Integumentary System PDF

Waterproof Stretchable Washable Permanent-press Invisibly repairs small cuts, rips and burns Guaranteed a lifetime with reasonable care SKIN INTEGUMENT Integument ary System Composed of: 1. cutaneous membrane or the skin 2. skin derivatives Sweat...

Waterproof Stretchable Washable Permanent-press Invisibly repairs small cuts, rips and burns Guaranteed a lifetime with reasonable care SKIN INTEGUMENT Integument ary System Composed of: 1. cutaneous membrane or the skin 2. skin derivatives Sweat glands Oil glands Hairs Nails  Skin… Exterior covering of the body. Weighs more than 6 pounds in the average adult Covers more than 3,000 square inches. The largest organ of the body.  Integumentary System Functions 1. Protects deeper tissues from: Contains KERATIN and Mechanical damage Pressure receptors (bumps) Has keratinized cells and Chemical damage (acids and Pain receptors bases) Bacterial damage Has unbroken surface, acid mantle UV radiation and phagocyctes Melanin produced by melanocytes Thermal (heat or cold) damage Has Desiccation (drying out) heat/cold/pain Waterproofing receptors substances – e.g. keratin  Integumentary System Functions 2. Aids in body heat loss or heat retention Heat Retention: Heat Loss: Not allowing blood Activating sweat to flush into skin glands and capillary beds allowing blood to flush into skin 3. Aids in excretion of urea capillary beds and uric acid by Perspiration sweat glands 4. Synthesizes vitamin D Modified cholesterol molecules in skin converted to vitamin D sunlight  The skin has two layers: 1. Epidermis 2. Dermis. The epidermis has 4 stră ta STRUCTURE OF THE SKIN Epidermis Composed of 5 zones or layers called strata Avascular (like all epithelial tissues) Explains why a man can shave and not bleed. Most cells are keratinocytes Epidermis … The stratum corneum Stratum corneum 20 to 30 cell layers thick (25 % of the epidermal thickness) The outermost stratum of the epidermis. Mostly dead cells, filled with a protein substance called keratin. Epidermis … The stratum corneum Stratum corneum The dead cell remnants are referred to as cornfiied or horny cells Thicker on the soles of the feet than on the eyelids …where there is less pressure. Its Epidermis … The stratum lucidum A translucent layer Stratum lucidum lying directly beneath the corneum May not even exist in thinner skin Cells in this layer are also dead or are in the process of dying. Epidermis … The stratum granulosum One or more layers of Stratum granulosum cells starting to die and become hard. They are in the process of keratinization… becoming fibrous protein similar to that in hair and nails. Epidermis … spinosum The stratum Mostly consists of keratinocytes held together by sticky proteins called desmosomes. Helps makes your skin flexible and strong Epidermis The stratum germinativum (basale) … Composed of several layers of living cells capable of cell division. The innermost layer of the Stratum germinativum epidermis, and contains melanin… the pigment that gives color to the skin. The more abundant the melanin… the darker the skin color. Damage to this layer, such as in severe burns, requires skin grafts.  The dermis… The dermis id your HIDE. It is beneath the epidermis and is composed of connective tissue. It contains the lymphatics, nerves, nerve endings, blood vessels, sebaceous and sweat glands, elastic fibers, and hair follicles.  The The dermis is divided into dermis… two layers… 1. the papillary layer is arranged into microscopic structures that form ridges. These are the finger- and footprints 2. The reticular layer is the deepest skin layer; it is a white fibrous tissue that supports the blood vessels  The The dermis is connected to underlying tissue by the dermis… The subcutaneous subcutaneous tissue. tissue or hypodermis is composed of adipose and connective tissue. It supports, nourishes, insulates, and cushions the skin. HYPODERMIS SKIN APPENDAGES  Sebaceous Sebaceous glands are oil glands. They have tiny glands… ducts that open into each hair follicle. Each sebaceous gland secretes sebum, which lubricates the hair and skin. The amount of secretion varies with age, puberty, and pregnancy.  Sudoriferous Glands… Sweat glands produce sweat or perspiration. As sweat collects on the skin surface, it evaporates and creates a cooling effect. Sweat also rids the body of waste through the pores of the skin. As it accumulates, sweat may become odorous by the action of bacteria. The average person loses approximately ½ liter of fluid through sweating each day.  