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106-465: Only after a fragment of the right scapula (shoulder blade) was retrieved was it possible to produce an accurate dating of the individual, an analysis and diagnostic of its morphological features, and a preliminary paleogenetic characterization. In a 2015 paper published in the Journal of Human Evolution , it was announced that the fossil was a Neanderthal , and dating of the calcite has revealed that

212-432: A fibrocartilaginous structure, the glenoidal labrum , which deepens the cavity. At its apex is a slight elevation, the supraglenoid tuberosity , to which the long head of the biceps brachii is attached. The anatomic neck of the scapula is the slightly constricted portion which surrounds the head and is more distinct below and behind than above and in front. The surgical neck of the scapula passes directly medial to

318-440: A bone experiences within long bones such as the femur . As far as short bones are concerned, trabecular alignment has been studied in the vertebral pedicle . Thin formations of osteoblasts covered in endosteum create an irregular network of spaces, known as trabeculae. Within these spaces are bone marrow and hematopoietic stem cells that give rise to platelets , red blood cells and white blood cells . Trabecular marrow

424-479: A long bone are separated by a growing zone of cartilage (the epiphyseal plate ). At skeletal maturity (18 to 25 years of age), all of the cartilage is replaced by bone, fusing the diaphysis and both epiphyses together (epiphyseal closure). In the upper limbs, only the diaphyses of the long bones and scapula are ossified. The epiphyses, carpal bones, coracoid process, medial border of the scapula, and acromion are still cartilaginous. The following steps are followed in

530-509: A mineralized organic matrix. The primary inorganic component of human bone is hydroxyapatite , the dominant bone mineral , having the nominal composition of Ca 10 (PO 4 ) 6 (OH) 2 . The organic components of this matrix consist mainly of type I collagen —"organic" referring to materials produced as a result of the human body—and inorganic components, which alongside the dominant hydroxyapatite phase, include other compounds of calcium and phosphate including salts. Approximately 30% of

636-419: A more fulfilling and healthier lifestyle. Bone is constantly being created and replaced in a process known as remodeling . This ongoing turnover of bone is a process of resorption followed by replacement of bone with little change in shape. This is accomplished through osteoblasts and osteoclasts. Cells are stimulated by a variety of signals , and together referred to as a remodeling unit. Approximately 10% of

742-457: A number of anatomical terms to describe the appearance, shape and function of bones. Other anatomical terms are also used to describe the location of bones . Like other anatomical terms, many of these derive from Latin and Greek . Some anatomists still use Latin to refer to bones. The term "osseous", and the prefix "osteo-", referring to things related to bone, are still used commonly today. Some examples of terms used to describe bones include

848-422: A number of chemical enzymes that either promote or inhibit the activity of the bone remodeling cells, controlling the rate at which bone is made, destroyed, or changed in shape. The cells also use paracrine signalling to control the activity of each other. For example, the rate at which osteoclasts resorb bone is inhibited by calcitonin and osteoprotegerin . Calcitonin is produced by parafollicular cells in

954-529: A positive correlation between the adaptations of resistance training and bone density. While nutritional and pharmacological approaches may also improve bone health, the strength and balance adaptations from resistance training are a substantial added benefit. Weight-bearing exercise may assist in osteoblast (bone-forming cells) formation and help to increase bone mineral content. High-impact sports, which involve quick changes in direction, jumping, and running, are particularly effective with stimulating bone growth in

1060-419: A recent study, there was a strong correlation between calcium intake and BMD across a variety of diverse populations of children and adolescence ultimately coming to the conclusion that fundamentally, achieving optimal bone health is necessary for providing our youth with the ability to undergo hormonal changes as well. They found in a study of over 10,000 children ages 8-19 that in females, African Americans, and

1166-408: A smaller number of randomly oriented collagen fibers, but forms quickly; it is for this appearance of the fibrous matrix that the bone is termed woven . It is soon replaced by lamellar bone, which is highly organized in concentric sheets with a much lower proportion of osteocytes to surrounding tissue. Lamellar bone, which makes its first appearance in humans in the fetus during the third trimester,

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1272-401: A strong nutritional plan with adequate amounts of Calcium sources can lead to strong bones but also can be a worth-while strategy into preventing further damage or degradation of bone stores as we age. The connection between Calcium intake & BMD and its effects on youth as a whole is a very world-wide issue and has been shown to affect different ethnicities in a variety of differing ways. In

1378-417: A throwing or serving motion, in order to avoid impingement of the rotator cuff tendons. If the scapula fails to properly elevate the acromion, impingement may occur during the cocking and acceleration phase of an overhead activity. The two muscles most commonly inhibited during this first part of an overhead motion are the serratus anterior and the lower trapezius. These two muscles act as a force couple within

