Integumentary System


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Integumentary System

  1. 1. HUMAN BODY CH. 34 - 39
  2. 2. Chapter 34 <ul><li>Protection, Support, </li></ul><ul><li>and Locomotion </li></ul>
  3. 3. Skin: The Body’s Protection <ul><li>Structure & Functions of Integumentary System </li></ul><ul><ul><li>Integumentary system consists of layers of the four types of body tissues: </li></ul></ul><ul><ul><ul><li>1) epithelial tissue - outer layer of skin </li></ul></ul></ul><ul><ul><ul><li>2) connective tissue - tough & flexible protein fibers that act to hold body together </li></ul></ul></ul><ul><ul><ul><li>3) muscle tissue - interact w/ hairs on skin & respond to stimuli like cold and fright </li></ul></ul></ul><ul><ul><ul><li>4) nervous tissue - detects external stimuli like pain and pressure </li></ul></ul></ul>
  4. 4. <ul><ul><ul><li>Main organ in integumentary system is the skin , which makes it the largest organ in the body since it is 12-15% of body weight! </li></ul></ul></ul><ul><ul><ul><ul><li>Made of two layers: </li></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>Epidermis : outer layer of skin </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>Dermis : inner layer of skin </li></ul></ul></ul></ul></ul>
  5. 5. Layers of Skin
  6. 6. <ul><li>Epidermis </li></ul><ul><ul><li>outermost layer of skin made of 2 parts: exterior and interior portions </li></ul></ul><ul><ul><ul><li>Exterior : 25-30 layers of dead, flattened cells that are continually being shed </li></ul></ul></ul><ul><ul><ul><ul><li>Even though dead, are important since contain keratin which helps protect living cells underneath </li></ul></ul></ul></ul><ul><ul><ul><li>Interior : living cells that continually divide to replace dead cells </li></ul></ul></ul><ul><ul><ul><ul><li>Contain pigment melanin that colors skin and protects it from damage by solar radiation </li></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>Melanin is not sole protector for sun damage – can get skin cancer if are dark pigmented! </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><li>process of shedding takes 28 days (4 weeks) </li></ul></ul></ul></ul>
  7. 7. <ul><li>Dermis </li></ul><ul><ul><li>Inner, thicker portion of skin </li></ul></ul><ul><ul><li>Contains many structures: </li></ul></ul><ul><ul><ul><li>Blood vessels (arteries & veins) </li></ul></ul></ul><ul><ul><ul><li>Nerves & nerve endings </li></ul></ul></ul><ul><ul><ul><li>Hair follicles </li></ul></ul></ul><ul><ul><ul><li>Sweat glands </li></ul></ul></ul><ul><ul><ul><li>Sebaceous (oil) glands </li></ul></ul></ul><ul><ul><ul><li>Muscles (to make hair stand up) </li></ul></ul></ul>
  8. 8. <ul><ul><li>Beneath dermis is subcutaneous layer </li></ul></ul><ul><ul><ul><li>Made of fat and connective tissue </li></ul></ul></ul><ul><ul><ul><ul><li>Help body absorb impacts, retain heat, store food </li></ul></ul></ul></ul>
  9. 10. <ul><li>Functions of Integumentary System </li></ul><ul><ul><li>Four main functions: </li></ul></ul><ul><ul><ul><li>1. Maintains homeostasis </li></ul></ul></ul><ul><ul><ul><ul><li>Regulates internal body temperature </li></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>When temperature rises, small blood vessels in dermis dilate (increase in circumference), allowing blood flow to increase, so blood loses heat </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>When temperature lowers, blood vessels constrict (decrease in circumference), decreasing blood flow, so blood keeps in heat </li></ul></ul></ul></ul></ul>Feedback loop: Backward/forward
  10. 11. Feedback Loop Internal Body Temperature Changes Blood vessels dilate Blood vessels constrict Blood flow increases Blood flow decreases Blood loses heat Blood keeps in heat Internal Body Temperature Normalizes + -
  11. 12. <ul><ul><ul><li>2. sensory organ </li></ul></ul></ul><ul><ul><ul><ul><li>Nerve cells get information from external environment about pain, pressure, and temperature and send message to brain </li></ul></ul></ul></ul><ul><ul><ul><li>3. produces Vitamin D </li></ul></ul></ul><ul><ul><ul><ul><li>When exposed to UV light, skin makes Vitamin D, which is essential to help body absorb calcium </li></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>Most calcium supplements contain Vitamin D for that same reason </li></ul></ul></ul></ul></ul><ul><ul><ul><li>4. protective layer </li></ul></ul></ul><ul><ul><ul><ul><li>Shields underlying tissues from physical and chemical damage and from invading microbes (viruses and bacteria) </li></ul></ul></ul></ul>
