Unit+V-+Integumentary+System.pdf

ANA 1 ANATOMY AND PHYSIOLOGY A Mark Joseph V. Liwanag, MSN, RN Course facilitator  MODULE 5 INTEGUMENTARY SYSTEM INTRODUCTION INTEGUMENTARY SYSTEM  consists of the skin and accessory structures, such as hair, glands, and nails.  Integument means cove...

ANA 1 ANATOMY AND PHYSIOLOGY A Mark Joseph V. Liwanag, MSN, RN Course facilitator  MODULE 5 INTEGUMENTARY SYSTEM INTRODUCTION INTEGUMENTARY SYSTEM  consists of the skin and accessory structures, such as hair, glands, and nails.  Integument means covering  is one of the more familiar systems of the body to everyone because it covers the outside of the body and is easily observed.  INTRODUCTION INTEGUMENTARY SYSTEM  appearance of the integumentary system can indicate physiological imbalances in the body.  Other disorders affect different parts of the body are reflected in the integumentary system  providing useful signs for diagnosis.  FUNCTIONS OF THE INTEGUMENTARY SYSTEM 1. PROTECTION:  protection against abrasion and ultraviolet light.  prevents microorganisms from entering the body and reduces water loss  LIPID: acts as barrier for water diffusion – prevent water loss  GLANDS: produces substances to prevents moisture loss.  SQUAMOUS EPITHELIUM: protection against abrasion  MELANIN: absorb UV rays  HAIR AND NAILS: protect the underlying tissue.  FUNCTIONS OF THE INTEGUMENTARY SYSTEM 2. SENSATION  has sensory receptors that can detect heat, cold, touch, pressure, and pain.  FUNCTIONS OF THE INTEGUMENTARY SYSTEM 3. VITAMIN D PRODUCTION:  skin produces a molecule that can be transformed into vitamin D  FUNCTIONS OF THE INTEGUMENTARY SYSTEM 4. TEMPERATURE REGULATION:  blood flow beneath the skin’s surface and the activity of sweat glands in the skin both help regulate body temperature  FUNCTIONS OF THE INTEGUMENTARY SYSTEM 5. EXCRETION  waste products are lost through the skin  Excrete lipids, metabolic waste such as H2O, urea and lactic acid.  1. SKIN  Is the primary organ of integumentary system  The largest organ of the body  skin is made up of two major tissue layers:  EPIDERMIS  DERMIS  1. SKIN A. EPIDERMIS  is the most superficial layer of skin.  It is a layer of epithelial tissue that rest on the dermis.  It is the roof  prevents water loss and resists abrasion 1. SKIN B. DERMIS  Layer of dense connective tissue  Forms the house  10 to 20 times thicker than the epidermis  responsible for most of the skin’s structural strength 1. SKIN * HYPODERMIS/ SUBCUTANEOUS TISSUE  is a layer of connective tissue.  not part of the skin  connect the skin to underlying muscle or bone  foundation on which a house rests  EPIDERMIS  is stratified squamous epithelium  new cells are produced by mitosis. As new cells form, they push older cells to the surface, where they slough, or flake off.  outermost cells protect the cells underneath, and the deeper, replicating cells replace cells lost from the surface.  CELLS OF THE EPIDERMIS  KERATINOCYTES (literally, keratin cells): The most abundant epidermal cells, their main function is to produce keratin fibrils.  Keratin is a fibrous protein that gives the epidermis its durability and protective capabilities.  DENDRITIC CELLS: Also called Langerhans cells, these cells play a role in immunity by performing phagocytosis. CELLS OF THE EPIDERMIS  MELANOCYTES: Spidery black cells that produce the brown to-black pigment called melanin.  TACTILE (MERKEL) CELLS: Occasional spiky hemispheres that, in combination with sensory nerve endings, form sensitive touch receptors called tactile or Merkel discs located at the epidermal- dermal junction.  EPIDERMIS KERATINIZATION  cells change shape and chemical composition.  cells become filled with the protein keratin  epithelial cells eventually die and produce an outer layer of dead, hard cells that resists abrasion and forms a permeability barrier EPIDERMIS  EPIDERMIS  distinct layers called strata can be seen in the epidermis STRATUM BASALE :  deepest stratum  consists of cuboidal or columnar cells that continue to divide  undergo mitotic divisions about every 19 days.  