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Rotator Cuff Muscles
The rotator cuff is a group of muscles and their tendons that act to stabilize the human shoulder and allow for its extensive range of motion. Of the seven scapulohumeral muscles, four make up the rotator cuff. The four muscles are the supraspinatus muscle, the infraspinatus muscle, teres minor muscle, and the subscapularis muscle. Structure Muscles composing rotator cuff The supraspinatus muscle spreads out in a horizontal band to insert on the superior facet of the greater tubercle of the humerus. The greater tubercle projects as the most Lateral (anatomy), lateral structure of the humeral head. Medial (anatomy), Medial to this, in turn, is the lesser tubercle of the humeral head. The subscapularis muscle Origin (anatomy), origin is divided from the remainder of the rotator cuff origins as it is deep to the scapula. The four tendons of these muscles converge to form the rotator cuff tendon. These tendinous Insertion (anatomy), insertions along with the articular capsule, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Suprascapular Artery
The suprascapular artery is a branch of the thyrocervical trunk on the neck. Structure At first, it passes downward and laterally across the scalenus anterior and phrenic nerve, being covered by the sternocleidomastoid muscle; it then crosses the subclavian artery and the brachial plexus, running behind and parallel with the clavicle and subclavius muscle and beneath the inferior belly of the omohyoid to the superior border of the scapula. It passes over the superior transverse scapular ligament in most of the cases while below it through the suprascapular notch in some cases. The artery then enters the supraspinous fossa of the scapula. It travels close to the bone, running through the suprascapular canal underneath the supraspinatus muscle, to which it supplies branches. It then descends behind the neck of the scapula, through the great scapular notch and under cover of the inferior transverse ligament, to reach the infraspinatous fossa, where it supplies infraspinatus a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Supraspinous Fossa
The supraspinous fossa (supraspinatus fossa, supraspinatous fossa) of the posterior aspect of the scapula (the shoulder blade) is smaller than the infraspinous fossa, concave, smooth, and broader at its vertebral than at its humeral end. Its medial two-thirds give origin to the Supraspinatus. Structure The fossa can be exposed by the removal of skin and the superficial fascia of the back and the trapezius muscle. The supraspinous fossa is bounded by the spine of scapula on the inferior side, acromion process on the lateral side and the superior angle of scapula on the superior side. Supraspinatus muscle originates from the supraspinous fossa. Distal attachment of the levator scapulae muscle is also on the medial aspect of the fossa. Function The suprascapular artery and nerve are found within the fossa. The posterior branch of the suprascapular artery supplies the supraspinatous muscle. Dorsal scapular artery also gives off a collateral branch and anastomoses with the supra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Subscapularis Muscle
The subscapularis is a large triangular muscle which fills the subscapular fossa and inserts into the lesser tubercle of the humerus and the front of the capsule of the shoulder-joint. Structure It arises from its medial two-thirds and Some fibers arise from tendinous laminae, which intersect the muscle and are attached to ridges on the bone; others from an aponeurosis, which separates the muscle from the teres major and the long head of the triceps brachii. The fibers pass laterally and coalesce into a tendon that is inserted into the lesser tubercle of the humerus and the anterior part of the shoulder-joint capsule. Tendinous fibers extend to the greater tubercle with insertions into the bicipital groove. Relations The tendon of the muscle is separated from the neck of the scapula by a large bursa, which communicates with the cavity of the shoulder-joint through an aperture in the capsule. The subscapularis is separated from the serratus anterior books.google.com/books ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Axillary Nerve
The axillary nerve or the circumflex nerve is a nerve of the human body, that originates from the brachial plexus (upper trunk, posterior division, posterior cord) 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. Structure The nerve lies at first behind the axillary artery, and in front of the subscapularis, and passes downward to the lower border of that muscle. It then winds from anterior to posterior around the neck of the humerus, in company with the posterior humeral circumflex artery, through the quadrangular space (bounded above by the teres minor, below by the teres major, medially by the long head of the triceps brachii, and laterally by the surgical neck of the humerus), and divides into an anterior, a posterior, and a collateral branch to the long head of the triceps brachii branch. * The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lateral Border
The scapula (plural scapulae or scapulas), also known as the shoulder blade, is the bone that connects the humerus (upper arm bone) with the clavicle (collar bone). 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. In compound terms, the prefix omo- is used for the shoulder blade in medical terminology. This prefix is derived from ὦμος (ōmos), the Ancient Greek word for shoulder, and is cognate with the Latin , which in Latin signifies either the shoulder or the upper arm bone. The scapula forms the back of the shoulder girdle. In humans, it is a flat bone, roughly triangular in shape, placed on a posterolateral aspect of the thoracic cage. Structure The scapula is a thick, flat bone lying on the thoracic wall that provides an attachment for three groups of muscles: intrins ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Teres Minor Muscle
