The quadrangular space, also known as the quadrilateral space f Velpeau'' and the foramen humerotricipitale, is one of the three spaces in the

axillary space The axillary spaces are anatomic spaces. through which axillary contents leave the axilla. They consist of the quadrangular space, triangular space, and triangular interval. It is bounded by teres major, teres minor, medial border of the humerus, ...

. The other two spaces are:

triangular space The triangular space (also known as the medial triangular space, upper triangular space, medial axillary space or foramen omotricipitale) is one of the three spaces found at the axillary space. The other two spaces are the quadrangular space and ...

and

triangular interval The triangular interval (also known as the lateral triangular space, lower triangular space, and triceps hiatus) is a space found in the axilla. It is one of the three intermuscular spaces found in the axillary space. The other two spaces are: q ...

Structure

The quadrangular space is one of the three spaces in the

Boundaries

The quadrangular space is defined by: - "Scapular Region: Quadrangular Space of Scapular Region" * ''above/superior:''

teres minor muscle The teres minor (Latin ''teres'' meaning 'rounded') is a narrow, elongated muscle of the rotator cuff. The muscle originates from the lateral border and adjacent posterior surface of the corresponding right or left scapula and inserts at both the ...

. * ''below/inferior:''

teres major muscle 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'', meani ...

. * ''medially:'' long head of the

triceps brachii muscle 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 responsibl ...

(lateral margin). * ''laterally:''

surgical neck of the humerus The surgical neck of the humerus is a bony constriction at the proximal end of shaft of humerus. It is situated distal to the greater tubercle and lesser tubercle, and proximal to the deltoid tuberosity. Clinical significance The surgical nec ...

. * ''anteriorly:''

subscapularis muscle The subscapularis is a large triangular muscle which fills the subscapular fossa and inserts into the lesser tubercle of the humerus and the front of the capsule of the shoulder-joint. Structure It arises from its medial two-thirds and Som ...

The quadrangular space transmits the

axillary nerve The axillary nerve or the circumflex nerve is a nerve of the human body, that originates from the brachial plexus (upper trunk, posterior division, posterior cord) at the level of the axilla (armpit) and carries nerve fibers from C5 and C6. The a ...

, and the

posterior humeral circumflex artery The posterior humeral circumflex artery (posterior circumflex artery, posterior circumflex humeral artery) arises from the third part of axillary artery at the lower border of the subscapularis, and runs posteriorly with the axillary nerve through ...

Clinical significance

The quadrangular space is a clinically important anatomic space in the arm as it provides the anterior regions of the

axilla The axilla (also, armpit, underarm or oxter) is the area on the human body directly under the shoulder joint. It includes the axillary space, an anatomical space within the shoulder girdle between the arm and the thoracic cage, bounded superior ...

a passageway to the posterior regions. In the quadrangular space, the

and the

can be compressed or damaged due to space-occupying lesions or disruption in the anatomy due to trauma.

Symptoms Signs and symptoms are the observed or detectable signs, and experienced symptoms of an disease, illness, injury, or condition. A sign for example may be a higher or lower temperature than normal, raised or lowered blood pressure or an abnormali ...

include axillary nerve related weakness 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 ...

in the case of any significant mass lesions in the quadrangular space.

History

The quadrangular space is so named because the three

skeletal muscles Skeletal muscles (commonly referred to as muscles) are organs of the vertebrate muscular system and typically are attached by tendons to bones of a skeleton. The muscle cells of skeletal muscles are much longer than in the other types of muscle ...

and one

long bone The long bones are those that are longer than they are wide. They are one of five types of bones: long, Short bone, short, Flat bone, flat, Irregular bone, irregular and Sesamoid bone, sesamoid. Long bones, especially the femur and tibia, are subj ...

that form its boundaries leave a space in the shape of a

complete quadrangle In mathematics, specifically in incidence geometry and especially in projective geometry, a complete quadrangle is a system of geometric objects consisting of any four Point (geometry), points in a Plane (geometry), plane, no three of which are C ...

. The quadrangular space is also known as the quadrilateral space, the quadrilateral space of Velpeau, and the foramen humerotricipitale.

Additional images

File:Gray412-spaces.png, Muscles on the dorsum of the scapula, and the Triceps brachii.

References

External links

*
Photo at umich.edu

Diagram at wustl.edu

Photo at ithaca.edu
Upper limb anatomy {{Portal bar, Anatomy