| Structure/Space | Description/Boundaries | Significance |
|---|---|---|
| adductor/interosseous compartment | a compartment in the hand bounded on its palmar surface by the fascia covering adductor pollicis m. and interosseous mm., and on its dorsal surface by the interosseous fascia | adductor/interosseous compartment contains the metacarpal bones, the adductor pollicis m. and the palmar & dorsal interosseous mm. |
| anterior (flexor) compartment of the arm | compartment bounded at its posterior extent by the medial and lateral intermuscular septa and the humerus; it is bounded anteriorly, laterally and medially by the brachial fascia | anterior compartment of the arm contains flexor muscles of the arm (biceps brachii m., coracobrachialis m., brachialis m.) which are innervated by the musculocutaneous nerve |
| anterior (flexor) compartment of the forearm | compartment bounded at its posterior extent by the medial and lateral intermuscular septa, the radius, the ulna and the interosseous membrane; it is bounded anteriorly, laterally and medially by the antebrachial fascia | anterior compartment of the forearm contains flexor muscles of the hand (superficially - pronator teres, flexor carpi radialis, palmaris longus, flexor carpi ulnaris; intermediate layer - flexor digitorum superficialis; deep layer - flexor digitorum profundus, flexor pollicis longus, pronator quadratus); it also contains the median n., ulnar n. and ulnar a. |
| anterior axillary fold | a fold of skin and muscle with the pectoralis major m. as its muscular component | axillary tail of the mammary gland courses along the anterior axillary fold |
| axilla | fat-filled space located lateral to the thoracic wall and anterior to the scapula; it is bounded: superiorly by the clavicle, scapula and 1st rib; inferiorly by the axillary fascia; anteriorly by the pectoralis major and minor mm.; posteriorly by the subscapularis m.; laterally by the humerus; medially by the serratus anterior m. and thoracic wall | axilla contains the infraclavicular part of the brachial plexus (divisions, cords and terminal branches), the axillary a. and v. and the axillary lymph nodes |
| carpal tunnel | an osseofibrous tunnel in the hand formed by the flexor retinaculum and the carpal bones | carpal tunnel contains the tendons of the flexors of the digits (flexor pollicis longus m., flexor digitorum superficialis m. flexor digitorum profundus m.) and the median nerve which may be compressed in this location resulting in carpal tunnel syndrome |
| cubital fossa | a shallow depression on the anterior surface of the elbow region; it is bounded superiorly by an imaginary line between the humeral epicondyles, medially by the lateral border of the pronator teres m. and laterally by the medial border of the brachioradialis m. | the median cubital v. crosses this region and is a site for phlebotomy |
| deltopectoral triangle | a triangle in the upper chest region that is bounded medially by the clavicle, superiorly by the deltoid m. and inferiorly by the pectoralis major m. | deltopectoral triangle is pierced by the cephalic vein on its course from the upper limb to join the axillary vein in the axilla |
| hypothenar compartment | compartment in the hand bounded by the fascia covering the intrinsic muscles of 5th digit | hypothenar compartment contains the short muscles of the 5th digit: (abductor digiti minimi m., flexor digiti minimi brevis m., opponens digiti minimi m.) |
| midpalmar space | a space in the palm bounded by: hypothenar fascia medially and the septum attaching the palmar aponeurosis to the third metacarpal bone laterally; palmar aponeurosis superficially and fascia of the interosseous mm. deeply | midpalmar space may cause infections to become localized in the palm |
| posterior (extensor) compartment of the arm | compartment bounded at its anterior extent by the medial and lateral intermuscular septa and humerus; it is bounded posteriorly, laterally and medially by the brachial fascia | posterior compartment of the arm contains the extensor muscles of the elbow (triceps brachii m., anconeus m.), the radial n.and the deep brachial a. |
| posterior (extensor) compartment of the forearm | compartment bounded at its anterior extent by the medial and lateral intermuscular septa, the radius, the ulna and the interosseous membrane; it is bounded posteriorly, laterally and medially by the antebrachial fascia | posterior compartment of the forearm contains extensor muscles of the hand and wrist (superficial group - brachioradialis m., extensor carpi radialis longus m., extensor carpi radialis brevis m., extensor digitorum m., extensor digiti minimi m., extensor carpi ulnaris m.; deep group - supinator m., abductor pollicis longus m., extensor pollicis brevis m., extensor pollicis longus m., extensor indicis m.); it contains the superficial and deep radial nn., the posterior interosseous artery and the radial artery |
| posterior axillary fold | a fold of skin and muscle with the teres major and latissimus dorsi mm. as the muscular components | the posterior extent of the floor of the axilla |
| quadrangular space | the space bounded by the teres minor m. superiorly, the teres major m. inferiorly, the long head of the triceps brachii m. medially and the humerus laterally | the axillary n. and the posterior circumflex humeral a. pass through this space |
| thenar compartment | compartment in the hand bounded by the fascia covering the intrinsic muscles of the thumb | thenar compartment contains the short muscles of the thumb (abductor pollicis brevis m., flexor pollicis brevis m., opponens pollicis m.) and the tendon of the flexor pollicis longus m. |
| triangular interval | the interval between the teres major m. superiorly, long head of the triceps brachii m. medially and humerus laterally | the radial n. passes through this interval to get from the axilla to the posterior surface of the humerus |
| triangular space | the space bounded by the teres minor m. superiorly, the teres major m. inferiorly and the long head of the triceps brachii m. laterally | the circumflex scapular vessels are located in this space as they pass from the axilla to the dorsum of the scapula |