chapter 6

Organ

Organ

Two or more types of tissues grouped together and performing specialized functions constitute an organ

Integumentary System

The skin and its accessory structures (hair, nails, glands, sensory receptors) make up the integumentary system

Epidermis

Outer layer of the skin, composed of startified squamous epithelium, resting on a basement membrane

Dermis

Deeper layer of the skin, thicker than the epidermis, composed of connective tissue containing collagenous and elastic fibers

Subcutaneous Layer

Layer beneath the dermis, consisting of areolar and adipose connective tissue, not considered part of the skin but contains blood vessels that supply the skin

Keratinization

Process of hardening, dehydration, and keratin accumulation in epidermal cells as they migrate outward

Keratin

Tough, fibrous, waterproof protein made and stored in the cells of the epidermis

Stratum Corneum

Outermost layer of the epidermis, consisting of dead, keratinized cells

Stratum Basale

Deepest layer of the epidermis, also known as the basal cell layer, containing cuboidal or columnar cells that divide and grow

Melanocytes

Cells located in the stratum basale that produce the dark pigment melanin, which absorbs UV light and provides skin color

Melanin

Pigment determining skin color

Albinos

Individuals lacking melanin

UV Light

Radiation affecting skin color

Carotene

Pigment from diet affecting skin color

Cyanosis

Bluish skin from low oxygenation

Vasodilation

Widening of blood vessels

Vasoconstriction

Constriction of blood vessels

Jaundice

Yellowing of skin from liver issues

Basal Cell Carcinoma

Skin cancer from epithelial cells

Squamous Cell Carcinoma

Skin cancer from epithelial cells

Melanomas

Skin cancer from melanocytes

Dermal Papillae

Structures binding epidermis and dermis

Papillary Layer

Superficial dermis layer with areolar tissue

Reticular Layer

Deeper dermis layer with dense tissue

Hair Follicles

Structures producing hair on skin

Nails

Protective coverings on fingers and toes

Hair Bulb

Base of hair follicle with dividing cells

Hair Root

Part of hair follicle anchoring hair

Hair Shaft

Visible part of hair made of dead cells

Arrector Pili Muscle

Muscle causing goosebumps

Sebaceous Glands

Glands producing sebum for skin and hair

Acne Vulgaris

Sebaceous gland disorder causing acne

Sweat Glands

Glands producing sweat for body temperature regulation

Evaporation

Process where sweat changes into a gas, carrying heat away

Thermoreceptors

Sensory receptors detecting changes in temperature

Hyperthermia

Abnormally high body temperature causing weakness and dizziness

Hypothermia

Abnormally low body temperature leading to confusion and lethargy

Shivering

Involuntary muscle contractions to generate heat

Homeostasis

Body's ability to maintain stable internal conditions

Vasodilation Collapse

Extreme widening of blood vessels leading to potential cardiovascular failure

Fever

Elevated body temperature to fight infection

Inflammation

Body's response to injury, restricting infection spread

Phagocytes

Cells that engulf and digest pathogens

Pyrogens

Substances causing fever by raising the body's set point

Healing Process

Series of events including clot formation, tissue repair, and scar formation

Scar Formation

Excess collagen fibers forming an elevated mass after wound healing

Burn Classification

Categorization based on the depth and severity of skin damage

Rule of Nines

Method to estimate extent of burn injuries for treatment planning

Aging Effects on Skin

Changes like thinning, dryness, and decreased sensory receptors

Melanin Production

Process slowing down with age, leading to whitening of hair

Vitamin D Production

Decreases with age due to reduced sun exposure