Sudoriferous Glands… Sudoriferous glands are sweat glands. About 2 million are distributed over the surface of the body, more numerous on the palms of the hands, soles of the feet, forehead, and underarms. Nails… Fingernails and toenails are hard keratin structures that protect the ends of the fingers and toes. The nail root, also called the germinal matrix or nailbed, begins several millimeters into the finger and extends to The under-surface the edge of the white, of the nail plate or crescent-shaped lunula. body of the nail has This is where the growth grooves that help occurs… approximately anchor it. 1 mm per week. Nails… The cuticle is also called the eponychium It fuses the nail plate and the skin of the finger together to form a waterproof barrier. The hyponychium is under the free edge of the nail. It also creates a waterproof barrier, fusing the skin of the finger to the underside of A lost fingernail- or the nail plate. toenail will regenerate. Hair and Hair follicles A hair is a flexible epithelial structure. The part of the hair enclosed in the follicle is the root, and the part projecting from the surface is the shaft. Formed by division of the stratum basale epithelial cells Hairs come in variety of sizes and shapes. SKIN COLOR Three pigments contribute to skin color: 1) The amount and kind (yellow, reddish brown, or black) of melanin in the epidermis. Three pigments contribute to skin color: 2) The amount of carotene deposited in the stratum corneum and subcutaneous tissue. 3. The amount of oxygen bound to hemoglobin in the dermal blood vessels Homeosta tic Imbalance Alert! When hemoglobin is poorly oxygenated, both the blood and the skin of Caucasians appear blue, a condition called cyanosis. Cyanosis is common during heart failure and severe breathing disorders. In black people, the skin does not appear cyanotic because of the masking effects of melanin, but cyanosis is apparent in their mucous membranes and nail beds. Skin color is also influenced by emotional stimuli, and many alterations in skin color signal certain disease states: Redness, or erythema: May indicate embarrassment (blushing), fever, hypertension, inflammation, or allergy Skin color is also influenced by emotional stimuli, and many alterations in skin color signal certain disease states: Pallor, or blanching: Under certain types of emotional stress (fear, anger and others), some people may become pale Pale skin may also signify anemia, low blood pressure, or impaired blood flow into the area Skin color is also influenced by emotional stimuli, and many alterations in skin color signal certain disease states: Jaundice or a yellow cast: An abnormal yellow skin tone usually signifies a liver disorder in which excess bile pigments are absorbed into the blood, circulated throughout the body, and deposited in body tissues Skin color is also influenced by emotional stimuli, and many alterations in skin color signal certain disease states: Bruises or black-and-blue marks: Reveal sites where blood has escaped from the circulation and has clotted in the tissue spaces. Such clotted blood masses are called hematomas. An unusual tendency to bruising may signify a deficiency of vitamin C in the diet or hemophilia (bleeder’s disease) HOMEOSTATIC IMBALANCES OF SKIN Homeostatic Imbalance It is difficult to scoff at anything that goes wrong with the skin because, when it rebels, it is quite a visible revolution. Loss of homeostasis in body cells and organs can reveal itself on the skin in ways that are sometimes almost unbelievable. The skin can develop more than 1000 different ailments. The most common result from allergies or bacterial, viral and fungal infections Less common, but far more damaging, are burns and skin cancer. I. Infections and Allergies 1) Athlete’s foot Aka: Tinea pedis An itchy, red, peeling condition of the skin between the toes, resulting from fungus infection  I. Infections and Allergies 2) Boils and carbuncles A boil (furuncle) is a pus-filled bump in the skin that is caused by a bacterial infection. A bit like a very big yellow pimple, but it’s deeper in the skin and hurts a lot more. Develop when a hair follicle and the surrounding tissue become infected. If several boils develop in neighboring hair follicles and merge into a larger connected area of infection under the skin, it’s called a carbuncle. The inflammation resulting from a carbuncle can also cause fever, making you feel weak and tired. I. Infections and Allergies 2) Boils and carbuncles Inflammation of hair follicles and sebaceous glands, common on the dorsal neck Composite boils typically caused by bacterial infection (often Staphylococcus aureus) I. Infections and Allergies 3) Cold sores Aka: Fever blisters Small fluid-filled blisters that itch and sting, caused by a herpes simplex infection The virus localizes in a cutaneous nerve, where it remains dormant until activated by emotional upset, fever or UV radiation Usually occurs around the lips and in the oral mucosa of the mouth I. Infections and Allergies 4) Contact dermatitis Itching, redness and swelling of the skin , progressing to blistering Caused by exposure of the skin to chemicals that provoke allergic responses in sensitive individuals I. Infections and Allergies 5) Impetigo Pink, water-filled, raised lesions (commonly around the mouth and nose) that develop a yellow crust and eventually rupture Caused by a highly