Integumentary System Lecture Notes PDF

MC_101_: ANATOMY AND PHYSIOLOGY LECTURE LECTURE 08: INTEGUMENTARY SYSTEM PROFESSOR: Prof. Daisy Sucaldito 1ST SEMESTER | A.Y 2022-2023...

MC_101_: ANATOMY AND PHYSIOLOGY LECTURE LECTURE 08: INTEGUMENTARY SYSTEM PROFESSOR: Prof. Daisy Sucaldito 1ST SEMESTER | A.Y 2022-2023 The amount of blood flow beneath the skin’s OBJECTIVES surface and the activity of sweat glands in the skin I. Identify and describe the major types of tissues both help regulate body temperature in the human body as well as their various functions. EXCRETION II. List the structural and functional characteristics Small amounts of waste products are lost through of the different membranes of the body. the skin and in gland secretions III. Describe the process of inflammation and explain why inflammation protects the body. SKIN IV. Describe the major events involved in tissue Also known as Cutaneous Membrane. repair. Covers the external surface of the body. V. Describe the age-related changes that occur in The skin is made up of 2 major tissue layers: the tissues. epidermis and the dermis. The epidermis is the most superficial layer of skin. It INTEGUMENTARY SYSTEM is a layer of epithelial tissue that rests on the Consists of the skin and accessory structures, such dermis. as hair, glands, and nails The dermis is a layer of dense connective tissue. Integumentary means covering The appearance of the integumentary system can EPIDERMIS AND DERMIS indicate physiological imbalances in the body A. The epidermis rests on the dermis. Dermal papillae project toward the epidermis B. As skin cells move from one stratum to the next, they undergo a series of changes called keratinization The five epidermal strata from deep to superficial, are: 1. Stratum basale mitosis - 2. Stratum spinosum 3. Stratum granulosum 4. Stratum lucidum 5. Stratum corneum Come Let’s Get Sun Burnt INTEGUMENTARY SYSTEM FUNCTIONS PROTECTION EPIDERMIS The skin provides protection against abrasion and Prevents water loss and resists abrasion. also known as ultraviolet light. Known as the cutaneous membrane, is a It also prevents microorganisms from entering the keratinized stratified squamous epithelium. body and reduces water loss, thus preventing KERATINIZATION ↳ oil-like covering dehydration. This process is called keratinization because the cells become filled with the protein keratin, which SENSATION makes them hard. The integumentary system has sensory receptors As keratinization proceeds, epithelial cells that can detect heat, cold, touch, pressure and pain eventually die and produce an outer layer of dead, hard cells that resists abrasion and forms a VITAMIN D PRODUCTION permeability barrier. When exposed to ultraviolet light, the skin produces a molecule that can be transformed into vitamin D, STRATUM BASALE an important regulator of calcium homeostasis. The deepest stratum. Consist of SQUAMOUS CUBOIDAL or COLUMNAR cells that undergo mitotic divisions TEMPERATURE REGULATION about every 19 days. MENESES, M., PADERES, J., PAREDES, S., PINO, R., PLURAD, N., QUIÑONES, M., RAMOS, A., REPE, A., TABANAO, K. | 1NU02 1  - STRATUM SPINOSUM DERMIS (cont.) Superficial to the stratum basale Dermal papillae are projections toward the Consist of 8-10 layers epidermis found in the upper part of the dermis Appears to be covered with thorns-like spikes. Small nippled-shaped structure that project into the under surface of the epidermis STRATUM GRANULOSUM Contain many blood vessels that supply the Middle of the epidermis overlying epidermis. for sensory in thick covering Consists of three to five layers. ; seen - SKIN COLOR STRATUM LUCIDUM Factors that determine skin color include pigments Present only in thick skin areas such as fingertips, in the skin, blood circulating through the skin, and palms and soles. the thickness of the stratum corneum Consists of 4-6 layers of flattened clear, dead The two primary pigments are melanin and keratinocytes that contain large amounts of keratin and thickened plasma membrane. carotene. STRATUM CORNEUM dead squamous cells filled with Keratin - MELANIN Cells continuously shed and are replaced by cells Is a group of pigment primarily responsible for skin, from deeper strata. hair, and eye color. Callus - Increased number of layers of the stratum Provides protection against ultraviolet light from the corneum due