Infobox Anatomy Name Endochondralossification Latin GraySubject GrayPage Image Hypertrophic Zone of Epiphyseal Plate.jpg Caption Endochondralossification progressing from normal chondrocytes top to degenerating ones, characteristically displaying a calcified matrix, bottom . Image2 Caption2 Width 300 System Precursor MeshName MeshNumber DorlandsPre DorlandsSuf Endochondralossification ref Etymology from lang el endon , within , and chondros , cartilage ref ref cite web url http www.myetymology.com english endochondral.html title Etymology of the English word endochondral publisher myEtymolgy accessdate December 2009 ref is one of the two essential processes during fetal development of the mammal ian skeleton skeletal system by which bone tissue is created. Unlike intramembranous ossification , which is the other process by which bone tissue is created, Hyaline cartilage cartilage is present during endochondralossification. It is also an essential process during the rudimentary ... Atlas of Histology, Klein and Noble Smith. During endochondralossification, four distinct zones ... the process of endochondralossification. References Reflist See also Intramembranous ossificationOssification Bone and cartilage Category Developmental biology Category Skeletal system es Osificaci n ... that develop from the perichondrium. Primary center of ossification Image Bone growth.png thumb 450px The first site of ossification occurs in the primary center of ossification, which is in the middle ... s in the primary center of ossification begin to grow hypertrophy . They stop secreting collagen ... s, break down spongy bone to form the medullary bone marrow cavity. Secondary center of ossification About the time of birth, a secondary ossification center appears in each end epiphysis of long bones ... in a primary ossification center. The cartilage between the primary and secondary ossification ... of the primary and secondary ossification centers is called the epiphyseal line. Appositional bone ... more details
wiktionary ossification Image Bonemetabolism.svg thumb 300 px right Bone is broken down by osteoclasts, and rebuilt by osteoblasts, both of which communicate through cytokine TGF , Insulin like growth factor IGF signalling. Ossification or osteogenesis is the process of laying down new bone material by cells called osteoblast s. It is synonymous with bone tissue formation. There are two processes resulting in the formation of normal, healthy bone tissue ref cite journal author Caetano Lopes J, Canh o H, Fonseca JE title Osteoblasts and bone formation journal Acta reumatol gica portuguesa volume 32 issue 2 pages 103 10 year 2007 pmid 17572649 ref Intramembranous ossification is the direct laying down of bone into the primitive connective tissue mesenchyme , while endochondralossification involves cartilage as a precursor. In fracture healing , endochondral osteogenesis is the most commonly occurring process, for example in fractures of long bones treated by plaster of Paris , whereas ... osteogenesis. Heterotopic ossification is a process resulting in the formation of bone tissue that is often atypical, at an extraskeletal location. Calcification is often confused with ossification ... and tissue. It is a process that occurs during ossification, but not vice versa . The exact mechanisms ... in some way. Timetable for human ossification class wikitable Time period ref name Morey Holton ... development Ossification in long bones beginning Fourth month Most primary ossification centers have appeared in the diaphyses of bone. Birth to 5 years Secondary ossification centers appear in the epiphyses 5 years to 12 years in females, 5 to 14 years in males Ossification is spreading ... describing ossification and bone loss Ossicone , the horn like or antler like protuberances on the heads ... reflist Bone and cartilage Bone cartilage physiology Ossification Category Animal physiology Category Skeletal system Category Tissues Ossification Musculoskeletal stub Cell biology stub bg ... more details
Image Gray206.png thumb Figure 5 Plan of ossification of the scapula. From seven centers. 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 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 http www.medcyclopaedia.com library topics volume vii o ossification.aspx http books.google.com books?id t70Ij7jHLIkC&pg PA97&lpg PA97&dq 22membranous ossification 22 scapula&source web&ots RUWL51g7YN&sig tAu1oyrdRHvWKvRdaDkc0e7DZZk&hl en&sa X&oi book result&resnum 23&ct result . After birth, the cartilaginous components would undergo endochondralossification . 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 the rest of the bone about the 15th year. Between the 14th and 20th months, the remaining parts ossify in quick succession, and usually in this 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 extremity of the acromion fifthly, in the vertebral border. The base of the acromion is formed by an extension from the spine the two ... ossification 22 scapula&source web&ots RUWL51g7YN&sig tAu1oyrdRHvWKvRdaDkc0e7DZZk&hl en&sa X&oi book result&resnum 23&ct result Facial Trauma Ossification Category Skeletal disorders sv Ossifikation av ... more details
