Integumentary System Long Test 2 PDF

INTEGUMENTARY SYSTEM ❁ SEMESTER 1 LONG TEST 2 | ZOOLONE | IANA ROSALES...

INTEGUMENTARY SYSTEM ❁ SEMESTER 1 LONG TEST 2 | ZOOLONE | IANA ROSALES SY. 2024-2025 rr INTRODUCTION Epidermis is 0.5 mm thick due to thick stratum ❓ Dermatology is the scientific study and medical corneum treatment of the integumentary system Covers the rest of the body 💡 Integumentary system - consists of skin, hair, nails, and associated glands Has sweat glands, hair Thin skin follicles, and sebaceous Skin (integument) - the body’s largest and glands heaviest organ ○ Two layers: Epidermis is 0.1 mm thick Epidermis: stratified squamous epithelium Dermis: deeper connective FUNCTIONS OF THE SKIN tissue layer ○ Hypodermis: below the dermis but Resistance to Keratin provides physical protection not part of the skin trauma and infection Dermcidin, defensins, and acid mantle protect against bacteria Other barrier Barrier to water, UV rays, harmful functions chemicals Vitamin D Skin carries out first step synthesis Sensation Nerve endings react to stimuli Thermoregulatio Alters blood flow to release or retain n (one example of heat homeostasis) Nonverbal Facial expressions communication THICK VS THIN SKIN Covers the palms, soles, and some surfaces of the Thick skin fingers and toes Only has sweat glands BY RIEBISCO 1  INTEGUMENTARY SYSTEM ❁ SEMESTER 1 LONG TEST 2 | ZOOLONE | IANA ROSALES SY. 2024-2025 rr EPIDERMIS LAYERS OF THE EPIDERMIS GENERAL FEATURES 💡 Composed of squamous epithelium keratinized stratified Avascular (lacks blood vessels) Contains sparse nerve endings CELLS OF THE EPIDERMIS Keratinocytes The majority of the epidermal cells Stratum corneum Plenty of layers of dead, scaly, keratinized cells Synthesize keratin Resists abrasion, penetration, Stem cells Undifferentiated cells that and water loss give rise to keratinocytes Stratum lucidum Thin, pale layers only found Located in the stratum basale in thick skin (deepest layer) Keratinocytes are packed with Melanocytes Synthesize melanin that eleidin (clear protein) shields DNA from UV radiation Stratum granulosum 3-5 layers of flat, living keratinocytes Also located in the stratum basale Cells contain dark-staining keratohyalin granules Distributes melanin through melanosomes Stratum spinosum Several layers of living keratinocytes joined by Tactile cells Touch receptor cells desmosomes and tight associated with dermal nerve junctions fibers (overall called tactile disc) Named after the spiny appearance of the cells Dendritic cells Phagocytic immune cells that defend against toxins and Stratum basale Single layer of stem cells and microbes keratinocytes, as well as scattered melanocytes and Found in stratum spinosum tactile cells and stratum granulosum BY RIEBISCO 2  INTEGUMENTARY SYSTEM ❁ SEMESTER 1 LONG TEST 2 | ZOOLONE | IANA ROSALES SY. 2024-2025 rr LIFE HISTORY OF A KERATINOCYTE?? Papillary layer Thin zone of areolar tissue that is rich in small blood Idk if isasali ko pa HHSHS vessels DERMIS Allows for mobility of leukocytes and other defense cells GENERAL FEATURES Reticular layer Deeper and thicker layer that 💡 Composed mainly of collagen, elastic and reticular fibers is composed of dense irregular connective tissue Supplied with blood vessels, sweat and Stretch marks sebaceous glands, nerve endings, hair follicles, nail roots HYPODERMIS (SUBCUTANEOUS TISSUE) ❓ Muscles of facial expression are attached to 💡 Layer of connective tissue beneath the skin that has more areolar and adipose tissue than the dermis the dermis Subcutaneous fat - refers to subcutaneous BOUNDARY BETWEEN DERMIS AND tissue that is comprised predominantly of EPIDERMIS adipose tissue ○ Energy reservoir 💡 Dermal papillae - upward, finger-like extensions of dermis ○ Thermal insulation Epidermal ridges - downward waves of epidermis ❓ Pads the body and binds skin to underlying tissues Common site of drug injection due to presence of blood vessels LAYERS OF THE DERMIS BY RIEBISCO 3  INTEGUMENTARY SYSTEM ❁ SEMESTER 1 LONG TEST 2 | ZOOLONE | IANA ROSALES SY. 2024-2025 rr SKIN SKIN GRAFTS 💡 Third-degree burns often require skin grafts ○ Autograft - tissue from another location on the same person’s body ○ Allograft - tissue from an unrelated person (usually deceased donors) SKIN COLORS OF DIAGNOSTIC VALUE SKIN COLOR Cyanosis (from cyan) Blueness due to oxygen deficiency Eumelanin (brown, black) Tan, brown, black skin Erythema Redness due to increased blood flow to skin Pheomelanin Yellowish to