1484-456: A very low shear stress strength (51.6 MPa). This means that bone resists pushing (compressional) stress well, resist pulling (tensional) stress less well, but only poorly resists shear stress (such as due to torsional loads). While bone is essentially brittle , bone does have a significant degree of elasticity , contributed chiefly by collagen . Mechanically, bones also have a special role in hearing . The ossicles are three small bones in

1590-441: Is mineralized tissue of two types, cortical bone and cancellous bone . Other types of tissue found in bones include bone marrow , endosteum , periosteum , nerves , blood vessels and cartilage . In the human body at birth, approximately 300 bones are present. Many of these fuse together during development, leaving a total of 206 separate bones in the adult, not counting numerous small sesamoid bones . The largest bone in

1696-415: Is a large, somewhat triangular or oblong process, flattened from behind forward, projecting at first laterally, and then curving forward and upward, so as to overhang the glenoid cavity. There are 3 angles: The superior angle of the scapula or medial angle , is covered by the trapezius muscle . This angle is formed by the junction of the superior and medial borders of the scapula. The superior angle

1802-510: Is attached a fibrous septum which separates the Teres muscles from each other. Its lower third presents a broader, somewhat triangular surface, the inferior angle of the scapula , which gives origin to the Teres major , and over which the Latissimus dorsi glides; frequently the latter muscle takes origin by a few fibers from this part. The acromion forms the summit of the shoulder, and

1908-474: Is called "osteoid". Around and inside collagen fibrils calcium and phosphate eventually precipitate within days to weeks becoming then fully mineralized bone with an overall carbonate substituted hydroxyapatite inorganic phase. In order to mineralise the bone, the osteoblasts secrete alkaline phosphatase, some of which is carried by vesicles . This cleaves the inhibitory pyrophosphate and simultaneously generates free phosphate ions for mineralization, acting as

2014-418: Is composed of a network of rod- and plate-like elements that make the overall organ lighter and allow room for blood vessels and marrow. Trabecular bone accounts for the remaining 20% of total bone mass but has nearly ten times the surface area of compact bone. The words cancellous and trabecular refer to the tiny lattice-shaped units (trabeculae) that form the tissue. It was first illustrated accurately in

2120-568: Is in an excellent state of preservation and is unaffected by weather and disarticulation (dispersion of skeletal structure by scavengers), the calcite preserved the bones, but it also covered them to a great extent. It was thought that excavating the remains would cause irreparable damage and thus the bones have remained in situ for decades since their modern discovery. 40°49′01″N 16°33′00″E  /  40.8170°N 16.5500°E  / 40.8170; 16.5500 Scapula The scapula ( pl. : scapulae or scapulas ), also known as

2226-589: Is less common to see, the necessity for a healthy routine especially when it comes to bone development is essential in our youth. Children that naturally have lower bone mineral density have a lower quality of life and therefore lead a life that is less fulfilling and uncomfortable. Factors such as increases in Calcium intake has been shown to increase BMD stores. Studies have shown that increasing calcium stores whether that be through supplementation or intake via foods and beverages such as leafy greens and milk have pushed

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2332-399: Is located at the approximate level of the second thoracic vertebra . The superior angle of the scapula is thin, smooth, rounded, and inclined somewhat lateralward, and gives attachment to a few fibers of the levator scapulae muscle . The inferior angle of the scapula is the lowest part of the scapula and is covered by the latissimus dorsi muscle . It moves forwards round the chest when

2438-400: Is mainly responsible for stabilization and rotation of the scapula, consists of the trapezius , serratus anterior , levator scapulae , and rhomboid muscles . These attach to the medial, superior, and inferior borders of the scapula. The head, processes, and the thickened parts of the bone contain cancellous tissue; the rest consists of a thin layer of compact tissue. The central part of

2544-518: Is mostly found in the bone marrow of the femur, the ribs, the vertebrae and pelvic bones . Bone receives about 10% of cardiac output. Blood enters the endosteum , flows through the marrow, and exits through small vessels in the cortex. In humans, blood oxygen tension in bone marrow is about 6.6%, compared to about 12% in arterial blood, and 5% in venous and capillary blood. Bone is metabolically active tissue composed of several types of cells. These cells include osteoblasts , which are involved in

2650-527: Is necessary during our childhood as these factors lead to a supportive and healthy lifestyle/bone health. Up till the age of 30, the bone stores that we have will ultimately start to decrease as we surpass this age. Influencing factors that can help us have larger stores and higher amounts of BMD will allow us to see less harmful results as we reach older adulthood. The issue of having fragile bones during our childhood leads to an increase in certain disorders and conditions such as juvenile osteoporosis , though it

2756-455: Is not fully known. Two types of bone can be identified microscopically according to the arrangement of collagen: woven and lamellar. Woven bone is produced when osteoblasts produce osteoid rapidly, which occurs initially in all fetal bones, but is later replaced by more resilient lamellar bone. In adults, woven bone is created after fractures or in Paget's disease . Woven bone is weaker, with

