Skeletal System: Skeletal System: Ch. 7Ch. 7

-Bones(206)

-Ligaments-Cartilage

Functions-Functions-1. Support: (framework

that shapes the body)

2. Protection: (skullbrain, 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)

Types of Bone:Types of Bone:1. Long - ex.= femur,

humerus, tibia, etc.

2. Short or Cubic - ex.= phalanges(fingers toes) carpals (wrist)

4. Irregular - ex.= vertebrae, facial bones

3. Flat - ex.= parts of the skull, scapula (shoulder blade), ribs

Parts of a Long Bone (pg 190):Parts of a Long Bone (pg 190):

Epiphysis:bulbous ends of

bone

Periosteum: Dense white fibrous covering of bone (tendons and ligaments “weave” into this)

Articular cartilage: hyaline cartilage of joint surfaces

Diaphysis: main shaft of the bone

Parts of a Long Bone (pg 190):Parts of a Long Bone (pg 190):Endosteum: thin epithelial

membrane lining medullary cavityBone tissue: •compact •spongy (cancellous)

Medullary Cavity: tubelike hollow center

Parts of a Long Bone (pg 190):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 2 Bone Tissues Compact Bone –

◦ dense cylinder shaped units- Haversian systems

Cancellous (spongy) Bone- ◦ only looks like a sponge -

NOT soft◦ open spaces contain red

marrow◦ bony spicules are called

trabeculae◦ NO Haversian system!

Spongy boneCompact bone

Haversian System of compact bone (p Haversian System of compact bone (p 192)192) - 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

Development of Bone:Development of Bone:- called “osteogenesis”-Long bone = endochondral ossification

(Cartilage becomes bone)-Flat bone=intermembranous ossification (membrane becomes bone)

-growth: epiphyseal Plate of cartilage thickens and becomes ossified lengthening long bones (p 199)

Types of Fractures:Types of Fractures: Simple: does not break the skin

Compound: breaks the skin

Spiral: from twisting injury

Greenstick: bending of the bone, (cracks on one side)

Comminuted: breaks into several pieces

Hangman’s: a very dangerous break of 1st or 2nd neck vertebrae

Types of CartilageTypes of Cartilage

1. Hyaline: lining of joints

2. Fibro- cartilage: shock absorbers of knees and spine

3. Elastic -ears, nose, etc.

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