One daughter cell becomes a new stratum basale cell and can divide again.  other daughter cell is pushed upward, becoming next stratum  EPIDERMIS STRATUM SPINOSUM  Is noted for its multilayer of distorted cells  Cells become distorted as they up from the deeper stratum basale  Stratum basale and stratum spinosum together are often called stratum germinativum  EPIDERMIS STRATUM GRANULOSUM  Is superficial to stratum spinosum  It contains flattened cells pushed up from the deeper strata  As the cell are pushed up through this stratum, they form the protein granules that give it the name granulosum  By the time cells leave this stratum, they have died  EPIDERMIS STRATUM LUCIDUM  Meaning light layer  A very thin layer present only in thick skin  Thick skin in found only in high-wear areas such as palms and soles  It is translucent, allowing light pass through it easily  EPIDERMIS STRATUM CORNEUM  is the most superficial stratum of the epidermis  Layer of dead, keratinized tissue (keratin gives structural strength)  Extremely thick in thick skin, providing a great deal of protection  Protect deeper tissues from mechanical injury and invasion by microorganism  Composed of 25 or more layers of dead squamous cells joined by desmosome  EPIDERMIS STRATUM CORNEUM  DANDRUFF: excessive stratum corneum cells sloughed from the surface of the scalp  CALLUS: when skin subjected to friction, number of layers greatly increases producing thickened area  CORN: found over bony prominence, stratum corneum can thicken to form a cone shaped structure  DERMIS  layer of the skin deep to the dermis  has a sheet of irregular fibrous connective tissue  much thicker than the epidermis  contain many blood vessels that supply the overlying epidermis with nutrients, remove waste products, and help regulate body temperature DERMIS  composed of dense collagenous connective tissue containing fibroblasts, adipocytes, and macrophages.  nerves, hair follicles, smooth muscles, glands, and lymphatic vessels extend into the dermis and elastic fibers are responsible for the structural strength of the dermis.  DERMIS TWO REGIONS OF THE DERMIS:  RETICULAR LAYER: is thick region of irregularly arranged protein fiber. Most of the fiber are collagenous, but a few are made of elastin  PAPILLARY LAYER: is the bumpy superficial portion of the dermis attached to epidermis.  Bumps, called papillae (meaning “nipples”)  HYPODERMIS  It is also called SUBCUTANEOUS TISSUE/SUPERFICIAL FASCIA  Deep to the skin layer and it is not part of the skin, but often studied along the skin  It is loose, fibrous (areolar) connective tissue that connects the skin to underlying muscles and bone  Some areolar tissue has been modified to become adipose tissue  ADIPOSE TISSUE: protection and insulation characteristics complement the protection and temperature regulation roles of the skin HYPODERMIS  Some areolar tissue has been modified to become adipose tissue  ADIPOSE TISSUE: protection and insulation characteristics complement the protection and temperature regulation roles of the skin FUNCTIONS OF FATS IN HYPODERMIS:  Padding and insulation  Responsible for some of the differences in appearance between men and women and between individual of same sex  SKIN COLOR Factors that determine skin color include:  pigments in the skin  blood circulating through the skin  thickness of the stratum corneum. MELANIN: is the group of pigments primarily responsible for skin, hair, and eye color.  Most melanin molecules are brown to black pigments, but some are yellowish or reddish.  