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Trochlea Of Humerus
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. Structure In humans and apes it is trochleariform (or trochleiform), as opposed to cylindrical in most monkeys and conical in some prosimians. It presents a deep depression between two well-marked borders; it is convex from before backward, concave from side to side, and occupies the anterior, lower, and posterior parts of the extremity. The trochlea has the capitulum located on its lateral side and the medial epicondyle on its medial. It is directly inferior to the coronoid fossa anteriorly and to the olecranon fossa posteriorly. In humans, these two fossae, the most prominent in the humerus, are occasionally transformed into a hole, the supratrochlear foramen, which is regularly present in, for example, dogs. Carrying angle When viewed from in front or behind, the trochlea looks roughly cylindrical, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 rounded head, a narrow neck, and two short processes (tubercles, sometimes called tuberosities). The body is cylindrical in its upper portion, and more prismatic below. The lower extremity consists of 2 epicondyles, 2 processes (trochlea & capitulum), and 3 fossae (radial fossa, coronoid fossa, and olecranon fossa). 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. Etymology The word "humerus" is derived from la, humerus, umerus meaning upper arm, shoulder, and is linguistically related to Gothic ''ams'' shoulder and Greek ''ōmos''. Structure Upper extremity The upper or pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Olecranon Fossa
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. Structure The olecranon fossa is located on the posterior side of the distal humerus. The joint capsule of the elbow attaches to the humerus just proximal to the olecranon fossa. Function The olecranon fossa provides space for the olecranon of the ulna during extension of the forearm, from which it gets its name. Other animals The olecranon fossa is present in various mammals, including dogs The dog (''Canis familiaris'' or ''Canis lupus familiaris'') is a domesticated descendant of the wolf. Also called the domestic dog, it is derived from the extinct Pleistocene wolf, and the modern wolf is the dog's nearest living relative. Do .... Additional images File:Slide1bgbg.JPG, Elbow joint. Deep dissection. Posterior view. File:Slide2bgbg.JPG, Elbow joint. Deep dissection. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Head Of Radius
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.''Gray's Anatomy'' (1918), see infobox Articular surfaces The head of the radius is shaped to articulate with a complex of articular surfaces during both flexion-extension at the elbow and supination-pronation in the forearm: Humeroradial joint The head's proximal surface is concave and cup-shaped to correspond to the spherical surface of the capitulum of the humerus. The radius can thus glide on the capitulum during elbow flexion-extension while simultaneously rotate about its own main axis during supination-pronation. Between the capitulum and the trochlea of the humerus is the capitulotrochlear groove. A semi-lunar surface around the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Olecranon
The olecranon (, ), is a large, thick, curved bony eminence of the ulna, a long bone in the forearm that projects behind the elbow. It forms the most pointed portion 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. Structure The olecranon is situated at the proximal end of the ulna, one of the two bones in the forearm. When the hand faces forward (supination) the olecranon faces towards the back (posteriorly). It is bent forward at the summit so as to present a prominent lip which is received into the olecranon fossa of the humerus during extension of the forearm. Its base is contracted where it joins the body and the narrowest part of the upper end of the ulna. Its posterior surface, directed backward, is triangular, smooth, subcutaneous, and covered by a bursa. Its superior surface is of quadrilateral form, marked behind by a rough impression for the insertion of the Tr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coronoid Process Of The Ulna
The coronoid process of the ulna is a triangular process projecting forward from the anterior proximal portion of the ulna. Structure Its ''base'' is continuous with the body of the bone, and of considerable strength. Anatomy Its ''apex'' is pointed, slightly curved upward, and in flexion of the forearm is received into the coronoid fossa of the humerus. Its ''upper surface'' is smooth, convex, and forms the lower part of the semilunar notch. Its ''antero-inferior'' surface is concave, and marked by a rough impression for the insertion of the brachialis muscle. At the junction of this surface with the front of the body is a rough eminence, the tuberosity of the ulna, which gives insertion to a part of the brachialis; to the lateral border of this tuberosity the oblique cord is attached. Its ''lateral surface'' presents a narrow, oblong, articular depression, the radial notch. Its ''medial surface'', by its prominent, free margin, serves for the attachment of part of the uln ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hinge Joint
