Anatomy and Physiology I Introduction to the The Skeletal System Bone Tissue Organization of the Skeleton Instructor: Mary Holman

Intro to the Skeletal System Osteology - the study of bone structure and treatment of bone disorders Complex dynamic living tissue – re-modeling Each bone is an organ – bone tissue, cartilage, dense connective tissues, epithelium, blood forming tissues, adipose tissue and nervous tissue

Functions of the Skeletal System Support Protection Assistance in Movement Mineral homeostasis Blood cell production

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Femur (The thigh bone) Periosteum Yellow marrow Medullary cavity Space containing red marrow Spongy bone Compact bone Articular cartilage Epiphyseal plates Proximal epiphysis Distal epiphysis Diaphysis Endosteum Fig. 7.2 condyles

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Nerve Blood vessels Compact bone Endosteum Fig. 7.4a

Spongy bone Compact bone Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. © Ed Reschke Fig. 7.3a

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Remnant of epiphyseal plate Spongy bone Compact bone Courtesy of John W. Hole, Jr. Fig. 7.3b

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Spongy bone Compact bone Courtesy of John W. Hole, Jr. Fig. 7.3c

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Osteon Nerve Blood vessels Perforating canal Periosteum Central canal containing blood vessels and nerves Spongy bone Compact bone Trabeculae Pores Central canal Fig. 7.4b The Haversian System

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Canaliculus Osteocyte Lacuna (space) Bone matrix Fig. 7.4c

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Central canal Canaliculus Lacuna Tissues and Organs: A Text-Atlas of Scanning Electron Microscopy, by R.G. Kessel and R.H. Kardon. © 1979 W.H. Freeman and Company Fig x An Osteon

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Cell process in canaliculus Osteocyte Lacuna © Secchi, Lecaque, Roussel, Uclaf, CNRA/SPL/Photo Researchers, Inc. Fig ,700x

Osteogenesis the formation of bone Bones are formed in two ways Intramembranous Endochondral Both involve replacing existing connective tissue

Intra- membranous bones forming Endochondral bones forming Fig. 7.6a Ossification in a 14 wk Human Fetus

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Cartilaginous model Fig. 7.8a & b p.207 Developing periosteum Calcified cartilage Fetal endochondral bone development

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Compact bone developing Primary ossification center Blood vessel Fig. 7.8c & d Medullary cavity Secondary ossification center Secondary ossification center Later stages of fetal endochondral bone development

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Medullary cavity Epiphyseal plate Epiphyseal plates Compact bone Fig. 7.8e&f Articular cartilage Medullary cavity Remnant of epiphyseal plate Remnants of epiphyseal plates Spongy bone Articular cartilage Spongy bone Child Adult

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Intra- membranous bones forming Endochondral bones forming © Biophoto Associates/Photo Researchers, Inc. Fig. 7.6a Ossification in a 14 wk Human Fetus

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Bone tissue of epiphysis Zone of resting cartilage 1 Zone of proliferating cartilage 2 Zone of hypertrophic cartilage 3 Zone of calcified cartilage Ossified bone of diaphysis 4 (a) (b) b: © The McGraw-Hill Companies, Inc./Al Telser, photographer Fig. 7.9 Epiphyseal Plate 100x

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. © James L. Shaffer Fig p. 209 X-ray of Epiphyseal Plates in a child’s femur etc.

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. © Martin Rotker Fig. 7.50a pg 243 X-ray of Adult femur, tibia, and fibula

Types of bone cells osteoblast - “budding” building cells, secrete matrix osteocyte - “cell” mature cell, maintenance activities osteoclast - “broken” cells that erode or destroy bone tissue From: Tortora & Grabowski Principles of A & P

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Developing medullary cavity Osteoclast © Biophoto Associates/Photo Researchers, Inc. Fig x Bone Resorption by Osteoclast s

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. © David Scharf/Peter Arnold; p. 193: Reprinted by permission from Macmillan Publishers Ltd: Nature, "Pleistocene Homo sapiens from Middle Awash, Ethiopia", FIG 1, VOL 423, © 2003 Osteoclast (1,240x)

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Sites of muscle attachments Courtesy of John W. Hole, Jr. Fig. 7.12

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. A greenstick fracture is incomplete, and the break occurs on the convex surface of the bend in the bone. A transverse fracture is complete, and the break occurs at a right angle to the axis of the bone. A spiral fracture is caused by twisting a bone excessively. An oblique fracture occurs at an angle other than a right angle to the axis of the bone. A fissured fracture involves an incomplete longitudinal break. A comminuted fracture is complete and fragments the bone. Fig. 7A p. 212 Types of Fractures

Compact bone Medullary cavity Hematoma New blood vessels Fibrocartilage Spongy bone Compact bone Medullary cavity Periosteum Bony callus (a) Blood escapes from ruptured blood vessels and forms a hematoma. (b) Spongy bone forms in regions close to developing blood vessels, and fibrocartilage forms in more distant regions. (c) A bony callus replaces fibrocartilage. (d) Osteoclasts remove excess bony tissue, restoring new bone structure much like the original. Fig. 7.7B Bone Repair

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Stimulus Blood calcium level increases. too high Normal blood calcium level Control center Thyroid gland releases calcitonin. Receptors Cells in the thyroid gland sense the increase in blood calcium. Effectors Osteoblasts deposit calcium in bones. Response Blood calcium level is returned toward normal. Fig. 7.13a Hormonal Control of the Resorption and Deposition of Bone Ca ++

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. too low Normal blood calcium level Control center Parathyroid glands release parathyroid hormone. Receptors Cells in the parathyroid gland sense the decrease in blood calcium. Effectors Osteoclasts break down bone to release calcium. Stimulus Blood calcium level decreases. Response Blood calcium level is returned to normal. Fig. 7.13b Hormonal Control of the Resorption and Deposition of Bone Ca ++

Skeletal Basics Approximately 206 bones total Axial Skeleton – 80 bones arranged along the central axis of the body – skull bones, auditory bones, hyoid bone, sternum, ribs, and vertebrae Appendicular Skeleton – 126 bones – bones of the upper and lower limbs and the bones of the girdles that attach the limbs to the axial skeleton

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Temporal bone Occipital bone Parietal bone Sutural bones Fig. 7.14

Hyoid Cranium Face Clavicle Scapula Sternum Ribs Humerus Ulna Hip bone Radius Femur Patella Tibia Fibula Tarsals Metatarsals Phalanges Skull Vertebral column Carpals Metacarpals (a) Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Fig. 7.15a Axial Skeleton Appendicular Skeleton

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Clavicle Scapula Ribs Humerus Ulna Hip bone Radius Femur Tibia Fibula Phalanges Vertebral column Sacrum Coccyx (b) Fig. 7.15b Axial Skeleton Appendicular Skeleton

Types of Bones Long Bones – femur, humerus Short bones – tarsal, trapezoid Flat bones – frontal, scapula Irregular bones – vertebrae Sesamoid bones – patella

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. (a) (e) (b) (c) (d) Fig. 7.1 Types of Bones tarsal parietal vertebra patella femur

Bone Surface Markings Depressions and Openings Sites allowing the passage of soft tissue or formation of joints fissure foramen fossa sulcus meatus

Bone Surface Markings Processes: projections or outgrowths on bone that form joints or attachment points for connective tissue such as ligaments or tendons A. Processes that form joints condyle facet head

Bone Surface Markings Processes (cont.) B. Processes that form attachment points for connective tissue: crest epicondyle linea spinous process trochanter tubercle tuberosity

Miscellaneous terms: suture sinus fontanel fovea Bone Surface Markings