-Bones (206) -Ligaments -Cartilage -Teeth Skeletal System: Ch. 7 -Bones (206) -Ligaments -Cartilage -Teeth

Functions- 2. Protection: (skullbrain, ribs heart) 1. Support: (framework that shapes the body) 2. Protection: (skullbrain, ribs heart)

3. Body Movement: (the levers that are moved by muscle) 4. Mineral Storage: (mostly Ca & P) (regulated by hormones) 5. Hematopoiesis: (blood cell formation)

6 Storage of Energy (fats in yellow marrow)

Types of Bone: 1. Long - ex.= femur, humerus, tibia, etc. 2. Short or Cubic - ex.= phalanges(fingers toes) carpals (wrist)

3. Flat - ex.= parts of the skull, scapula (shoulder blade), ribs 4. Irregular - ex.= vertebrae, facial bones

*Sesamoid bone, ex. – Patella (kneecap) *Sutural bones, between suture joints in skull * Not one of the 4 main bone types

Parts of a Long Bone (pg 190): Epiphysis: bulbous ends of bone Diaphysis: main shaft of the bone Periosteum: Dense white fibrous covering of bone (tendons and ligaments “weave” into this) Articular cartilage: hyaline cartilage of joint surfaces

Parts of a Long Bone (pg 190): Endosteum: thin epithelial membrane lining medullary cavity Bone tissue: compact spongy (cancellous) Medullary Cavity: tubelike hollow center

Parts of a Long Bone (pg 190): Marrow: red:-in the spongy bone of epiphysis -makes blood cells (red, white, platelets) yellow: -in the medullary cavity -mostly fat but makes some white bl. Cells

2 Bone Tissues Compact Bone – dense cylinder shaped units- Haversian systems (osteons) Cancellous (spongy) Bone- only looks like a sponge - NOT soft open spaces contain red marrow Beams of bone are called trabeculae NO Haversian system!

Spongy bone Compact bone

Haversian System of compact bone: - also known as “osteons” and are made of 4 structures: 1. Lamellae- concentric layers of hard calcified matrix 2. Lacunae- “little lakes” where bone cells lie “imprisoned” between the lamellae. 3. Canaliculi- “tiny canals” connecting cells of the lacunae 4. Haversian canal- runs through the center of the Haversian system and contains blood vessels (Volkmann’s canals – like Haversian canal but perpendicular)

Types of Bone Cells Osteoblast- makes bone Osteoclast- break down bone to release minerals Osteocytes- mature osteoblasts “frozen” in lacunae

Types of Cartilage 1. Hyaline: lining of joints 2. Fibro- cartilage: shock absorbers of knees and spine (meniscus in knees, intervertebral discs in spine) 3. Elastic -ears, nose, etc.

Development of Bone: - called “osteogenesis” – 2 kinds: -Long bone = endochondral ossification (Cartilage becomes bone) -Flat bone=intermembranous ossification (fibrous membrane becomes bone) -growth: epiphyseal plate (growth plate) cartilage thickens and becomes ossified lengthening long bones osteoBlasts=bone Builder cells osteoCLasts= bone CLearer cells

Types of Fractures: Simple: does not break the skin Greenstick: bending of the bone, (cracks on one side) Comminuted: breaks into several pieces Spiral: from twisting injury Compound: breaks the skin Hangman’s: a very dangerous break of 1st or 2nd neck vertebrae