Copyright © 2005, Elsevier, Inc. All rights reserved. Slide 0 0 Copyright © 2005, Elsevier, Inc. All rights reserved. Slide 0 HS120 Anatomy & Physiology Seminar 4 The Skeletal System

1 Functions of Bone Supports and gives shape to the body Protects internal organs Helps make movement possible Stores calcium Hematopoiesis

2 Types of Bones Long  Humerus (upper arm) Short  Carpals (wrist) Flat  Frontal (skull) Irregular  Vertebrae (spinal cord)

3 Structure of Long Bones Structural components  Diaphysis or shaft  Medullary cavity  hollow area inside diaphysis containing yellow marrow  Epiphyses or ends of the bone  spongy bone contains red bone marrow

4 Structure of Long Bones (Cont’d) Longitudinal Section of a Long Bone

5 Microscopic Structure: Bone and Cartilage (cont’d) Bone types  Spongy  Texture results from needlelike threads of bone called trabeculae surrounded by a network of open spaces  Compact (Dense)  Structural units are called osteons, Haversian systems

6 Microscopic Structure: Bone and Cartilage (cont’d) Cartilage  Cell type called chondrocyte  Has the flexibility of firm plastic  Matrix is gel-like and lacks blood vessels  Has no blood vessels, so nutrients must diffuse through the matrix to reach cell

7 Microscopic Structure of Bone

8 Bone Formation and Growth The process of “remodeling”  A newborn’s skeleton has many bones that have not completely ossified.  Cartilage models replaced by calcified bone matrix Osteoblasts form new bone Osteoclasts resorb bone Note: –As long as the epiphyseal plate remains between epiphyses and diaphysis, growth continues –The epiphyseal line marks where two centers of ossification have fused together

Copyright © 2005, Elsevier, Inc. All rights reserved. Slide 9 9 Copyright © 2005, Elsevier, Inc. All rights reserved. Slide 9 The Skeleton Two major divisions The Skeleton Two major divisions

10 Divisions of the Skeleton Skeleton: Two divisions and their subdivisions  Axial skeleton  Skull  Spine  Thorax  Hyoid bone  Appendicular skeleton  Upper extremities, including shoulder girdle  Lower extremities, including hip girdle

11 Divisions of the Skeleton Axial skeleton overview  Skull  Spine (Vertebral Column)  Consists of a series of separate bones called vertebrae  Sections called cervical, thoracic, lumbar, sacrum, coccyx  Curves of the spine give strength to support body

12 Axial Skeleton - The Skull

13 Axial Skeleton - Spinal Column

14 Axial Skeleton - Thorax  Thorax is formed by  Thin, Flat, Curved  24 bones arranged in 12 pairs of ribs  Three Categories  True ribs  Connected to the sternum (breastbone )  False ribs  Floating Ribs  Thoracic vertebrae

15 Divisions of the Skeleton (cont’d) Appendicular skeleton overview  Upper extremity formed by  Scapula (shoulder blade)  Clavicle (collarbone )  Attached by sternoclavicular joint  Humerus  Radius and ulna  Wrist and hands  27 bones in all

16 Bones of the Arm, Elbow Joint, and Forearm Appendicular Skeleton

17 Appendicular Skeleton  Lower Extremity  Two coxal (pelvic) bones  Femur; longest bone in the body o Articulates proximally with coxal bone in socket called the acetabulum  Patella (kneecap)  Tibia (shinbone)  Fibula (slender bone in the lower leg)  Phalanges are composed of metatarsals and tarsals

18 Bones of the Thigh, Knee Joint, and Leg Appendicular Skeleton

19 Bones of the Right Foot Appendicular Skeleton

20 Differences: A Man’s & a Woman’s Skeleton Size— –male skeleton generally larger Shape of pelvis –male pelvis deep and narrow –female pelvis broad and shallow Size of pelvic inlet –female pelvic inlet generally wider –normally large enough for baby’s head to pass through Pubic angle –angle between pubic bones of female generally wider

21 Differences: A Man’s & a Woman’s Skeleton Comparison of the Male and Female Pelvis Note: the blue circled areas

22 Types of Joints (Articulations)  Synarthrosis (no movement)  Fibrous connective tissue grows between articulating bones  Example: Sutures of skull  Amphiarthrosis (slight movement)  Cartilage that connects articulating bones  Example: Symphysis pubis  Diarthrosis (free movement)—most joints belong to this class  Structures of freely movable joints—joint capsule and ligaments hold adjoining bones together but permit movement at joint  Articular cartilage—covers joint ends of bones and absorbs jolts  Synovial membrane—lines joint capsule and secretes lubricating fluid  Joint cavity—space between joint ends of bones  Types of freely movable joints—ball-and-socket, hinge, pivot, saddle, gliding, and condyloid

23 Joint (Articulations) cont’d  Synarthrosis (no movement)Amphiarthrosis (slight movement)

24 Types of Diarthrotic Joints Joints (Articulations) (cont’d.)

25 Types of Joint Movements

Copyright © 2005, Elsevier, Inc. All rights reserved. Slide Copyright © 2005, Elsevier, Inc. All rights reserved. Slide 26 Let’s Review! Chapter 6

27 Review Question What are the primary functions of the bone?

28 Review Question What are the four types of bones?

29 Review Question All of our bones are composed of the same material. What are the two components?

30 Review Question A role of the skeletal system is to____? A.Protect vital organs B.Produce blood tissue C.Enable movement of the body D.Provide a framework for the body E.All of these are correct

31 Review Question The fatty material inside long bones is_____? A.Red bone marrow B.White bone marrow C.Yellow bone marrow D.Blood-producing tissue E.Made mostly of calcium

32 Review Question The layers of bone material that build up to form cylindrical units of bone tissue are called_______? A.Osteons B.Lamellae C.Lacunae D.Canaliculi

33 Review Question Bone-making cells are called ______? A.Osteoblasts B.Osteocytes C.Osteoclasts D.Fibroblasts E.Osteomalacia

34 Review Question The acetabulum is located in the_____? A.Skull B.Hip C.Ankle D.Neck E.Thoracic cage

35 QUESTIONS??