Integumentary System Notes PDF

INTEGUMENTARY SYSTEM - consists of the skin and its derivatives such as hair, nails, and other types of glands. CUTANEOUS/INTEGUMENT/SKIN - covers the rest of the body. Skin is composed of 15-20% of an adult’s body weight. 1.5 - 2 meters squared of the surface area of the adult individual. - 2.7 to...

INTEGUMENTARY SYSTEM - consists of the skin and its derivatives such as hair, nails, and other types of glands. CUTANEOUS/INTEGUMENT/SKIN - covers the rest of the body. Skin is composed of 15-20% of an adult’s body weight. 1.5 - 2 meters squared of the surface area of the adult individual. - 2.7 to 4 kilograms or 6 - 9 pounds. Largest organ in the body in terms of weight - Self-repairs cuts, rips, and burns. 1cm2 of skin contains 6 million cells, 5000 sensory points, and a sebaceous gland. - skin is thinness in the eyelids and thickest on the sole. Regulate temperature and prevents heat loss. Includes odoriferous gland (sweat) and Sebaceous glands (oil), hairs, and nails. CHANGES OF THE SKIN a. Cyanosis is the medical term for when your skin, lips or nails turn blue due to a lack of oxygen in your blood. b. Liver disorder such as Jaundice which causes yellowish skin due to build up of bile. c. Skin cancer - check texture like growth of mass and wounds that do not feel. d. Cold - Clammy skin simply refers to skin that is wet from sweating. LAYERS OF THE SKIN A. EPIDERMIS - first layer. Stratified squamous epithelium, stratified keratinized squamous epithelium. No blood. Thickest on the palm and soles. Dead cells are here. 5 LAYERS OF THE EPIDERMIS 1. STRATUM CONRNEUM - flat keratinized layer of dead cells. Outer layer of the epidermis. Prevents most evaporation. Barriers of chemicals and pathogens. *KERATIN* - fibrous protein produced by epidermal cells KERATINOCYTES are the primary type of cell found in the epidermis, the outermost layer of the skin. In humans, they constitute 90% of epidermal skin cells. Produce keratin. 2. STRATUM LUCIDUM - consists of flat translucent layers of dead cells; contains a protein called Eleidin which is clear intracellular protein which is present in the stratum lucidum of the skin. - Eleidin, derived from keratohyalin which is then converted to keratin in the upper stratum lucidum and stratum corneum. - protects the skin, commonly to be damaged 3. STRATUM GRANULOSUM - below the stratum lucidum, cells come from the stratum spinosum. The process of keratinization occurs here. - Keratinization is the maturing of cells that undergo a hardening process, associated with the dying of cells. 4. STRATUM SPINOSUM - Active synthesis takes place indicating that cell division and growth of those cells are occurring. 5. STRATUM BASALE/STRATUM GERMINATIVUM - rests on the basement membrane of the dermis, sprouting cells develop for the keratin. Mitosis occurs here. Keratin is produced in this layer. 3 PROCESSES SYNCHRONIZED TO MAINTAIN THE EPIDERMIS 1. SHEDDING of the keratin cells from the surface. 2. Effective KERATINIZATION of cells approaching the surface. 3. CONTINUAL CELL DIVISION in the deeper layer which newly forms cells being pushed to the surface. B. DERMIS “TRUE SKIN” - greater part of the skin. Location of the sebaceous gland that secrete an oily substance called SEBUM. - SEBUM slows the evaporation of H2O and has an antibacterial effect. - composed of collagenous reticular and elastic fibers. - collagenous fibers are thick that give the skin much of its toughness. - Thickest dermis are found at the back of the thigh and abdomen. - this layer contain blood capillaries, nerve endings, sweat glands, hair follicles, and lymphatic vessels which are all embedded. 2 LAYERS OF THE DERMIS 1. PAPILLARY LAYER - consists of loose connective tissue *Papillae* - Fingerlike projections that join the ridges of the epidermis to the dermis. Nourishes the epidermis - Corpuscles of touch (Meissner's corpuscle) act as sensitive touch receptors. 2. RETICULAR LAYER - dense connective tissue with course collagenous fiber bundles that crisscross for string and elastic skin. - lymphatic vessels, glands, and hair roots are embedded in this layer C. HYPODERMIS - The third layer of the skin, lies underneath the dermis. - loose areolar connective tissue. SUBCUTANEOUS layer, not strictly as a skin. - made up of fatty acids, thicker than the dermis, richly supplied with lymphatic blood vessels and nerves. PARTS OF THE SUBCUTANEOUS LAYER 1. AREALAR CONNECTIVE TISSUE - connects the skin to the muscle, contains WBC, and contains cells HISTAMINE. Histamine is a chemical your immune system releases. It's mainly known for its role in causing allergy symptoms. - Participates in allergic responses like Bronchoconstriction - Allergic responses have leukotrienes and other chemicals involved in inflammation.  2. ADIPOSE TISSUE - contains stored energy in the form of fats - Cautions the bony prominences. Contributes to appetite, contributes to the use of insulin - Produces cytokines that activate WBC and regulate the immune system FUNCTIONS OF THE SKIN 1. COVERING AND PROTECTION of inner organs and prevents dehydration. 