| Olecranon fossa | |
|---|---|
 Left humerus. Posterior view (olecranon fossa visible at bottom center) | |
 Left humerus. Posterior view (olecranon fossa visible at bottom center) | |
| Details | |
| Identifiers | |
| Latin | fossa olecrani |
| TA98 | A02.4.04.024 |
| TA2 | 1204 |
| FMA | 23450 |
| Anatomical terms of bone | |
The olecranon fossa is a deep triangular depression on the posterior side of the humerus, superior to the trochlea. It provides space for the olecranon of the ulna during extension of the forearm.
The olecranon fossa is located on the posterior side of the distal humerus. [1] [2]
The joint capsule of the elbow attaches to the humerus just proximal to the olecranon fossa. [3] [4]
The olecranon fossa provides space for the olecranon of the ulna during extension of the forearm, from which it gets its name. [2] [5]
The olecranon fossa is present in various mammals, including dogs. [6]
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 ulna or ulnar bone is a long bone in the forearm stretching from the elbow to the wrist. It is on the same side of the forearm as the little finger, running parallel to the radius, the forearm's other long bone. Longer and thinner than the radius, the ulna is considered to be the smaller long bone of the lower arm. The corresponding bone in the lower leg is the fibula.
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 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 way of the brachioradialis tendon, and to the lateral supracondylar ridge of the humerus.
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 used to describe the entire appendage of the upper limb, but which in anatomy, technically, means only the region of the upper arm, whereas the lower "arm" is called the forearm. It is homologous to the region of the leg that lies between the knee and the ankle joints, the crus.
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 ulnar collateral ligament (UCL) or internal lateral ligament is a thick triangular ligament at the medial aspect of the elbow uniting the distal aspect of the humerus to the proximal aspect of the ulna.
The olecranon, is a large, thick, curved bony process on the proximal, posterior end of the ulna. It forms the protruding part of the elbow and is opposite to the cubital fossa or elbow pit. The olecranon serves as a lever for the extensor muscles that straighten the elbow joint.
The anconeus muscle is a small muscle on the posterior aspect of the elbow joint.
In human anatomy, the supinator is a broad muscle in the posterior compartment of the forearm, curved around the upper third of the radius. Its function is to supinate the forearm.
In the human arm, the humeral trochlea is the medial portion of the articular surface of the elbow joint which articulates with the trochlear notch on the ulna in the forearm.
The medial epicondyle of the humerus is an epicondyle of the humerus bone of the upper arm in humans. It is larger and more prominent than the lateral epicondyle and is directed slightly more posteriorly in the anatomical position. In birds, where the arm is somewhat rotated compared to other tetrapods, it is called the ventral epicondyle of the humerus. In comparative anatomy, the more neutral term entepicondyle is used.
Beneath the neck of the radius, on the medial side, is an eminence, the radial tuberosity; its surface is divided into:
The glenoid labrum is a fibrocartilaginous structure attached around the rim of the glenoid cavity on the shoulder blade. The shoulder joint is considered a ball-and-socket joint. However, in bony terms the 'socket' is quite shallow and small, covering at most only a third of the 'ball'. The socket is deepened by the glenoid labrum, stabilizing the shoulder joint.
The coronoid process of the ulna is a triangular process projecting forward from the anterior proximal portion of the ulna.
Superior to the anterior portion of the trochlea is a small depression, the coronoid fossa, which receives the coronoid process of the ulna during flexion of the forearm. It is directly adjacent to the radial fossa of the humerus.
The tuberosity of the ulna is a rough eminence on the proximal end of the ulna. It occurs at the junction of the antero-inferior surface of the coronoid process with the front of the body. It provides an insertion point to a tendon of the brachialis.
The radial fossa is a slight depression found on the humerus above the front part of the capitulum. It receives the anterior border of the head of the radius when the forearm is flexed.
The head of the radius has a cylindrical form, and on its upper surface is a shallow cup or fovea for articulation with the capitulum of the humerus. The circumference of the head is smooth; it is broad medially where it articulates with the radial notch of the ulna, narrow in the rest of its extent, which is embraced by the annular ligament.
The elbow is the region between the upper arm and the forearm that surrounds the elbow joint. The elbow includes prominent landmarks such as the olecranon, the cubital fossa, and the lateral and the medial epicondyles of the humerus. The elbow joint is a hinge joint between the arm and the forearm; more specifically between the humerus in the upper arm and the radius and ulna in the forearm which allows the forearm and hand to be moved towards and away from the body. The term elbow is specifically used for humans and other primates, and in other vertebrates it is not used. In those cases, forelimb plus joint is used.
This article incorporates text in the public domain from page 212 of the 20th edition of Gray's Anatomy (1918)
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