to friction in the skin. sun. corn Produced by melanocytes. CAROTENE Is a yellow pigment found in plants such as squash and carrots. Most melanin molecules are brown to black pigments, but some are yellowish or reddish. Lipid-soluble; accumulates in the lipids of the stratum corneum and in the adipocytes of the Dandruff - Excessive sloughing of stratum corneum dermis and subcutaneous tissue. cells from the surface of the scalp. MELANIN TRANSFER TO EPITHELIAL CELLS DERMIS The dermis is composed of dense collagenous connective tissue containing fibroblasts, adipocytes, and macrophages. Collagen fibers and eclectic fibers are responsible for the structural strength of the dermis and resistance to strength. Melanosomes are produced by the Golgi apparatus of the melanocyte CLEAVAGE LINES Melanosomes move into the melanocyte cell processes The orientation Epithelial cells phagocytize the tips of the of collagen fibers melanocyte cell processes produces cleavage lines, The melanosomes, which were produced inside the or tension lines, in the melanocytes, have been transferred to epithelial skin. cells and are now inside them Cleavage lines, or tension lines, SKIN COLOR (cont.) in the skin, are more A large amount of melanin from freckles or moles in resistant to stretch. some regions of the skin. Melanin production is determined by genetic factors, exposure to light, and hormones. Genetic factors are responsible for the amount of melanin in different races. STRETCHMARKS MENESES, M., PADERES, J., PAREDES, S., PINO, R., PLURAD, N., QUIÑONES, M., RAMOS, A., REPE, A., TABANAO, K. | 1NU02 2  A form of internal scarring, can result from the Hair is produced in cycles, with a growth stage and internal damage to dermis that occurs when skin is resting stage stretched too much. Eyelashes grow for about 30 days and rest for 105 days, whereas scalp hairs grow for 3 years FRECKLES and rest to 1 to 2 years Caused by increased melanin production. ALBINISM HAIR FOLLICLE A recessive genetic trait that causes a deficiency or an absence of melanin. DERMIS The partial loss or complete loss of melanocytes from patches of skin that produce irregular white spots. SUN TAN Ultraviolet light in sunlight stimulates melanocytes to increase melanin production. LINEA NIGRA Hormones such as Estrogen and Melanocyte Stimulating Hormone Cause an increase in melanin production during pregnancy in the mother. GLANDS SUBCUTANEOUS TISSUE Major glands of the skin are sebaceous glands and Where the cutaneous membrane rests the sweat glands. Also known as HYPODERMIS SEBACEOUS GLANDS Secretion of oil ; acinar · Loose connective tissue, including adipose tissue - Simple branched acinar glands, with most being that contains about half the body’s stored lipids connected by a duct to the superficial part of a hair Attaching skin to underlying bone and muscle follicle. supplies it with blood vessels and nerves. They produce sebum The acceptable percentage of body fat varies from Sebum - oily white substance rich in lipids; released 21% to 30% for females and from 13% to 25% for by holocrine secretion and lubricates the hair and males the surface of the skin, prevents drying and protects against some bacteria. HAIR ECCRINE SWEAT GLANDS secretion of water ; tubular · Found everywhere on the skin except on the palm, Simple, coiled, tubular glands and release sweat soles, lips, nipples, parts of the genitalia and distal by merocrine secretion. segments of fingers and toes. Located almost every part of the skin, most Hair Follicle - An invagination of the epidermis that numerous in the palms and soles. extends deep into the dermis Produce a secretion that is mostly water with a Hair Shaft - protrudes above the surface few salts. ○ Root - below the surface Have ducts that open the surface of the skin ○ Hair bulb - expanded base of the root; through sweat pores and are for thermal regulation. where hair produced Cortex - surrounds medulla APOCRINE SWEAT GLANDS active during puberty ; tubular ○ Medulla - innermost and soft center Simple, coiled, tubular glands that produce a Cuticle - single layer of overlapping cells that holds thick secretion rich in organic substances the hair in hair follicle; covers the cortex It become active at puberty because of the Hair Papilla - An extension of the dermis that influence of sex hormones. protrudes into the hair bulb and