  12. 13. <ul><li>Skin injury and Healing </li></ul><ul><ul><li>Injuries to skin can occur due to scrapes, cuts, or burns but how skin heals depends on severity </li></ul></ul><ul><ul><ul><li>Mild scrape (no blood, epidermis only) </li></ul></ul></ul><ul><ul><ul><ul><li>Deepest layer of affected epidermal cells start to divide to fill in gap left by abrasion </li></ul></ul></ul></ul><ul><ul><ul><li>Cut (blood, epidermis and dermis) </li></ul></ul></ul><ul><ul><ul><ul><li>Blood flows out of wound until clot forms </li></ul></ul></ul></ul><ul><ul><ul><ul><li>Scab develops, creating barrier b/t bacteria on skin and underlying tissues </li></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>Bacteria already present in wound gets killed by white blood cells that migrate to site </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><li>New skin cells begin repairing wound from beneath </li></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>Large wound needs high amount of connective tissue which may form a scar </li></ul></ul></ul></ul></ul>
  13. 14. Healing of a Cut Before Cut in skin Blood pools, creating scab Skin cells regenerate from bottom up
  14. 15. <ul><ul><ul><li>Burn (sun, chemicals, hot objects) </li></ul></ul></ul><ul><ul><ul><ul><li>First degree (mild sunburn) </li></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>Death of epidermal cells </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>Redness and mild pain </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>Heal in 1 week w/out scar </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><li>Second degree </li></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>Damage of both epidermal and dermal cells </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>Blistering and scaring may occur </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><li>Third degree </li></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>Destruction of both epidermal and dermal cells </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>Skin function is lost, so skin grafts are required </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><li>Fourth degree </li></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>Destruction through skin and into muscles, tendons, ligaments, and bone </li></ul></ul></ul></ul></ul>
  15. 16. 1 st Degree Burn
  16. 17. 2 nd Degree Burn
  17. 18. 3 rd Degree Burn
  18. 19. <ul><li>Skeletal System Structure </li></ul><ul><ul><li>Adult human skeleton contains 206 bones! Made of two main parts: </li></ul></ul><ul><ul><ul><li>Axial skeleton : skull and bones that support it like vertebral column, ribs, sternum </li></ul></ul></ul><ul><ul><ul><li>Appendicular skeleton : bones of arms and legs (appendages), and all structures associated with them (shoulder, hips, wrists, ankles, fingers, toes) </li></ul></ul></ul>Ch. 34.2 - Bones: The Body’s Support
  19. 20. Axial vs. Appendicular Skeleton
  20. 21. <ul><ul><li>Bones meet other bones at areas called joints </li></ul></ul><ul><ul><ul><li>Joints facilitate movement of bones in relation to one another </li></ul></ul></ul><ul><ul><ul><ul><li>Joints can be fixed (non-moveable) or non-fixed (moveable) </li></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>Fixed joints : skull </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>Non-fixed joints : knee, wrist, etc. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>- 4 types of moveable joints: </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>* Ball-and-socket : hips, shoulders </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>* Pivot : twisting arm at elbow </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>* Hinge : elbows, knees, fingers, toes </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>* Gliding : wrists, ankles </li></ul></ul></ul></ul></ul>
  21. 22. Types of Joints Found in Human
  22. 23. Types of Joints Found in Human
  23. 24. <ul><li>Joints are held together by ligaments </li></ul><ul><ul><li>Ligament : tough band of connective tissue that attaches one bone to another </li></ul></ul><ul><ul><ul><li>Joints with a large range of motion (knee) have many ligaments </li></ul></ul></ul>
  24. 25. <ul><li>Ends of joints are covered in cartilage </li></ul><ul><ul><li>Allows for smooth movement b/t bones </li></ul></ul>
  25. 26. <ul><li>Certain joints have fluid-filled sacs called bursae ( bursa is singular) </li></ul><ul><ul><li>Outside of joint b/t tendon and bone to reduce friction </li></ul></ul>
