Skeletal System Skeleton= Greek for “a dried body”

Functions/Purposes Protection- inner organs Storage- Ca, P & fat Movement/Support- muscles pull bones Blood cell formation- in long bones of arms & legs

Vitamins Vitamin D Milk, dairy, sunlight Without bones are soft and don’t calcify Vitamin A Milk, green veggies, carrots, pumpkins Good for vision Without slows cartilage growth and maturing

As bones age… Formation slows or stops Become brittle Density will decrease Fractures easily occur

The Skeleton 206 bones Two parts of skeleton Axial: head, vertebra, thoracic Appendicular: arms, legs

80 Bones in Axial Skeleton 126 Bones in Appendicular Skeleton

PARTS/ STRUCTURE

Bones Are ALIVE!! Living organs composed of connective tissues and minerals Strong & lightweight

2 Types of Bone Tissue Compact Bone Tissue that does not have any visible open spaces Spongy Bone Tissue with many open spaces Provides most of the strength & support

Styles of Bones Long Bones Strong shafts made of compact bone tissue. Larger ends of spongy tissue Curved to absorb shock Examples Humerus, ulna, femur, fibula, metatarsals

Long Bones

Styles of Bones Short Bones Strong irregular cubes of spongy bone covered with compact tissue Examples: patella, carpals, tarsals, phalanges

Short Bones

Styles of Bones Flat Bones Provide broad surfaces for protection Good for anchoring muscles Examples: scapula, ribs, sternum, pelvis

Flat Bones

Styles of Bones Irregular Bones Shapes are so different that they don’t fit into other groups Examples: vertebra, facial bones

Irregular Bones

Marrow 2 types of soft connective tissue RED & YELLOW Red produces blood cells Yellow stores fat

Cartilage Soft, Flexible connective tissue Reduces friction where bones rub together

Ligaments Strong connective tissue that holds movable joints together Similar to leather…when stretched they stay stretched. When torn they stay torn and heal with scar tissue

Joints Place in body where 2 bones come together 2 main types: Immovable Movable

Immovable Do not move!! Found in between bones in the cranium

Types of Movable Joints

Ball & Socket Allows movement in all directions Ex: shoulder

Hinge Allows movement in one plane (flex & extend) Ex: elbow

Pivot Allows rotation around an axis Ex: found in neck

Sliding/Gliding Flat surfaces gliding across each other Ex: found in between vertebrae