| Surgical neck of the humerus | |
|---|---|
 Left humerus. Anterior view. (Surgical neck labeled at upper right.) | |
| Details | |
| Identifiers | |
| Latin | collum chirurgicum humeri |
| TA98 | A02.4.04.004 |
| TA2 | 1183 |
| FMA | 23359 |
| Anatomical terminology | |
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.
The surgical neck is much more frequently fractured than the anatomical neck of the humerus. This type of fracture takes place when the humerus is forced in one direction while the joint capsule and the rotator cuff muscles remain intact. A fracture in this area is most likely to cause damage to the axillary nerve and posterior circumflex humeral artery. Damage to the axillary nerve affects function of the teres minor and deltoid muscles, resulting in loss of abduction of arm (from 15-90 degrees), weak flexion, extension, and rotation of shoulder as well as loss of sensation of the skin over a small part of the lateral shoulder.
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 and the elbow joint. The distal part of the upper limb between the elbow and the radiocarpal joint is known as the forearm or "lower" arm, and the extremity beyond the wrist is the hand.
The scapula, also known as the shoulder blade, is the bone that connects the humerus with the clavicle. Like their connected bones, the scapulae are paired, with each scapula on either side of the body being roughly a mirror image of the other. The name derives from the Classical Latin word for trowel or small shovel, which it was thought to resemble.
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 rounded head, a narrow neck, and two short processes. The body is cylindrical in its upper portion, and more prismatic below. The lower extremity consists of 2 epicondyles, 2 processes, and 3 fossae. As well as its true anatomical neck, the constriction below the greater and lesser tubercles of the humerus is referred to as its surgical neck due to its tendency to fracture, thus often becoming the focus of surgeons.
The axillary nerve or the circumflex nerve is a nerve of the human body, that originates from the brachial plexus at the level of the axilla (armpit) and carries nerve fibers from C5 and C6. The axillary nerve travels through the quadrangular space with the posterior circumflex humeral artery and vein to innervate the deltoid and teres minor.
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 common. This nerve is directly connected to the little finger, and the adjacent half of the ring finger, innervating the palmar aspect of these fingers, including both front and back of the tips, perhaps as far back as the fingernail beds.
The human shoulder is made up of three bones: the clavicle (collarbone), the scapula, and the humerus as well as associated muscles, ligaments and tendons.
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 of three distinct sets of muscle fibers, namely the
The teres minor 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 greater tubercle of the humerus and the posterior surface of the joint capsule.
The triceps, or triceps brachii, 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 responsible for extension of the elbow joint.
The supraspinatus is a relatively small muscle of the upper back that runs from the supraspinous fossa superior portion of the scapula to the greater tubercle of the humerus. It is one of the four rotator cuff muscles and also abducts the arm at the shoulder. The spine of the scapula separates the supraspinatus muscle from the infraspinatus muscle, which originates below the spine.
The shoulder joint is structurally classified as a synovial ball-and-socket joint and functionally as a diarthrosis and multiaxial joint. It involves an articulation between the glenoid fossa of the scapula and the head of the humerus. Due to the very loose joint capsule that gives a limited interface of the humerus and scapula, it is the most mobile joint of the human body.
The deep artery of arm is a large artery of the arm which arises from the brachial artery. It descends in the arm before ending by anastomosing with the radial recurrent artery.
The anterior humeral circumflex artery is an artery in the arm. It is one of two circumflexing arteries that branch from the axillary artery, the other being the posterior humeral circumflex artery. The anterior humeral circumflex artery is considerably smaller than the posterior and arises nearly opposite to it, from the lateral side of the axillary artery.
The posterior humeral circumflex artery arises from the third part of the axillary artery at the distal border of the subscapularis.
The quadrangular space, also known as the quadrilateral space (of Velpeau) and the foramen humerotricipitale, is one of the three spaces in the axillary space. The other two spaces are: triangular space and triangular interval.
A humerus fracture is a break of the humerus bone in the upper arm. Symptoms may include pain, swelling, and bruising. There may be a decreased ability to move the arm and the person may present holding their elbow. Complications may include injury to an artery or nerve, and compartment syndrome.
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, and long head of triceps brachii.
The following outline is provided as an overview of and topical guide to human anatomy:
Axillary nerve palsy is a neurological condition in which the axillary nerve has been damaged by shoulder dislocation. It can cause weak deltoid and sensory loss below the shoulder. Since this is a problem with just one nerve, it is a type of Peripheral neuropathy called mononeuropathy. Of all brachial plexus injuries, axillary nerve palsy represents only .3% to 6% of them.
A proximal humerus fracture is a break of the upper part of the bone of the arm (humerus). Symptoms include pain, swelling, and a decreased ability to move the shoulder. Complications may include axillary nerve or axillary artery injury.
This article incorporates text in the public domain from page 209 of the 20th edition of Gray's Anatomy (1918)
 | This human musculoskeletal system article is a stub. You can help Wikipedia by expanding it. |
