Source: OpenStax Anatomy and Physiology OpenStax Anatomy and Physiology When a bone breaks, blood flows from any vessel torn by the fracture. These vessels could be in the periosteum, osteons, and/or medullary cavity. The blood begins to clot, and about six to eight hours after the fracture, the clotting blood has formed a fracture hematoma. … Continue reading How Bone Repairs?
By ShakataGaNai - Own work, CC BY-SA 2.5, https://commons.wikimedia.org/w/index.php?curid=1284831 OpenStax Anatomy and Physiology Osteogenesis imperfecta (OI) is a genetic disease in which bones do not form properly and therefore are fragile and break easily. It is also called brittle bone disease. The disease is present from birth and affects a person throughout life. The genetic … Continue reading Osteogenesis Imperfecta
Source: OpenStax Anatomy and Physiology Source: OpenStax Anatomy and Physiology OpenStax Anatomy and Physiology The epiphyseal plate is the area of growth in a long bone. It is a layer of hyaline cartilage where ossification occurs in immature bones. On the epiphyseal side of the epiphyseal plate, cartilage is formed. On the diaphyseal side, cartilage … Continue reading How Bones Grow in Length?
Endochondral ossification follows five steps. (a) Mesenchymal cells differentiate into chondrocytes. (b) The cartilage model of the future bony skeleton and the perichondrium form. (c) Capillaries penetrate cartilage. Perichondrium transforms into periosteum. Periosteal collar develops. Primary ossification center develops. (d) Cartilage and chondrocytes continue to grow at ends of the bone. (e) Secondary ossification centers … Continue reading Endochondral Ossification
Intramembranous ossification follows four steps. (a) Mesenchymal cells group into clusters, and ossification centers form. (b) Secreted osteoid traps osteoblasts, which then become osteocytes. (c) Trabecular matrix and periosteum form. (d) Compact bone develops superficial to the trabecular bone, and crowded blood vessels condense into red marrow. Source: OpenStax Anatomy and Physiology OpenStax Anatomy and … Continue reading Intramembranous Ossification
Source: OpenStax Anatomy and Physiology OpenStax Anatomy and Physiology The spongy bone and medullary cavity receive nourishment from arteries that pass through the compact bone. The arteries enter through the nutrient foramen (plural = foramina), small openings in the diaphysis. The osteocytes in spongy bone are nourished by blood vessels of the periosteum that penetrate … Continue reading Blood and Nerve Supply in Bones
Source: OpenStax Anatomy and Physiology OpenStax Anatomy and Physiology Paget’s disease usually occurs in adults over age 40. It is a disorder of the bone remodeling process that begins with overactive osteoclasts. This means more bone is resorbed than is laid down. The osteoblasts try to compensate but the new bone they lay down is … Continue reading Paget’s Disease
(a) This cross-sectional view of compact bone shows the basic structural unit, the osteon. (b) In this micrograph of the osteon, you can clearly see the concentric lamellae and central canals. LM × 40. (Micrograph provided by the Regents of University of Michigan Medical School © 2012) OpenStax Anatomy and Physiology Compact bone is the … Continue reading Compact and Spongy Bone
Source: OpenStax Anatomy and Physiology OpenStax Anatomy and Physiology Bone contains a relatively small number of cells entrenched in a matrix of collagen fibers that provide a surface for inorganic salt crystals to adhere. These salt crystals form when calcium phosphate and calcium carbonate combine to create hydroxyapatite, which incorporates other inorganic salts like magnesium … Continue reading Bone Cells and Tissue
Source: OpenStax Anatomy and Physiology Source: OpenStax Anatomy and Physiology OpenStax Anatomy and Physiology The surface features of bones vary considerably, depending on the function and location in the body. There are three general classes of bone markings: (1) articulations, (2) projections, and (3) holes. As the name implies, an articulation is where two bone … Continue reading Bone Markings