2862-403: Is not uniformly solid, but consists of a flexible matrix (about 30%) and bound minerals (about 70%), which are intricately woven and continuously remodeled by a group of specialized bone cells. Their unique composition and design allows bones to be relatively hard and strong, while remaining lightweight. Bone matrix is 90 to 95% composed of elastic collagen fibers, also known as ossein, and

2968-422: Is probable that the detached segment was never united to the rest of the bone . "In terms of comparative anatomy the human scapula represents two bones that have become fused together; the (dorsal) scapula proper and the (ventral) coracoid. The epiphyseal line across the glenoid cavity is the line of fusion. They are the counterparts of the ilium and ischium of the pelvic girdle." The following muscles attach to

3074-730: Is stimulated by the secretion of growth hormone by the pituitary , thyroid hormone and the sex hormones ( estrogens and androgens ). These hormones also promote increased secretion of osteoprotegerin. Osteoblasts can also be induced to secrete a number of cytokines that promote reabsorption of bone by stimulating osteoclast activity and differentiation from progenitor cells. Vitamin D , parathyroid hormone and stimulation from osteocytes induce osteoblasts to increase secretion of RANK- ligand and interleukin 6 , which cytokines then stimulate increased reabsorption of bone by osteoclasts. These same compounds also increase secretion of macrophage colony-stimulating factor by osteoblasts, which promotes

3180-561: Is stronger and filled with many collagen fibers parallel to other fibers in the same layer (these parallel columns are called osteons). In cross-section , the fibers run in opposite directions in alternating layers, much like in plywood , assisting in the bone's ability to resist torsion forces. After a fracture, woven bone forms initially and is gradually replaced by lamellar bone during a process known as "bony substitution". Compared to woven bone, lamellar bone formation takes place more slowly. The orderly deposition of collagen fibers restricts

3286-448: Is the osteon . Cancellous bone or spongy bone , also known as trabecular bone , is the internal tissue of the skeletal bone and is an open cell porous network that follows the material properties of biofoams . Cancellous bone has a higher surface-area-to-volume ratio than cortical bone and it is less dense . This makes it weaker and more flexible. The greater surface area also makes it suitable for metabolic activities such as

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3392-400: Is through the anatomical neck of the scapula. The other more common type of fracture is through the surgical neck of the scapula. The surgical neck exits medial to the coracoid process . An abnormally protruding inferior angle of the scapula is known as a winged scapula and can be caused by paralysis of the serratus anterior muscle . In this condition the sides of the scapula nearest

3498-514: 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 (h)umerus , 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

3604-492: Is very minimal. Being able to consistently meet calcium needs while also engaging in weight-bearing exercise is essential for building a strong initial bone foundation at which to build upon. Being able to reach our daily value of 1300mg for ages 9-18 is becoming more and more necessary and as we progress in health, the chance that osteoporosis and other factors such as bone fragility or potential for stunted growth can be greatly reduced through these resources, ultimately leading to

3710-423: The Teres major and Teres minor muscles. The upper two-thirds of the surface between the ridge and the axillary border is narrow, and is crossed near its center by a groove for the scapular circumflex vessels; the Teres minor attaches here. The broad and narrow portions above alluded to are separated by an oblique line, which runs from the axillary border, downward and backward, to meet the elevated ridge: to it

3816-401: The glenoid cavity . This plate extends to form the chief part of the bone, the scapular spine growing up from its dorsal surface about the third month. Ossification starts as membranous ossification before birth. After birth, the cartilaginous components would undergo endochondral ossification . The larger part of the scapula undergoes membranous ossification. Some of the outer parts of

3922-436: The head of the scapula is the thickest part of the scapula. It is broad and bears the glenoid fossa on its articular surface which is directed forward, laterally and slightly upwards, and articulates with the head of the humerus . The inferior angle is broader below than above and its vertical diameter is the longest. The surface is covered with cartilage in the fresh state; and its margins, slightly raised, give attachment to

4028-426: The infraspinous fossa . The two fossae are connected by the spinoglenoid notch , situated lateral to the root of the spine. There is a ridge on the outer part of the back of the scapula. This runs from the lower part of the glenoid cavity, downward and backward to the vertebral border, about 2.5 cm above the inferior angle. Attached to the ridge is a fibrous septum, which separates the infraspinatus muscle from

4134-611: The mastoids and the general architecture of the cranial vault, which according to the research team of the Sapienza University of Rome support accepted speciation chronology. "It shows archaic traits, making the Altamura Man a sort of morphological bridge between the previous human species such as Homo heidelbergensis and the Neanderthals". Chronological studies on twenty faunal remains retrieved from

4240-724: The middle ear which are involved in sound transduction. The cancellous part of bones contain bone marrow . Bone marrow produces blood cells in a process called hematopoiesis . Blood cells that are created in bone marrow include red blood cells , platelets and white blood cells . Progenitor cells such as the hematopoietic stem cell divide in a process called mitosis to produce precursor cells. These include precursors which eventually give rise to white blood cells , and erythroblasts which give rise to red blood cells. Unlike red and white blood cells, created by mitosis, platelets are shed from very large cells called megakaryocytes . This process of progressive differentiation occurs within