  26. 27. <ul><li>Muscles are attached to bones with tendons </li></ul><ul><ul><li>Are thick bands of connective tissue </li></ul></ul>
  28. 29. <ul><li>Joints can become diseased </li></ul><ul><ul><li>Arthritis : inflammation of the joints </li></ul></ul><ul><ul><ul><li>Bone spurs are outgrowths of bone inside the joints so it limits mobility </li></ul></ul></ul>
  29. 30. Types of Bone <ul><li>are two types of bone tissue: </li></ul><ul><ul><li>Compact bone and spongy bone </li></ul></ul><ul><ul><ul><li>Compact bone : hard bone that contains tubular structures called osteons or Haversian systems </li></ul></ul></ul><ul><ul><ul><ul><li>Surrounds spongy bone to protect it </li></ul></ul></ul></ul><ul><ul><ul><li>Spongy (cancellous) bone : less dense bone with many holes and spaces </li></ul></ul></ul><ul><ul><li>Living bone cells are called osteocytes , which receive oxygen and nutrients from small blood vessels </li></ul></ul>
  30. 31. Types of Bone
  31. 32. <ul><li>Formation of Bone </li></ul><ul><li>Skeleton of human embryo is actually made of cartilage , not bone (same as what nose is made out of) </li></ul><ul><ul><li>Not until embryo is 9 weeks does cartilage get replaced by bone </li></ul></ul><ul><ul><ul><li>When blood vessels penetrate cartilage membrane, stimulate it to become osteoblasts (precursors to osteocytes) </li></ul></ul></ul>
  32. 33. <ul><li>How do osteoblasts become osteocytes ? </li></ul><ul><ul><li>Osteoblasts secrete protein collagen </li></ul></ul><ul><ul><li>Minerals like calcium and other ions (found in bloodstream) are deposited in collagen </li></ul></ul><ul><ul><li>Osteoblasts are now osteocytes </li></ul></ul>
  33. 34. Osteoblasts to Osteocytes osteoblast osteocyte collagen + + & Calcium ions
  34. 35. Bone
  35. 36. Osteocytes
  36. 37. <ul><li>Human skeleton is almost 100% bone, with cartilage found only in places where flexibility is needed – nose, ears, vertebral disks, and joint linings </li></ul><ul><li>Bone grows in length and diameter as result of sex hormones released during growth </li></ul><ul><ul><li>Length : from cartilage plates at ends of bones </li></ul></ul><ul><ul><li>Diameter : from outer surface of bone </li></ul></ul><ul><li>After growth stops, bone-forming cells are involved in repair and maintenance </li></ul>
  37. 38. <ul><li>Skeletal System Functions </li></ul><ul><li>Function of skeleton is five-fold: </li></ul><ul><ul><li>1. Provide framework for tissues of body </li></ul></ul><ul><ul><ul><li>Allows muscles to attach to bones so they can provide movement to body </li></ul></ul></ul><ul><ul><li>2. Protects internal organs </li></ul></ul><ul><ul><li>3. Produce blood cells </li></ul></ul><ul><ul><ul><li>Red marrow : where red blood cells, white blood cells, blood clotting factors are produced </li></ul></ul></ul><ul><ul><ul><ul><li>found in humerus, femur, sternum, ribs, vertebrae, pelvis </li></ul></ul></ul></ul><ul><ul><li>4. Store fat </li></ul></ul><ul><ul><ul><li>Yellow marrow : many other bones store fat in here </li></ul></ul></ul><ul><ul><li>5. Mineral storage </li></ul></ul><ul><ul><ul><li>Body’s supply of calcium and phosphate is stored in bone </li></ul></ul></ul>
  38. 39. <ul><li>Skeleton is vulnerable to injury and disease </li></ul><ul><ul><li>Broken bones </li></ul></ul><ul><ul><ul><li>Too much force against bone can cause it to break or fracture </li></ul></ul></ul><ul><ul><ul><ul><li>Physician must set bone back in place so new osteocytes may form in broken area and put two ends back together </li></ul></ul></ul></ul><ul><ul><li>Osteoporosis </li></ul></ul><ul><ul><ul><li>Loss of bone volume and mineral content which leads to bones becoming more porous and brittle and more susceptible for breakage </li></ul></ul></ul><ul><ul><ul><ul><li>More common in older women since they produce lower amounts or estrogen which aids in bone formation </li></ul></ul></ul></ul>
  39. 40. Fracture Types
  40. 41. Fracture Types
  41. 42. <ul><li>Three Type of Muscles </li></ul><ul><ul><li>Nearly half of body mass is muscle ! </li></ul></ul><ul><ul><ul><li>Muscle : groups of fibers, or cells, bound together. Almost all muscle fibers have been present since birth </li></ul></ul></ul><ul><ul><ul><ul><li>3 main types of muscle: </li></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>Smooth muscle : walls of internal organs and blood vessels </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>Cardiac muscle : heart muscle </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>Skeletal muscle : muscles attached to bones </li></ul></ul></ul></ul></ul>Ch. 34.3 – Muscles for Locomotion
