1. The Integumentary System
SKIN

2. The Integumentary System
On average, adult skin covers over 3,000 square inches of surface area and accounts for about 15% of the total body weight.
Skin is the largest organ of the body.
Epidermal cells live about 2-4 weeks and as humans, we are constantly shedding dead skin cells.

3. More skin Facts
You replace the entirety of your skin approximately every 15 years.
30,000 to 40,000 dead skin cells fall off per minute, resulting in about 8.8 pounds of dead skin cells fall off your body per year.
75-90% of household dust is composed of dead skin cells.
About 80 percent of the material seen floating in a sunbeam is, in fact, flakes of dead skin.
You can drastically reduce the amount of dead skin contributing to dust in your home by exfoliating 3-4 times per week when you bathe.

4. A. Layers of Skin
Epidermis- The outermost layer of skin that is made up of 5-6 layers and contains no blood vessels.
Two main layers of epidermis:
1. Stratum corneum- The outermost layer where cells constantly shed.
2. Stratum germinativum- Provides cells to replace cells in the strata corneum.

5. Epidermis Pic
Stratum germinativum
Stratum corneum
Dermis

7. Diagram of the Skin

8. 2. Dermis The dermis is also called the dorium or true skin.
A. It has a framework of connective tissue that contains blood vessels, lymph vessels, nerves, involuntary muscle, sweat and oil glands, and hair follicles.
B. The top of the dermis is covered with papillae.

9. Dermis continued
Papillae- are elevations of the dermis that fit into ridges on the stratum germinativum of the epidermis. (Goose bumps!!!!)
1. The ridges that the papillae fit into form lines or striations on the skin.
2. The pattern of ridges makes our finger prints and foot prints and is unique for each individual.
3. The friction ridge skin helps us GRIP things.

10. Fingerprints
Fingerprints begin to form in the womb during the 3rd or 4th month of gestation. During this time the middle layer of skin, called the basal layer, begins to outgrow the inner dermis and epidermis skin layers.
It is believed that the buckling and folding of this skin layer is partially responsible for the unique stresses in fingertip pads that become visible as the fetus continues to develop.

11. Fingerprints continued
The first identifying marks that occur on a fetus's skin are called ridges. Ridges are the faint lines on the fingertips that create the foundation of a fingerprint.
As a fetus touches surrounding structures, her exact position in the womb and the density of the womb's amniotic fluid determine how every individual ridge will form.
The level of activity of a fetus and the general chaos of the conditions of the womb prevent fingerprints from developing the same way in fetuses.

12. I want to get rid of my prints
Getting rid of your prints is harder than you think. Prints originate in the Dermis. This is why you can’t shave or cut them off. To do so you must cut all the way past the dermis (almost to the bone). OUCH!!!
Any significant cuts on your fingers will simply result in scarring and will make you even more unique.

13. How about using acid to get rid of my prints???
A famous gangster by the name of John Dillinger tried that method.
It was a dismal failure and quite painful as well.
All it did was give Mr. Dillinger some pretty unique scars. 

15. 3. Hypodermis or Subcutaneous fascia
The innermost layer of skin which connects skin to the underlying muscles.
It is made of elastic and fibrous connective tissue and adipose (fatty) tissue.

17. B. Glands of the Skin
1. Sudoriferous glands- aka. Sweat glands are coiled tubes that extend through the dermis and open on the surface of the skin at an opening called a pore.

18. Sweat glands continued
A. Sudoriferous glands function to eliminate sweat or perspiration that contains water, salts, and some body wastes.
B. Sweat contains body wastes and is basically odorless. When sweat interacts with bacteria on skin, body odor occurs.
C. The process of perspiration removes excess water from the body and cools body as sweat evaporates into the air.

19. 2. Sebaceous glands
A. Sebaceous glands, also called oil glands, usually open onto a hair follicle.
B. Sebaceous glands produce oil called sebum.

20. Oil glands continued
1. Sebum keeps hair from becoming dry and brittle and is slightly acidic so it acts as an antibacterial and antifungal secretion to help prevent infections.
2. A blackhead or pimple occurs when oil glands become plugged with dirt and oil.

23. Blackhead VS. Whitehead
Blackheads- If there is a plug of cells in the pore and the pore opening expands, so that it's not entirely blocked off, then a blackhead appears. The portion of the comedo­ that is nearest the surface has a concentration of melanin, giving it its appearance and appropriate name.
Whiteheads form when the pore is totally blocked, and the growing matter has forced the comedo (blockage) to just beneath the surface of the skin.

24. Zits (pustules)
Pustules­. Less-scientific circles commonly refer to pustules as "zits." These are the pus-filled pimples that form in your follicles and sweat glands.

