ANPH 1001 UNIT 2 FINAL EXAM 2025

Integumentary System - -System made up of skin and its appendages (modifications of skin) such as hairs, nails, sebaceous and sweat glands Skin - -Skin actively produces vitamin D (UV sunlight required) necessary to stimulate intake of calcium and phosphorus in our intestines. Vitamin D - -Necessary to stimulate intake of calcium and phosphorus in our intestines. Vitamin D production occurs at liver and kidney Functions of Integumentary System - -Secretion, sensation protection, and thermoregulation. Protects from harmful UV radiation by producing pigment melanin Barrier to most harmful chemicals Helps regulates body temperature by sweating Layers of Skin - -2 main layer of skin: Epidermis (upper) and Dermis (true) Epidermis - -Outermost layer of skin, layer of epithelial tissue divided into sub layers contains to blood vessels (avascular) Composed of stratifies, squamous, keratinized (skin flakes) epithelial cells locked together by desmosomes Thickest around palms of halons and soles of feet for more protection Epidermis rests on basement membrane of connective tissue Lower most cells on membrane divide by mitosis so new cells push older cells up towards the surface losing water and eventually die (keratinization) Dermis - -Inner layer of skin containing blood vessels, layer of dense connective tissue connective skin to tissues (fat/muscle) below Subcutaneous Layer - -Below the Dermis, sometimes called hypodermis (fatty layer) Keratinization - -Forms 5 layers of epidermis called strata (plural) or stratum (singular ) Divides by mitosis so new cells push older cells up towards the surface losing water and eventually dieting Dead outermost cells constantly being she's and serve to form a protective barrier 5 layers of strata ( outermost to deepest ) - -1. Stratum corneum 2. Stratum Lucidum 3. Stratum Granulosum 4. Stratum spinosum 5. Stratum germinativium ANPH 1001 AHN 572 Stratum Corneum - -Outermost strong layer of epidermis consisting of dead cells called keratinized cells (lost water and filled keratin protein) Barrier to light, heat, chemicals and microorganisms Stratum Lucidum - -Thin, transparent and flat cells only one or two layers thick Stratum Granulosum - -Two or three layers of flattened cells accumulating granules Active keratinization losing nuclei becoming compact and brittle Stratum Spinosum - -Several layers of prickly spiny shaped cells containing desomsomes Stratum Germinativium - -Deepest and most important layer of skin Only cells of oxides is capable of dividing by mitosis giving rise to other layers Epidermis will regenerate itself only if this layer remain intact Contains melanocytes: cells responsible for skin colour by producing melanin pigment All races have same number of melanocytes but genetically produce more melanin in people with dark skin Melanocytes - -Cells responsible for skin colour by producing melanin Are activated to produce melanin by exposure to sunlight Albinism: condition is a mutation preventing production of melanin resulting in a very fair skin, white hair and pink eyes Dermis - -Lies beneath the epidermis and referred to and the True Skin (vascular containing glands) Found in the dermis are sweat glands, blood vessels, nerves, lymph vessels, hair follicles and sebaceous glands Elderly bean become sensitive to the cold due to poor blood circulation in the dermis 2 portions of Dermis - -Papillary Portion and Reticular Portion Papillary Portion - -Area located within epidermis Reticular portion - -Found between papillary portion and fatty subcutaneous Subcutaneous - -Sometimes called Hypodermis. Is layers of fat below the dermis Cyanosis - -Discolouration of the skin caused by lack of Oxygen in the blood due to suffocation or drowning (bluish tinge for light skin and greyish tinge for dark skin) Hair - -Covers most of the body except palms, soles and external genitalia 3 parts of hair - -Cuticle( outermost portion) consisting of several layers of overlapping scale like cells ANPH 1001 AHN 572 Cortex (principal portion) consists of elongated cells forming flattened fibres Medulla (middle portion) consisting of cells with air space Other parts of the hair - -Shaft: visible portion of the hair Root: invisible portion of the hair found in epidermis tube called hair follicle Hair Growth - -Hair grows in cycles of growth (3years) and rest (1 or 2) Genetic factors controlling the nature of keratin of hair determines hair texture (straight, curly or tight curly) Grey/white hair occurs when pigment is absent from cortex Battery baldness is the term for genetic, permanent hair loss due to follicle loss Nails - -Modified epidermal cells found at ends of fingers and toes to protect digits Modified epidermal cells composed fo very hard keratin Lunula: white crescent at proximal end of nail and free end formed by air mixed in keratin Nail body: visible part of nail Nail root : part covered by skin and attached to nail body where growth occurs (1mm per week) Sebaceous Glands - -Produce sebum: oily substance responsible for lubricating (moisturizing) surface of skin, gives glossy appearance and waterproof properties Under control of endocrine system increasing at puberty and decreasing later in life. Modified sebaceous glands line the auditory ear canal producing earwax Sebum - -Oily substance from sebaceous glands, responsible for lubricating skin, has anti fungal and antibacterial properties preventing infection Sweat Glands - -Producing perspiration most numerous in palms and soles Produce more sweat to maintain homeostasis when hot outside as heat is required to evaporate the water in sweat Consists of mainly salt and some urea, Uric asked (considered excretion) Is odourless but bacterial feeding on sweat are responsible for body door Sensation - -Receptor sites in skin detect changes in temperature and pressure Responsible for sensations like pressures burning, itching or tickling Protection - -Skin Provides covering preventing passage of harmful physical and chemical agents Skin Impermeable to carbohydrates, fats and proteins Melanin protection from UV radiation Skins acid mantle kills most bacterial and ,microorganism that make contact Nails protect need of our digits Hair acts an insulation form heat loss and filter for our nose. Eye lashed Skin is thermoregulatory helping us maintain a contain temperature (37C) ANPH 1001 AHN 572 Skeletal System - -Works with muscles to allow for movement and helping us breath (diaphragm) Functions of skeletal system - -Support and stabilize, surrounding iTunes (suck as muscles, blood vessels, nerves, fat, skin) Protects vital organs (such as brain, spinal cord, heart, lungs) Assists in body movement by providing attachments for muscles that pull bones that act as levers Manufacture blood cells (process called hematopeiesis) occurring mainly in red bone marrow Storages mineral salts (cartilage, ligaments, tendons) Cartilage - -Connective tissue Environment in which bone deveops in fetus Found at ends of certain bones and in joints of adults Ligaments - -Tough connective tissue Structures that attach bones to bones Tendons - -Tough connective tissue Similar structures that attach muscle to bone Growth and formation of bones - -Fetus skeleton (predominantly cartilage) is completely formed by the end of 3rd month of pregnancy Longitudes growth continues until 15 years of age for girls and 16 for boys. Bone maturation until 21 years old Deposition of Bone - -Developed from osteoblasts:swindle-shaped cells which eventually form osteocytes :which are bone forming cells forming new bone Osteoblasts - -Spindle shaped cells which eventually for osteocytes , are formed from undifferentiated bone called osteoprogenitor cells Atrophy in bones - -Bone/muscle mass decr