1. The Skeletal System

2. The Skeleton Supports the body Protects internal organs
Aids in movement
Stores minerals
Make blood cells
The Skeleton

3. The Skeleton 206 bones Bone is living tissue
Contains living bone cells, blood vessels and nerves.
Bone marrow stores fat and makes blood cells
Bone starts out as cartilage and ossifies into bone.
The Skeleton

4. Figure 36-3 The Structure of Bone
Section 36-1
Spongy bone
compact bone
Periosteum
Bone marrow
Haversian canal
Compact bone
Osteocyte
Artery
Vein

5. Joints Elastic ligaments hold bones together at joints.
Cartilage protects bones at joints.
Hinge joints – elbow and knee
Ball and socket joint – shoulder and hip
Pivot joint – neck
Gliding joint – wrist and ankle
Joints

6. Section 36-1 Muscle Tendon Femur Patella Bursa Ligament Synovial fluid
Cartilage
Fat
Fibula
Tibia

7. Skeletal Disorders Arthritis – inflammation of joints
Osteoporosis – mineral loss; weakening
Sprains – ligaments are stretched or torn.
Skeletal Disorders

8. Muscular System

9. Muscular Tissue The only tissue that contracts. Three types:
Skeletal = attached to bones; voluntary
Cardiac = in the heart; involuntary
Smooth = make up digestive tract, blood vessels and other organs; involuntary
Muscular Tissue

10. Section 36-2

11. Protein fibers called actin and myosin slide over each other.
This requires lots of energy.
Muscle cells have lots of mitochondria, like nerve cells.
Muscle Contraction

12. Muscles contract when nerves tell them to.
Muscle Contraction

13. Movement Inelastic tendons attach muscle to bone.
Muscles can only pull, not push.
Muscles work in opposing pairs to move a bone.
One muscle bends the joint and another muscle straightens the joint.
Movement

14. Movement Movement Section 36-2 Biceps (relaxed) Biceps (contracted)
Triceps (contracted)
Triceps (relaxed)

15. Regular exercise keeps the muscles in a partial state of contraction called muscle tone.
This is important to survival.
Muscle Tone

16. Integumentary System
Hair, skin, nails

17. Skin First line of defense against disease.
Helps regulate body temperature.
Aids in waste removal (excretion).
Protects against UV radiation.
Skin

18. Section 36-3

19. UV radiation can cause mutations in skin cells resulting in abnormal growth.
The tendency towards skin cancer is hereditary.
Skin Cancer

20. Hair provides protection from UV radiation and filters particulates from the nose, ear and eyes.
Hairs as well as attached skin cells are used as forensic evidence.
Nails grow from the base called the root.
Some nails get invaded by a fungus and look nasty.
Hair and Nails