25. C. Other Parts of the Integumentary System
1. Hair- consists of a hair shaft and a root that grows in a hollow tube called a follicle.

27. More about hair
A. Hair helps protect the body and covers all body surfaces except the palms of the hands and feet.
B. Alopecia- aka. Baldness is a genetic condition that is common in men, but can also occur in women and involves the permanent loss of hair on the scalp.

28. Cool hair facts It is normal to lose 40-100 hairs a day.
A human hair on your head can live for 3-7 years.
Only 90% of your hair follicles are active at a time. The other 10% are in a rest phase.
On average, the scalp contains 100,000 strands of hair. That’s 1000 hairs per square inch.
One strand of hair can carry a weight of 100 grams.

29. 2. Nails
Nails are made of dead keratinized epidermal epithelial cells, which are packed closely together to form a thick dense surface.

30. Nails continued
A. Nails function to protect the fingers and toes from injury.
B. Nail cells form in the nail bed and will continue to grow and regrow as long as the nail bed is not damaged.

32. Cool Nail Facts
The longest nail was on a man from India and it measured 4 feet long!!!
Men’s nails grow faster than women’s.
The middle fingernail grows fastest and the thumb nail grows slowest.
Nails, like hair, grow faster in warmer climates.
How fast do nails grow? A lot of factors influence the rate, but a general rule is ½ to 4 inches per year.
Onychophagia is the scientific term for nail biting.

33. D. Functions of the Integumentary System
1. Protection- It serves as a barrier for sun’s ultraviolet rays, protects against invasion of pathogens or germs, and holds moisture in preventing deep tissues from drying out.
2. Sensory perception- Nerves present in the skin responds to pain, pressure, temperature, and touch sensations.

34. Functions continued
3. Regulation of body temperature- Blood vessels in the skin help retain or release heat.
A. When blood vessels dilate, they allow excess heat to escape through the skin.
B. When blood vessels constrict, they retain heat.
C. Sudoriferous (sweat) glands also help cool the body through evaporation of perspiration.

35. More Functions
4. Storage- Skin has tissues for temporary storage of fat, glucose, water, vitamins, and salts. Stores adipose tissue in subcutaneous fascia, which is a source of energy.
5. Absorption- certain substances are absorbed through the skin. This is called transdermal absorption.
Ex. Medications for motion sickness, nitroglycerine for heart trouble, and nicotine patches to help a person quit smoking.

36. Couple More Functions
6. Excretion- Helps the body eliminate salt, wastes, and excess water through the act of perspiration.
7. Production- Skin helps in production of vitamin D by using the ultraviolet rays fro the sun to form an initial molecule of vitamin D that matures in the liver.

37. E. Skin Color
1. Pigmentation- Skin color is inherited and determined by pigments in epidermis.
A. Melanin- is a brownish-black pigment produced in the epidermis by specialized cells called melanocytes.
B. Everyone has the same number of melanocytes. Genes present in each racial group determine the amount of melanin produced.

38. More about melanin
C. Melanin causes a black, brown, or yellowish skin tint depending on racial origin and the amount of melanin produced.
D. Ultraviolet light activates melanocytes to produce more melanin to protect and tan the skin.
E. Small concentrated areas of melanin pigment form freckles.
F. Carotene- yellowish-red pigment tat also helps determine skin color.

39. More about
Pigments!!!! Get it??
2. Albino- absence of color pigments producing skin that has a pinkish tint, hair that is pale yellow or white, and eyes that are red in color and are very sensitive to light.

40. Not albino

41. Red pigments 3. Abnormal colors-
A. Erythema- reddish color caused by burns or a congestion of blood in vessels.

42. Yellow pigments
B. Jaundice- yellowish discoloration that can indicate the presence of bile in blood as a result of liver or gallbladder disease. Also seen in certain diseases that involve destruction of red blood cells.

43. Blue Pigments
C. Cyanosis- bluish discoloration caused by insufficient oxygen and is commonly associated with heart, lung, and circulatory diseases.

44. Gray or Brown Discoloration
D. Gray or Brown Discoloration- signs of chronic poisoning.
Silver toxicity

45. F. Skin Eruptions
1. Macules (macular rash)- flat spots on the skin. Ex. Freckles

46. More Skin
2. Papules (popular rash)- firm raised areas as in pimples and stages of chicken pox.

47. More Eruptions
3. Vesicles- blisters or sacs full of fluid.

48. Krakatoa
4. Pustules- Sacs filled with pus.

49. SCABS
5. Crusts- areas of dried pus and blood commonly called scabs.

50. Hives and Insect Bites
6. Wheals- Itchy elevated areas with an irregular shape often seen in hives and insect bites.

51. Ulcers
7. Ulcers- Deep loss of skin surface that may extend into the dermis and may cause periodic bleeding and formation of scars.

