It is separated from the anterior compartment by the interosseous membrane between the radius and ulna. Struct ...

Intermuscular septa

The lateral intermuscular septum extends from the lower part of the crest of the greater tubercle of the humerus, along the lateral supracondylar ridge, to the lateral epicondyle; it is blended with the tendon of the

deltoid muscle The deltoid muscle is the muscle forming the rounded contour of the human shoulder. It is also known as the 'common shoulder muscle', particularly in other animals such as the domestic cat. Anatomically, the deltoid muscle appears to be made up o ...

, gives attachment to the

triceps brachii The triceps, or triceps brachii (Latin for "three-headed muscle of the arm"), is a large muscle on the back of the upper limb of many vertebrates. It consists of 3 parts: the medial, lateral, and long head. It is the muscle principally respon ...

behind, and to the brachialis, brachioradialis, and extensor carpi radialis longus muscles in front. It is perforated by the radial nerve and profunda branch of the brachial artery. The medial intermuscular septum, is thicker than the lateral intermuscular septum. It extends from the lower part of the crest of the lesser tubercle of the humerus below the

teres major The teres major muscle is a muscle of the upper limb. It attaches to the scapula and the humerus and is one of the seven scapulohumeral muscles. It is a thick but somewhat flattened muscle. The teres major muscle (from Latin ''teres'', meaning ...

, and passes along the medial supracondylar ridge to the medial epicondyle; it is blended with the tendon of the

coracobrachialis The coracobrachialis muscle is the smallest of the three muscles that attach to the coracoid process of the scapula. (The other two muscles are pectoralis minor and the short head of the biceps brachii.) It is situated at the upper and medial part ...

, and gives attachment to the

behind and the brachialis in front. It is perforated by the ulnar nerve, the

superior ulnar collateral artery The superior ulnar collateral artery (inferior profunda artery), of small size, arises from the brachial artery a little below the middle of the arm; it frequently springs from the upper part of the a. profunda brachii. It pierces the medial in ...

, and the posterior branch of the

inferior ulnar collateral artery The inferior ulnar collateral artery (anastomotica magna artery) is an artery in the arm. It arises about 5 cm. above the elbow from the brachial artery. Course It passes medialward upon the Brachialis, and piercing the medial intermuscular s ...

Anterior compartment

The anterior compartment of the arm is also known as the ''flexor compartment'' of the arm as its main action is that of flexion. The anterior compartment is one of the two anatomic compartments of the upper arm, the other being the posterior compartment. The compartment contains three muscles; the biceps brachii, the brachialis and the

. These muscles are all innervated by the

musculocutaneous nerve The musculocutaneous nerve arises from the lateral cord of the brachial plexus, opposite the lower border of the pectoralis major, its fibers being derived from C5, C6 and C7. Structure The musculocutaneous nerve arises from the lateral cor ...

which arises from the fifth and sixth and seventh cervical spinal nerves. The blood supply is from the brachial artery.

Posterior compartment

The posterior compartment of the arm is also known as the "extensor compartment", as its main action is extension. The muscles of this compartment are the

and anconeus muscle and these are innervated by the radial nerve. Their blood supply is from the

profunda brachii The deep artery of arm (also known as arteria profunda brachii and the deep brachial artery) is a large vessel which arises from the lateral and posterior part of the brachial artery, just below the lower border of the teres major. Structure It ...

. The ''triceps brachii'' is a large muscle containing three heads a lateral, medial, and middle. The ''anconeus'' is a small muscle that stabilizes the elbow joint during movement. Some embryologists consider it as the fourth head of the triceps brachia as the upper and lower limbs have similar embryological origins, and the lower limb contains the

quadriceps femoris The quadriceps femoris muscle (, also called the quadriceps extensor, quadriceps or quads) is a large muscle group that includes the four prevailing muscles on the front of the thigh. It is the sole extensor muscle of the knee, forming a large ...

muscle which has four heads, and is the lower limb equivalent of the triceps.

References

External links

* *
elbow/muscles/muscles2
at the

Dartmouth Medical School The Geisel School of Medicine at Dartmouth is the graduate medical school of Dartmouth College in Hanover, New Hampshire. The fourth oldest medical school in the United States, it was founded in 1797 by New England physician Nathan Smith. It is o ...

's Department of Anatomy
Dissection at tufts.edu
* https://web.archive.org/web/20080103065905/http://anatomy.med.umich.edu/musculoskeletal_system/axilla_ans.html {{Authority control Muscles of the upper limb

Intermuscular septa

Anterior compartment

Posterior compartment

See also

References

External links