Skeletal and Muscular Systems Movement and Support in Animals

There Are Two Types of Skeletal Systems Exoskeletons Endoskeletons

Functions of the Skeleton 1.Supports the body 2.Protects the soft body organs 3.Makes blood cells and platelets 4.Stores calcium and other minerals 5.Helps with movement Do you know the bones of the skeleton?

Cranium Clavicle Humerus Maxilla Mandible Radius Ulna Carpals Metacarpals Phalanges Femur Patella Tibia Fibula Sternum Scapula Pelvis Tarsals Metatarsals Phalanges Sacrum Vertebrae Ribs

Bone Growth Baby Adult

Bone Structure Growth Plate (Contains Red Marrow) (Also called compact bone) (Periosteum)

6 Tissues Make up Bone Tissue Type Function 1. LigamentsConnect one bone to another 2. PeriosteumSupplies blood to the bone 3. Compact boneVery strong – Stores Calcium 4. Spongy boneLight but very strong 5. MarrowMakes blood cells 6. CartilageCushions bones at joints

Joints – Where Bones Meet Gliding joint. Slight movement. There are4 Main Types of Joints One direction only. Greatest range of motion. No movement

There Are Three Types of Muscle Tissue

Smooth Muscles Work automatically without thinking about it. Works even while you sleep. Controlled by the nervous system. Small, spindle shaped cells. Found in intestines, stomach, arteries, urinary bladder and other organs.

Cardiac Muscle Only found in the heart. Never gets tired. Cells connected like a tightly woven bag. Cells have a striped (striated) appearance.

Voluntary Muscles Skeletal muscles (striated muscles). Only operate when you want them to. Controlled by the nervous system. Necessary for movement of the skeletal system. Composed of long cells called “fibers”. Cells have striped appearance.

Structure of a Skeletal Muscle

How Do Muscles Work? A muscle can only pull. It does this by becoming shorter. When it contracts, the joint bends.

Muscles Work In Pairs One muscle bends (flexes) a joint, and an opposing muscle is needed to straighten (extend) it.

Opposing Muscles Move Us

Skeletal System Problems  Fractured bones (cracks and breaks).  Sprains: stretched or torn ligaments (bone- to-bone).  Strains: stretched or torn tendons (muscle- to-bone).  Diseases: Arthritis, osteoporosis, cancer, leukemia.

Fractures

Worn out joints may sometimes be replaced with artificial ones.

New Surfaces Replace Worn Ones

Sometimes Knees Wear Out Too Daily Herald, Monday, March 29, 2004

Implants Replace Worn or Damaged Joint Surfaces In The Knee