4346-479: The osteonic canal . Volkmann's canals at right angles connect the osteons together. The columns are metabolically active, and as bone is reabsorbed and created the nature and location of the cells within the osteon will change. Cortical bone is covered by a periosteum on its outer surface, and an endosteum on its inner surface. The endosteum is the boundary between the cortical bone and the cancellous bone. The primary anatomical and functional unit of cortical bone

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4452-473: 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-

4558-427: The thoracic cage . The scapula is a thick, flat bone lying on the thoracic wall that provides an attachment for three groups of muscles: intrinsic, extrinsic, and stabilizing and rotating muscles. The intrinsic muscles of the scapula include the muscles of the rotator cuff —the subscapularis, teres minor, supraspinatus , and infraspinatus. These muscles attach to the surface of the scapula and are responsible for

4664-420: The thyroid gland , and can bind to receptors on osteoclasts to directly inhibit osteoclast activity. Osteoprotegerin is secreted by osteoblasts and is able to bind RANK-L, inhibiting osteoclast stimulation. Osteoblasts can also be stimulated to increase bone mass through increased secretion of osteoid and by inhibiting the ability of osteoclasts to break down osseous tissue . Increased secretion of osteoid

4770-448: The 12-15 adolescent groups that at 2.6-2.8g/kg of body weight, they began to see a decrease in BMD. They elaborate on this by determining that this is strongly influenced by a lower baseline in calcium intake throughout puberty. Genetic factors have also been shown to influence lower acceptance of calcium stores. Ultimately, the window that youth have for accruing and building resilient bones

4876-615: The Cave of Lamalunga based on Uranium-thorium dating by Maria Elisabetta Branca and Mario Voltaggio of IGAG (Institute of Environmental Geology and Geoengineering) and CNR (Italian National Research Council) in Rome and published in 2010 show a deposition age varying between 45,000 and 17,000 BP, with the majority of remains varying between 45,000 and 30,000 years ago. Accumulation of cave deposits were found to begin around 170,000 years ago and ended 17,000 years ago. Researchers associated with

4982-589: The University of Bari have carried out laser scans of the find, obtaining numerical maps, models and three-dimensional videos of the fossil. Results of a study of the DNA sample taken from the scapula determined that it belongs to the genetic variability of the "Neanderthal of Southern Europe". Between 1998 and 2000, the "Sarastro" project was carried out by Digamma Research Consortium, using integrated tele-operated systems that allowed remote access and observation of

5088-420: The acellular component of bone consists of organic matter, while roughly 70% by mass is attributed to the inorganic phase. The collagen fibers give bone its tensile strength , and the interspersed crystals of hydroxyapatite give bone its compressive strength . These effects are synergistic . The exact composition of the matrix may be subject to change over time due to nutrition and biomineralization , with

5194-420: The arch serves to support the spine and acromion . The costal surface superior of the scapula is the origin of 1st digitation for the serratus anterior origin. The back of the scapula (also called the dorsal or posterior surface) is arched from above downward, and is subdivided into two unequal parts by the spine of the scapula. The portion above the spine is called the supraspinous fossa , and that below it

5300-432: The arm is abducted. The inferior angle is formed by the union of the medial and lateral borders of the scapula. It is thick and rough and its posterior or back surface affords attachment to the teres major and often to a few fibers of the latissimus dorsi. The anatomical plane that passes vertically through the inferior angle is named the scapular line . The lateral angle of the scapula or glenoid angle also known as

5406-409: The base of the coracoid process. There are three borders of the scapula: The scapula is ossified 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. Ossification of the body begins about the second month of fetal life, by an irregular quadrilateral plate of bone forming, immediately behind

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5512-479: The body is the femur or thigh-bone, and the smallest is the stapes in the middle ear . The Greek word for bone is ὀστέον (" osteon "), hence the many terms that use it as a prefix—such as osteopathy . In anatomical terminology , including the Terminologia Anatomica international standard, the word for a bone is os (for example, os breve , os longum , os sesamoideum ). Bone

5618-432: The body, and enable mobility . Bones come in a variety of shapes and sizes and have complex internal and external structures. They are lightweight yet strong and hard and serve multiple functions . Bone tissue (osseous tissue), which is also called bone in the uncountable sense of that word, is hard tissue , a type of specialised connective tissue . It has a honeycomb -like matrix internally, which helps to give

5724-416: The bone marrow. After the cells are matured, they enter the circulation . Every day, over 2.5 billion red blood cells and platelets, and 50–100 billion granulocytes are produced in this way. As well as creating cells, bone marrow is also one of the major sites where defective or aged red blood cells are destroyed. Determined by the species, age, and the type of bone, bone cells make up to 15 percent of

