Essentials of anatomy, including the anatomy of the viscera : arranged in the form of questions & answers prepared especially for students of medicine / Charles Nancrede.

Charles B. Nancrede

Date:: 1899

Credit: Essentials of anatomy, including the anatomy of the viscera : arranged in the form of questions & answers prepared especially for students of medicine / Charles Nancrede. Source: Wellcome Collection.

Provider: This material has been provided by the Augustus C. Long Health Sciences Library at Columbia University and Columbia University Libraries/Information Services, through the Medical Heritage Library. The original may be consulted at the the Augustus C. Long Health Sciences Library at Columbia University and Columbia University.

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$trie laineUce around the Haversian canals, other lamellae are found arranged concentrically to the circumference of the bone, called circumferential or fundamental lameUst. All lamellae are thin plates of bone ; they are held together by \\\ki l)erforat- i](g fbcrs of Sltarpei/. What are the periosteum and the endosteiim ? The periosteum is a membrane serving as a scaffolding to enable the blood-vessels to reach all portions of the exterior of the bone except its articular ends and the points of attachment of strong tendons. It is composed of two portions : the outer or fibrous layer is dense and protective ; the inner layer is vas- cular and contains many osteoblasts, or bone-forming cells, upon which the growth in thickness of the bone depends. The term endosteum is applied to the delicate connective- tissue lining of the medullary and cancellous cavities which contains numerous bone-forming cells. Describe the medulla or marrow. There are two varieties,^e/fo?c and red: yellow marrow occurs in adult long bones, and is OG per cent, fat ; red marrow contains 72 per cent, of water and a trace of fat. It is found in all fetal and infantile bones ; in the adult it is in the short and flat bones, ends of long bones, vertebra), cranial bones, sternum, and ribs. Marrow possesses five kinds of cells: fat-cells; marrow-cells proper, resembling leukocytes ; nucleated red cells ; cells con- taining red corpuscles ; and giant-cells. Do bones receive blood only from vessels in the periosteum ? Xo ; for the medullary tissue of all long bones receives a good-sized artery (the medullary artery), whichobliquely pene- trates the compact tissue, after which it divides into two main branches, one ascending, the other descending, in the medullary canal; the veins chiefly emerge through numerous openings near the articular ends of the bones. Describe the process of ossification. There are two methods, viz. : (1) in membrane and subperios- teolly; (2) in cortihge. The bones of the vertex of the skull and those of the face, with few exceptions, are formed in mem- brane ; the base of the skull and the other bones of the body and limbs are formed in cartilage. (1) In the former the bone-$