2. TEMPERATURE REGULATION - 36.8 degrees is the normal when taken at the Axilla - Regulated by the hypothalamus, cooling effects - Insulators, retain body warmth, heat is produced by muscle contraction - Dermis contains a dense bed of blood vessels; blood vessels dilate on warm days and constrict on cold days 3. EXCRETION - sweat eliminates salts, excess water, urea, and 1 gram of waste nitrogen. 4. SYNTHESIS - formation of simple compounds to make a whole compound - Screen out excessive UV rays from the sun. Concerts the sun’s rays to Vitamin D3 which are vital to the bones and teeth. 5. SENSORY RECEPTION CUTANEOUS SENSORY RECEPTORS 1. MEISSNER’s CORPUSCLE - beneath the epidermis within the dermal papillae. - corpuscle of touch - detects light motion against the skin. - distributed in various areas of the skin but concentrated on areas sensitive to light such as fingers. - tells the shape and feel of an object to the brain 2. FREE NERVE ENDINGS - dermis - lie near the blood vessels between the epithelial layer of the skin, cornea, and connective tissue. - detects changes in temperature, and responds to tissue trauma, and pain. - most abundant type 3. ROOT HAIR PLEXUS - dermis - detect the movement of hair receptor - mechanoreceptor conveying touch sensation 4. PACINIAN CORPUSCLE/VATER-PACINI - detects deep pressure and high vibration - informs the brain when a limb has moved after its movement if it moves correctly - deep layer of the dermis, and also in the hypodermis 5. ORGANS OF RUFFINI/BULBOUS CORPUSCLE - detects deep pressure and stretch - in the dermis within the joints, periosteum, connective tissue, and internal organs. 6. BULBS OF KRAUSE - detects light pressure and low-frequency vibration. - found in the skin, conjunctiva, lips, and tongue - high density of KRAUSE CORPUSCLE found at the female clitoris. COLOR OF THE SKIN - presence of MELANIN which is a dark pigment produced by MELANOCYTES (found in the Stratum Basale and Epidermis that have a process called Melanogenesis) - it functions to screen out UV rays. - present in the hair, retina, and iris of the eyes - sun stimulates Melanocytes to produce more Melani - it turns into Melanin when it approaches the middle layer of the skin - 7-9 AM for 15 minutes to generate vitamin D and stimulate the melanocytes. GLANDS OF THE SKIN 1. SUDORIFEROUS (SWEAT) GLANDS TYPES a. ECCRINE or MEROCRINE - small sweat glands distributed across nearly the entire body. - found at the soles, palms, forehead, and upper lips. - sweat contains neutral fats, urea and albumin, lactic acid, potassium chloride, sugar and ascorbic acid, and salts. b. APOCRINE (ODIFEROUS) GLAND - armpits dark regions around the nipples, the outer lips of the vulva, and the anal and genital regions. - the odor and starts to be active at puberty. Breast milk is produced by apocrine glands. 2. SEBACEOUS (OIL) GLAND - found in the dermis with functions of lubrication and protection. - It has EMOLLIENT which softens the skin and protects pathogens. - secretes SEBUM, an oily substance that protects your skin from drying out. - The sebaceous gland gets inflamed when sebum accumulates. Blackheads: These are small, dark spots that appear on the skin due to clogged hair follicles. The dark appearance is due to oxidation when the clogged material (sebum and dead skin cells) is exposed to air. Pimples: A general term for inflamed spots or bumps on the skin. Pimples occur when hair follicles become blocked with oil, bacteria, and dead skin cells. Acne: A broader term for a skin condition where the hair follicles become clogged with oil and dead skin cells, leading to pimples, blackheads, whiteheads, or even deeper nodules and cysts. Acne Vulgaris: The most common form of acne, characterized by the elevation of the papule or elevation of the pimple - the older we get the less sebum is secreted which causes the skin to be dry and fragile. 3. CERUMINOUS GLAND - dermis of the ear canal. It secretes CERUMEN or earwax. - Earwax contains mostly sebum — dead skin cells and hair combined with a number of different substances, including: Keratin. Cholesterol. Long-chain fatty acids (saturated and unsaturated). - keeps the surface of the ear pliable and prevents drying - modified as Apocrine glands HAIR - dead keratinized cells which provide strength and hardness of the hair. - protein filaments, grow from the follicles of the Dermis. 1. SCALPHAIR - acts as an insulator against temperature, protects head from injury. - reach into the hypodermis. 2. EYE BROWS AND EYE LASHES - protect eyes by preventing sweat from running into them, and preventing foreign particles. 3. HAIR IN NOSTRILS - filter inhaled air 4. HAIRS IN THE EXTERNAL EAR CANAL - prevent foreign particles to penetrate inside. 2 REGIONS OF THE HAIR 1. HAIR SHAFT -projects from the skin. The shape of the follicle determines the curliness of the hair. - round shaft - straight hair - oval shaft - wavy hair - flat shaft - kinky hair 2. HAIR ROOT - it extends from the epidermal surface into the dermis - Embedded in the epidermis, dermis, and sometimes in the hypodermis. - Contains the hair matrix (where mitosis takes place) - Melanocytes mixed with hair matrix determine hair color - Keratinocytes form hair shafts. Hair Color THREE TUBES OF THE HAIR SHAFT 1. CUTICLE - outer tube made up of one layer of heavily keratinized cells. 