contains blood ○ Testosterones - sex hormones for male vessels ○ Estrogen & Progesterone - sex Hair color - Determined by vary amount of melanin hormones for female Arrector Pili muscle - Contract and cause the hair The secretion generally is odorless, but when to become perpendicular to the skin’s surface released quickly breaks down by bacterial action Hair is produced in cycles, with a growth stage and giving body odor. resting stage - Armpits and Genitalia During growth stage, hair is formed by mitosis of epithelial cells within the hair bulb During resting stage, growth stops, and the hair is held in the hair follicle MENESES, M., PADERES, J., PAREDES, S., PINO, R., PLURAD, N., QUIÑONES, M., RAMOS, A., REPE, A., TABANAO, K. | 1NU02 3  a.Hair in the head - acts as insulator b. Eyebrows - keeps sweat out of the eyes c. Eyelashes - protect eyes from foreign objects d. Hair in the nose and ears - prevents entry of dust and other materials 6. Nail protect the end of the fingers and toes from damage SENSORY RECEPTORS Receptors in the epidermis and dermis can detect pain ,heat, cold, and pressure Sensory around hair follicle can detect movement of a hair VITAMIN D PRODUCTION 1. UV lights causes the skin to produce a precursor molecule of vitamin D. dehydrocholesterol- 7 2. The precursor molecule is carried by the NAIL blood to the liver where it is enzymatically Thin plate, consisting of layers of dead stratum converted. corneum cells that contain a very hard type of 3. The enzymatically converted molecule is keratin. carried by the blood to the kidneys where Nail Body - visible part of the nail it is converted again to the active form Nail Root - part of the nail covered by the skin of Vitamin D. Eponychium - also called as cuticle; is a stratum 4. Vitamin D stimulates the small intestine corneum that extends onto the nail body to absorb calcium and phosphate for Nail Bed - located distal to the nail matrix many body functions. Nail Matrix - gives rise to the cells that form the nail ○ Lunula - whitish crescent-shaped area at TEMPERATURE REGULATION the base of the nail Regulations of body temperature is important because the rate of chemical reactions within the body can be increased or decreased by changes in the body temperature. Even slight changes in temperature can make enzymes operate less efficiently and disrupt the normal rates of chemical changes in the body Exercise,fever,and an increase in environmental temperature tend to raise body temperature. In order to maintain homeostasis,the body must rid itself of excess heat. Blood vessels in the dermis dilate and enable more blood to flow within the skin,thus causing heat to dissipate from the body. Sweat also assists in loss of heat through evaporative cooling If body temperature begins to drop below normal,heat can be observed by the constriction INTEGUMENTARY SYSTEM PROTECTIONS of dermal blood vessels,which reduces blood flow to It performs many protective functions: the skin, 1. Reduction in body water loss Less heat is transferred from deeper structures to 2. Acts as a barrier that prevents the skin,and heat loss is reduced. microorganisms and other foreign With smaller amounts of warm blood flowing substances through the skin,the skin temperature decreases/. 3. Protects underlying structures against Too cold : constriction of blood resoels abrasion Too hot : dilation of blood vessels caring sweating 4. Melanin absorbs UV light and protects HEAT EXCHANGE IN THE SKIN underlying structures from its damaging effects 5. Hair protection: MENESES, M., PADERES, J., PAREDES, S., PINO, R., PLURAD, N., QUIÑONES, M., RAMOS, A., REPE, A., TABANAO, K. | 1NU02 4  Part of the stratum basel remains viable, and regeneration of the epidermis occurs from within the burn area. Subdivided into first and second degree burn FIRST DEGREE BURN Epidermis is the only - affected one They can be caused by sunburn or brief exposure to very hot or cold object They heal without scarring in about a week AInvolve only the epidermis Red and painful Slight edema may be present SECOND DEGREE BURN Both Epidermis and Dermis - affected are Minimal dermal damage: ○ Redness, pain, edema and blisters ○ Wound appears red, tan or white Damage both the epidermis and the dermis If the body temperature has increased the blood FULL THICKNESS BURN Both Epidermis and dermis · destroyed are vessel