contagious staphylococcus infection Common in elementary school- aged children I. Infections and Allergies 6) Psoriasis A chronic condition characterized by reddened epidermal lesions covered with dry, silvery scales Cause is unknown; may be hereditary in some cases Attacks often triggered by trauma, infection, hormonal II. Burns The skin is only as thick as a paper towel, and yet, when it is severely damaged, nearly every body system suffers Metabolism accelerates or may be impaired Changes in the immune system occur Cardiovascular system may falter A burn is tissue damage and cell death caused by intense heat, electricity, UV radiation (sunburn) or certain chemicals (such as acids) II. Burns When skin is burned and its cells are destroyed, two life-threatening problems result: 1. The body loses its precious supply of fluids containing proteins and electrolysis as these seep from the burned surfaces 2. Dehydration and electrolyte imbalance follow and can lead to a shutdown of the kidneys and circulatory shock Circulatory shock – inadequate circulation of blood caused by low blood volume Burns are classified according to their severity or depth 1) First-degree burns Only the epidermis is damaged The area becomes red and swollen Except for temporary discomfort, this is not usually serious and generally heals in 2-3 days without any special attention Sunburn is usually a 1st-degree burn 2) Second-degree burns Involve injury to the epidermis and the upper region of the dermis Skin is red and painful; blisters appear Regrowth of the epithelium can still occur Because sufficient numbers of epithelial cells are still present Ordinarily, no permanent scars result, if care is taken to prevent infection  First- and second- degree burns are referred to as partial- thickness burns 3) Third-degree burns Destroy the entire thickness of the skin Also called as full-thickness burns The burned area appears blanched (gray-white) or blackened Since the nerve endings are destroyed, the burned area is not painful Regeneration is not possible; skin grafting must be done to cover the underlying exposed tissues 4) Fourth-Degree Burns This is the most severe and potentially life-threatening type of burn. Fourth-degree burns are the highest degree, and affect all layers of skin, muscles, tendons, and bones. When are burns considered critical? 1) Over 25 percent of the body has second-degree burns 2) Over 10 percent of the body has third-degree burns 3) There are third-degree burns of the face hands or feet Facial burns are dangerous Because of the possibility of burned respiratory passageways which can swell and cause suffocation III. Skin Cancer The single most common type of cancer in humans Most skin tumors are benign and do not metastasize e.g. Wart – a neoplasm caused by a virus The cause of most skin cancer is unknown but the most risk factor is overexposure to UV radiation in sunlight Frequent irritation of the skin by infections, chemicals, or physical trauma also seems to be a predisposing factor III. Skin Cancer 1) Basal cell carcinoma Least malignant and most common skin cancer Cells of the stratum basale are altered so that they cannot form keratin Invades the dermis and the subcutaneous tissue Lesions occur most often on sun-exposed areas and appear as shiny, dome-shaped nodules that later develop a central ulcer with a “pearly” beaded edge Relatively slow-growing and metastasis seldom occurs Full cures in 99 percent of the cases where the lesion is removed surgically III. Skin Cancer 2) Squamous cell carcinoma Arises from the cells of the stratum spinosum Lesion appears as a scaly, reddened papule (small, rounded elevation) This variety appears most often on the scalp, ears, dorsum of the hands, and lower lip Grows rapidly and metastasizes to adjacent lymph nodes if not removed Believed to be sun-induced Chance of complete cure is good, if remedied early III. Skin Cancer 3) Malignant melanoma Cancer of the melanocytes Often deadly Accounts for about 5 percent of the skin cancer cases Can begin wherever there is pigment – most appear spontaneously, while some develop from pigmented mole Usually appears as a spreading brown to black patch that metastasizes rapidly Chance survival is 50 percent if detected early  The American Cancer Society suggests the application of ABCDE rule A. Asymmetry: the two sides of the pigmented spot or mole do not match B. Border irregularity: the borders of the lesion are not smooth but exhibit indentations C. Color: the pigmented spot contains areas of different colors (black, brown, tan, and sometimes blue and red) D. Diameter: the spot is larger than 6 mm in diameter (the size of a pencil eraser E. Evolving: the spot changes in size, shape, color or texture Sources https://www.informedhealth.org/boils-and-carbuncles.ht ml https://www.mayoclinic.org/diseases-conditions/impetig o/symptoms-causes/syc-20352352 https://phoenix-society.org/resources/understanding-the -healing-stages-of-a-burn-wound