52. G. Diseases and abnormal conditions
1. Acne vulgaris- inflammation of sebaceous glands usually occurring during adolescence as a result of hormonal changes and increased sebum.
A. Symptoms- include papules, pustules, and blackheads all occurring when hair follicle becomes blocked with dirt, cosmetics, excess oil and/or bacteria.
B. Treatment- frequent thorough washing of skin, avoid creams and heavy makeup, antibiotics or vitamin A ointment, ultraviolet light treatments.

53. Acne Vulgaris Pics

54. More Diseases
2. Athlete’s Foot- Contagious fungal infection usually on the feet.
A. Symptoms- itchy skin, blisters, and cracks which may turn in to open sores.
B. Treatment- antifungal medication, keep area dry and clean.

55. Athlete’s Foot!!!!

56. Diseases continued…
3. Cancer- has many causes and occurs in different forms.
A. Causes/ indicators-
1. A mole that changes in color, shape, size, or texture.
2. Bleeding or itching of mole.
3. Exposure to the sun, prolonged use of tanning beds
4. Irritating chemicals or radiation.
B. Treatments- involve surgical removal of the cancer, radiation, and/or chemotherapy

57. Cancer Continued… C. Types of Cancer:
1. Basal Cell Carcinoma- Cancer of the basal cells in the epidermis of the skin which grows slowly and usually does not spread.
Lesions can be pink to yellow-white and are usually smooth with a depressed center having an irregular shaped border.

58. Cancer Continued…
2. Squamous Cell Carcinoma- affects the thin cells of the epithelium but can spread quickly to other areas of the body.
Lesions start as small, firm, red flat sores that later scale or crust.
Sores that do not heal are frequently squamous cell carcinomas.

59. Cancer continued…
3. Malignant Melanoma- Develops in the melanocytes of the epidermis and is the most dangerous type of skin cancer.
Lesions can be brown, black, pink, or multicolored.
They are usually flat or raised, slightly asymmetric, and irregular or notched on the edges.

60. More Diseases and Abnormal Conditions
4. Dermatitis- Inflammation of the skin.
A. Caused by any substance that irritates the skin such as an allergic reaction to detergents, cosmetics, pollen, or certain foods.
B. Contact Dermatitis- is caused by contact with poison ivy, poison sumac, or poison oak.
C. Symptoms of dermatitis include dry skin, erythema, edema, itching, macular-papular rashes and scaling.
D. Treatments- eliminate allergen, use anti-inflammatory ointment, antihistamines, and steroids

61. Dermatitis

62. More Diseases and Abnormal Conditions
5. Eczema- noncontagious inflammatory skin disorder.
A. Caused by a reaction to allergen or irritant, diet, cosmetics, soaps, medications and/ or emotional distress.
B. Symptoms include dryness, erythema, edema, itching, vesicles, crusts, and scaling
C. Treatment includes removing the irritant and applying corticosteroids.

63. Eczema

64. Some More D.A.A.C.
6. Impetigo- highly contagious streptococcal or staphylococcal skin infection.
A. Symptoms include dryness, erythema, oozing vesicles, pustules, formation of yellow crusts.
B. Treatment includes washing lesions with soap and water, keep dry, use topical and oral antibiotics.

65. Impetigo

66. Still More D.A.A.C.
7. Psoriasis- Chronic, noncontagious, inherited skin disease characterized by periods of exacerbations (symptoms present) followed by remission (symptoms decrease or disappear).
A. Although the cause is hereditary, symptoms tend to be exacerbated by stress, cold weather, sunlight, pregnancy, and endocrine changes.
B. Symptoms include red thick areas covered with white or silver scales.
C. Treatment- NO CURE, chronic condition. Coal tar, cortisone ointments, ultraviolet light, and removal of scales can help with symptoms.

67. Psoriasis

68. And Some More D.A.A.C.
8. Ringworm- highly contagious fungus infection of the skin or scalp.
A. Symptoms include flat or raised circular area with clear central area surrounded by an itchy, scaly, or crusty outer ring.
B. Treatment includes oral and topical antifungal medications.

69. Ringworm

70. Last D.A.A.C. 9. Verrucae or Warts- Viral infection of the skin.
A. Symptoms include the formation of rough, hard, elevated, rounded surface on the skin.
B. Plantar warts- usually occur at pressure points on the soles of the feet.
C. Treatment includes the removal with electricity, liquid nitrogen, acid, chemicals, or laser. Some disappear spontaneously.

71. Warts

72. THE END 