5830-548: The bone matrix. The release of these growth factors from the bone matrix could cause the proliferation of osteoblast precursors. Essentially, bone growth factors may act as potential determinants of local bone formation. Cancellous bone volume in postmenopausal osteoporosis may be determined by the relationship between the total bone forming surface and the percent of surface resorption. A number of diseases can affect bone, including arthritis, fractures, infections, osteoporosis and tumors. Conditions relating to bone can be managed by

5936-523: The bone rigidity. Bone tissue is made up of different types of bone cells . Osteoblasts and osteocytes are involved in the formation and mineralisation of bone; osteoclasts are involved in the resorption of bone tissue. Modified (flattened) osteoblasts become the lining cells that form a protective layer on the bone surface. The mineralised matrix of bone tissue has an organic component of mainly collagen called ossein and an inorganic component of bone mineral made up of various salts. Bone tissue

6042-429: The bone. Growth factor storage—mineralized bone matrix stores important growth factors such as insulin -like growth factors, transforming growth factor, bone morphogenetic proteins and others. Strong bones during our youth is essential for preventing osteoporosis and bone fragility as we age. The importance of insuring factors that could influence increases in BMD while lowering our risks for further bone degradation

6148-530: The bones are between 128,000 and 187,000 years old. Altamura Man is one of the most complete Paleolithic skeletons ever to be discovered in Europe as "even the bones inside the nose are still there"; as of 2016, it represents the oldest sample of Neanderthal DNA to have been sequenced successfully. The skull was discovered in October 1993 by speleologists of CARS (Centro Altamurano Ricerche Speleologiche) in

6254-426: The breakdown of bones by the process of bone resorption . New bone is then formed by the osteoblasts. Bone is constantly remodeled by the resorption of osteoclasts and created by osteoblasts. Osteoclasts are large cells with multiple nuclei located on bone surfaces in what are called Howship's lacunae (or resorption pits ). These lacunae are the result of surrounding bone tissue that has been reabsorbed. Because

6360-458: The cartilage called "primary ossification centers". They mostly appear during fetal development, though a few short bones begin their primary ossification after birth . They are responsible for the formation of the diaphyses of long bones, short bones and certain parts of irregular bones. Secondary ossification occurs after birth and forms the epiphyses of long bones and the extremities of irregular and flat bones. The diaphysis and both epiphyses of

6466-458: The cave of Lamalunga in Altamura , Italy . While exploring the cave, the researchers stumbled upon a 10 m (33 ft) deep karst sinkhole, formed by the action of running water on limestone. The sinkhole merges into a tunnel about 60 m (200 ft) long in which they found the Altamura Man incorporated into the calcium carbonate concretions that had formed by water dribbling down

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6572-545: The cave walls. The finding was reported to researchers at the University of Bari . The fossilized skull of a 35-year-old adult male displays the anthropological features of the hypodigm of Homo neanderthalensis who lived during the Middle-Upper Pleistocene between 170,000 and 130,000 BP. Yet a number of phenetic peculiarities exist, such as the shape of the brow ridges, the relative dimension of

6678-447: The conversion of cartilage to bone: Bone development in youth is extremely important in preventing future complications of the skeletal system. Regular exercise during childhood and adolescence can help improve bone architecture, making bones more resilient and less prone to fractures in adulthood. Physical activity, specifically resistance training, stimulates growth of bones by increasing both bone density and strength. Studies have shown

6784-417: The coracoid bone has fused with the scapula, to become the coracoid process. These changes are associated with the upright gait of mammals, compared with the more sprawling limb arrangement of reptiles and amphibians; the muscles formerly attached to the procoracoid are no longer required. The altered musculature is also responsible for the alteration in the shape of the rest of the scapula; the forward margin of

6890-440: The costal or ventral surface) has a broad concavity called the subscapular fossa , to which the subscapularis muscle attaches. The medial two-thirds of the fossa have 3 longitudinal oblique ridges, and another thick ridge adjoins the lateral border; they run outward and upward. The ridges give attachment to the tendinous insertions, and the surfaces between them to the fleshy fibers, of the subscapularis muscle. The lateral third of

6996-567: The creation and mineralization of bone tissue, osteocytes , and osteoclasts , which are involved in the reabsorption of bone tissue. Osteoblasts and osteocytes are derived from osteoprogenitor cells, but osteoclasts are derived from the same cells that differentiate to form macrophages and monocytes . Within the marrow of the bone there are also hematopoietic stem cells . These cells give rise to other cells, including white blood cells , red blood cells , and platelets . Osteoblasts are mononucleate bone-forming cells. They are located on

7102-487: The current official Latin nomenclature, Terminologia Anatomica . Shoulder blade is the colloquial name for this bone. In fish, the scapular blade is a structure attached to the upper surface of the articulation of the pectoral fin , and is accompanied by a similar coracoid plate on the lower surface. Although sturdy in cartilagenous fish , both plates are generally small in most other fish, and may be partially cartilagenous, or consist of multiple bony elements. In

