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Subacromial Bursa
The subacromial bursa is the synovial cavity located just below the acromion, which communicates with the subdeltoid bursa in most individuals, forming the so-called subacromial-subdeltoid bursa (SSB). The SSB bursa is located deep to the deltoid muscle and the coracoacromial arch and extends laterally beyond the humeral attachment of the rotator cuff, anteriorly to overlie the intertubercular groove, medially to the acromioclavicular joint, and posteriorly over the rotator cuff. The SSB decreases friction, and allows free motion of the rotator cuff relative to the coracoacromial arch and the deltoid muscle. French anatomist and surgeon Jean-François Jarjavay is credited as the first to describe morbid processes of the SSB in 1867. Since then, histologic studies have documented that synovial membrane may undergo inflammatory and/or degenerative changes and many now believe that they correspond to different stages in the spectrum of disease, with long-lasting inflammation leading ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acromion
In human anatomy, the acromion (from Greek: ''akros'', "highest", ''ōmos'', "shoulder", plural: acromia) is a bony process on the scapula (shoulder blade). Together with the coracoid process it extends laterally over the shoulder joint. The acromion is a continuation of the scapular spine, and hooks over anteriorly. It articulates with the clavicle (collar bone) to form the acromioclavicular joint. Structure The acromion forms the summit of the shoulder, and is a large, somewhat triangular or oblong process, flattened from behind forward, projecting at first lateralward, and then curving forward and upward, so as to overhang the glenoid fossa.''Gray's Anatomy'' 1918, see infobox It starts from the base of acromion which marks its projecting point emerging from the spine of scapula. Surfaces Its superior surface, directed upward, backward, and lateralward, is convex, rough, and gives attachment to some fibers of the deltoideus, and in the rest of its extent is subcutaneous. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Synovial Bursa
Synovial () may refer to: * Synovial fluid * Synovial joint * Synovial membrane * Synovial bursa Synovial () may refer to: * Synovial fluid * Synovial joint * Synovial membrane The synovial membrane (also known as the synovial stratum, synovium or stratum synoviale) is a specialized connective tissue that lines the inner surface of capsule ... {{disambiguation ... [...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] |
Bicipital Groove
The bicipital groove (intertubercular groove, sulcus intertubercularis) is a deep groove on the humerus that separates the greater tubercle from the lesser tubercle. It allows for the long tendon of the biceps brachii muscle to pass. Structure The bicipital groove separates the greater tubercle from the lesser tubercle. It is usually around 8 cm long and 1 cm wide in adults. It lodges the long tendon of the biceps brachii muscle between the tendon of the pectoralis major muscle on the lateral lip and the tendon of the teres major muscle on the medial lip. It also transmits a branch of the anterior humeral circumflex artery to the shoulder joint. The insertion of the latissimus dorsi muscle is found along the floor of the bicipital groove. The teres major muscle inserts on the medial lip of the groove. It runs obliquely downward, and ends near the junction of the upper with the middle third of the bone. It is the lateral wall of the axilla. Function The bicipital groove all ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acromioclavicular Joint
The acromioclavicular joint, or AC joint, is a joint at the top of the shoulder. It is the junction between the acromion (part of the scapula that forms the highest point of the shoulder) and the clavicle. It is a plane synovial joint. Structure Ligaments The joint is stabilized by three ligaments: * The acromioclavicular ligament, which attaches the clavicle to the acromion of the scapula. Superior Acromioclavicular Ligament This ligament is a quadrilateral band, covering the superior part of the articulation, and extending between the upper part of the lateral end of the clavicle and the adjoining part of the upper surface of the acromion. It is composed of parallel fibers, which interlace with the aponeuroses of the Trapezius and Deltoideus; below, it is in contact with the articular disk when this is present. Inferior Acromioclavicular Ligament This ligament is somewhat thinner than the preceding; it covers the under part of the articulation, and is attached to the adjoi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Friction
Friction is the force resisting the relative motion of solid surfaces, fluid layers, and material elements sliding against each other. There are several types of friction: *Dry friction is a force that opposes the relative lateral motion of two solid surfaces in contact. Dry friction is subdivided into ''static friction'' ("stiction") between non-moving surfaces, and ''kinetic friction'' between moving surfaces. With the exception of atomic or molecular friction, dry friction generally arises from the interaction of surface features, known as asperities (see Figure 1). *Fluid friction describes the friction between layers of a viscous fluid that are moving relative to each other. *Lubricated friction is a case of fluid friction where a lubricant fluid separates two solid surfaces. *Skin friction is a component of drag, the force resisting the motion of a fluid across the surface of a body. *Internal friction is the force resisting motion between the elements making up a so ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jean-François Jarjavay
