The fascial compartments of arm refers to the specific anatomical term of the compartments within the upper segment of the

upper limb The upper limbs or upper extremities are the forelimbs of an upright-postured tetrapod vertebrate, extending from the scapulae and clavicles down to and including the digits, including all the musculatures and ligaments involved with the shoulde ...

(the arm) of the

body Body may refer to: In science * Physical body, an object in physics that represents a large amount, has mass or takes up space * Body (biology), the physical material of an organism * Body plan, the physical features shared by a group of anima ...

. 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 The forearm is the region of the upper limb between the elbow and the wrist. The term forearm is used in anatomy to distinguish it from the arm, a word which is most often used to describe the entire appendage of the upper limb, but which in anat ...

. Each of these segments is further divided into two compartments which are formed by

deep fascia Deep fascia (or investing fascia) is a fascia, a layer of dense connective tissue that can surround individual muscles and groups of muscles to separate into fascial compartments. This fibrous connective tissue interpenetrates and surrounds the m ...

– tough

connective tissue Connective tissue is one of the four primary types of animal tissue, along with epithelial tissue, muscle tissue, and nervous tissue. It develops from the mesenchyme derived from the mesoderm the middle embryonic germ layer. Connective tiss ...

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 The anterior compartment of the forearm (or flexor compartment) contains the following muscles: The muscles are largely involved with extension and supination. The superficial muscles have their origin on the common flexor tendon. The ulnar ner ...

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 The greater tubercle of the humerus is the outward part the upper end of that bone, adjacent to the large rounded prominence of the humerus head. It provides attachment points for the supraspinatus, infraspinatus, and teres minor muscles, thr ...

of the

humerus The humerus (; ) is a long bone in the arm that runs from the shoulder to the elbow. It connects the scapula and the two bones of the lower arm, the radius and ulna, and consists of three sections. The humeral upper extremity consists of a roun ...

, along the

lateral supracondylar ridge The lateral supracondylar ridge is a prominent, rough margin on the lower part of the lateral border of the humerus. It presents an anterior lip for the origin of forearm extensors, including the brachioradialis muscle above, and the extensor carp ...

, 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 Vertebrates () comprise all animal taxa within the subphylum Vertebrata () ( chordates with ba ...

behind, and to the brachialis,

brachioradialis The brachioradialis is a muscle of the forearm that flexes the forearm at the elbow. It is also capable of both pronation and supination, depending on the position of the forearm. It is attached to the distal styloid process of the radius by ...

, and extensor carpi radialis longus muscles in front. It is perforated by the

radial nerve The radial nerve is a nerve in the human body that supplies the posterior portion of the upper limb. It innervates the medial and lateral heads of the triceps brachii muscle of the arm, as well as all 12 muscles in the posterior osteofascial comp ...

and profunda branch of the

brachial artery The brachial artery is the major blood vessel of the (upper) arm. It is the continuation of the axillary artery beyond the lower margin of teres major muscle. It continues down the ventral surface of the arm until it reaches the cubital fossa ...

. The medial intermuscular septum, is thicker than the lateral intermuscular septum. It extends from the lower part of the crest of the

lesser tubercle The lesser tubercle of the humerus, although smaller, is more prominent than the greater tubercle: it is situated in front, and is directed medially and anteriorly. The projection of the lesser tubercle is anterior from the junction that is found ...

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 The inferior third of the medial border of the humerus is raised into a slight ridge, the medial supracondylar ridge (or medial supracondylar line), which becomes very prominent below; it presents an anterior lip for the origins of the Brachiali ...

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 In human anatomy, the ulnar nerve is a nerve that runs near the ulna bone. The ulnar collateral ligament of elbow joint is in relation with the ulnar nerve. The nerve is the largest in the human body unprotected by muscle or bone, so injury is ...

, 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 ...

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 biceps or biceps brachii ( la, musculus biceps brachii, "two-headed muscle of the arm") is a large muscle that lies on the front of the upper arm between the shoulder and the elbow. Both heads of the muscle arise on the scapula and join t ...

, 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 cord ...

which arises from the fifth and sixth and seventh

cervical spinal nerve A spinal nerve is a mixed nerve, which carries motor, sensory, and autonomic signals between the spinal cord and the body. In the human body there are 31 pairs of spinal nerves, one on each side of the vertebral column. These are grouped into th ...

s. The blood supply is from the

Posterior compartment

The posterior compartment of the arm is also known as the "extensor compartment", as its main action is

extension Extension, extend or extended may refer to: Mathematics Logic or set theory * Axiom of extensionality * Extensible cardinal * Extension (model theory) * Extension (predicate logic), the set of tuples of values that satisfy the predicate * E ...

. The muscles of this compartment are the

and

anconeus The anconeus muscle (or anconaeus/anconæus) is a small muscle on the posterior aspect of the elbow joint. Some consider anconeus to be a continuation of the triceps brachii muscle. Some sources consider it to be part of the posterior compartmen ...

muscle and these are innervated by the

. 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 (anatomy)#Left and right .28lateral.29.2C and medial, lateral and Posterior (anatomy), posterior part of t ...

. 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 Embryology (from Greek ἔμβρυον, ''embryon'', "the unborn, embryo"; and -λογία, ''-logia'') is the branch of animal biology that studies the prenatal development of gametes (sex cells), fertilization, and development of embryos a ...

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