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Scapulohumeral Muscles
The scapulohumeral muscles are a group of seven muscles that connect the humerus to the scapula. They are amongst the muscles that act on and stabilise the glenohumeral joint in the human body. They include : *coracobrachialis muscle *deltoid muscle *rotator cuff muscles : :*infraspinatus muscle :*subscapularis muscle :*supraspinatus muscle :*teres minor muscle *teres major muscle See also Other muscles that attach to the humerus and affect its rotation and stability : *latissimus dorsi muscle *pectoralis major muscle The pectoralis major () is a thick, fan-shaped or triangular convergent muscle, situated at the chest of the human body. It makes up the bulk of the chest muscles and lies under the breast. Beneath the pectoralis major is the pectoralis minor, a ... {{muscle-stub Shoulder Upper limb anatomy ... [...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] |
Scapula
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: intrin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glenohumeral Joint
The shoulder joint (or glenohumeral joint from Greek ''glene'', eyeball, + -''oid'', 'form of', + Latin ''humerus'', shoulder) 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 (shoulder blade) and the head of the humerus (upper arm bone). 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. Structure The shoulder joint is a ball-and-socket joint between the scapula and the humerus. The socket of the glenoid fossa of the scapula is itself quite shallow, but it is made deeper by the addition of the glenoid labrum. The glenoid labrum is a ring of cartilaginous fibre attached to the circumference of the cavity. This ring is continuous with the tendon of the biceps brachii above. Spaces Significant joint spaces are: * The normal glenohumeral space is 4– ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Human Body
The human body is the structure of a Human, human being. It is composed of many different types of Cell (biology), cells that together create Tissue (biology), tissues and subsequently organ systems. They ensure homeostasis and the life, viability of the human body. It comprises a human head, head, hair, neck, Trunk (anatomy), trunk (which includes the thorax and abdomen), arms and hands, human leg, legs and feet. The study of the human body involves anatomy, physiology, histology and embryology. The body anatomical variability, varies anatomically in known ways. Physiology focuses on the systems and organs of the human body and their functions. Many systems and mechanisms interact in order to maintain homeostasis, with safe levels of substances such as sugar and oxygen in the blood. The body is studied by health professionals, physiologists, anatomists, and by artists to assist them in their work. Composition The composition of the human body, human body is composed of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coracobrachialis Muscle
The coracobrachialis muscle is the smallest of the three muscles that attach to the coracoid process of the scapula. (The other two muscles are pectoralis minor and the short head of the biceps brachii.) It is situated at the upper and medial part of the arm. Structure Coracobrachialis muscle arises from the apex of the coracoid process, in common with the short head of the biceps brachii, and from the intermuscular septum between the two muscles. It is inserted by means of a flat tendon into an impression at the middle of the medial surface and border of the body of the humerus (shaft of the humerus) between the origins of the triceps brachii and brachialis. Innervation Coracobrachialis muscle is perforated by and innervated by the musculocutaneous nerve, which arises from the anterior division of the upper trunk ( C5, C6) and middle trunk ( C7) of the brachial plexus. Development Variation Function The action of the coracobrachialis is to flex and adduct the arm at the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Deltoid Muscle
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 # anterior or clavicular part (pars clavicularis) # posterior or scapular part (pars scapularis) # intermediate or acromial part (pars acromialis) However, electromyography suggests that it consists of at least seven groups that can be independently coordinated by the nervous system. It was previously called the deltoideus (plural ''deltoidei'') and the name is still used by some anatomists. It is called so because it is in the shape of the Greek capital letter delta (Δ). Deltoid is also further shortened in slang as "delt". A study of 30 shoulders revealed an average mass of in humans, ranging from to . Structure Previous studies showed that the insertions of the tendons of the delto ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rotator Cuff
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 structure of the humeral head. Medial to this, in turn, is the lesser tubercle of the humeral head. The subscapularis muscle 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 insertions along with the articular capsule, the coracohumeral ligament, and the glenohumeral ligament complex, ... [...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] |
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] |
Supraspinatus Muscle
The supraspinatus (plural ''supraspinati'') is a relatively small muscle of the upper back that runs from the supraspinous fossa superior portion of the scapula (shoulder blade) 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. Structure The supraspinatus muscle arises from the supraspinous fossa, a shallow depression in the body of the scapula above its spine. The supraspinatus muscle tendon passes laterally beneath the cover of the acromion. Research in 1996 showed that the postero-lateral origin was more lateral than classically described. The supraspinatus tendon is inserted into the superior facet of the greater tubercle of the humerus. The distal attachments of the three rotator cuff muscles that insert into the greater tubercle of the humerus can be abbreviated as SIT when vie ... [...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] |
Teres Major Muscle
The teres major muscle is a muscle of the upper limb. It attaches to the scapula and the humerus and is one of the seven scapulohumeral muscles. It is a thick but somewhat flattened muscle. The teres major muscle (from Latin ''teres'', meaning "rounded") is positioned above the latissimus dorsi muscle and assists in the extension and medial rotation of the humerus. This muscle is commonly confused as a rotator cuff muscle, but it is not because it does not attach to the capsule of the shoulder joint, unlike the teres minor muscle for example. Structure The teres major muscle originates on the dorsal surface of the inferior angle and the lower part of the lateral border of the scapula. The fibers of teres major insert into the medial lip of the intertubercular sulcus of the humerus. Relations The tendon, at its insertion, lies behind that of the latissimus dorsi, from which it is separated by a bursa, the two tendons being, however, united along their lower borders fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
