In anatomy, scapula (skopula scapula or plural , also known as shoulder bone , shoulder bone or wing bone ) is the bone that connects the humerus (the upper arm bone) with the clavicle (the collarbone). As their bones are connected, the shoulder blades are attached, with shoulder blades on both sides of the body that are roughly mirror images of the others. In early Roman times, people thought his bones resembled a shovel, a small shovel.
In compound terms, the omo - prefix is ​​used for shoulder blades in Latin medical terminology. This prefix comes from ???? (? mos), Ancient Greek word for shoulder, and cognate with Latin (h) umerus .
Scapula forms the back of the shoulder girdle. In humans, it is a flat bone, approximately triangular in shape, placed on the posterolateral aspect of the thoracic cage.
Video Scapula
Structure
The scapula is a flat, wide bone located on the thoracic wall that provides attachment to three muscle groups: intrinsic, extrinsic, and stabilizing and spinning muscles. The intrinsic muscles of the scapula include rotator cuff - subscapularis muscle, teres minor, supraspinatus, and infraspinatus. These muscles attach to the surface of the scapula and are responsible for internal and external rotation of the shoulder joint, along with the abduction of the humeral.
Extrinsic muscles include the biceps, triceps, and deltoid muscles and attach to coracoid processes and supraglenoid tubules of the scapula, the infraglenoid tubule, the scapula, and the spinal bone. These muscles are responsible for some action of the glenohumeral joint.
The third group, which is primarily responsible for the stabilization and rotation of the scapula, consists of trapezius, serratus anterior, levator scapula, and rhomboid muscle. It attaches to the medial, superior, and inferior border of the scapula.
The head, the process, and the thickened part of the bone containing the cancellous tissue; the remainder consists of a thin layer of dense tissue.
The central part of the supraspinatus fossa and the upper part of the infraspinatous fossa, but especially the first, is usually very thin in humans such as being semitransparent; sometimes bones are found wanting in this situation, and the adjacent muscles are only separated by fibrous tissue. Scapula has two surfaces, three borders, three corners, and three processes.
Surface
- Front or subscapular fosses
The front of the scapula (also known as the costal or ventral surface) has a broad basin called the subscapular fossa , which is connected by the subscapularis muscle. The two-thirds medial of the fossa has 3 longitudinal oblique bulges, and the other thick ridge is adjacent to the lateral border; they ran out and up. The ridge provides attachment to tendon insertion, and the surface between them with fleshy fibers, from the subscapularis muscle. The lateral third of the fossa is smooth and covered by these muscle fibers.
At the top of the fossa is a transverse depression, in which the bone appears to bend upon itself along the line at right angles to and through the center of the glenoid cavity, forming a considerable angle, called the subscapular angle; this gives a greater force to the bone body with a curved shape, while the crest of the arch serves to support the spine and acromion.
Superior superior surfaces of the scapula are the origin of 1 digit for anterior serratus origin.
- Back
The back of the scapula (also called the dorsal or posterior surface) curves from top to bottom, and is divided into two unequal parts by the spine of the scapula. The upper part of the spine is called the supraspinosa fossa, and underneath it is the infraspinosa fossa. The two fosses are connected by the spinoglenoid notch, located in the lateral root of the spine.
- fossa supraspinosa , which is smaller than the two, concave, smooth, and wider on its vertebral than at the end of its humerian; his medial two-thirds gave origin to Supraspinatus.
- The infraspinous fossa is much larger than the previous one; toward the vertebral margin, the shallow basin seen at the top; the center presents a prominent convexity, while near the axillary border is a deep groove stretching from the top to the bottom. Medial two-thirds of the fossa give origin to Infraspinatus; the lateral third is covered by this muscle.
There is a ridge on the outside of the back of the scapula. It runs from the bottom of the glenoid cavity, down and back to the vertebral border, about 2.5 cm above the inferior angle. Attached to the ridge is the fibrous septum, which separates the infraspinatus muscle from the major Teres and Teres minor muscles. The upper two thirds of the surface between the ridge and the narrow axilla boundary, and crossed near its center by a groove for circumflex vessels; Minor teres are attached here.
The broad and narrow portion above is alluded to being separated by a slash, extending from the axillary, down and back borders, to meet the high ridge: for it is attached to the fibrous septum that separates the muscle Teres from each other.
The lower third represents a wider and slightly triangular surface, the Inferior angle of the scapula, which gives origin to the Teres majors, and which Latissimus dorsi passes; often the latter muscle takes origin by some fibers from this part.
- The side
Akromion forms the top of the shoulder, and is a large, rather triangular or longitudinal process, flattened from back to front, projecting at first laterally, and then curving forward and upward, thrusting into the glenoid cavity.
Angle
There are 3 angles:
superior angle of the scapula or medial angle , covered by trapezius muscle. This angle is formed by the intersection of the superior and medial border of the scapula. The superior angle lies at the approximate level of the second thoracic vertebra. The superior angle of the scapula is thin, smooth, rounded, and tends to be somewhat lateral, and gives attachment to some levator muscle fiber fibers.
The inferior angular skapula is the lowest part of the shoulder bladder and is covered by the latissimus dorsal muscle. Move forward around the chest when the arm is abducted. The inferior angle is formed by the merging of the medial boundary and lateral scapula. It is thick and rugged and the posterior or rear surfaces provide an attachment to the core core and often to some fibers of latissimus dorsi. The anatomical field that passes vertically through an inferior angle is named after the scapula line.
The lateral angle of the scapula or the glenoid angle also known as the scapula head is the thickest part of the scapula. It is broad and contains a glenoid cavity on its articular surface which is directed forward, lateral and slightly upward, and articulated with the humeral head. The inferior angle is wider at the bottom than the top and the vertical diameter is the longest. The surface is covered with cartilage in a fresh state; and the margin, slightly raised, provides an attachment to the fibrocartilaginous structure, the glenoidal labrum, which deepens the cavity. At its peak is a slight elevation, supraglenoid tuberosity, in which the long head brachii biceps are attached.
The neck of the scapula is a slightly narrower part that surrounds the head and more clearly underneath and behind than above and above.
Border
There are three limits of scapula:
- The superior is the shortest and the thinnest; it is concave, and extends from the superior angle to the base of the coracoid process. This is called the skull boundary in animals.
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- In the lateral part is the semicircular notch, the curve of the scapula, formed partly by the base of the coracoid process. This notch is converted into a foramen by the superior transverseal transcellular ligament, and serves to run the suprascapular nerve; sometimes ligaments harden.
- The adjacent portion of the superior border provides attachment to omohyoideus.
- The ax
limit (or "lateral border") is the thickest of the three. It starts at the top at the lower margin of the glenoid cavity, and tilts tilted down and backward to the inferior angle. This is referred to as the tail border in animals.
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- It starts up at the lower margin of the glenoid cavity, and it tilts tilted down and backward into the inferior angle.
- Immediately under the glenoid cavity is a rough impression, infraglenoid tuberosity, about 2.5 cm (1 inch). length, which gives origin to the long head of triseps brachii; in front of this is a longitudinal groove, which extends as far as one third below this border, and gives the origin to part of the subscapularis.
- One inferior third is thin and sharp, and serves to attach some fibers from the teres core behind, and from the subscapularis in front.
- The median limit (also called the vertebral or medial boundary) is the longest of the three boundaries, and extends from the superior angle to the inferior angle. This animal is referred to as dorsal border .
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- Four muscles attached to the medial boundary. The anterior serratus has a long attachment to the anterior lip. Three muscles insert along the posterior lips, levator scapula (uppermost), rhomboid minor (center), and to rhomboid major (lower center).
Development
The scapula hardens from 7 or more centers: one for the body, two for the coracoid process, two for the acromion, one for the vertebral border, and one for the inferior angle. The body's olification begins around the second month of fetal life, by an irregular bony rectangular plate just behind the glenoid cavity. This plates extend to form the head of the bone, the scapular spine growing from its dorsal surface around the third month. Osification begins as a membranous ossification before birth. After birth, the cartilage component will undergo endocondral ossification. The larger portion of the scapula undergoes membrane ossification. Some of the outer parts of the scapula are cartilage at birth, and therefore will have endokhondral ossification.
At birth, most of the shoulder blades are osseous, but the glenoid cavity, the coracoid process, the acromion, the vertebral border and the inferior angle are cartilage. From the 15th to the 18th of the month after birth, hardening occurs in the middle of the coracoid process, which usually joins the remaining bone around the 15th year.
Between 14 and 20 years, the remaining portions harden sequentially, and usually in the following order: first, at the roots of the coracoid process, in the form of a broad scale; second, near the base of the acromion; third, at the inferior angle and adjacent portion of the vertebral border; fourth, near the outer end of the acromion; fifth, on the vertebral border. The base of the acromion is formed by the extension of the spine; two cores of the united acromion, and then joined by the extension of the spine. The upper third of the glenoid cavity hardens from a separate center (sub coracoid), which occurs between the 10th and 11th years and joins between 16 and 18 years. Furthermore, epiphysial plates appear to the bottom of the glenoid cavity, and the end of the coracoid process often has a separate nucleus. These various epiphytes combine to bone in the 25th year.
