SKELETON, MUSCLES, AND SKIN

1. SKELETON, MUSCLES, AND SKIN

2. PROTECTION - INTEGUMENTARY SYSTEM

3. The Skin (Largest organ of the body) is composed of all four types of body tissues: EPITHELIUM – lining of organ CONNECTIVE – made of collagen and elastin protein fibers NERVE – transmit impulses MUSCLE – associated with hairs

4. The Skin’s Roles 1. Regulates Body Temperature A. Blood vessel dilation and constriction B. Sweat cools the body

5. 2. Protects body from injury and disease 3. Sense Organ 4. Removes waste products 5. Layer of fat insulates the body 6. Produces Vitamin D when exposed to sunlight

6. Structures of the Skin • I. EPIDERMIS • Outer thin layer • A. OUTER LAYER – • Dead cells • B. INNER LAYER – • Living cells • MELANOCYTES – Produce melanin (colors and protects skin • by absorbing UV light) • 2. KERATINOCYTES – Produce keratin (tough fibrous protein that waterproofs the skin)

7. II. DERMIS – inner, thicker layer of skin; contains collagen fibers, blood vessels, smooth muscle, nerves, sweat glands, hair follicles, and oil glands *Sweat Glands Regulate body temperature and excrete wastes in sweat *Sebaceous Glands Produce sebum (oily) – Keeps skin flexible and waterproof

8. FANCY WORD FOR FAT!!!! III. SUBCUTANEOUS LAYER (hypodermis) – Below the dermis; Contains fat which cushions, insulates, retains heat and stores energy

9. HAIR • HAIR FUNCTIONS - • Protects and provides insulation • 2. Prevents particle from entering • the body (in nose and ear) • *Produced from hair follicles in the • dermis • *Hair is dead cells filled with keratin • *Oil glands keep hairs from becoming brittle OIL GLAND HAIR FOLLICLE

10. NAILS Nails form from nail root Made of keratin Fingernails grow 4X as fast as toenails!

11. SKIN DISORDERS CARCINOMAS – Skin cancers in non-pigmented cells Usually high cure rate MALIGNANT MELANOMA – In pigmented cells Usually low cure rates

12. ACNE–Clogged oil duct and infection PSORIASIS – Inherited; Rapid growth of Epidermal cells causing scaly white skin

13. SUPPORT - SKELETAL SYSTEM

14. FUNCTIONS OF THE SKELETAL SYSTEM 1. Provides a framework 2. Protects internal organs 3. Efficient movement 4. Produces blood cells 5. Stores minerals

15. STRUCTURE OF BONE PERIOSTEUM – Outside membrane; supplies nutrients and oxygen to bone COMPACT BONE - Hard layer of bone under the membrane SPONGY BONE - Less dense bone; adds strength without mass; under compact bone at ends of long bones and in middle of short flat bones

16. BONE MARROW Soft tissue filling center spaces in most large bones Two Types: 1. RED MARROW - Makes blood cells; Mainly found in flat bones and ends of long bones 2. YELLOW MARROW - Mainly fat, can make blood cells if needed; in center of long bones GREEN BOXES SHOW MARROW CAVITY

17. BONE STRUCTURE

18. Formation of Bones - Ossification Bone from cartilage cells which are in protein fibers of tough collagen and flexible elastin Immature bones (OSTEOBLASTS) secrete minerals that replace cartilage in response to force

19. In compact bone, layers of collagen and calcium salts form around hollow channels called HAVERSIAN CANALS that contain blood vessels and nerves Bone cells are trapped in the rings and are then called OSTEOCYTES (mature bone cells) HAVERSIAN CANAL OSTEOCYTE OSTEOCLASTS break down bone so it can be rebuilt by osteoblasts

20. Growth Plates In the ends of long bones Cartilage grows causing an increase in the length of the bone Growth continues until cartilage is replaced by bone In adults, cartilage is still found in ears, nose, where ribs attach to sternum

21. GROWTH PLATES IN THE HAND AND WRIST

22. AFFECTS OF AGE ON THE SKELETAL SYSTEM OSTEOPOROSIS- Loss of bone mass; more common in older woman When work of osteoclasts and osteoblasts isn’t balanced, bones are weakened.