reddish tones of Asians and Native Americans, Pallor Paleness due to decreased pinkish tones of white skin blood flow to skin Albinism White skin due to genetic lack 💡 People of different color have the same number of melanocytes, but vary in melanin of melanin Jaundice Yellowing due to bilirubin in production and longevity blood (can be due to liver) Hematoma Bruising due to clotted blood under skin Darker skin Lighter skin Melanocytes produce greater Melanin clumped near amounts of melanin keratinocyte nucleus SKIN MARKINGS Melanin breaks down more Friction ridges The markings on the slowly fingertips (the ones that leave the fingerprint, basically) Melanin granules more spread Little melanin seen beyond out in keratinocytes stratum basale Flexion lines / creases Lines on the flexor surfaces of the digits, palms, wrists, Melanized cells seen elbows throughout epidermis Freckle Flat, melanized patch Mole (nevus) Elevated, melanized patch BY RIEBISCO 4  INTEGUMENTARY SYSTEM ❁ SEMESTER 1 LONG TEST 2 | ZOOLONE | IANA ROSALES SY. 2024-2025 rr (often with hair) STRUCTURE OF HAIR Hemangioma (birthmark) Patches of discolored skin HAIR AND NAILS 💡 Hair, nails, and cutaneous glands are the accessory organs (appendages) of the skin Composed of mostly dead, keratinized cells ○ Soft keratin - stratum corneum ○ Hard keratin - hair and nails Shaft - portion above skin surface Root - portion below skin surface ○ Hair root ends with dilated bulb HAIR (PILUS / PILI) Three layers of the hair: A slender filament of keratinized cells growing from 1. Medulla - core of loosely arranged cells a tube in the skin (hair follicle) 2. Cortex - bulk of the hair; layers of elongated cells 3. Cuticle - outermost region ❓ Hair does NOT cover the palms, soles of Structure of a hair follicle: fingers and toes, lips, nipples, and parts of 1. Epithelial root sheath genitals 2. Connective tissue root sheath - surrounds #1 HAIR CYCLE TYPES OF HAIR Downy hair (lanugo) Fine, unpigmented hair that Anagen (6-8 years) The growth stage (90% of appears on the fetus in the last scalp follicles) 3 months of development Catagen (2-3 weeks) The degeneration stage where Vellus hair Fine, pale hair that replaces hair can easily be pulled out the lanugo upon birth by brushing (club hair) Terminal hair Larger, coarser, and more Telogen (1-3 months) The resting stage heavily pigmented Eyebrows, eyelashes, scalp hair BY RIEBISCO 5  INTEGUMENTARY SYSTEM ❁ SEMESTER 1 LONG TEST 2 | ZOOLONE | IANA ROSALES SY. 2024-2025 rr NAILS MAMMARY GLANDS Modified apocrine sweat glands CUTANEOUS GLANDS Milk-producing glands that develop during pregnancy and lactation SWEAT GLANDS ❓ Mammary ridges / milk lines - two rows of Eccrine (merocrine) sweat Most numerous skin glands mammary glands in most mammals glands that are dense on the palms, soles, and forehead Apocrine sweat glands Become active in puberty as a response to stress and sexual SKIN CANCER stimulation Basal cell carcinoma Most common type and the Produces sweat that is milky least dangerous because it and contains fatty acids seldom spreads / metastasizes Groin, anal region, axilla, Forms from cells in stratum areola, beard area in mean basale ❓ Myoepithelial cells are found in both Squamous cell carcinoma Lesions usually on scalp, ears, lower lip, back of the hand apocrine and eccrine glands Can metastasize to the lymph nodes Types of perspiration: Insensible perspiration - not noticed; does not Arises from keratinocytes of produce visible wetness of skin stratum spinosum Diaphoresis - sweating with wetness of the skin, in response to heat, exercise, circulatory shock Malignant melanoma Arises from melanocytes due to people who had severe sunburn as a child (less than SEBACEOUS GLANDS 5% of skin cancers) Produce sebum (oily secretion) Familial history is the biggest Keeps skin and hair from becoming dry factor CERUMINOUS GLANDS Modified apocrine glands found only on the external ear canal Produce cerumen (earwax) BY RIEBISCO 6  INTEGUMENTARY SYSTEM ❁ SEMESTER 1 LONG TEST 2 | ZOOLONE | IANA ROSALES SY. 2024-2025 rr BURNS First-degree burn - only involves the epidermis ○ Heals within days Second-degree burn - involves part of the dermis ○ 2 weeks to 7 seven months healing time ○ May leave scars Third- degree burn - involves all of the dermis and some deeper tissues ○ Requires skin grafts ❓ Burns can result in death due to fluid loss, infection, and toxic effects of eschar—the burned, dead tissue Source is lecture recording ni sir BY RIEBISCO 7