bone occurs, this blood vessel becomes the central canal of the osteon. See also EndochondralossificationOssification References Reflist Martin, RB DB Burr NA Sharkey 1998 , Skeletal Tissue Mechanics ...Intramembranous ossification ref Literally bone formation within membrane . ref is one of the two essential processes during fetal development of the mammal ian skeleton skeletal system by which bone tissue is created. Unlike endochondralossification , which is the other process by which bone tissue is created, cartilage is not present during intramembranous ossification. It is also an essential process during the natural healing of bone healing bone fractures ref name Brighton Brighton, Carl T. and Robert M. Hunt 1991 , Early histological and ultrastructural changes in medullary fracture callus , Journal of Bone and Joint Surgery , 73 A 6 832 847 ref and the rudimentary formation of bone s of the Human skull head . ref name Netter Frank H. Netter Netter, Frank H. 1987 , Musculoskeletal system anatomy, physiology, and metabolic disorders . Summit, New Jersey Ciba Geigy Corporation ISBN 0914168886, p.129 ref Creation of bone tissue Image Mesenchymal Stem Cell.jpg thumb 264px Mesenchymal stem cell Mesenchymal stem cell s, or MSCs, within mesenchyme or the medullary cavity of a bone fracture initiate the process of intramembranous ossification. A MSC is an unspecialized cell whose Morphology biology morphology undergoes characteristic changes as it develops into an osteoblast . Before it begins to develop, the morphological characteristics of a MSC are a small cell body with a few cell processes that are long and thin a large, round Cell nucleus nucleus with a prominent nucleolus that is surrounded by finely dispersed chromatin particles, giving the nucleus a clear appearance ... trabecular network. Primary center of ossification The periosteum is formed around the trabeculae by differentiating mesenchymal cells. The primary center of ossification is the area where bone ... more details
Image Gray105.png thumb 300px The axis is ossified from five primary and two secondary centers. The axis anatomy axis is Endochondral ossification ossified from five primary and two secondary centers. The body and vertebral arch are ossified in the same manner as the corresponding parts in the other vertebrae , viz., one center for the body, and two for the vertebral arch . The centers for the arch appear about the seventh or eighth week of fetal life, while the centers for the body appear in about the fourth or fifth month. The dens or odontoid process consists originally of a continuation upward of the cartilaginous mass, in which the lower part of the body is formed. About the sixth month of fetal life, two centers make their appearance in the base of this process they are placed laterally, and join before birth to form a conical bilobed mass deeply cleft above the interval between the sides of the cleft and the summit of the process is formed by a wedge shaped piece of cartilage. The base of the process is separated from the body by a cartilaginous disk, which gradually becomes ossified at its circumference, but remains cartilaginous in its center until advanced age. In this cartilage, rudiments of the lower epiphysial lamella of the atlas and the upper epiphysial lamella of the axis may sometimes be found. The apex of the odontoid process has a separate center which appears in the second and joins about the twelfth year this is the upper epiphysial lamella of the atlas. In addition to these there is a secondary center for a thin epiphysial plate on the under surface of the body of the bone. Gray s Category Skeletal system ... more details
Infobox Anatomy Name Ossification center Latin centrum ossificationis GraySubject 18 GrayPage 93 Image Gray79.png Caption Section of fetal bone of cat. ir. Irruption of the subperiosteal tissue. p. Fibrous layer of the periosteum. o. Layer of osteoblasts. im. Subperiosteal bony deposit. Image2 Caption2 System Precursor MeshName MeshNumber DorlandsPre c 20 DorlandsSuf 12227335 The first step in ossification of the cartilage is that the cartilage cells, at the point where ossification is commencing and which is termed a ossification center , enlarge and arrange themselves in rows. The matrix in which they are imbedded increases in quantity, so that the cells become further separated from each other. A deposit of calcareous material now takes place in this matrix, between the rows of cells, so that they become separated from each other by longitudinal columns of calcified matrix, presenting a granular and opaque appearance. Here and there the matrix between two cells of the same row also becomes calcified, and transverse bars of calcified substance stretch across from one calcareous column to another. Thus there are longitudinal groups of the cartilage cells enclosed in oblong cavities, the walls of which are formed of calcified matrix which cuts off all nutrition from the cells the cells, in consequence, atrophy, leaving spaces called the primary areol . Types of ossification centers There are two types of ossification centers primary and secondary. A primary ossification center ... have multiple primary centers. A secondary ossification center is the area of ossification that appears after the primary ossification center has already appeared most of which appear during the postnatal and adolescent years. Most bones have more than one secondary ossification center. In long bones, the secondary centres appear in the epiphyses . Gray s Ossification Category Physiology Category Skeletal system Category Tissues Ossification musculoskeletal stub developmental biology stub ... more details
Unreferenced date December 2009 Generalize date October 2009 Image Gray217.png thumb Figure 1 Plan of ossification of the radius. From three centers. Image Gray218.png thumb Figure 2 Epiphysial lines of radius in a young adult. Anterior aspect. The line of attachment of the articular capsule of the wrist joint is in blue. The radius is one of the two bone s in the forearm . The radius bone radius is ossified from three centers one for the body, and one for either extremity. That for the body makes its appearance near the center of the bone, during the eighth week of fetal life. About the end of year, ossification commences in the lower end and at the fifth year, in the upper end. The upper epiphysis fuses with the body at the age of seventeen or eighteen years, the lower about the age of twenty. An additional center sometimes found in the radial tuberosity, appears about the fourteenth or fifteenth year. Ossification DEFAULTSORT Ossification Of Radius Category Upper limb anatomy ... more details
Unreferenced date December 2006 Image Gray215.png thumb Plan of ossification of the ulna. From three centers. Image Gray216.png thumb Epiphysial lines of ulna in a young adult. Lateral aspect. The lines of attachment of the articular capsules are in blue. The ulna is ossified from three centers one each for the body, the inferior extremity, and the top of the olecranon . Ossification begins near the middle of the body, about the eighth week of fetal life, and soon extends through the greater part of the bone. At birth the ends are cartilaginous. About the fourth year, a center appears in the middle of the head, and soon extends into the styloid process . About the tenth year, a center appears in the olecranon near its extremity, the chief part of this process being formed by an upward extension of the body. The upper epiphysis joins the body about the sixteenth, the lower about the twentieth year. Ossification DEFAULTSORT Ossification Of Ulna Category Skeletal system ... more details
Image Gray260.png thumb Plan of ossification of the tibia. From three centers. Image Gray261.png thumb Epiphysial lines of tibia and fibula in a young adult. Anterior aspect. The tibia a bone in the Human Body is ossified from three centers one for the body and one for either extremity. Ossification begins in the center of the body, about the seventh week of fetal life, and gradually extends toward the extremities. The center for the upper epiphysis appears before or shortly after birth at close to 34 weeks gestation it is flattened in form, and has a thin tongue shaped process in front, which forms the tuberosity that for the lower epiphysis appears in the second year. The lower epiphysis fuses with the tibial shaft at about the eighteenth, and the upper one fuses about the twentieth year. Two additional centers occasionally exist, one for the tongue shaped process of the upper epiphysis, which forms the tuberosity, and one for the medial malleolus. Gray s Ossification Category Bones of the lower limb ... more details
Unreferenced date December 2009 Image Gray210.png thumb Figure 4 Plan of ossification of the humerus. Image Gray211.png thumb Figure 5 Epiphysial lines of humerus in a young adult. Anterior aspect. The lines of attachment of the articular capsules are in blue. The humerus is ossified from eight centers, one for each of the following parts the body, the head, the greater tubercle, the lesser tubercle, the capitulum, the trochlea, and one for each epicondyle. One primary and seven secondary centres . The center for the body appears near the middle of the diaphysis in the eighth week of fetal life, and soon extends toward the extremities. This is the primary centre At birth the humerus is ossified in nearly its whole length, only the extremities remaining cartilaginous. During the first year, sometimes before birth, ossification commences in the head of the bone, and during the second year the center for the greater tubercle, and during the fifth that for the lesser tubercle, make their appearance. By the sixth year the centers for the head and tubercles have joined, so as to form a single large epiphysis, which fuses with the body about the twentieth year. The lower end of the humerus is ossified as follows. At the end of the second year ossification begins in the capitulum, and extends medialward, to form the chief part of the articular end of the bone the center for the medial part of the trochlea appears about the age of twelve. Ossification begins in the medial epicondyle about the fifth year, and in the lateral about the thirteenth or fourteenth year. About the sixteenth or seventeenth year, the lateral epicondyle and both portions of the articulating surface, having already joined, unite with the body, and at the eighteenth year the medial epicondyle becomes joined to it. Ossification DEFAULTSORT Ossification Of Humerus Category Skeletal disorders ... more details
Heterotopic ossification HO is the process by which bone tissue forms outside of the skeleton . Diagnosis ... url http www.spinalcord.ar.gov Publications FactSheets sheets1 5 fact1.html title Heterotopic Ossification ... ref Causes Study on heterotopic ossification has suggested that it may be linked to injuries to the spinal ... tissues of the body, it results in heterotopic ossification. The condition often appears in the form of periarticular ossification, especially around the site of hip injuries. ref cite web url http www.wisegeek.com what is heterotopic ossification.htm title What is Heterotopic Ossification ... heterotopic ossification following total hip arthoplasty replacement or severe fracture of the long ... ossification. Heterotopic ossification jeopardizes functional outcome, impairs rehabilitation .... Patients with heterotopic ossification after a previous hip arthoplasty are at greatest risk of developing additional heterotopic ossification, with incidence between 50 and 90 . Symptoms In addition, the bone scan will show heterotopic ossification seven to ten days earlier than an x ray. The three ... title Heterotopic Ossification SCI InfoSheet 12 accessdate 2008 06 28 ref Treatment The effect of Didronel ... calcium that has already been deposited. It is a preventative drug, and has no effect on existing ossification .... In most cases, there will be a brief flare up of the heterotopic ossification following discontinuation ... reliable tests to indicate that the heterotopic ossification is inactive and treatment can be safely ... FactSheets sheets1 5 fact1.html title Heterotopic Ossification accessdate 2008 06 28 archiveurl http ... of postoperative heterotopic ossification, but the outcome has been contradictory. Indomethacin .... Prophylactic radiation therapy for the prevention of heterotopic ossification has been employed since ... of heterotopic ossification after total hip replacement. ref name ReferenceA See also Myositis ... DukeOrtho heterotopic ossification eMedicine pmr 112 eMedicine radio 336 http www.physorg.com news172924973.html ... more details
the bone consists of two parts, united by a fibrous symphysis, in which ossification takes place during the first year. The foregoing description of the ossification of the mandible is based on the researches of Low 44 and Fawcett, 45 and differs somewhat from that usually given. Gray s Ossification Category Physiology Category Skeletal system Category Tissues Ossification musculoskeletal stub ... more details
Infobox Bone Name Ossification of ethmoid Latin GraySubject 36 GrayPage 153 Image Gray194.png Caption Sagittal section of skull. Ethmoid bone visible as white structure to left. Image2 Caption2 Origins Insertions Articulations MeshName MeshNumber The ethmoid is ossified in the cartilage of the nasal capsule by three centers one for the perpendicular plate, and one for each labyrinth. The labyrinths are first developed, ossific granules making their appearance in the region of the lamina papyracea between the fourth and fifth months of fetus fetal life, and extending into the conch . At birth, the bone consists of the two labyrinths, which are small and ill developed. During the first year after birth, the perpendicular plate and crista galli begin to ossify from a single center, and are joined to the labyrinths about the beginning of the second year. The cribriform plate is ossified partly from the perpendicular plate and partly from the labyrinths. The development of the ethmoidal cells begins during fetal life. Gray s Ossification Category Skull musculoskeletal stub developmental biology stub ... more details
the third month, and almost at once undergoes ossification Fawcett . The medial joins the lateral pterygoid ... occasionally ossify. Gray s Ossification Category Physiology Category Skeletal system Category Tissues Ossification ... more details
Image Gray118.png thumb Figure 4 Ossification of the sternum. Image Gray119.png thumb Figure 5 Image Gray120.png thumb Figure 6 Peculiarities. Image Gray121.png thumb Figure 7 The Human sternum sternum originally consists of two cartilaginous bars, situated one on either side of the median plane and connected with the cartilages of the upper nine ribs of its own side. These two bars fuse with each other along the middle line to form the cartilaginous sternum which is ossified from six centers one for the manubrium, four for the body, and one for the xiphoid process Fig. 4 . The ossific centers appear in the intervals between the articular depressions for the costal cartilages, in the following order in the manubrium and first piece of the body, during the sixth month of fetal life in the second and third pieces of the body, during the seventh month of fetal life in its fourth piece, during the first year after birth and in the