HUMAN SYSTEMS:Skeletal

System

SKELETAL SYSTEM

Bones and cartilage Alive and active 206 bones in humans Support and protection Helps maintaining homeostasis Store minerals, make blood cells

SKELETAL SYSTEM

Functions of bones1. Protect organs (ribs protect heart and

lungs)2. Store minerals 3. Role in movement4. Bone marrow (making blood cells)

SKELETAL SYSTEM

BONE STRUCTURE

Bone is a living organ made up of different types of tissues

1. Connective tissue and minerals2. Osteoblast cells – mineral deposition3. Spongy bone – open spaces in bone4. Compact bone – no visible open spaces

Bone marrow – two types1. Red marrow – red and white blood cells

synthesis2. Yellow marrow – stores fats

BONE STRUCTURE

BONE GROWTH

During development most bones are soft Bone formation initiates as flexible tissue -

cartilage As development occurs cartilage is replaced

by bone During growth, bones also increase in size During childhood, most bones still have

growth plates of cartilage These growth plates provide a place for

bones to continue to grow

JOINTS A place where two or more bones meet is called

a joint Some joints, such as fixed joints, allow little or

no movement Many of the joints in the skull are fixed joints Other joints, such as your shoulder, allow a lot of

movement

Joints can be classified based on how the bones in a joint move1. Gliding or sliding joints2. Hinge joints3. Ball and socket joints

JOINTS

JOINTS Joints are often placed under a great deal of

stress But they can withstand a lot of wear and tear

because of their structure

Joints are held together by ligaments Ligaments are strong elastic bands of

connective tissue They connect the bones in a joint

Also, cartilage covers the ends of many bones. Cartilage helps cushion the area in a joint where bones meet.

INJURIES AND DISEASES

1. Fracture2. Dislocation of joint3. Sprain – ligament stretched or torn

4. Osteoporosis Bone density decreases Bones become weak

5. Arthritis - joints may swell or stiffen

6. Gout – accumulation of uric acid

7. Nutrition and bone heath