provides protection against ultraviolet light from the sun.  is produced by melanocytes  SKIN COLOR  MELANOCYTES: are irregularly shaped cells with many long processes that extend between the epithelial cells of the deep part of the epidermis  MELANOSOMES: the golgi apparatuses of the melanocytes package melanin into vesicles  move into the cell processes of the melanocytes > epithelial cells*  SKIN COLOR  LARGE AMOUNT of melanin occur in some region of the skin:  Freckles  Moles  Genitalia  Nipples  Pigmented - circular areas around the nipple  LESS MELANIN:  Lips  Palms of the hands  Soles of the feet ALL RACES HAVE ABOUT THE SAME NUMBER OF MELANOCYTES Melanin production is determined by: Genetic factors Exposure to light (stimulate melanocyte to increase melanin production) Hormones – during pregnancy   ALBINISM: is a recessive genetic trait that causes a deficiency or an absence of melanin.  have fair skin, white hair, and unpigmented irises in the eyes  REDDISH: when blood flow increases, the red color intensifies  PALE: decrease in blood flow, as occurs in shock  CYANOSIS: decrease in the ALBINISM blood O2 content produces a bluish color of the skin.  BIRTHMARKS: are congenital (present at birth) disorders of the blood vessels (capillaries) in the dermis.  YELLOWISH: large amounts of carotene are consumed  Carotene - is a yellow pigment found in plants such as squash and carrots  is lipid-soluble; when consumed, it accumulates in the lipids of the stratum corneum and in the adipocytes of the dermis and subcutaneous tissue. ACCESSORY SKIN STRUCTURES  accessory skin structures are hair, glands, and nails  Both hair and nails are modified form of stratum corneum or keratinized tissue  HAIR  is found everywhere on the skin, except on the palms, the soles, the lips, the nipples, parts of the genitalia, and the distal segments of the fingers and toes. STRUCTURE OF HAIR  HAIR FOLLICLE  hair arises from a hair follicle, an extension of the epidermis that originates deep in the dermis  hair follicle can play an important role in repair of the skin  HAIR  SHAFT of the hair protrudes above the surface of the skin, whereas the ROOT and HAIR BULB are below the surface.  A hair has a hard CORTEX, which surrounds a softer center, the MEDULLA  cortex is covered by the CUTICLE, a single layer of overlapping cells that holds the hair in the hair follicle.  HAIR BULB: site of hair production; which rests on the hair papilla  BLOODS VESSELS: supply the hair bulb with the nourishment needed to produce the hair.  HAIR  HAIR COLOR: is determined by varying amounts and types of melanin.  The production and distribution of melanin by melanocytes occurs in the hair bulb by the same method as in the skin.  ARRECTOR PILI: are smooth muscle cells  Contraction; causes the hair to become more perpendicular to the skin’s surface, or to “stand on end,”  1. GROWTH STAGE (ANAGEN): HAIR GROWTH CYCLE  It is formed by epithelial cell within the hair bulb  Cells divide and undergo keratinization  Hair root and shaft consist of column of dead keratinized epithelial cells 2. TRANSITION STAGE (CATAGEN):  Follicle detaches 3. RESTING STAGE (TELOGEN):  Growth stops, and hair is held in the hair follicle 4. EARLY GROWTH (EARLY ANAGEN)  A new hair is formed and old hair falls out.  GLANDS MAJOR GLANDS OF THE SKIN:  The major glands of the skin are the sebaceous glands and the sweat glands  GLANDS 1. SEBACEOUS GLANDS  Are simple, acinar glands; connected by a duct to a superficial part of hair follicle  Produce fatty substances called SEBUM that coats the hair and skin  SEBUM  prevents moisture loss and conditions the hair and skin so that it doesn’t become brittle and easily broken  lubricates the hair and skin, which prevent drying and protects againts some bacteria  GLANDS 1. SEBACEOUS GLANDS cont.  