1. The Human Body Unit Powerpoint Mrs. April Derochers

2. Histology: The Study of Tissues

4. Connective Tissue
Connective tissues bind structures together, form a framework and support for organs and the body as a whole, store fat, transport substances, protect against disease, and help repair tissue damage.
They occur throughout the body.
Connective tissue cells are able to reproduce but not as rapidly as epithelial cells.
Most connective tissues have a good blood supply but some do not.

6. Muscle Tissue Function of Muscle
• Movement
– Contraction (shortening) causes movement
– Of the body as a whole when connected to skeleton
– Of materials through the body (blood, food, etc.)
• Maintenance of posture
– Continual maintenance of posture via muscle contractions to either keep body standing or sitting
• Joint stabilization
– Muscle tone stabilizes and strengthens joints Muscle tone stabilizes and strengthens joints
• Heat generation– Muscles produce heat as a by product of contraction

9. Characteristics of Muscle Tissue
• Contractility– Forceful contraction, fibers in cells shorten
• Excitability– Excited by nerve cell electrical impulse to contract
• Extensibility– Ability of muscle to stretch by the contraction of opposing muscles
• Elasticity– After stretching, muscles can recoil passively

10. Classification of Muscle Tissue
• Skeletal
• Smooth
• Cardiac
• Each of these muscle types is an organ composed of mostly muscle tissue with blood
vessels.
• Largest amount of tissue of body ≈ 40% of body weight

11. Nervous Tissue
The function of nervous tissue is to transmit and receive external and internal stimuli.
Transmit electrical signals from sensory receptors and to effectors (muscles and glands) which control their activity
Found in the brain, spinal cords, and nerves.

14. Epithelial Tissue
They form the covering of all body surfaces, line body cavities and hollow organs, and are the major tissue in glands.
They perform a variety of functions that include protection, secretion, absorption, excretion, filtration, diffusion, and sensory reception.

15. Epithelial Tissue

16. Epithelial Tissue

19. Human Body Systems to Learn:
1. Integumentary System
2. Muscular System
3. Skeletal System
4. Digestive System
5. Circulatory System
6. Respiratory System
7. Urinary System
8. Nervous System
9. Endocrine System
10. Immune System

20. What’s the largest organ in your body?
THINK ABOUT IT

21. What’s the largest organ in your body?
The largest human organ is the skin.
THINK ABOUT IT

22. Integumentary System
The Skin, Hair and Nails

23. Integumentary System Functions
What are the principal functions of the integumentary system?

24. What are the principal functions of the integumentary system?
Integumentary System Functions
What are the principal functions of the integumentary system?
The integumentary system:
serves as a barrier against infection and injury.
helps to regulate body temperature.
removes wastes from the body.
gathers information.
helps to produce vitamin D.

25. The integumentary system includes the skin, hair, and nails.
Integumentary System Functions
The integumentary system includes the skin, hair, and nails.
The skin has many different functions, but its most important function is protection.

26. The skin forms a barrier that: blocks out pathogens and debris
Protection
The skin forms a barrier that:
blocks out pathogens and debris
prevents the body from drying out.
provides protection from the sun’s ultraviolet radiation.

27. Nails:
*protect the tips of fingers and toes
*are produced by the skin.

28. The skin releases excess heat generated by working cells.
Body Temperature Regulation
The skin releases excess heat generated by working cells.
Skin keeps in enough heat to maintain normal body temperature.
Hair also helps to prevent heat loss from the head.

29. Excretion
A small amount of sweat is constantly released from your sweat glands.
Sweat contains waste products such as urea and salts that need to be excreted from the body.

30. Information Gathering
The skin serves as the gateway through which sensations such as pressure, heat, cold, and pain are transmitted from the outside environment to the nervous system.

31. The skin produces vitamin D:
Vitamin D Production
The skin produces vitamin D:
*needed for the adequate absorption of calcium and phosphorus from the small intestine.
  a. Sunlight is needed for one of the chemical reactions that produce vitamin D in skin cells.

32. Integumentary System Structures
What are the structures of the integumentary system?

33. What are the structures of the integumentary system?
Integumentary System Structures
What are the structures of the integumentary system?
Skin and its related structures—the hair, nails, and several types of glands—make up the integumentary system.

34. The skin is made up of two main layers—the epidermis and the dermis.
Integumentary System Structures
The skin is made up of two main layers—the epidermis and the dermis.
Beneath the dermis is a layer of fat (the hypodermis) and loose connective tissue that helps insulate the body.

35. The outer layer of the skin is the epidermis, which has two layers.
The outer layer of the epidermis—the layer that you can see—is made up of dead cells.
 The inner layer of the epidermis is made up of living cells, including stem cells that produce new skin.