7208-641: The differentiation of progenitor cells into osteoclasts, and decrease secretion of osteoprotegerin. Bone volume is determined by the rates of bone formation and bone resorption. Certain growth factors may work to locally alter bone formation by increasing osteoblast activity. Numerous bone-derived growth factors have been isolated and classified via bone cultures. These factors include insulin-like growth factors I and II, transforming growth factor-beta, fibroblast growth factor, platelet-derived growth factor, and bone morphogenetic proteins. Evidence suggests that bone cells produce growth factors for extracellular storage in

7314-412: The early tetrapods , these two structures respectively became the scapula and a bone referred to as the procoracoid (commonly called simply the " coracoid ", but not homologous with the mammalian structure of that name). In amphibians and reptiles (birds included), these two bones are distinct, but together form a single structure bearing many of the muscle attachments for the forelimb. In such animals,

7420-453: The engravings of Crisóstomo Martinez . Bone marrow , also known as myeloid tissue in red bone marrow, can be found in almost any bone that holds cancellous tissue . In newborns , all such bones are filled exclusively with red marrow or hematopoietic marrow, but as the child ages the hematopoietic fraction decreases in quantity and the fatty/ yellow fraction called marrow adipose tissue (MAT) increases in quantity. In adults, red marrow

7526-429: The exchange of calcium ions. Cancellous bone is typically found at the ends of long bones, near joints, and in the interior of vertebrae. Cancellous bone is highly vascular and often contains red bone marrow where hematopoiesis , the production of blood cells, occurs. The primary anatomical and functional unit of cancellous bone is the trabecula . The trabeculae are aligned towards the mechanical load distribution that

7632-410: The foci for calcium and phosphate deposition. Vesicles may initiate some of the early mineralization events by rupturing and acting as a centre for crystals to grow on. Bone mineral may be formed from globular and plate structures, and via initially amorphous phases. Five types of bones are found in the human body: long, short, flat, irregular, and sesamoid. In the study of anatomy , anatomists use

7738-410: The formation of bone from cartilage . Intramembranous ossification mainly occurs during formation of the flat bones of the skull but also the mandible, maxilla, and clavicles; the bone is formed from connective tissue such as mesenchyme tissue rather than from cartilage. The process includes: the development of the ossification center , calcification , trabeculae formation and the development of

7844-590: The formation of osteoid to about 1 to 2  μm per day. Lamellar bone also requires a relatively flat surface to lay the collagen fibers in parallel or concentric layers. The extracellular matrix of bone is laid down by osteoblasts , which secrete both collagen and ground substance. These cells synthesise collagen alpha polypetpide chains and then secrete collagen molecules. The collagen molecules associate with their neighbors and crosslink via lysyl oxidase to form collagen fibrils. At this stage, they are not yet mineralized, and this zone of unmineralized collagen fibrils

7950-406: The fossa is smooth and covered by the fibers of this muscle. At the upper part of the fossa is a transverse depression, where the bone appears to be bent on itself along a line at right angles to and passing through the center of the glenoid cavity , forming a considerable angle, called the subscapular angle; this gives greater strength to the body of the bone by its arched form, while the summit of

8056-399: The glenohumeral joint to properly elevate the acromion process, and if a muscle imbalance exists, shoulder impingement may develop. Other conditions associated with scapular dyskenesis include thoracic outlet syndrome and the related pectoralis minor syndrome . The name scapula as synonym of shoulder blade is of Latin origin. It is commonly used in medical English and is part of

8162-475: The groundwork for bone health later in life, reducing the risk of bone-related conditions such as osteoporosis. Bones have a variety of functions: Bones serve a variety of mechanical functions. Together the bones in the body form the skeleton . They provide a frame to keep the body supported, and an attachment point for skeletal muscles , tendons , ligaments and joints , which function together to generate and transfer forces so that individual body parts or

8268-417: The internal and external rotation of the shoulder joint , along with humeral abduction. The extrinsic muscles include the biceps , triceps , and deltoid muscles and attach to the coracoid process and supraglenoid tubercle of the scapula, infraglenoid tubercle of the scapula, and spine of the scapula . These muscles are responsible for several actions of the glenohumeral joint. The third group, which

8374-431: The lower part of the glenoid cavity, and the tip of the coracoid process frequently has a separate nucleus. These various epiphyses are joined to the bone by the 25th year. Failure of bony union between the acromion and spine sometimes occurs (see os acromiale ), the junction being effected by fibrous tissue , or by an imperfect articulation; in some cases of supposed fracture of the acromion with ligamentous union, it