Jean-François Jarjavay (25 April 1815 – 22 April 1868) was a French anatomist and surgeon who was a native of Savignac-les-Églises in the department of Dordogne. He practised medicine at the Hôpital Lourcine and Hôpital Beaujon in Paris, and in 1859 became a professor of anatomy. In 1867 Jarjavay provided the first description of the morbid processes associated with subacromial bursitis, a disorder also known as subacromial impingement syndrome. His name is lent to "Jarjavay's ligament", which is a fold of peritoneum that is also known as a sacrouterine fold, and "Jarjavay's muscle", which is a structure arising from the ramus of the ischium and inserted into the constrictor muscle of the vagina. Written works Among his written works is an 1856 book on the urethra The urethra (from Greek οὐρήθρα – ''ourḗthrā'') is a tube that connects the urinary bladder to the urinary meatus for the removal of urine from the body of both females and males. In human f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Synovial Membrane
The synovial membrane (also known as the synovial stratum, synovium or stratum synoviale) is a specialized connective tissue that lines the inner surface of capsules of synovial joints and tendon sheath. It makes direct contact with the fibrous membrane on the outside surface and with the synovial fluid lubricant on the inside surface. In contact with the synovial fluid at the tissue surface are many rounded macrophage-like synovial cells (type A) and also type B cells, which are also known as fibroblast-like synoviocytes (FLS). Type A cells maintain the synovial fluid by removing wear-and-tear debris. As for the FLS, they produce hyaluronan, as well as other extracellular components in the synovial fluid. Structure The synovial membrane is variable but often has two layers: * The outer layer, or subintima, can be of almost any type of connective tissue – fibrous (dense collagenous type), adipose (fatty; e.g. in intra-articular fat pads) or areolar (loose collagenous typ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inflammation
Inflammation (from la, wikt:en:inflammatio#Latin, inflammatio) is part of the complex biological response of body tissues to harmful stimuli, such as pathogens, damaged cells, or Irritation, irritants, and is a protective response involving immune cells, blood vessels, and molecular mediators. The function of inflammation is to eliminate the initial cause of cell injury, clear out necrotic cells and tissues damaged from the original insult and the inflammatory process, and initiate tissue repair. The five cardinal signs are heat, pain, redness, swelling, and Functio laesa, loss of function (Latin ''calor'', ''dolor'', ''rubor'', ''tumor'', and ''functio laesa''). Inflammation is a generic response, and therefore it is considered as a mechanism of innate immune system, innate immunity, as compared to adaptive immune system, adaptive immunity, which is specific for each pathogen. Too little inflammation could lead to progressive tissue destruction by the harmful stimulus (e.g. b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Degeneration (medical)
Degeneration is deterioration in the medical sense. Generally, it is the change from a higher to a lower form. More specifically, it is the change of tissue to a lower or less functionally active form. *True degeneration: when there is actual chemical change of the tissue itself. *Infiltration: when the change consists of the deposit of abnormal matter in the tissues *Degenerative disease See also *macular degeneration *neurodegenerative disease A neurodegenerative disease is caused by the progressive loss of structure or function of neurons, in the process known as neurodegeneration. Such neuronal damage may ultimately involve cell death. Neurodegenerative diseases include amyotrophic ... References Dorland's Illustrated Medical Dictionary (Twenty-sixth Edition) () Medical terminology {{med-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fibrosis
Fibrosis, also known as fibrotic scarring, is a pathological wound healing in which connective tissue replaces normal parenchymal tissue to the extent that it goes unchecked, leading to considerable tissue remodelling and the formation of permanent scar tissue. Repeated injuries, chronic inflammation and repair are susceptible to fibrosis where an accidental excessive accumulation of extracellular matrix components, such as the collagen is produced by fibroblasts, leading to the formation of a permanent fibrotic scar. In response to injury, this is called scarring, and if fibrosis arises from a single cell line, this is called a fibroma. Physiologically, fibrosis acts to deposit connective tissue, which can interfere with or totally inhibit the normal architecture and function of the underlying organ or tissue. Fibrosis can be used to describe the pathological state of excess deposition of fibrous tissue, as well as the process of connective tissue deposition in healing. Define ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
