Skeletal and Muscular Systems

Movement and Support in Animals

There Are Two Types of Skeletal Systems

ExoskeletonsEndoskeletons

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

ClavicleHumerus

Maxilla

Mandible

Radius

UlnaCarpals

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. Ligaments Connect one bone to another

2. Periosteum Supplies blood to the bone

3. Compact bone Very strong – Stores Calcium

4. Spongy bone Light but very strong

5. Marrow Makes blood cells

6. Cartilage Cushions 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