8480-487: The notion that prepuberty or even early pubertal children will see increases in BMD with the addition of increase Calcium intake. Another research study goes on to show that long-term calcium intake has been proven to significantly contribute to overall BMD in children without certain conditions or disorders. This data shows that ensuring adequate calcium intake in children reinforces the structure and rate at which bones will begin to densify. Further detailing how structuring

8586-405: The original bone became the spine and acromion, from which the main shelf of the shoulder blade arises as a new structure. In dinosaurs the main bones of the pectoral girdle were the scapula (shoulder blade) and the coracoid , both of which directly articulated with the clavicle . The clavicle was present in saurischian dinosaurs but largely absent in ornithischian dinosaurs. The place on

8692-478: The osteoblast puts up collagen fibers. These collagen fibers are used as a framework for the osteoblasts' work. The osteoblast then deposits calcium phosphate which is hardened by hydroxide and bicarbonate ions. The brand-new bone created by the osteoblast is called osteoid . Once the osteoblast is finished working it is actually trapped inside the bone once it hardens. When the osteoblast becomes trapped, it becomes known as an osteocyte. Other osteoblasts remain on

8798-502: The osteoclasts are derived from a monocyte stem-cell lineage, they are equipped with phagocytic -like mechanisms similar to circulating macrophages . Osteoclasts mature and/or migrate to discrete bone surfaces. Upon arrival, active enzymes, such as tartrate-resistant acid phosphatase , are secreted against the mineral substrate. The reabsorption of bone by osteoclasts also plays a role in calcium homeostasis . Bones consist of living cells (osteoblasts and osteocytes) embedded in

8904-456: The osteocyte cell processes occupy channels called canaliculi. The many processes of osteocytes reach out to meet osteoblasts, osteoclasts, bone lining cells, and other osteocytes probably for the purposes of communication. Osteocytes remain in contact with other osteocytes in the bone through gap junctions—coupled cell processes which pass through the canalicular channels. Osteoclasts are very large multinucleate cells that are responsible for

9010-427: The periosteum. Endochondral ossification occurs in long bones and most other bones in the body; it involves the development of bone from cartilage. This process includes the development of a cartilage model, its growth and development, development of the primary and secondary ossification centers , and the formation of articular cartilage and the epiphyseal plates . Endochondral ossification begins with points in

9116-684: The ratio of calcium to phosphate varying between 1.3 and 2.0 (per weight), and trace minerals such as magnesium , sodium , potassium and carbonate also be found. Type I collagen composes 90–95% of the organic matrix, with the remainder of the matrix being a homogenous liquid called ground substance consisting of proteoglycans such as hyaluronic acid and chondroitin sulfate , as well as non-collagenous proteins such as osteocalcin , osteopontin or bone sialoprotein . Collagen consists of strands of repeating units, which give bone tensile strength, and are arranged in an overlapping fashion that prevents shear stress. The function of ground substance

9222-462: The remainder is ground substance . The elasticity of collagen improves fracture resistance. The matrix is hardened by the binding of inorganic mineral salt, calcium phosphate , in a chemical arrangement known as bone mineral , a form of calcium apatite . It is the mineralization that gives bones rigidity. Bone is actively constructed and remodeled throughout life by special bone cells known as osteoblasts and osteoclasts. Within any single bone,

9328-411: The rest of the bone about the 15th year. Between the 14th and 20th years, the remaining parts ossify in quick succession, and usually in the following order: first, in the root of the coracoid process, in the form of a broad scale; secondly, near the base of the acromion; thirdly, in the inferior angle and contiguous part of the vertebral border; fourthly, near the outer end of the acromion; fifthly, in

9434-417: The scapula are cartilaginous at birth, and would therefore undergo endochondral ossification. At birth, a large part of the scapula is osseous, but the glenoid cavity, the coracoid process, the acromion, the vertebral border and the inferior angle are cartilaginous . From the 15th to the 18th month after birth, ossification takes place in the middle of the coracoid process, which as a rule becomes joined with

9540-399: The scapula is usually a relatively simple plate, lacking the projections and spine that it possesses in mammals. However, the detailed structure of these bones varies considerably in living groups. For example, in frogs, the procoracoid bones may be braced together at the animal's underside to absorb the shock of landing, while in turtles, the combined structure forms a Y-shape in order to allow

9646-410: The scapula to retain a connection to the clavicle (which is part of the shell). In birds, the procoracoids help to brace the wing against the top of the sternum . In the fossil therapsids , a third bone, the true coracoid , formed just behind the procoracoid. The resulting three-boned structure is still seen in modern monotremes , but in all other living mammals, the procoracoid has disappeared, and

9752-459: The scapula where it articulated with the humerus (upper bone of the forelimb) is called the glenoid . The scapula serves as the attachment site for a dinosaur's back and forelimb muscles. Bone A bone is a rigid organ that constitutes part of the skeleton in most vertebrate animals. Bones protect the various other organs of the body, produce red and white blood cells , store minerals , provide structure and support for

