Support, movement and locomotion INTRODUCTION

Objectives: List and describe the major functions of the skeletal system.List and describe the major functions of the skeletal system. List, describe and give specific examples of the types of bones.List, describe and give specific examples of the types of bones. List and describe the two major divisions of the skeletal system and the bones which compose each.List and describe the two major divisions of the skeletal system and the bones which compose each. Describe the process of bone formation.Describe the process of bone formation. List and describe the various types of joints.List and describe the various types of joints.

Functions of the Skeletal System Support of the bodySupport of the body Protection of soft organsProtection of soft organs Movement due to attached skeletal musclesMovement due to attached skeletal muscles Storage of minerals and fatsStorage of minerals and fats Blood cell formationBlood cell formation

Classification of Bones by Shape Long bones – –Typically longer than wide – –Have a shaft (long, central cylinder) with heads at both ends – –Contain mostly compact bone Examples: Femur, humerus Short bones – –Generally cube-shape – –Contain mostly spongy bone Examples: Carpals, tarsals Flat bones – –Thin and flattened – –Usually curved – –Thin layers of compact bone around a layer of spongy bone Examples: Skull, ribs, sternum Irregular bones – –Irregular shape – –Usually with projections (processes) or openings (foramen) – –Do not fit into other bone classification categories Example: Vertebrae and hip Sesamoid bones: These are bones that are imbedded in ligaments and are not directly attached to other bones. Example: Patella

Classification of Bones by Shape

Divisions of the Skeleton The Skeleton is divided into two major regions:The Skeleton is divided into two major regions: a. Axial Skeleton b. Appendicular Skeleton The Axial Skeleton forms the longitudinal part of the bodyThe Axial Skeleton forms the longitudinal part of the body Divided into three partsDivided into three parts –Skull –Vertebral column –Bony thorax The Appendicular skeleton is composed of the appendages and the joints which attach them to the axial skeletonThe Appendicular skeleton is composed of the appendages and the joints which attach them to the axial skeleton Limbs (appendages) Pectoral girdle (shoulder, scapula, and clavicle) Pectoral girdle (shoulder, scapula, and clavicle) Pelvic girdle (pelvis) Pelvic girdle (pelvis)

Divisions of the Skeleton

Axial Skeleton: The Skull Two sets of bonesTwo sets of bones –Cranium –Facial bones Bones are joined by sutures (fixed, non- movable joints)Bones are joined by sutures (fixed, non- movable joints) Only the mandible is attached by a freely movable jointOnly the mandible is attached by a freely movable joint

Axial Skeleton: The Skull

Axial Skeleton: Hyoid Bone  The only bone that does not articulate with another bone  Serves as a moveable base for the tongue Figure 5.12

Axial Skeleton: Vertebral Column  Vertebrae are separated by intervertebral discs composed of fibrocartilage  The spine has a normal curvature  Each vertebrae is given a name according to its location

Axial Skeleton: Vertebral Column

Axial Skeleton: Anterior Thorax  Forms a cage to protect major organs  Made-up of two parts 1. Sternum 1. Sternum 2. Ribs 2. Ribs

Appendicular Skeleton: Pectoral Girdle Composed of two bonesComposed of two bones –Clavicle – collarbone –Scapula – shoulder blade These bones allow the upper limb to have exceptionally free movementThese bones allow the upper limb to have exceptionally free movement

Appendicular Skeleton: Pectoral Girdle (Shoulder)

Appendicular Skeleton: Brachium Region  The arm is formed by a single bone  Humerus

Appendicular Skeleton: Antebrachium Region The forearm has two bonesThe forearm has two bones Ulna (side adjacent to little finger)Ulna (side adjacent to little finger) Radius (side adjacent to thumb)Radius (side adjacent to thumb)

Appendicular Skeleton: Carpus, Manus, and Digits Region  The hand  Carpals – wrist  Metacarpals – palm  Phalanges – fingers

Articulations: Joints A joint is a location where two or more bones meet. Functions of joints – –Hold bones together – –Allow for mobility Ways joints are classified – –Functionally – –Structurally

Types of Joints Fibrous jointsFibrous joints –Generally immovable (sutures of skull) Cartilaginous jointsCartilaginous joints –Immovable or slightly moveable (vertebral disc) Synovial jointsSynovial joints –Freely moveable (shoulder, pelvis, knee, elbow, digits) –Articulating bones are separated by a joint cavity –Synovial fluid is found in the joint cavity

Structure of a Synovial Joint Figure 5.28

Type of Synovial Joints

Types of Synovial Joints

Diseases and Disorders of the Skeletal System A fracture is a break in a bone Types of bone fractures – –Closed (simple) fracture – break that does not penetrate the skin – –Open (compound) fracture – broken bone penetrates through the skin Bone fractures are treated by reduction and immobilization – –Realignment of the bone

Diseases and Disorders of the Skeletal System: Fractures Simple Greenstick radius Simple Complete fibula Compound Fracture tibia and fibula Comminuted Fracture radius

Diseases and Disorders of the Skeletal System Osteoporosis: This illness afflict both men and women but it is most common in post menopausal women. The bone tissue becomes brittle and breaks easily with little applied stress. Due to loss of calcium from the bone matrix.Osteoporosis: This illness afflict both men and women but it is most common in post menopausal women. The bone tissue becomes brittle and breaks easily with little applied stress. Due to loss of calcium from the bone matrix.

Diseases and Disorders of the Skeletal System Rickets: Rickets is a disease associated with a deficiency of vitamin D in the diet. It prevents the body from absorbing calcium needed for the formation of strong, bone matrix. Typically the long bones are soft and bend under the stress from the weight of the body. It results in “bowed legs”. This disease often affects children who are undernourished.Rickets: Rickets is a disease associated with a deficiency of vitamin D in the diet. It prevents the body from absorbing calcium needed for the formation of strong, bone matrix. Typically the long bones are soft and bend under the stress from the weight of the body. It results in “bowed legs”. This disease often affects children who are undernourished.