The teres minor (Latin ''teres'' meaning 'rounded') 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 primary function of the teres minor is to modulate the action of the deltoid, preventing the humeral head from sliding upward as the arm is abducted. It also functions to rotate the humerus laterally. The teres minor is innervated by the axillary nerve. Structure It arises from the dorsal surface of the axillary border of the scapula for the upper two-thirds of its extent, and from two aponeurotic laminae, one of which separates it from the infraspinatus muscle, the other from the teres major muscle. Its fibers run obliquely upwards and laterally; the upper ones end in a tendon which is inserted into the lowest of the three impressions on the greater tub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cervical Spinal Nerve 6
The cervical spinal nerve 6 (C6) is a spinal nerve of the cervical segment. It originates from the spinal column from above the cervical vertebra 6 (C6). The C6 nerve root shares a common branch from C5, and has a role in innervating many muscles of the rotator cuff and distal arm, including: *Subclavius *Supraspinatus *Infraspinatus * Biceps Brachii * Brachialis * Deltoid *Teres Minor *Brachioradialis *Serratus Anterior *Subscapularis *Pectoralis Major *Coracobrachialis *Teres Major * Supinator *Extensor Carpi Radialis Brevis * Extensor Carpi Radialis Longus * Latissimus Dorsi Damage to the C6 motor neuron, by way of impingement, ischemia, trauma, or degeneration of nerve tissue, can cause denervation Denervation is any loss of nerve supply regardless of the cause. If the nerves lost to denervation are part of the neuronal communication to a specific function in the body then altered or a loss of physiological functioning can occur. Denervati ... of one or more of the asso ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
External Rotation
Motion, the process of movement, is described using specific anatomical terms. Motion includes movement of organs, joints, limbs, and specific sections of the body. The terminology used describes this motion according to its direction relative to the anatomical position of the body parts involved. Anatomists and others use a unified set of terms to describe most of the movements, although other, more specialized terms are necessary for describing unique movements such as those of the hands, feet, and eyes. In general, motion is classified according to the anatomical plane it occurs in. ''Flexion'' and ''extension'' are examples of ''angular'' motions, in which two axes of a joint are brought closer together or moved further apart. ''Rotational'' motion may occur at other joints, for example the shoulder, and are described as ''internal'' or ''external''. Other terms, such as ''elevation'' and ''depression'', describe movement above or below the horizontal plane. Many anatomica ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Infraspinous Fossa
The infraspinous fossa (infraspinatus fossa or infraspinatous fossa) of the scapula is much larger than the supraspinatous fossa; toward its vertebral margin a shallow concavity is seen at its upper part; its center presents a prominent convexity, while near the axillary border is a deep groove which runs from the upper toward the lower part. The medial two-thirds of the fossa give origin to the Infraspinatus; the lateral third is covered by this muscle. Additional images File:Infraspinatus fossa of left scapula- animation.gif, Left scapula. Infraspinatous fossa shown in red. File:Infraspinatus fossa - animation.gif, Animation. Infraspinatous fossa shown in red. File:Infraspinatous fossa of scapula01.png, Still image. File:Gray203.png, Left scapula. Dorsal surface. ("Infra-spinatous" fossa visible at bottom right.) File:Scapula post.jpg, Left scapula. Dorsal surface. Infraspinatous fossa not labeled, but visible at center. File:Infraspinatus muscle back2.png, Infraspin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Infraspinatus Muscle
In human anatomy, the infraspinatus muscle is a thick triangular muscle, which occupies the chief part of the infraspinatous fossa.'' Gray's Anatomy'', see infobox. As one of the four muscles of the rotator cuff, the main function of the infraspinatus is to externally rotate the humerus and stabilize the shoulder joint. Structure It attaches medially to the infraspinous fossa of the scapula and laterally to the middle facet of the greater tubercle of the humerus. The muscle arises by fleshy fibers from the medial two-thirds of the infraspinatous fossa, and by tendinous fibers from the ridges on its surface; it also arises from the infraspinatous fascia which covers it, and separates it from the teres major and teres minor. The fibers converge to a tendon, which glides over the lateral border of the spine of the scapula and passing across the posterior part of the capsule of the shoulder-joint, is inserted into the middle impression on the greater tubercle of the humerus. The t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cervical Spinal Nerve 5
The cervical spinal nerve 5 (C5) is a spinal nerve of the cervical segment. Nervous System -- Groups of Nerves It originates from the spinal column from above the (C5). It contributes to the phrenic nerve, , and before joining |
Suprascapular Nerve
The suprascapular nerve is a nerve that branches from the upper trunk of the brachial plexus. It is responsible for the innervation of two of the muscles that originate from the scapula, namely the supraspinatus muscle, supraspinatus and infraspinatus muscles. Structure The suprascapular nerve arises from the upper trunk of the brachial plexus which is formed by the union of the Anterior ramus of spinal nerve, ventral rami of the fifth and sixth cervical nerves. After branching from the upper trunk, the nerve passes across the posterior triangle of the neck parallel to the inferior belly of the omohyoid muscle and deep to the trapezius muscle. It then runs along the Scapula#Borders, superior border of the scapula through the suprascapular canal, in which it enters via the suprascapular notch inferior to the superior transverse scapular ligament and enters the supraspinous fossa. It then passes beneath the supraspinatus, and curves around the lateral border of the spine of the scapul ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
