1. Integumentary System

2. Functions Protection against abrasion and ultraviolet light
Protection from entry of microorganisms and dehydration
Sensation receptors for heat, cold, touch, pressure, and pain
Production of precursors to Vitamin D when exposed to
ultraviolet light
Regulation of temperature by controlling blood flow to the skin
and activity of sweat glands
Excretion of waste products through the skin and the gland
secretions

3. Weighs 9-11 lbs (largest organ in the body) s.a. = 1.5-2m2
Facts
The integumentary system consists of the skin and the structures derived from it including hair, nails, and glands.
Weighs 9-11 lbs (largest organ in the body)
s.a. = 1.5-2m2
1 cm2 has 70 blood vessels, 55 Nerves, 100 sweat glands, 15 oil glands, 230 sensory receptors
New skin produced in days
The study of the integument is called dermatology.

4. Anatomy of Skin
Epidermis - the five outermost thin layers, mitosis in the deepest layer produces new cells as the older cells move towards the most superficial layer where they are sloughed off
Dermis - the thicker layer below the epidermis containing blood vessels, nerve endings, hair follicles, smooth muscles, lymphatic vessels, sweat glands, and sebaceous glands
Hypodermis - the layer of loose connective tissue under the dermis and not considered part of the skin, it contains half of the body’s stored fat which acts as padding and insulation, it attaches to underlying bones and muscles

5. Anatomy of the Skin

6. This image shows the
epidermis partially
peeled away
from the dermis.
Note the numerous
blood vessels extending
into the dermis from the
hypodermis.
Note the fat in the

7. This is a micrograph of actual skin sliced thinly and stained.
Note the epidermis, dermis, and hypodermis. The outer cells of the epidermis are sloughing off.
The dermal papillae are projections of the dermis which extend into the epidermis. They contain tiny blood vessels that supply the epidermis and aid in regulation of body temperature.
Fingerprints are projections of the dermal papillae into the epidermis of the fingertips. They increase friction and help improve grip.

8. This image shows the five layers of the epidermis.
The outermost layer is called the stratum corneum:
-25 layers of dead skin cells
-Keratinized
Keratin is a protein that builds up in cells of the epidermis as they move from the deepest layer, the stratum basale, towards the skin’s surface. This process is called keratinization and takes 2-4 weeks.

9. Epidermal Layers - Blisters, Calluses &Psoriasis
Composed primarily of keratinized stratified squamous
epithelial cells -- consisting of 4-5 layers:
stratum corneum: outermost layer, keratinized dead epithelium
stratum lucidum: layer found in thickest areas of skin
stratum granulosum: 3-5 layers of flattened granular cells, developing keratin fibers
stratum spinosum: multiple layers of cells
stratum basale: deepest layer of single cuboidal or columnar cells, also contains melanocytes
- Blisters, Calluses &Psoriasis

10. Skin Color - Genetics, Environment & Physiology:
# of melanocytes - difference in kind, amount & size
sunlight, UV light, etc.
blood in dermis, blood vessels, freckles & moles
other pigments - carotinoids
jaundice – liver disorder

11. Skin, hair, and eye color are all due to a molecule called melanin
Skin, hair, and eye color are all due to a molecule called melanin. This provides protection from the sun’s ultraviolet rays.
Melanin is made by special cells in the stratum basale called melanocytes which have extensions reaching towards the skin’s surface. Note the pigment granules in these cell extensions.

12. Variations in skin color are due to the color, amount, and distribution of melanin, not to the number of melanocytes present in the epidermis.

13. Special Features of the Dermis
Hair follicles - hair grows from hair bulbs in the follicle, the follicles are actually extensions of the epidermis deep into the dermis
Arrector pili (muscles) - an arrector pili muscle is associated with each hair follicle, when the muscle contracts the hair stands on end, contraction of these muscles also causes goose bumps
Sweat glands - sweat is produced in these coiled glands and is secreted on the skin’s surface through pores, sweat is sometimes produced due to emotional stress but is usually produced in order to decrease body temperature by evaporative cooling
Sebaceous glands - most sebaceous glands are connected to hair follicles and produce an oily substance called sebum, the sebum protects against drying of the hair and skin and against some bacteria

14. Skin Glands Sweat glands:
Sebaceous glands:
- assoc. w/ hair follicles,
secrete sebum - oils hair,
lubricates skin & prevent
water loss
- acne vulgaris
Sweat glands:
Eccrine: deep in dermis or subcutaneous layer, odorless secretions, function in thermoregulation
Apocrine: found near hair follicles, in axillary regions, released during pain, fear & stress or sexual arousal
- Ceruminous & mammary glands

15. Note the extension of the epidermis far into the dermis forming the hair follicle. Also, note the coiled sweat gland and the sebaceous gland connected to the hair follicle.