SEBUM  lubricates the hair and skin, which prevent drying and protects againts some bacteria  few sebaceous glands located in the lips, in the eyelids (meibomian glands)  in the genitalia – sebaceous glands are not associated with hairs but open directly onto the skin surface  GLANDS 2. SWEAT GLANDS  Found in many area of skin, exocrine gland that produces water solution, sweat, that coats the skin  Sweat serves primarily to improve heat loss by the skin through evaporation  GLANDS 2.1. ECCRINE SWEAT GLANDS (MEROCRINE SWEAT GLANDS) Are simple, coiled tubular glands located in almost every part of the skin and are most numerous in the palms and soles; which produce thin watery sweat Produce secretion that is mostly water with a few salts Have ducts that open onto a surface of the skin through sweat pores  GLANDS 2.1. ECCRINE SWEAT GLANDS (MEROCRINE SWEAT GLANDS)  coiled part of the gland produces: isotonic fluid that is mostly water, contains salts (sodium chloride) and small amounts of ammonia, urea, uric acid, and lactic acid.  resulting hyposmotic fluid that leaves the duct is called sweat  most numerous in the palms of the hands and the soles of the feet but are absent from the margin of the lips, the labia minora, and the tips of the penis and clitoris.  GLANDS 2.2 APOCRINE SWEAT GLANDS  Are simple, coiled tubular glands that produce a thick secretion in organic substances  Open in hair follicle, but only in the axillae and genetalia/pubic region  Active at puberty because od sex hormones  3-methyl-2-hexenoic acid ; essentially odorless when first released but are quickly metabolized by bacteria to cause what commonly is known as body odor  OTHER GLANDS CERUMINOUS GLANDS  are modified merocrine sweat glands located in the ear canal (external auditory meatus).  Cerumen, or earwax, is the combined secretions of ceruminous glands and sebaceous glands.  protect the eardrum MAMMARY GLANDS  are modified apocrine sweat glands located in the breasts.  they produce milk.  NAILS  nail is a thin plate, consisting of layers of dead stratum corneum cells that contain a very hard type of keratin.  a modified portion of stratum germinativum also forms the toenail or fingernail STRUCTURES OF NAIL  NAIL BODY: visible part of the nail  NAIL ROOT: part of the nail covered by skin  LUNULA: crescent shaped area at the base of the nail. NAILS  CUTICLE /EPONYCHIUM: is stratum corneum that extends onto the nail body.  HYPONYCHIUM: beneath the free edge of the nail body; a thickened region of the stratum corneum  NAIL BED: the nail root and nail body attach to it. It is a matrix that produces the nail plate  lateral and proximal edges of the nail are covered by skin called the NAIL FOLD  the edges are held in place by the NAIL GROOVE  NAILS  NAIL MATRIX : the proximal portion of the nail bed  production within the nail matrix causes the nail to grow.  nail matrix and bed are epithelial tissue with a stratum basale that gives rise to the cells that form the nail.  nail is stratum corneum;contains a hard keratin, which makes the nail hard  grow at an average rate of 0.5–1.2 mm per day, and fingernails grow more rapidly than toenails.  grow continuously throughout life and do not have a resting phase. Physiology of the Integumentary System HEAT EXCHANGE   vitamin A deficiency, the INTEGUMENTARY SYSTEM AS A skin produces excess DIAGNOSTIC AID keratin and assumes a characteristic sandpaper texture  iron-deficiency anemia the nails lose their normal contour and become flat or concave (spoon-shaped).  Hair concentrates many substances that can be detected by laboratory analysis  E.g., lead poisoning results in high levels of lead in the hair. INTEGUMENTARY SYSTEM AS A DIAGNOSTIC AID  CYANOSIS: a bluish color to the skin caused by decreased blood O2content, is an indication of impaired circulatory or respiratory function.  JAUNDICE: a yellowish skin color, can occur when the liver is damaged by a disease, such as viral hepatitis.  liver secretes bile pigments, BILE pigments are yellow, and their buildup in the blood and tissues can indicate impaired liver function. Integumentary System as a Diagnostic Aid  Rashes and lesions in the skin can be symptoms of problems elsewhere in the body.  