Failure of bone union between acromion and spine occasionally occurs (see os acromiale), intersection by fibrous tissue, or by imperfect articulation; in some cases of alleged fracture of acromion with ligament union, it is likely that a separate segment never united with the rest of the bone.
"In terms of comparative anatomy the human shoulder blade represents two bones that have fused together, the right (dorsal) spinal and the corral (ventral).The epiphyseal line across the glenoid cavity is the fusion line, they are the counterparts of the ilium and iscium of the pelvic girdle. "
Maps Scapula
Function
The following muscles attach to the scapula:
Movement
The movement of the scapula is caused by a scapular muscle. Scapula can perform six actions:
- Elevation: upper trapezius and levator scapula
- Depression: trapezius down
- Retractions (adductions): rhomboids and middle trapezius
- Protraction (abduction): serratus anterior
- Upward rotation: upper and middle trapezius
- Downward rotation: rhomboids
Clinical interests
Skapular fracture
Due to its sturdy structure and protected location, scapular fractures are rare. When they occur, they are an indication that severe chest trauma has occurred. A sapular fracture involving the neck of the scapula has two patterns. One rare type of fracture is through neck anatomy on the scapula. Another more common type of fracture is through surgical neck on the scapula. The surgical neck goes from medial to coracoid process.
An abnormally prominent inferior scalar angle is known as a winged scapula and can be caused by anterior muscle partial serratus. In this condition the sides of the scapula nearest the spine are positioned outwards and backward. The appearance of the upper back is said to be like a wing. In addition, any condition that causes anterior serratus muscle weakness may cause scapular "winging".
Overdelivery syndrome
The scapula plays an important role in shoulder slump syndrome.
Abnormal skapular function is called scapular dyskinesis. One action the scapula performs during throwing or service is enhancement of the acromion process to avoid the impact of rotator cuff tendon. If the scapula fails to raise the acromion properly, impingement may occur during the locking and acceleration phases of overhead activity. The two muscles most often inhibited during the first part of the above movement are the serratus anterior and the lower trapezius. Both of these muscles act as a force pair in the glenohumeral joint to improve the acromion process, and if there is a muscle imbalance, there can be a shoulder collision.
History
Etymology
Os latum scapularum and related
The Roman Encyclopaedia Aulus Cornelius Celsus, who lived in the early days, also used the scapulae to refer to back . He uses the os latum scapularum to refer to the shoulder bones. This expression can be translated as wide (Latin: latin) bones (Latin: os) from the back (latin: scapularum).
Similar phrases in ancient Greek can be seen in the writings of Greek philosopher Aristotle and in the writings of Greek physician Galen. They both use the name ???????? to refer to the shoulder bones. These compounds are made up of ancient Greek ?, I> shoulders and ??, blade or flat or wide objects . ????? in plural form ?????? without ??? - also used in ancient Greek to refer to the shoulder bones. In Latin anatomy, ???????? Translated in Latin as omoplata.
Latin umerus related to ????. Roma is called umerus for what is now known in English as the following three bones: humerus or bones on the arms , < i> or collarbone and shoulder bling or shoulder bling . The humerus spelling is in fact not true in classic Latin.
The three bones are referred to as ossa (Latin: bone) umeri (Latin: from umerus). Umerus is also used to refer specifically to the shoulders. It reflects the use ???? in ancient Greek that could refer to the shoulders with the upper arm or to the shoulder alone .
Because Celsus, os umeri can refer specifically to the upper bones of arms . 16th-century anthropists Andreas Vesalius uses humerus to refer to the clavicle. In addition to the so-called os latum scapularum, Celsus uses the os latum umeri to refer to the shoulder bones. Similarly, Laurentius uses the latitude expression (Latitude = width, width ) to refer to the shoulder blade .
Pala
The Roman physician, Caelius Aurelianus (5th century) used nutmeg to refer to the shoulder blades. The name nutmeg is commonly used to refer to Spathula/?????
During the Middle Ages spathula was used to refer to shoulder blades. Spathula is a small spatha, with the latter basically means broad, double-edged sword with no point, broad, flat, wooden instrument to stir any liquid, spatte, spatula or < i> the spathe of the palm tree and the size used in classical and latin Latin to refer to pig's foot or a little palmbranch.
The English word spatula is actually derived from the Latin spatula , an orthographic variant of spathula . Strangely, the classic non-small Latin language spatha can be translated as English spatula , while its small Latin spatula is not translated as English > spatula .