19. Nails

21. Wound healing

24. (C)Tissue Repair Blood vessels dilate
WBC & clotting agents (platelets) released
Scab forms

25. (d)Tissue Repair Granulation tissue forms (fibrous CT replaces clot)
Capillary beds invade clot
Clean up begins

26. (e)Tissue Repair Scar area (fibrous connective tissue) has contracted
Epithelium regeneration begins

29. Classification of Burns*
07/16/96
Classification of Burns
Superficial
Superficial partial-thickness
Deep partial-thickness
Full-thickness *
3##

30. The Skin
The skin, the largest organ of the body, consists of two layers-the epidermis and dermis. The depth or degree of burn depends on which layers of skin are damaged or destroyed. The epidermis is the outer layer that forms the protective covering. The thicker or inner layer of the dermis contains blood vessels, hair follicles, nerve endings, sweat and sebaceous glands. When the dermis is destroyed, so are the nerve endings that allow a person to feel pain, temperature, and tactile sensation.

31. *
07/16/96
1st- Superficial
Very painful, dry, red burns which blanch with pressure. They usually take 3 to 7 days to heal without scarring. Also known as first-degree burns. The most common type of first-degree burn is sunburn. First-degree burns are limited to the epidermis, or upper layers of skin. *
4##

33. 2nd- Superficial Partial-Thickness*
07/16/96
2nd- Superficial Partial-Thickness
Very painful burns sensitive to temperature change and air exposure. More commonly referred to as second-degree burns. Typically, they blister and are moist, red, weeping burns which blanch with pressure. They heal in 7 to 21 days. Scarring is usually confined to changes in skin pigment. Extends into superficial dermis. Increases the risk of infection. *
5##

35. 2nd-Deep Partial-Thickness*
07/16/96
2nd-Deep Partial-Thickness
Blistering or easily unroofed burns which are wet or waxy dry, and are painful to pressure. Their color may range from patchy, white to red, and they do not blanch with pressure. They take over 21 days to heal and scarring may be severe. It is sometimes difficult to differentiate these burns from full-thickness burns.
Extends into the deep dermis *
6##

37. 3rd-Full-Thickness
Burns which cause the skin to be waxy white to a charred black and tend to be painless. Healing is very slow, if at all, and may require skin grafting. Severe scarring usually occurs. Extends through the entire dermis.

39. 4th degree burn
Extends through the skin into underlying muscle and bone
Eschar – dead tissue
Amputation, significant functional impairment, possible death

41. Treatment
Treatment should begin immediately to cool the area of the burn. This will help alleviate pain. Gradual changes only.
For deep partial-thickness burns or full- thickness burns, begin immediate plans to transport the victim to competent medical care. For any burn involving the face, hands, feet, or completely around an extremity, or deep burns; immediate medical care should be sought. Not all burns require immediate physician care but should be evaluated within 3-5 days.
Remove any hot or burned clothing.

42. Treatment
4. Use cool (54 degree F.) saline solution to cool the area for minutes. Avoid ice or freezing the injured tissue. Be certain to maintain the victim’s body temperature while treating the burn.
5. Wash the area thoroughly with plain soap and water. Dry the area with a clean towel. Ruptured blisters should be removed, but the management of clean, intact blisters is controversial. You should not attempt to manage blisters but should seek competent medical help.
6. If immediate medical care is unavailable or unnecessary, antibiotic ointment may be applied after thorough cleaning and before the clean gauze dressing is applied.

43. Rule of 9’s
An adult who has been burned, the percent of the body involved can be calculated as follows:
Head = 9%
Chest (front) = 9%
Abdomen (front) = 9%
Upper/mid/low back and buttocks = 18%
Each arm = 9% (front = 4.5%, back = 4.5%)
Groin = 1%
Each leg = 18% total (front = 9%, back = 9%)