will be dilates-the blood will flow beneath the Also known as THIRD DEGREE BURN skin causing of the heat loss across the The epidermis and the dermis are completely epidermis will increase destroyed If the body temperature drops below the body Appears white tan, brown, black or deep cherry red normal temperature the blood vessel will Usually painless Since sensory receptors destroyed are constrict-reduction of the blood flow the resulting heat loss across the epidermis decreases. EXCRETION The integumentary system plays a minor role in excretion,the removal of waste products from the body. In addition to water and salts,sweat contains small amounts of waste products,such as urea,uric acid,and ammonia. Even though the body can lose large amounts of sweat, glands do not play a significant role in the excretion of waste production.. RULE OF NINE Estimate the severity of the burns DIAGNOSTIC ACID Divides body into areas that are - 9% or multiples of The integumentary system is useful in diagnosis 9% of the total body area because it is observed easily. Younger patient are different Burns considered critical if: CYANOSIS brish ; due to lack of o · ○ Over 25% of the body has second degree A bluish color to the skin caused by decreased burns blood O2 content ○ Over 10% of the body has third degree An indication of impaired circulatory or burns respiratory function. ○ There are third degree burns on face, hands, or feets JAUNDICE yellow ; due liver problem to A yellowish skin discoloration When the liver is damaged by a disease. BURNS Injury to a tissue caused by heat, cold, friction, chemicals, electricity or radiation. Burns are classified according to their depth Partial thickness burns are classified as first and second degree A full-thickness burn is a third degree burn PARTIAL-THICKNESS BURN First Degree only epidermis SKIN CANCER - dermis Second Degree - epidermis and Third Degree - destruction of epidermis and dermis It is the most common type of cancer MENESES, M., PADERES, J., PAREDES, S., PINO, R., PLURAD, N., QUIÑONES, M., RAMOS, A., REPE, A., TABANAO, K. | 1NU02 5  Most often associated with exposure to ultraviolet between eczema and allergy to dust mites has not light from the sun been proven. PREDISPOSING FACTORS: Symptoms are usually managed with moisturizers, ○ Fair-skinned corticosteroid creams, and immunosuppressants. ○ Older than 50 years old TYPES OF SKIN CANCERS BASAL CELL CARCINOMA stratum basale nase na The most frequent type of skin cancer Begins with cells in the stratum basel and extends into the dermis to produce an open ulcer MANAGEMENT: Surgically removed or Radiation therapy Basal Cell Carcinoma-cancer of stratum barale ACNE Is a a skin disturbance that typically occurs on areas of the skin that are rich in sebaceous glands (FACE AND BACK) It is most common along with the onset of puberty due to associated hormonal changes, but can also occur in infants and continue into adulthood. hormones , such as androgens, stimulate the release of serebum. An overproduction and accumulation of sebum along with keratin can block SQUAMOUS CELL CARCINOMA -from basale corneum to hair follicles. Develops from cells immediately superficial to the This plug is initially white, the sebum, when oxidized stratum basel by exposure to air, turns black. If left untreated, the tomur can invade the dermis, Acne results from infection by acne-causing metastasize bacteria (Propionibacterium and Staphylococcus), which can lead to redness and potential scarring due to the natural wound healing process. MALIGNANT MELANOMA Rare form of skin cancer that arises from melanocytes The melanoma can appear as a large, flat, AGING AND THE INTEGUMENT spreading lesion or as a deeply pigmented nodule Blood flow decreases and skin becomes thinner due to decreased amount of collagen Decreased activity of sebaceous and sweat glands make temperature regulation more difficult Loss of elastic fibers cause skin to sag and wrinkle SKIN DISEASE ECZEMA Is an allergic reaction that manifests as dry, itchy patches of skin that resemble rashes. It may be accompanied by swelling of the skin, flaking, and in severe cases, bleeding. Many who suffer from eczema have antibodies against dust mites in their blood, but the link MENESES, M., PADERES, J., PAREDES, S., PINO, R., PLURAD, N., QUIÑONES, M., RAMOS, A., REPE, A., TABANAO, K. | 1NU02 6