  42. 43. Muscle Types
  43. 44. Muscle Types
  44. 45. <ul><li>Smooth Muscle </li></ul><ul><ul><li>Made up of sheets of cells that form a lining for organs </li></ul></ul><ul><ul><li>Most common function is to squeeze via contractions, exerting pressure on space inside tube or organ to move material inside it </li></ul></ul><ul><ul><ul><li>Ex: food bolus gets squeezed through digestive system until it comes out; sperm gets squeezed through vas deferens, then urethra until it comes out </li></ul></ul></ul>
  45. 46. Movement of Smooth Muscle Direction of movement Smooth muscle of vessel or organ <ul><li>Contractions are involuntary (can’t be controlled by human) so muscle is considered to be an involuntary muscle </li></ul>Contraction (AKA peristalsis) Item to be moved
  46. 47. <ul><li>Cardiac Muscle </li></ul><ul><ul><li>Found in heart and is adapted to generate and conduct electrical impulses! </li></ul></ul><ul><ul><li>Considered an involuntary muscle </li></ul></ul>
  47. 48. <ul><ul><li>Muscle that is attached to and moves bones </li></ul></ul><ul><ul><li>Makes up majority of muscles in body which work in opposing pairs </li></ul></ul><ul><ul><ul><li>Muscle X on one side of bone, Muscle Y on other side of bone </li></ul></ul></ul><ul><ul><ul><ul><li>If Muscle X is contracted, Muscle Y is relaxed, and vice versa </li></ul></ul></ul></ul><ul><ul><li>Considered a voluntary muscle since contractions can be controlled </li></ul></ul><ul><ul><ul><li>How do we contract our muscles? </li></ul></ul></ul><ul><li>Skeletal Muscle </li></ul>
  48. 49. Opposing Muscle Pairs Muscle Contracted Muscle Relaxed
  49. 50. Muscle Names
  50. 51. <ul><li>Skeletal Muscle Contraction </li></ul><ul><li>All muscle tissue is made of muscle fibers , which are very long, fused muscle cells </li></ul><ul><ul><li>Each fiber is made of smaller units called myofibrils </li></ul></ul><ul><ul><ul><li>Myofibrils made of thick and thin filaments </li></ul></ul></ul><ul><ul><ul><ul><li>Thick filaments: myosin </li></ul></ul></ul></ul><ul><ul><ul><ul><li>Thin filaments: actin </li></ul></ul></ul></ul><ul><ul><ul><li>Myofibril can be divided into segments called sarcomeres </li></ul></ul></ul>
  51. 53. Muscle Contraction <ul><ul><li>How do muscles contract? How do they know that you want to “make a muscle?” </li></ul></ul><ul><ul><ul><li>Sliding Filament Theory </li></ul></ul></ul>Actin Myosin Relaxed Sarcomere Z Disc
  52. 54. Sliding Filament Theory <ul><li>Sliding filament theory : when signaled, actin filaments within each sarcomeres slide toward one another, shortening sarcomeres in a fiber and causing muscle to contract </li></ul><ul><ul><li>Myosin fibers do NOT move </li></ul></ul><ul><ul><li>When skeletal muscle receives a signal (via brain), calcium is released inside muscle fibers, causing two sides of sarcomere to “slide” toward each other = contraction </li></ul></ul><ul><ul><li>When signal is gone, calcium gets absorbed, sarcomeres relax and slide away into place </li></ul></ul>
  53. 55. Sliding Filament Theory Contracted Sarcomere
  54. 56. Yellow = actin (thin) Pink = myosin (thick) Black = Z disk
  55. 57. <ul><li>Muscle Strength and Exercise </li></ul><ul><li>Muscle strength does not depend on amount of fibers but does depend on thickness of fibers </li></ul><ul><ul><li>You are born with the number of fibers you will always have, but exercise can increase thickness of each fiber making entire muscle bigger </li></ul></ul><ul><ul><ul><li>Exercise stresses muscle fibers slightly, so to compensate for workload, fibers increase in diameter by adding myofibrils </li></ul></ul></ul>
  56. 58. <ul><li>Energy that muscles need to contract comes from ATP produced by cellular respiration (aerobic and anaerobic processes) </li></ul><ul><ul><li>Most energy comes from aerobic respiration when oxygen (from breathing) is delivered to muscle cells during rest or MODERATE activity </li></ul></ul>
  57. 59. <ul><ul><li>During VIGOROUS activity (when we have tendency to hold our breaths & delivery of oxygen is not as fast as it needs to be), anaerobic respiration kicks in and in addition to ATP being made, lactic acid fermentation makes lactic acid which makes muscles cramp up </li></ul></ul><ul><ul><ul><li>Lactic acid build up gets sent into bloodstream, where triggers rapid breathing (panting!) </li></ul></ul></ul><ul><ul><ul><li>Inhalation of oxygen again breaks down lactic acid & cramps go away </li></ul></ul></ul>
  58. 60. Lactic Acid Build Up (During Vigorous Exercise)