2. CORTEX - middle tube containing several layers of cells. Pigments - black hair Air bubbles - white hair 3. MEDULLA - inner tube composed of 2 or 3 rows of cells containing pigments. ARRECTOR PILI MUSCLE -produces goosebumps. - smooth muscle of the skin associated with hair follicle attached halfway down the follicle. - when it contracts it pulls the hair follicle to an erect position producing goosebump (pilomotor reflex) when cold, in fear, or excitement. THREE KINDS OF HUMAN HAIR 1. LANUGO - fine silky fetal hair that appears in the last 3 months of pregnancy. - unknown function but maybe for the maturation of the hair follicles. 2. ANGORA HAIR - continuously growing in the scalp face of sexually matured males. 3. DEFINITIVE HAIR - grows to a certain length, and stops growing. - eyelashes, eyebrows, pubic hair, and axillary hair NAILS - found at the epidermis - are hard plates of tightly packed keratinized cells - clear and dorsal of the last phalanges - matrix - between the nail root - nail matrix is thick and is only composed of the deeper layer of the epidermis called the stratum basale. EPONYCHIUM - developing nail - medial or proximal nail fold. Protects and supports the tips of the fingers and nails. Capillary Refill: This is a simple test used to assess blood circulation, especially in the extremities (fingers and toes). To perform the test, you press on the skin (usually a fingertip or nail bed) until it turns white, then release. The time it takes for the color to return to normal is the capillary refill time. Normally, this should happen within 2 seconds. A delayed capillary refill might indicate poor blood flow or circulation issues. Oxygen Saturation: This refers to the percentage of oxygen-carrying hemoglobin in the blood relative to the total hemoglobin. It’s usually measured using a pulse oximeter, a device clipped onto a finger. Normal oxygen saturation levels typically range from 95% to 100%. Levels below this range may indicate that the body isn’t getting enough oxygen, which can be a sign of respiratory or cardiovascular issues. 3 REGIONS OF THE NAIL 1. NAIL BODY - portion of the nail that is visible. The nail body rests on the bed; epithelium made only of the stratum basale and the stratum spinosum 2. FREE EDGE - visible portion of the nail that extends past the end of the digit. 3. NAIR ROOT - mitosis takes place here. Hidden potion of the nail that is embedded in a fold of skin. - the root is the part hidden under the skin folds of the nail groove *The basence of the lunula is UNKOWN* - Can indicate anemia, malnutrition, or depression - The RBC that carries Iron that reaches the hemoglobin does not work properly; and does not produce enough RBW, which causes O2 deficiency that results in paleness. PROBLEMS RELATED TO THE INTEGUMENTARY SYSTEM - Burns from heat, electric, chemical, or radioactivity. - Extent - the percentage of the damaged skin - Depth - How deep are the damaged tissues TYPES OF BURNS 1. First Degree Burn - damages epidermis (red pink, paleness, blanches, pain, no blisters, and nerves are not damaged FIRST AID TREATMENT - Cold water and sterile bandages - Immersed in cold water or a cold compress can be applied 2. Second Degree Burn - epidermis, dermis, underlying tissue, and some parts of the hypodermis are damaged. - oozing blisters form scarring - deep red in color, slow blanching, very painful, and moist in appearance The body will be able to regenerate new skin 3. Third Degree Burn - epidermis, dermis, underlying tissue, and some parts of the hypodermis are damaged. - Nerves are damaged causing numbness - white in color, black, brown, gray, or charred - no blanching, decrease or void of sensation, no blisters, dry leathery in appearance. Shocked victim - a surgical operation called skin grafting is required to heal the victim COMMON SKIN DISORDERS 1. ACNE - mostly on the face, chest, upper back, and shoulder - Acne vulgaris 2. BED SORES/DECUBITUS ULCER/PRESSURE SORES- are produced in bony, unprotected areas where the skin is close to a bone and undergoes constant pressure. - typical problem areas are the hips, elbows, tailbone, knees, heels, ankles, and shoulder blades. - The first signs are warm reddened spots on the skin - breaks in the skin may follow, bacterial infection is common if left unchecked. 3. PSORIASIS - unknown source/autoimmune - marked by lesions that are red dry, elevated, and covered with silvery scaly patches. - usual sites are the elbows, knees, scalp, face, and lower back 4. CELLULITIS - this is a spreading infection caused by anaerobic microbes on streptococcus perfringens - if untreated, the products of inflammation may enter the blood causing septicemia - redness, tenderness, swelling, and warmth in affected areas. 5. RINGWORM AND TINEA PEDIS - these are superficial infections of the skin caused by fungi. - outward spreading of inflammation - Tinea pedis (athlete’s foot) affects the area between the toes. - Both infections are spread by direct contact.