xiphoid process, between the fifth and eighteenth years. The centers make their appearance at the upper parts of the segments, and proceed gradually downward. To these may be added the occasional existence of two small episternal centers, which make their appearance one on either side of the jugular notch they are probably vestiges of the episternal bone of the monotremata and lizards. Occasionally some of the segments are formed from more than one center, the number and position of which vary Fig. 6 . Thus, the first piece may have two, three, or even six centers. When two are present, they are generally situated one above the other, the upper being the larger the second piece has seldom more than one the third, fourth, and fifth pieces are often formed from two centers placed laterally, the irregular union of which explains the rare occurrence of the sternal foramen Fig. 7 , or of the vertical fissure which occasionally intersects this part of the bone .... DEFAULTSORT Ossification Of Sternum Category Skeletal disorders ... more details
Image Gray136.png thumb 300px Figure 3 Frontal bone at birth The frontal bone is ossified Fig. 3 in membrane from two primary centers, one for each half, which appear toward the end of the second month of fetal life, one above each supraorbital margin. From each of these centers ossification extends upward to form the corresponding half of the squama, and backward to form the orbital plate. The spine is ossified from a pair of secondary centers, on either side of the middle line similar centers appear in the nasal part and zygomatic processes. At birth the bone consists of two pieces, separated by the frontal suture , which is usually obliterated, except at its lower part, by the eighth year, but occasionally persists throughout life. It is generally maintained that the development of the frontal sinuses begins at the end of the first or beginning of the second year, but Onodi s researches indicate that development begins at birth. The sinuses are of considerable size by the seventh or eighth year, but do not attain their full proportions until after puberty. Gray s Ossification Category Skeletal system ... more details
image Gray131.png thumb right Figure 3 Occipital bone at birth. The planum occipitale Fig. 3 of the squama of the occipital bone is developed in membrane biology membrane , and may remain separate throughout life when it constitutes the interparietal bone the rest of the bone is developed in cartilage. The number of nuclei for the planum occipitale is usually given as four, two appearing near the middle line about the second month, and two some little distance from the middle line about the third month of fetal life . The planum nuchale of the squama is ossified from two centers, which appear about the seventh week of fetal life and soon unite to form a single piece. Union of the upper and lower portions of the squama takes place in the third month of fetal life . An occasional center Kerckring appears in the posterior margin of the foramen magnum during the fifth month this forms a separate ossicle sometimes double which unites with the rest of the squama before birth. Each of the lateral parts begins to ossify from a single center during the eighth week of fetal life . The basilar portion is ossified from two centers, one in front of the other these appear about the sixth week of fetal life and rapidly coalesce. Mall states that the planum occipitale is ossified from two centers and the basilar portion from one. About the fourth year the squama and the two lateral portions unite, and about the sixth year the bone consists of a single piece. Between the 18th and 25th years the occipital and sphenoid become united, forming a single bone. In other animals In many animals these parts stay separate through life e.g. in the dog as four parts supraoccipital the squama left and right exoccipital the lateral parts basioccipital the basilar part . Gray s Ossification Category Skeletal system Category Skull ... more details
Image Gray175.png thumb Vomer of infant. At an early period the nasal septum septum of the nose consists of a plate of cartilage , the ethmovomerine cartilage . The postero superior part of this cartilage is ossified to form the perpendicular plate of the ethmoid its antero inferior portion persists as the septal cartilage, while the vomer is ossified in the membrane covering its postero inferior part. Two ossific center s, one on either side of the middle line, appear about the eighth week of fetus fetal life in this part of the membrane, and hence the vomer consists primarily of two lamell . About the third month these unite below, and thus a deep groove is formed in which the cartilage is lodged. As growth proceeds, the union of the lamell extends upward and forward, and at the same time the intervening plate of cartilage undergoes absorption. By the onset of puberty the lamell are almost completely united to form a median plate, but evidence of the bilaminar origin of the bone is seen in the everted al of its upper border and the groove on its anterior margin. Gray s Category Skeletal system Category Skull ... more details
