 Skin is called the cutaneous or integument  Skin has two regions  The epidermis  The dermis

 Epidermis  The outer thinner region of the skin  Made up of stratified squamous epithelium  Divided into the stratum basale and the stratum corneum

 Epidermis  Stratum basale- just superior of the dermis  Langerhans cells- macrophages found deep in the epidermis that phagocytize microbes and simulate the immune system  Melanocytes- specialized cells in the deeper epidermis that produce melanin, responsible for skin color

 Epidermis  Stratum corneum- the uppermost layer of the skin  Keratin- a fibrous, waterproof cell  Mechanical barrier against microbe invasion

 Epidermis

 Dermis  A deeper and thicker region  Composed of dense irregular connective tissue  Dermal papillae causes ridges resulting in fingerprints  Contains collagenous and elastic fibers

 Dermis  Collagenous fibers prevent skin from being torn and great resistance from over stretching  Elastic fibers allow movement but maintain normal skin tension  A deeper and thiker region

 Dermis

 Decubitus ulcers- sore caused by a lacked of blood flow in a particular area that is restricted

 Hypodermis  Subcutaneous tissue  Lies below the dermis  Composed of loose connective tissue including adipose

 Hair  Found everywhere on the body except:  Palms  Soles  Lips  Nipples

 Hirsutism: excessive body and facial hair

 Alopecia- lack of hair or baldness

 Hair follicles:  Are formed from epidermal cells  But are located in the dermis  Root- portion of the hair found in the follicle  Shaft- portion of the hair found above the skin

 Hair follicles:  Are formed from epidermal cells  But are located in the dermis  Root- portion of the hair found in the follicle  Shaft- portion of the hair found above the skin

 Hair follicles:

 Nails:  From special epithelial cells at the base of the nail called the nail root  Nail body is the visible portion of the nail  Lunula is the whitish half moon shaped base

 Glands: specialized cells that produce and secrete a substance into ducts

 Sweat gland:  Present in all skin  Tubular  Glands are active under stress

 Sweat gland:  Apocrine gland  Open into hair follicles  In anal, groin, and armpits  Begins secreting at puberty

 Sweat gland:  Eccrine glands  Open to surface of the skin  Active when a person is hot  Contains water, salts, urea, and waste

 Sebaceous glands  Associate with a hair follicle  Secrete sebum : an oil substance  Lubricates and waterproofs

 Acne vulgaris  Most common  Inflammation of the sebaceous glands

 Mammary glands  Located in breast  Produces milk

 Athlete’s Foot: fungal infection of the toes and sole

 Impetigo: highly contagious bacterial infection that results in pustules

 Psoriasis: chronic condition, the skin is reddish pink patches covered by silver scales

 Eczema: an inflammation of the skin caused by sensitivity

 Cyanosis: condition in which the skin has a bluish tint caused by insufficient oxygen in the blood

 Jaundice: yellowing of the skin caused by an accumulation of bilirubin

 Albinism: loss of pigment in the skin creating patches of white skin

 Freckles: melanin concentrated in local areas

 Dandruff: flaking of the scalp due to accelerated keratinization

 Uricaria: hive caused by an allergic reaction

 Nonmelanoma: Basal cell carcinoma  Most common  Caused from UV exposure  Signs are tumors, open sores, reddish patches, smooth growths, shiny bumps or pale marks

 Nonmelanoma: Basal cell carcinoma

 Nonmelanoma: Squamous cell carcinoma  More like to spread  Signs bleeding warts and scabs

 Nonmelanoma: Squamous cell carcinoma

Squamous cell carcinoma Basal cell

 Melanoma:  Starts as a mole  Skin around mole turns colors  Occurs mostly in fair skinned individuals with a history of sunburns as a child

 Melanoma:

 Moles: due to an overgrowth of melanocyte

 Warts: caused by a virus

 Burns  Caused by Chemicals, Radiation, and Heat  Extent of a burn is determined by the “Rule of Nine”  Classified by depth of the burn and the extent of the burn

 First Degree Burns  Only the epidermis  Reddness and pain, no blisters  Subside in 2-3 days

 Second Degree Burns  Only the epidermis and dermis  Reddness, pain, and blisters  Subside in days

 Third Degree Burns  Destroys entire thickness of the skin  Leathery surface of brown, black, tan, white or red  Destroyed nerves, blood vessels, glands, and follicles

 Third Degree Burns

 Fourth Degree Burns  Destroyed down to bone  Limited chance of survival

 Major concerns with burns:  Fluid loss  Heat loss  Bacterial infections

 Autografting  Graft taken from another part of the patients body  Preferred method  Heterografting  Graft taken from another person

 Skin Grafts

 Epidermis  Maintain thickness but cell turnover decreases  Skin is looser

 Dermis  Thinner  Flattened  Collagenous fibers coarser, thicker, far apart  Upper layer lost  Decrease in melanocytes

 Hypodermis  Adipose tissue decreases

 Wrinkles caused by:  Loose epidermis  Fibers are fewer and disorganized  Less padding

 Functions of the skin  Protective function  Helps regulate water loss  Produces vitamin  Regulates body temperature  Gathers sensory information

 Hypothermia: Body temperature below normal  Characterized by  Uncontrolled shivering  Incoherent speech  Lack of coordination Progresses to pulse rate slows hallucinations shallow breathing rigidity

 Hyperthermia: Body temperature above normal  Heat stroke- body temperature above 110 degrees F w/o sweating  Fever