A hinge joint (ginglymus or ginglymoid) is a bone joint in which the articular surfaces are molded to each other in such a manner as to permit motion only in one plane. According to one classification system they are said to be uniaxial (having one degree of freedom).Platzer, Werner (2008) ''Color Atlas of Human Anatomy', Volume 1p.28/ref> The direction which the distal bone takes in this motion is seldom in the same plane as that of the axis of the proximal bone; there is usually a certain amount of deviation from the straight line during flexion. The articular surfaces of the bones are connected by strong collateral ligaments. The best examples of ginglymoid joints are the Interphalangeal joints of the hand and those of the foot and the joint between the humerus and ulna. The knee joints and ankle joints are less typical, as they allow a slight degree of rotation or of side-to-side movement in certain positions of the limb. The knee is the largest hinge joint in the human b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Supratrochlear Foramen
The supratrochlear foramen is a small hole located above the trochlea of the humerus of several mammals, it is found frequently in dogs and sometimes in humans, especially women and in the left humerus. It is covered by a layer of connective tissue. It is not currently recognized with a Terminologia Anatomica name in human anatomy, but the term is still found in older texts and in discussing anatomical variation. See also * Entepicondylar foramen The entepicondylar foramen is an opening in the distal (far) end of the humerus (upper arm bone) present in some mammals. It is often present in primitive placentals, such as the enigmatic Madagascan ''Plesiorycteropus''. In most Neotominae and al ... References Mammal anatomy {{Vertebrate anatomy-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coronoid Fossa
Superior to the anterior portion of the Trochlea of humerus, 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. Additional images File:Human arm bones diagram.svg, Human arm bones diagram File:Elbow joint - deep dissection (anterior view, human cadaver).jpg, Elbow joint. Deep dissection. Anterior view. File:Slide2xzxzxz.JPG, Elbow joint. Deep dissection. Anterior view. References External links * Humerus {{musculoskeletal-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Elbow
The elbow is the region between the arm and the forearm that surrounds the elbow joint. The elbow includes prominent landmarks such as the olecranon, the cubital fossa (also called the chelidon, or the elbow pit), 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 forelimb plus joint is used. The name for the elbow in Latin is ''cubitus'', and so the word cubital is used in some elbow-related terms, as in ''cubital nodes'' for example. Structure Joint The elbow joint has three different portions surrounded by a common joint capsule. These are joints between the three bones of the elbow, the humerus of the upper arm, and the radius and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Medial Epicondyle Of The Humerus
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. The medial epicondyle gives attachment to the ulnar collateral ligament of elbow joint, to the pronator teres, and to a common tendon of origin (the common flexor tendon) of some of the flexor muscles of the forearm: the flexor carpi radialis, the flexor carpi ulnaris, the flexor digitorum superficialis, and the palmaris longus. The medial epicondyle is located on the distal end of the humerus. Additionally, the medial epicondyle is inferior to the medial supracondylar ridge. It is also proximal to the olecranon fossa. The medial epicondyle protects the uln ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Capitulum Of The Humerus
In human anatomy of the arm, the capitulum of the humerus is a smooth, rounded eminence on the lateral portion of the distal articular surface of the humerus. It articulates with the cupshaped depression on the head of the radius, and is limited to the front and lower part of the bone. In non-human tetrapods, the name capitellum is generally used, with "capitulum" limited to the anteroventral articular facet of the rib (in archosauromorphs). Lepidosauromorpha Lepidosaurs show a distinct capitellum and trochlea on the centre of the ventral (anterior in upright taxa) surface of the humerus at the distal end. Archosauromorpha In non-avian archosaurs, including crocodiles, the capitellum and the trochlea are no longer bordered by distinct etc.- and entepicondyles respectively, and the distal humerus consists two gently expanded condyles, one lateral and one medial, separated by a shallow groove and a supinator process. Romer (1976) homologizes the capitellum in Archosauromorphs w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