Unreferenced date December 2009 A dermal bone membrane bone the pattern and form of bones derived from intramembranous ossification , versus endochondral bone formed by endochondral ossification define essential components of the vertebrate skeleton including the skull, jaws, gills, fins and exoskeleton. The function of dermal bone is conserved throughout vertebrates, varying in shape and numbers of bones in the skull roof and postcranial structures. In bony fish , dermal bone is found throughout the body in the fin rays and scales. Dermal bone is formed within the Dermis Grows by accretion only outer portion of the bone depositing more by use of osteocytes e.g. Clavicle, Patella, os cordis References reflist DEFAULTSORT Dermal Bone Category Vertebrate anatomy Category Dermal and subcutaneous growths Musculoskeletal stub dermatology stub te ... more details
Cell nucleus nucleus N and Mitochondrion mitochondria M gallery See also Endochondralossification Intramembranous ossification References cite journal author Dominici M, Hofmann T, Horwitz E title ... more details
Orphan date February 2009 Henry Kronenberg floruit fl. 2000s is an American physician and academic. As of 2006 he is Division Head of Endocrinology at the Massachusetts General Hospital in Boston , MA and a Professor of Medicine at the Harvard Medical School . He is noted for his work on parathyroid hormone and the use of genetic mouse models to understand the role of parathyroid hormone and parathyroid hormone related protein in the regulation of bone formation and remodeling. Accomplishments Dr. Kronenberg has made a series of fundamental observations of importance to the understanding of how several peptides regulate the formation and remodeling of bone. These include the cloning of a cDNA for parathyroid hormone , ref Cloning and nucleotide sequence of DNA coding for bovine preproparathyroid hormone. Kronenberg HM, McDevitt BE, Majzoub JA, Nathans J, Sharp PA, Potts JT Jr, Rich A. Proc Natl Acad Sci U S A. 1979 Oct 76 10 4981 5 ref the identification of a role for parathyroid hormone related protein in endochondral ossification through indian hedgehog IHH activation, ref Ihh signaling is directly required for the osteoblast lineage in the endochondral skeleton. Long F, Chung UI, Ohba S, McMahon J, Kronenberg HM, McMahon AP. Development. 2004 Mar 131 6 1309 18. ref ref Indian hedgehog signals independently of PTHrP to promote chondrocyte hypertrophy. Mak KK, Kronenberg HM, Chuang PT, Mackem S, Yang Y. Development. 2008 Jun 135 11 1947 56. ref and studies that identified a role for parathyroid hormone in the regulation of the bone marrow stem cell niche. ref Osteoblastic cells regulate the haematopoietic stem cell niche. Calvi LM, Adams GB, Weibrecht KW, Weber JM, Olson DP, Knight MC, Martin RP, Schipani E, Divieti P, Bringhurst FR, Milner LA, Kronenberg HM, Scadden DT. Nature. 2003 October 23 425 6960 841 6 ref He has served as the President of the American Society for Bone and Mineral Research. He is currently a member of the Board of Advisors of the Rolanette a ... more details
Infobox Bone Name Calvaria skull Latin GraySubject 47 GrayPage 189 Image Kort lang skalle.gif Caption Image2 Caption2 Origins Insertions Articulations MeshName MeshNumber DorlandsPre c 03 DorlandsSuf 12206548 The calvaria or calva , skullcap , plural calvariae is the upper part of the Human cranium cranium and surrounds the cranial cavity containing the brain. It is formed by the following bones The calvarium skull cap is made up of the frontal, occipital and right and left parietals. The outer surface of the skull possess a number of land marks. The point at which the two parietal bones and frontal bones meet is known as Bregma . The point at which the two parietal and occipital bone meet is known as Lambda Not only do these land marks indicate the fontanelle in newborns they also act as referance points in medicine and surgery In the fetus, the formation of the Calvaria involves a process known as intramembranous ossification , although the base of the skull underlying the brain develops through endochondral ossification . Inner surface of the skull cap The inner surface of the skull cap is concave and presents depressions for the convolutions of the cerebrum , together with numerous furrows for the lodgement of branches of the meningeal vessels. Along the middle line is a longitudinal groove, narrow in front, where it commences at the frontal crest, but broader behind it lodges the superior sagittal sinus, and its margins afford attachment to the falx cerebri . On either side of it are several depressions for the arachnoid granulations , and at its back part, the openings of the parietal foramina when these are present. It is crossed, in front, by the coronal suture , and behind by the lambdoidal , while the sagittal lies in the medial plane between the parietal bones. References cite journal last Tubbs first R Shane authorlink coauthors Loukas Marios, Shoja Mohammadali M, Apaydin Nihal, Salter E George, Oakes W Jerry year 2008 month April title The intriguing hi ... more details
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