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Supinator Crest
The ulna or ulnar bone (: ulnae or ulnas) 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. Structure The ulna is a long bone found in the forearm that stretches from the elbow to the wrist, and when in standard anatomical position, is found on the medial side of the forearm. It is broader close to the elbow, and narrows as it approaches the wrist. Close to the elbow, the ulna has a bony process, the olecranon process, a hook-like structure that fits into the olecranon fossa of the humerus. This prevents hyperextension and forms a hinge joint with the trochlea of the humerus. There is also a radial notch for the head of the radius, and the ulnar tuberosity to which muscles a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Standard Anatomical Position
The standard anatomical position, or standard anatomical model, is the scientifically agreed upon reference position for anatomical location terms. Standard anatomical positions are used to standardise the position of appendages of animals with respect to the main body of the organism. In medical disciplines, all references to a location on or in the body are made based upon the standard anatomical position. A straight position is assumed when describing a proximo- distal axis (towards or away from a point of attachment). This helps avoid confusion in terminology when referring to the same organism in different postures. For example, if the elbow is flexed, the hand remains distal to the shoulder even if it approaches the shoulder. Human anatomy In standard anatomical position, the human body is standing erect and at rest. Unlike the situation in other vertebrates, the limbs are placed in positions reminiscent of the supine position imposed on cadavers during autopsy. Ther ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Head Of The 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] |
Flexor Digitorum Superficialis Muscle
Flexor digitorum superficialis (''flexor digitorum sublimis'') or flexor digitorum communis sublimis is an extrinsic flexor muscle of the fingers at the proximal interphalangeal joints. It is in the anterior compartment of the forearm. It is sometimes considered to be the deepest part of the superficial layer of this compartment, and sometimes considered to be a distinct, "intermediate layer" of this compartment. It is relatively common for the Flexor digitorum superficialis to be missing from the little finger, bilaterally and unilaterally, which can cause problems when diagnosing a little finger injury. Structure The muscle has two classically described heads – the humeroulnar and radial – and it is between these heads that the median nerve and ulnar artery pass. The ulnar collateral ligament of elbow joint gives its origin to part of this muscle. Four long tendons come off this muscle near the wrist and travel through the carpal tunnel formed by the flexor retinaculu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ulnar Collateral Ligament Of Elbow Joint
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. Structure It consists of two portions, an anterior and posterior united by a thinner intermediate portion. Note that this ligament is also referred to as the medial collateral ligament and should not be confused with the lateral ulnar collateral ligament (LUCL). The ''anterior portion'', directed obliquely forward, is attached, above, by its apex, to the front part of the medial epicondyle of the humerus; and, below, by its broad base to the medial margin of the coronoid process of the ulna. The ''posterior portion'', also of triangular form, is attached, above, by its apex, to the lower and back part of the medial epicondyle; below, to the medial margin of the olecranon. Between these two bands a few intermediate fibers descend from the medial epicondyle to blend with ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brachialis
The brachialis (brachialis anticus) is a muscle in the upper arm that flexes the elbow. It lies beneath the biceps brachii, and makes up part of the floor of the region known as the cubital fossa (elbow pit). It originates from the anterior aspect of the distal humerus; it inserts onto the tuberosity of the ulna. It is innervated by the musculocutaneous nerve, and commonly also receives additional innervation from the radial nerve."Brachialis Muscle." Kenhub. Kenhub, Aug. 2001 The brachialis is the prime mover of elbow flexion generating about 50% more power than the biceps.Saladin, Kenneth S, Stephen J. Sullivan, and Christina A. Gan. Anatomy & Physiology: The Unity of Form and Function. 2015. Print. Structure Origin The brachialis originates from the anterior surface of the distal half of the humerus, near the insertion of the deltoid muscle, which it embraces by two angular processes. Its origin extends below to within 2.5 cm of the margin of the articular surface of t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anconeus Muscle
The anconeus muscle (or anconaeus/anconæus) is a small muscle on the posterior aspect of the elbow joint. Some consider anconeus to be a continuation of the triceps brachii muscle. Some sources consider it to be part of the posterior compartment of the arm, while others consider it part of the posterior compartment of the forearm. The anconeus muscle can easily be palpated just lateral to the olecranon process of the ulna. Structure Anconeus originates on the posterior surface of the lateral epicondyle of the humerus and inserts distally on the superior posterior surface of the ulna and the lateral aspect of the olecranon. Innervation Anconeus is innervated by a branch of the radial nerve (cervical roots 7 and 8) from the posterior cord of the brachial plexus called the nerve to the anconeus. The somatomotor portion of radial nerve innervating anconeus bifurcates from the main branch in the radial groove of the humerus. This innervation pattern follows the rules of innervat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flexor Carpi Ulnaris
The flexor carpi ulnaris (FCU) is a skeletal muscle, muscle of the forearm that flexion, flexes and Adduction, adducts at the wrist joint. Structure Origin The flexor carpi ulnaris has two heads; a humeral head and ulnar head. The humeral head originates from the medial epicondyle of the humerus via the common flexor tendon. The ulnar head originates from the medial margin of the olecranon of the ulna and the upper two-thirds of the dorsal border of the ulna by an aponeurosis. Between the two heads passes the ulnar nerve and ulnar artery. Insertion The flexor carpi ulnaris inserts onto the pisiform bone, pisiform, hook of the hamate (via the pisohamate ligament) and the anterior surface of the base of the fifth metacarpal bone, fifth metacarpal (via the pisometacarpal ligament). Action The flexor carpi ulnaris flexes and adducts at the Wrist, wrist joint. Innervation The flexor carpi ulnaris is innervated by the ulnar nerve. The corresponding spinal nerves are Cervical spinal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Triceps Brachii
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 three parts: the medial, lateral, and long head. All three heads cross the elbow joint. However, the long head also crosses the shoulder joint. The triceps muscle contracts when the elbow is straightened and expands when the elbow is bent. The long head gets a further contraction when the arm is behind the torso due to how it crosses the shoulder joint. It is the muscle principally responsible for extension of the elbow joint (straightening of the arm). Structure * The long head arises from the infraglenoid tubercle of the scapula. It extends distally anterior to the teres minor and posterior to the teres major. * The medial head arises proximally in the humerus, just inferior to the groove of the radial nerve; from the dorsal (back) surface of the humerus; from the medial intermuscular septum; and its distal ... [...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 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 (also called the chelidon, or the elbow pit), and the lateral and t ... 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. Additional images File:Slide1bgbg.JPG, Elbow joint. Deep dissection. Posterior view. File:Slide2bgbg.JPG, Elbow joint. De ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Semilunar Notch
The trochlear notch (), also known as semilunar notch and greater sigmoid cavity, is a large depression in the upper extremity of the ulna that fits the trochlea of the humerus (the bone directly above the ulna in the arm) as part of the elbow joint. It is formed by the olecranon 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 (trochlear notch). The olecranon serves as a lever ... and the coronoid process. About the middle of either side of this notch is an indentation, which contracts it somewhat, and indicates the junction of the olecranon and the coronoid process. The notch is concave from above downward, and divided into a medial and a lateral portion by a smooth ridge running from the summit of the olecranon to the tip of the coronoid process. The medial portion is the larger, and is slightly concave transversely; the lat ... [...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. 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 ulnar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Olecranon
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 (trochlear notch). 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 triceps brachi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
