Fig. 7.1 Articular cartilage Epiphysis Red bone marrow Epiphyseal line Copyright © McGraw-Hill Education. Permission required for reproduction or display. Articular cartilage Epiphysis Red bone marrow Epiphyseal line Marrow cavity Yellow bone marrow Periosteum Nutrient foramen Diaphysis Site of endosteum Compact bone Spongy bone Epiphyseal line Epiphysis Articular cartilage (a) Living (b) Dried

Suture Outer compact bone Spongy bone (diploe) Trabeculae Fig. 7.2 Copyright © McGraw-Hill Education. Permission required for reproduction or display. Suture Outer compact bone Spongy bone (diploe) Trabeculae Inner compact bone

Fig. 7.3 Osteogenic cell Osteoblast Osteocyte Rough endoplasmic Copyright © McGraw-Hill Education. Permission required for reproduction or display. Osteogenic cell Osteoblast Osteocyte Rough endoplasmic reticulum Secretory vesicles Nucleus Mitochondrion (a) Osteocyte development Osteocyte Osteoclast Osseous tissue Stem cells Periosteum Resorption bay Nuclei Osteoclast Fusion Ruffled border Lysosomes (b) Osteoclast development

Fig. 7.4 Copyright © McGraw-Hill Education. Permission required for reproduction or display. Bone marrow Trabecula Pelvic bone Head of femur Spongy bone Compact bone (a) (c) Nerve Blood vessel Spicules Trabeculae Spongy bone Endosteum Periosteum Perforating fibers Perforating canal Central canal Osteon Lacuna Collagen fibers Lacunae Concentric lamellae Circumferential lamellae Canaliculi Central canal (b) Lamella (d) 20 m a: © D.W. Fawcett/Visuals Unlimited; c: © Science VU/Visuals Unlimited; d: © Donald Fawcett/Visuals Unlimited

© Robert Calentine/Visuals Unlimited Fig. 7.5 Copyright © McGraw-Hill Education. Permission required for reproduction or display. Greater trochanter Head Trabeculae of spongy bone Compact bone Lines of stress Shaft (diaphysis) © Robert Calentine/Visuals Unlimited

Fig. 7.6

Fig. 7.7 Osteoid tissue Blood vessel Bone trabecula Osteoid tissue Copyright © McGraw-Hill Education. Permission required for reproduction or display. Osteoid tissue Blood vessel Bone trabecula Osteoid tissue Marrow spaces Osteoblasts Osteocyte Mesenchyme Osteoblast Mesenchymal cell 1 Deposition of osteoid tissue into embryonic mesenchyme 2 Calcification of osteoid tissue and entrapment of osteocytes Mesenchyme Periosteum Periosteum Compact bone Spongy bone Spongy bone Compact bone Periosteum Periosteum Bone trabeculae 3 Honeycomb of spongy bone with developing periosteum 4 Filling of space to form compact bone at surfaces, leaving spongy bone in middle

Periosteum: Fibrous layer Osteogenic layer Osteoid tissue Fig. 7.8 Copyright © McGraw-Hill Education. Permission required for reproduction or display. Periosteum: Fibrous layer Osteogenic layer Osteoid tissue Osseous tissue (bone) Osteoblasts Osteocytes ©Ken Saladin

Fig. 7.9 Articular cartilage Spongy bone Epiphyseal line Perichondrium Copyright © McGraw-Hill Education. Permission required for reproduction or display. Articular cartilage Spongy bone Epiphyseal line Perichondrium Hyaline cartilage Secondary marrow cavity Epiphyseal plate Periosteum 1 Early cartilage model Epiphysis Nutrient foramen Secondary ossification center Marrow cavity Metaphysis Compact bone Enlarging chondrocytes Blood vessel Diaphysis Bony collar Primary marrow cavity Primary ossification center Metaphysis Secondary ossification center Periosteum Cartilage 2 Formation of primary ossification center, bony collar, and periosteum 3 Vascular invasion, formation of primary marrow cavity, and appearance of secondary ossification center 4 Bone at birth, with enlarged primary marrow cavity and appearance of secondary marrow cavity in one epiphysis 5 Bone of child, with epiphyseal plate at distal end 6 Adult bone with a single marrow cavity and closed epiphyseal plate

©Biophoto Associates/Science Source Copyright © McGraw-Hill Education. Permission required for reproduction or display. Fig. 7.10 Cranial bones Mandible Vertebrae Humerus Radius Ulna Scapula Ribs Femur Pelvis ©Biophoto Associates/Science Source