36. Epidermis
Cells in the inner layer of the epidermis divide rapidly, producing new cells that push older cells to the surface of the skin.
The older cells flatten, their organelles disintegrate, and they begin making keratin, a tough, fibrous protein.

37. Epidermis
Eventually, the older cells die and form a tough, flexible, waterproof covering on the surface of the skin that is shed every four to five weeks.

38. Epidermis
The epidermis also contains melanocytes, which are cells that produce a dark brown pigment called melanin.
Melanin helps protect the skin by absorbing ultraviolet rays from the sun.
The melanocytes of people with darker skin produce more melanin than the melanocytes of people with lighter skin.

39. Dermis
The dermis lies beneath the epidermis and contains the protein collagen, blood vessels, nerve endings, glands, sensory receptors, smooth muscles, and hair follicles.

40. Structures in the dermis help to regulate body temperature.
When the body needs to conserve heat, the blood vessels in the dermis narrow, bringing blood closer to the body’s core and preventing heat from escaping through the skin.

41. Dermis
On hot days, the blood vessels widen, bringing heat from the body’s core to the skin.

42. Dermis
Excess heat is also released when sweat glands produce perspiration, or sweat. When sweat evaporates, it takes heat away from your body.

43. Dermis
The skin also contains sebaceous glands, which secrete an oily substance called sebum that is released at the surface of the skin.

44. The basic component of human hair and nails is keratin.
Hair on the head protects the scalp from the sun and provides insulation from the cold.
Hairs in the nostrils, external ear canals, and around the eyes (in the form of eyelashes) prevent dirt and other particles from entering the body.

45. Hair
Hair is produced by cells at the base of structures called hair follicles, which are tubelike pockets of epidermal cells that extend into the dermis.

46. Hair
Individual hairs are actually large columns of cells that have filled with keratin and then died.
Rapid cell growth at the base of the hair follicle causes the hair to grow longer.

47. Hair
Hair follicles are in close contact with sebaceous glands. The oily secretions of these glands help hairs stay soft and flexible.

48. Nails
Nails grow from an area of rapidly dividing cells known as nail roots, which are located near the tips of the fingers and toes.
During cell division, the cells of the nail root fill with keratin and produce a tough, platelike nail that protects the tips of the fingers and toes.

49. Nails
Nails grow at an average rate of 3 mm per month, with fingernails growing about four times faster than toenails.

50. Skin Problems
What are some problems that affect the skin?

51. Skin Problems What are some problems that affect the skin?
The skin’s constant interaction with the environment can lead to problems of varying degrees of severity such as acne, hives, and skin cancer.

52. Acne
Acne develops when sebum and dead skin cells form plugs in hair follicles.
Bacteria are often trapped in the plug, which leads to infection and inflammation.
One hypothesis about acne suggests that high hormone levels during puberty lead to increased sebum production.

53. Hives
Allergic reactions to food or medicine often display themselves as red welts commonly called hives.
When the body experiences an allergic reaction, a chemical called histamine may be released, which causes small blood vessels to widen.
Fluid can ooze from the vessels into surrounding tissues which causes the swelling that leads to hives.

54. Skin Cancer
Excessive exposure to the ultraviolet radiation in sunlight and artificial radiation from tanning beds can produce skin cancer, an abnormal growth of cells in the skin.
Examples of the three most common types of skin cancer (basal cell, squamous cell, and melanoma) are shown.

55. Skin Cancer
You can protect yourself from skin cancer by wearing a hat, sunglasses, and protective clothing outside.
You should always wear sunscreen that protects against both UV-A rays and UV-B rays and that has an SPF of at least 15.

56. Muscular System:

63. Three Types of Muscles:
Smooth Muscles- Which include the muscles of internal organs and blood vessels. These muscles move involuntary.
Cardiac Muscle- Found only in the heart and also involuntary.
Skeletal Muscles- Are voluntary and help you move.

64. Involuntary- Automatically move without you knowing.
Voluntary- Brain sends message to muscle. You control the movements.

73. You have over 30 facial muscles which create looks like surprise, happiness, sadness, and frowning.
Eye muscles are the busiest muscles in the body. Scientists estimate they may move more than 100,000 times a day!
The largest muscle in the body is the gluteus maximus muscle in the buttocks

75. Skeletal System:

80. The human hand has 27 bones; your face has 14!
The longest bone in your body? Your thigh bone, the femur -- it's about 1/4 of your height.
The smallest is the stirrup bone in the ear which can measure 1/10 of an inch.
Did you know that humans and giraffes have the same number of bones in their necks? Giraffe neck vertebrae are just much, much longer!
You have over 230 moveable and semi-moveable joints in your body.

82. Digestive System:

86. Circulatory System:

87. Respiratory System:

88. Urinary System:

89. Immune System:

90. Endocrine System:

91. Immune System: