Integumentary System and Accessory Organs

1. Integumentary System and Accessory Organs The skin, or integument, is considered an organ because it consists of two tissues: epithelial and connective. In addition, accessory organs, such as glands, hair, and nails, are present, and together with the skin make up the integumentary system.

2. Skin • The skin consists of two layers, the epidermis and the underlying dermis . Although technically not part of the skin, the hypodermis (subcutaneous layer, or superficial fascia) lies beneath the dermis. • The skin performs a variety of functions: • Protection is provided against biological invasion, physical damage, and ultraviolet radiation. • Sensation for touch, pain, and heat is provided by nerve endings. • Thermoregulation is supported through the sweating and regulation of blood flow through the skin. • Metabolism of vitamin D occurs in the skin. • Storage of blood that can be shunted to other parts of the body when needed takes place in the skin. • Excretion of salts and small amounts of wastes (ammonia and urea) occurs with the production of sweat.

3. Skin Makes up about 16 percent of total body weight; large surface area (1.5-2 square meters--about 18 square feet of skin in a man) It forms the interface between ourselves and the exterior environment Two major components--cutaneous membrane, and the accessory structures cutaneous membrane = epidermis (epithelial) and dermis (connective) accessory structures = hair, nails, glands underlying the epidermis and dermis is the subcutaneous layer or hypodermis most of the body is covered by thin skin with 4 layers, but the palms and soles are thick skin with 5 layers Below is a diagram of skin anatomy with some of the accessory structures:

5. Accessory Organs of the Skin - Sebaceous • Sebaceous glands are one part of the pilosebaceous unit, which also contains a hair follicle and a hair. These units are found everywhere on the body except on the palms, soles, top of the feet, and the lower lip. The number of pilosebaceous units is greatest on the face, upper neck, and chest. • Sebaceous glands produce a substance called sebum, which is responsible for keeping the skin and hair moisturized. During adolescence, sebaceous glands enlarge and produce more sebum under the influence of hormones called androgens. After about age 20, sebum production begins to decrease.

6. Accessory organs of the Skin - sudoriferous • It is sweat glands that have the scientific name of sudoriferous glands. In human beings there are two kinds of sudoriferous glands; one is the eccrinesudoriferousglands and another one is apocrinesudoriferousglands.The eccrinesudoriferousglands are distributed on the entire surface of the body with more abundance on palms, soles and on the forehead. The seat that these glands produce is mainly composed of water and various salts. The prime function of these glands is to regulate the temperature of the body.The apocrinesudoriferousglands are found mainly in the armpits and around the genital organs and it is these glands that cause odor in sweat because of the presence of bacteria. The sweat produced from these glands contains mainly fatty materials.

7. Accessory organs of the skin - hair • Insulation • The primary function of human hair is to insulate the human body. Hair does this in two ways: it serves as a physical barrier between external cold air and the skin, and it also traps warm air in between the skin and the hair, keeping the body warmer. • Protection from External Factors • Hair protects skin from external factors, such as sun damage and chapped skin from wind damage. It also blocks dust and dirt from settling on the skin. • Friction Buffer • Hair serves as a buffer against friction. This is one of the reasons that hair is present on the legs, genitals and underarms. It also soaks up sweat for easier evaporation so that the sweat isn't stuck to the body during physical activity, which can cause chapping and blistering. • Differentiation and Beautification • Hair is widely used in all mammals for differentiation and beautification. Male lions have manes, deer have decorative spots and many birds have coloring to distinguish males from females. Humans have hair for the same purpose, which is why men grow facial hair and women do not. Hair is also considered to add beauty, which is why women often have elaborate hairstyles and why men go to great lengths to battle baldness. • Redirect Sweat and Water • Hair also soaks up sweat from the skin so that it won't cause irritation from friction and it also redirects sweat so that certain parts of the body can dry faster and stay protected. Hair in the armpits pulls sweat from the armpits to cool the area and eyebrows redirect sweat from the forehead away form the eyes.

8. Accessory organs of the skin - nail • Nails are plates of tightly packed, hard, dead, keratinized cells of the epidermis. Each nail consists of a nail body, free edge, and nail root. Functionally, nails help us to grasp and manipulated small objects, provide protection to the ends of the fingers and toes, and allow us to scratch. • Nails grow at an average rate of 3 millimeters (1/8 inch) a month. Fingernails require 3 to 6 months to regrow completely, and toenails require 12 to 18 months. Actual growth rate is dependent upon age, gender, season, exercise level, diet, and hereditary factors. Nails grow faster in the summer than in any other season. Contrary to popular belief, nails do not continue to grow after death; the skin dehydrates and tightens, making the nails (and hair) appear to grow. • nail root: is the portion that is not visible. • nail bed: is the portion of the nail is visible. It also determines what shape the nail will grow. • nail body: Most of the body is pink because of the underlying blood capillaries. • lunula: The whitish semilunar area near the nail root Cuticle: dead skin that forms around the cuticle. The function is to protect the area between the nail and epidermis from exposure to harmful bacteria.  • Matrix: The only living part of the nail. It is situated behind and underneath the nail fold and produces the keratin which makes up the nail plate. If the matrix is damaged, growth of the nail plate is affected.

9. Pathological

10. AbrasionThe scraping down or rubbing away or removal of the superficial layers of the skin or mucous membrane in a limited area

11. abscessAn abscess (Latin: abscessus) is a collection of pus (dead neutrophils) that has accumulated in a cavity formed by the tissue in which the pus resides on the basis of an infectious process (usually caused by bacteria or parasites) or other foreign materials (e.g., splinters, bullet wounds, or injecting needles). Abscesses and carbuncles are histologically similar but carbuncles (and furuncles) arise from infection of the hair follicles. Abscesses can arise from infection tracking in from the skin surface but are usually deeper than carbuncles and can also be a complication of bacteremia.

12. furuncleA Staphylococcal skin infection which involves a hair follicle, often referred to as a boil or a furuncle

13. carbuncleCluster of furuncles – subcutaneous tissueA carbuncle is an abscess larger than a boil, usually with one or more openings draining pus onto the skin. It is usually caused by bacterial infection most commonly Staphylococcus aureus. The infection is contagious and may spread to other areas of the body or other people.A carbuncle is made up of several skin boils. The infected mass is filled with fluid, pus, and dead tissue. Fluid may drain out of the carbuncle, but sometimes the mass is so deep that it cannot drain on its own. Carbuncles may develop anywhere, but they are most common on the back and the nape of the neck. Men get carbuncles more often than women. Because the condition is contagious, family members may develop carbuncles at the same time. Often, the direct cause of a carbuncle cannot be determined. Things that make carbuncle infections more likely include friction from clothing or shaving, generally poor hygiene and weakening of immunity. For example, persons with diabetes and immune system diseases are more likely to develop staphylococcal infections.The carbuncle may be the size of a pea or as large as a golf ball. It may be red and irritated and might hurt when touched. It may also grow very fast and have a white or yellow center. It may crust or spread to other skin areas. Sometimes, other symptoms may occur. These may include fatigue, fever and general discomfort or sick feeling. Sometimes an itching occurs before the carbuncle develops.

14. acneAcne vulgaris (commonly called acne) disease of the sebaceous follicles – comedos, papules, pustules. Is a common human skin disease, characterized by areas of skin with multiple noninflammatory follicular papules or comedones and by inflammatory papules, pustules, and nodules in its more severe forms.

15. alopeciaabsence or loss of hair

16. comedo (blackhead)

17. cystA cyst is a closed sac or pouch under the skin, having a distinct membrane and division on the nearby tissue. It may contain air, fluids, or semi-solid material. A collection of pus is called an abscess, not a cyst. Once formed, a cyst could go away on its own or may have to be removed through surgery.

18. eczema e= erythr/o = redEczema, or dermatitis redness of the skin

19. hemorrhageLoss of large amounts of blood in a short period of time

20. contusion (bruise)hemorrhage under the skin

21. ecchymosislarge irregular hemorraghic area black and blue

22. petechiaSmall red spots on the skin that usually indicate a low platelet countpinpoint hemorrhage

23. hematomaElevated localized blood trapped under the skin

24. hirsutismHirsutism (from Latin hirsutus = shaggy, hairy) is the excessive and increased hair growth on female humans in those parts of the body where terminal hair does not normally occur or is minimal - for example, a beard or chest hair. It refers to a male pattern of body hair (androgenic hair) and it is therefore primarily of cosmetic and psychological concern. Hirsutism is a symptom rather than a disease and may be a sign of a more serious medical condition, especially if it develops well after puberty

25. impetigoImpetigo is a highly contagious disease caused by streptococcus or staphylococcus bacteria. It causes a superficial skin infection which appears red with yellow or golden crusts. It is seen frequently in children on the face, upper trunk, and arms. Note that the nose is also infected.Isolated pustules that crusted and ruptured.

26. psoriasisPsoriasis (pronounced /səˈraɪəsɪs/) is a chronic, non-infectious diseasethat affects mainly the skin. It is currently suspected to be autoimmune in origin.It commonly causes itchy red, silvery scaly patches to appear on the skin.

27. scabiesScabies is an itchy skin condition caused by the microscopic mite Sarcoptesscabei. It is common all over the world, and it affects people of all races and social classes. Scabies spreads quickly in crowded conditions where there is frequent skin-to-skin contact between people.

28. skin lesionsA skin lesion is an abnormal growth or patch of skin that doesn't look like the area nearby. Skin lesions can be divided into two categories: primary and secondary.Primary skin lesions are variations in color or texture that may be present at birth, such as moles or birthmarks. They also may appear during a person's lifetime, such as warts, acne, or psoriasis, allergic reactions such as hives or sunburn. Reaction pathologically altered tissue.Secondary skin lesions include changes in the skin caused by primary skin lesions, either as a natural progression or because of infection, scratching, trauma, diseases or picking at the skin.

29. primary skin lesions

30. tinea (ringworm)Ringworm is a skin infection caused by a fungus. Ringworm can affect skin on your body (tineacorporis), scalp (tineacapitis), groin area (tineacruris), also called jock itch), or feet (tineapedis), also called athlete's foot).

31. pressure or decubitus ulcerPressure sores are areas of damaged skin caused by staying in one position for too long (prolonged pressure).

32. urticariaHives are frequently caused by allergic reactions; allergic reaction of the skin

33. verruca or warts Rounded epidermal growths

34. vitiligo - leukodermaThere are several diseases marked by a lack of pigment in the skin that are grossly referred to as leukoderma; some are caused by an inability of melancocytes to produce melanin, while others are caused by melanocytes either not being present or being destroyed.

35. Diagnostic Procedures

36. biopsy • A biopsy is a medical test involving the removal of cells or tissues for examination. It is the medical removal of tissue from a living subject to determine the presence or extent of a disease.

37. skin test Skin testing for allergies is used to identify the substances that are causing your allergy symptoms. It is often performed by applying an extract of an allergen to your skin, scratching or pricking the skin to allow exposure, and then evaluating the skin's reaction. It may also be done by injecting the allergen under the skin, or by applying it to a patch that is worn on the skin for a specified period of time.

38. cryosurgery Cryosurgery (cryotherapy) is the application of extreme cold to destroy abnormal or diseased tissue.

39. debridement surgical removal of foreign material and dead tissue from a wound in order to prevent infection and promote healing

40. electrodessicationHigh frequency electrical sparks are used to dehydrate and destroy diseased tissue.

41. incision and drainage

42. skin graft Skin grafting is a type of medical grafting involving the transplantation of skin

43. Allograft (allo = other) The of the same species with a different genotype. A transplant from transplant of an organ or tissue from one individual to anotherone person to another, but not an identical twin, is an allograft. Allografts account for many human transplants, including those from cadaveric, living related, and living unrelated donors.

44. Autograft (auto = self)transplant of healthy tissue from one site to another in the same individual

45. synthetic skin grafttransplation of artifical skin produced from collagen fivers arranged in lattice pattern. Burke and Yannas then created a kind of artificial skin using polymers from shark cartilage and collagen from cowhide. This mixture was dried and sterilized to make a thin membrane (a covering through which things can pass) similar to the human dermis layer. Added to the membrane was a protective top layer of silicone that acted like the human epidermis.

46. xenograftTissue or organs from an individual of one species transplanted into or grafted onto an organism of another species, genus, or family. A common example is the use of pig heart valves in humans. . The prefix "xeno-" means foreign. It comes from the Greek word "xenos" meaning stranger, guest, or host. (Xeno- and xen- are variant forms of the same prefix.)

47. skin resurfacingProcedure that repairs damaged skin

48. chemical peelchemical used to remove outer layer of skin

49. skin resurfacing cutaneous laser dermabrasion Dermabrasion is a surgical procedure that involves the controlled abrasion (wearing away) of the upper layers of the skin with sandpaper, wire brush, or other mechanical means. • several laser treatments