Fig. 7.12 1 2 3 4 5 Zone Zone Zone of reserve cartilage Copyright © McGraw-Hill Education. Permission required for reproduction or display. Zone 1 Zone 5 1 Zone of reserve cartilage Typical histology of resting hyaline cartilage 2 Zone of cell proliferation Chondrocytes multiplying and lining up in rows of small flattened lacunae Multiplying chondrocytes Enlarging chondrocytes 3 Zone of cell hypertrophy Cessation of mitosis; enlargement of chondrocytes and thinning of lacuna walls Breakdown of lacunae 4 Zone of calcification Temporary calcification of cartilage matrix between columns of lacunae Calcifying cartilage 5 Zone of bone deposition Breakdown of lacuna walls, leaving open channels; death of chondrocytes; bone deposition by osteoblasts, forming trabeculae of spongy bone Bone marrow Osteoblasts Osteocytes Trabeculae of spongy bone © Victor Eroschenko

Fig. 7.14 7-dehydrocholesterol HO Ultraviolet light Vitamin D3 Copyright © McGraw-Hill Education. Permission required for reproduction or display. OH HO 7-dehydrocholesterol Ultraviolet light Vitamin D3 (cholecalciferol) CH2 Calcidiol Calcitriol Bone resorption Reduced excretion of Ca2+ Absorption of Ca2+ and phosphate

Fig. 7.16 Blood Ca2+ returns to normal Blood Ca2+ excess Blood Ca2+ Copyright © McGraw-Hill Education. Permission required for reproduction or display. Blood Ca2+ returns to normal Blood Ca2+ excess Blood Ca2+ deficiency Blood Ca2+ returns to normal Parathyroid hormone secretion Calcitonin secretion Increased osteoclast activity More bone resorption Reduced osteoclast activity Less bone resorption Reduced osteoblast activity Less bone deposition Increased osteoblast activity More bone deposition More urinary phosphate excretion Prevention of hydroxyapatite formation (a) Correction for hypercalcemia Less urinary calcium excretion Conservation of calcium (b) Correction for hypocalcemia

Fig. 7.18 Marrow cavity Fibrocartilage Hard callus Hematoma Copyright © McGraw-Hill Education. Permission required for reproduction or display. Marrow cavity Fibrocartilage Hard callus Hematoma Soft callus Spongy bone New blood vessels Compact bone 1 Hematoma formation The hematoma is converted to granulation tissue by invasion of cells and blood capillaries. 2 Soft callus formation Deposition of collagen and fibrocartilage converts granulation tissue to a soft callus. 3 Hard callus formation Osteoblasts deposit a temporary bony collar around the fracture to unite the broken pieces while ossification occurs. 4 Bone remodeling Small bone fragments are removed by osteoclasts, while osteoblasts deposit spongy bone and then convert it to compact bone.

Page 225 INTEGUMENTARY SYSTEM Bones lying close to the body Copyright © McGraw-Hill Education. Permission required for reproduction or display. INTEGUMENTARY SYSTEM Bones lying close to the body surface support and shape the skin. LYMPHATIC/ IMMUNE SYSTEM White blood cells produced in the bone marrow carry out the body’s immune functions. MUSCULAR SYSTEM Bones are the attachment sites for most skeletal muscles and provide leverage for muscle action; calcium homeostasis, important for muscle contraction, is achieved partly through a balance between bone deposition and resorption. RESPIRATORY SYSTEM Ventilation of the lungs is achieved by musculoskeletal actions of the thoracic cage; the thoracic cage protects the delicate lungs from trauma; bones support and shape the nasal cavity. NERVOUS SYSTEM The cranium and vertebral column protect the brain and spinal cord; osseous tissue provides the calcium homeostasis needed for nerve function. URINARY SYSTEM The thoracic cage partially protects the kidneys, and the pelvic girdle protects the lower urinary tract. DIGESTIVE SYSTEM Osseous tissue interacts with the digestive system in maintaining calcium homeostasis; the thoracic cage and pelvic girdle protect portions of the digestive tract; musculoskeletal movements are necessary for chewing. ENDOCRINE SYSTEM Bones protect endocrine glands in the head, thorax, and pelvis; bones secrete the hormone osteocalcin, which promotes insulin action. CIRCULATORY SYSTEM Bone marrow forms blood cells and platelets; osseous tissue provides the calcium homeostasis needed for cardiac function and blood clotting. REPRODUCTIVE SYSTEM The pelvic girdle protects the internal reproductive organs; childbirth is adapted to the anatomy of the female pelvic girdle; ligaments anchor the penis and clitoris to the pelvic girdle.