E.g., scarlet fever results when bacteria infecting the throat release a toxin into the blood  development of a rash can also indicate an allergic reaction to foods or to drugs, such as penicillin.  BURNS  burn is injury to a tissue caused by heat, cold, friction, chemicals, electricity, or radiation.  Burns are classified according to their depth  BURNS are classified as either partial-thickness or full-thickness burns 1. PARTIAL – THICKNESS BURNS  FIRST DEGREE BURNS: involve only the epidermis and are red and painful, and slight edema (swelling) may occur.  can be caused by sunburn or brief exposure to hot or cold objects  they heal in a week or so without scarring.  SECOND DEGREE BURNS: damage the epidermis and the dermis. Minimal dermal damage causes redness, pain, edema, and blisters.  Healing takes approximately 2 weeks, and no scarring results.  BURNS are classified as either partial-thickness or full-thickness burns 2. FULL _ THICKNESS BURNS/THIRD DEGREE BURNS  epidermis and dermis are completely destroyed, and deeper tissue may be involved.  is usually painless  appear white, tan, brown, black, or deep cherry red in color.  Skin can regenerate in a third-degree burn only from the edges, and skin grafts are often necessary. SKIN CANCER  skin cancers result from damage caused by the ultraviolet (UV) radiation in sunlight.  Some skin cancers are induced by chemicals, x-rays, depression of the immune system, and inflammation, and some are inherited.  UV radiation damages the genes (DNA) in epidermal cells, producing mutations.  Oncogenes and tumor suppressing genes in epidermal cells can lead to uncontrolled cell division and skin cancer  THERE ARE THREE TYPES OF SKIN CANCER: 1. BASAL CELL CARCINOMA:  most common type of skin cancer, arises from cells in the stratum basale. 2. SQUAMOUS CELL CARCINOMA:  arises from cells in the stratum spinosum and can appear as a wartlike growth 3. MELANOMA:  arise from melanocytes, most melanomas are black or brown  invades the dermis and metastasizes to other parts of the body, it is difficult to treat and can be deadly.  OTHER SKIN CONDITIONS  BACTERIAL INFECTIONS: Staphylococcus aureus is commonly found in pimples, boils, and carbuncles and causes  ACNE: is a disorder of the hair follicles and sebaceous glands  exact cause of acne is unknown, four factors are believed to be involved: hormones, sebum, abnormal keratinization within hair follicles, and the bacterium Propionibacterium acnes.  OTHER SKIN CONDITIONS  VIRAL INFECTIONS: some of the well- known viral infections of the skin include chicken pox (varicellazoster), measles, and German measles (rubella)  FUNGAL INFECTIONS : Ringworm is a fungal infection that affects the keratinized portion of the skin, hair, and nails and produces patchy scaling and an inflammatory response. OTHER SKIN CONDITIONS  DECUBITUS: ulcers, also known as bedsores, or pressure sores, develop in patients who are immobile  PSORIASIS: is characterized by a thicker than normal stratum corneum that sloughs to produce large, silvery scales.  ECZEMA and DERMATITIS: are general terms used for inflammatory condition of the skin.  OTHER SKIN CONDITIONS  VITILIGO: is the development of patches of white skin because the melanocytes in the affected area are destroyed  MOLE: is an elevation of the skin that is variable in size and is often pigmented and hairy  XERODERMA PIGMENTOSUM: is a rare, autosomal recessive trait in which a DNA repair gene is defective. OTHER CONCERNS:  LANUGO: the hairy “cloak” of the fetus  MILIA: small white bumps on the skin of newborn babies, resulting from accumulation of sebaceous gland materials  VERNIX CASEOSA: oily substances produced by the fetus sebaceous glands. It is cheesy like substances, all over the body of the fetus REFERENCES: VanPutte C. et.al. (2019). Seeley’s Essentials of Anatomy & Physiology. 10th edition. New York: McGraw Hill Co. Inc.