9858-403: The scapula: Movements of the scapula are brought about by the scapular muscles. The scapula can perform six actions: Because of its sturdy structure and protected location, fractures of the scapula are uncommon. When they do occur, they are an indication that severe chest trauma has occurred. Scapular fractures involving the neck of the scapula have two patterns. One (rare) type of fracture

9964-411: The site. More recent research analysis that began in 2009 and based on Uranium-thorium dating revealed that the calcite was formed 172,000 to 130,000 years ago during the penultimate quaternary glaciation period. The Altamura man remains embedded in a matrix of limestone to this day. As such, a running challenge exists among experts to devise a way to remove the fossil intact. The remaining skeleton

10070-578: The skeletal mass of an adult is remodelled each year. The purpose of remodeling is to regulate calcium homeostasis , repair microdamaged bones from everyday stress, and to shape the skeleton during growth. Repeated stress, such as weight-bearing exercise or bone healing, results in the bone thickening at the points of maximum stress ( Wolff's law ). It has been hypothesized that this is a result of bone's piezoelectric properties, which cause bone to generate small electrical potentials under stress. The action of osteoblasts and osteoclasts are controlled by

10176-405: The spine are positioned outward and backward. The appearance of the upper back is said to be wing-like. In addition, any condition causing weakness of the serratus anterior muscle may cause scapular "winging". The scapula plays an important role in shoulder impingement syndrome. Abnormal scapular function is called scapular dyskinesis. The scapula performs elevation of the acromion process during

10282-399: The supraspinatus fossa and the upper part of the infraspinatous fossa , but especially the former, are usually so thin in humans as to be semitransparent; occasionally the bone is found wanting in this situation, and the adjacent muscles are separated only by fibrous tissue. The scapula has two surfaces, three borders, three angles, and three processes. The front of the scapula (also known as

10388-469: The surface of osteon seams and make a protein mixture known as osteoid , which mineralizes to become bone. The osteoid seam is a narrow region of a newly formed organic matrix, not yet mineralized, located on the surface of a bone. Osteoid is primarily composed of Type I collagen . Osteoblasts also manufacture hormones , such as prostaglandins , to act on the bone itself. The osteoblast creates and repairs new bone by actually building around itself. First,

10494-450: The term "foramen" to describe a hole through which something passes, and a "canal" or "meatus" to describe a tunnel-like structure. A protrusion from a bone can be called a number of terms, including a "condyle", "crest", "spine", "eminence", "tubercle" or "tuberosity", depending on the protrusion's shape and location. In general, long bones are said to have a "head", "neck", and "body". When two bones join, they are said to "articulate". If

10600-419: The tissue is woven into two main patterns, known as cortical and cancellous bone, each with a different appearance and characteristics. The hard outer layer of bones is composed of cortical bone , which is also called compact bone as it is much denser than cancellous bone. It forms the hard exterior (cortex) of bones. The cortical bone gives bone its smooth, white, and solid appearance, and accounts for 80% of

10706-417: The top of the new bone and are used to protect the underlying bone, these become known as bone lining cells. Osteocytes are cells of mesenchymal origin and originate from osteoblasts that have migrated into and become trapped and surrounded by a bone matrix that they themselves produced. The spaces the cell body of osteocytes occupy within the mineralized collagen type I matrix are known as lacunae , while

10812-412: The total bone mass of an adult human skeleton . It facilitates bone's main functions—to support the whole body, to protect organs, to provide levers for movement, and to store and release chemical elements, mainly calcium. It consists of multiple microscopic columns, each called an osteon or Haversian system. Each column is multiple layers of osteoblasts and osteocytes around a central canal called

10918-418: The two bones have a fibrous connection and are relatively immobile, then the joint is called a "suture". The formation of bone is called ossification . During the fetal stage of development this occurs by two processes: intramembranous ossification and endochondral ossification . Intramembranous ossification involves the formation of bone from connective tissue whereas endochondral ossification involves

11024-402: The vertebral border. The base of the acromion is formed by an extension from the spine; the two nuclei of the acromion unite, and then join with the extension from the spine. The upper third of the glenoid cavity is ossified from a separate center (sub coracoid), which appears between the 10th and 11th years and joins between the 16th and the 18th years. Further, an epiphysial plate appears for

11130-430: The whole body can be manipulated in three-dimensional space (the interaction between bone and muscle is studied in biomechanics ). Bones protect internal organs, such as the skull protecting the brain or the ribs protecting the heart and lungs . Because of the way that bone is formed, bone has a high compressive strength of about 170  MPa (1,700  kgf/cm ), poor tensile strength of 104–121 MPa, and

11236-421: The youth. Sports such as soccer, basketball, and tennis have shown to have positive effects on bone mineral density as well as bone mineral content in teenagers. Engaging in physical activity during childhood years, particularly in these high-impact osteogenic sports, can help to positively influence bone mineral density in adulthood. Children and adolescents who participate in regular physical activity will place

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