23. HEALING OF BROKEN BONES

24. HUMAN BODY HAS 206 BONES Two Main Parts - 1. AXIAL SKELETON - Bones of skull, vertebrae, ribs and sternum 2. APPENDICULAR SKELETON - Arms, legs, shoulders, pelvis

25. JOINTS – Where two bones meet Can be movable or immovable (fixed) STRUCTURES OF MOVABLE JOINTS: LIGAMENTS (connect bone to bone) TENDONS (connect muscle to bone) SYNOVIAL MEMBRANE – produces synovial fluid to lubricate BURSA – sac of SYNOVIAL FLUID for shock absorption and reducing friction CARTILAGE – end of bones

26. THREE MAIN TYPES OF JOINTS 1. IMMOVABLE – Little or no movement – skull 2. SLIGHTLY MOVABLE – Limited movement- vertebrae 3. FREELY MOVABLE – Allows Movement in one or more directions: A. Ball and socket- shoulder B. Hinge- knee C. Pivot- neck to head D. Saddle- thumb E. Gliding- foot

27. Pivot - A ring of bone rotating around another bone. For example, the neck. • Ball-and-Socket - Allows movement in all directions. For example, the shoulder joint. • Hinge - Allows the joint to bend and straighten, but does not rotate. For example, the elbow joint. • Ellipsoid - A less flexible version of the ball-and-socket joint. For example, the wrist joint. • Saddle - Fit together to allow all movements except rotation. For example, the thumb joint. • Gliding - Two generally flat surfaces gliding over each other. For example, the joints between the tarsals of the foot. TYPES OF MOVEABLE JOINTS

28. COMMON PROBLEMS WITH JOINTS SPRAINS - Injury due to forcible twisting ARTHRITIS- Inflammation of joint BURSITIS - Inflammation of the bursa RHEUMATOID ARTHRITIS – Immune system attacks joints and deposits bone in them

29. LOCOMOTION - MUSCULAR SYSTEM

30. THREE TYPES OF MUSCLE 1. SMOOTH - Found in internal organs and blood vessels Involuntary slow contractions

31. 2. CARDIAC MUSCLE - Found in heart Striped (Striated) Involuntary interconnected for rhythmic contractions

32. 3. SKELETAL MUSCLE - Attached to bones to move them Voluntary and consciously controlled by the central nervous system Striped (Striated) with dark and light bands

33. MAKING THE SKELETON MOVE ORIGIN – End attached to stationary bone INSERTION – End attached to moving bone which moves toward the origin Muscles work in opposing pairs (ANTAGONISTIC)– FLEXOR – Bends the joint EXTENSOR – Straightens the joint

34. STRUCTURE OF SKELETAL MUSCLES Skeletal muscle is composed of MUSCLE FIBERS, Composed of smaller structures (MYOFIBRILS) Muscle fiber

35. Composed of two types of smaller structures (FILAMENTS): A. Thick Filaments - Protein MYOSIN B. Thin Filaments - Protein ACTIN Alternating myosin and actin give striped appearance of muscle

36. SARCOMERE– Section of myofibril containing actin and myosin and bound by Z lines which are discs attached to actin

37. SLIDING FILAMENT THEORY Actin filaments slide towards each other during contraction as myosin heads attach to actin bending inward MYOSIN

39. Exercise tones muscle and increases strength by increasing the size of the fibers Energy comes from ATP from aerobic cellular respiration When there isn’t enough oxygen  Anaerobic respiration  Lactic acid (causes cramping until more oxygen is available)

40. Muscle Injuries Muscle Sprain – Torn or overly stretched muscle, ligament or tendon Muscle Strain – Pulled muscle; overstretching usually because not warmed up Tendonitis – Inflammation of tendons