Latin Spatha comes from ancient Greece ?????. Therefore, the shape of spathula is more similar to the origin than the spatula . Ancient greek ????? has the same meaning as Latin spatha, such as any knife , and can also refer to spatula or to wide swords . , but also to the paddle blade . The above mentioned ?????? for a knife is also used for paddle blades . Concrete ????? also used to refer to the shoulder bladder.
Interestingly, the English word
It seems os latum scapularum , ????????, ??????, nutmeg , spathula and ?? ??? all referring to the same aspect of the shoulder blade, ie being a flat blade, wide , with the last three etymologically related words to each other.
Scapula after the Middle Ages
After the Middle Ages, the name scapula for the scapula became dominant. The word scapula is etymologically explained by its association with the ancient Greek verbs ????????, to dig . This linkage raises several possible explanations.
First, the nouns ????????, trenches derived from this verb, and the associated nouns ?????, which are also derived from the aforementioned verbs, perhaps connecting scapula to the idea of ​​the cavity (con). The name scapula may be related due to the presence of spinal bone, there is a hollow in the scapula. Otherwise, the appointment of scapulae is also seen as a synonym of the ancient Greek ???????, the space between the shoulder blade , which is clearly sunken. ??????? consists of ???, along with , and ????, shoulders .
Second, scapula , because of its relationship with ???????? may originally mean spade . Similar to the similarity between the Latin nutmeg (shovel) and the shoulder blade, the similarity can be felt between the shovel shape and the shoulder blade. Or, the shoulders may be used initially to dig and shovel. Shoulder
Shoulder blades are the everyday name for this bone. Shoulder is equal to German and Dutch equivalent Schulter and schouder . There are several etymological explanations for shoulders . The first thought that the shoulder can be literally translated as what protects or protects , as it may be related to Icelandic skioldr , shield and skyla , to cover, to defend. The second explanation relates to shoulders to ancient Greece ??????, leg . The latter finds the possibility of root skel - , which means to bend , to curve . The third explanation connects root skel - to to split . This meaning can refer to the shape of the shoulder blade.
In other animals
In fish, the sapular knife is the structure attached to the upper surface of the pectoral fin articulation, and is accompanied by the same coracoid plate on the lower surface. Though firm in cartilagenous fish, these two plates are generally small in most other fish, and may be partially cartilagenous, or composed of several bone elements.
In the early tetrapods, these two structures each become the scapula and the bone referred to as procoracoid (commonly called only "coracoid", but not homologous to the mammalian structure of the name). In amphibians and reptiles (birds included), these two bones are different, but together form a single structure containing many muscle bonds for the forelimb. In such animals, the scapula is usually a relatively simple plank, lacking the projection and spine that mammals possess. However, the detailed structure of these bones varies in living groups. For example, in frogs, procoracoid bones can be fitted together under animals to absorb landing surprises, while in turtles, the combined structure forms a Y-shape to allow the scapula to maintain connections to the clavicle (which is part of the shell). In birds, procoracoids help to strengthen the wings to the top of the breastbone.
In the fossil therapsids, the third bone, the actual corboid , is formed just behind the procoracoid. The resulting three-bone structure is still visible in modern monotremes, but in all other living mammals, the procoracoid has disappeared, and the coracoid bone has merged with the scapula, to become a coracoid process. This change is related to the upright lifestyle of mammals, compared to the wider reptile and amphibian settings; muscles previously attached to procoracoid are no longer needed. The changing muscles are also responsible for changes in the form of residual scapula; the front margin of the original bone into the spine and acromion, from which the main shelf of the shoulder blade appears as a new structure. In dinosaurs
The main bone dinosaurs of the bodice of the chest are scapula (scapula) and coracoid, both directly articulated with the clavicle. The clavicle is present in the saurischian dinosaurs but is largely absent in the ornithischian dinosaurs. The spot on the shoulder blades where it is articulated with the humerus (the upper bone of the forelimb) is the so-called glenoid. Scapula serves as an attachment site for the back and front muscles of the dinosaur spine.
Gallery
See also
- Scapulimancy/Oracle bone
References
- This article combines text in the public domain of page 202 of the 20th edition of Gray's Anatomy (1918)
- Nickel, Schummer, & amp; Seiferle; Lehrbuch der Anatomie der HaussÃÆ'¤ugetiere .
External links
- Photo anatomy: 10: st-0301 in SUNY Downstate Medical Center - "Combination of Upper Limbs: Scapula"
- shoulders/bones/bones at the Dartmouth School of Anatomy Department
- shoulders/surface/surface2 at the Department of Anatomy of Dartmouth Medical School
- radiographsul at The Anatomy Lesson by Wesley Norman (Georgetown University) ( xrayleftshoulder )
Source of the article : Wikipedia
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