APHY 101 Ch 5: The Integumentary System Ivy Tech Diagram | Quizlet

Components of integumentary system

skin, hypodermis (subcutaneous membrane), sweat glands, hair, nails

components of integument (skin)

epidermis (superficial region) is epithelial tissue; dermis (underlies epidermis) is mostly fibrous connective tissue

TERM

Hypodermis

DEFINITION

subcutaneous tissue (bottom layer) technically not a part of the skin, shares protection functions, composed of adipose tissue, anchors the skin to underlying structures, shock absorber and insulator

Epidermis

a keratinized stratified squamous epithelium (keratinocytes) also contain melanocytes, Langerhans (dendritic) cells, Merkel cells; avascular

2 layers of the skin (superficial to deep)

epidermis, dermis

keratinocytes

primary cell type in epidermis, produce keratin which is a fibrous protein that gives protection properties; produced by stem cells in stratum basale; pushed through the layers of skin as new cells are formed; die by apoptosis as distance from capillaries increase; cells slough off as dander and dandruff

melanocytes

spider shaped cells, synthesize melanin, found in the deepest layer of epidermis (stratum basale)

langerhans/ dendritic cells

arise from bone marrow, ingest foreign substances (phagocytosis), key factors in immune system

tactile (Merkel) cells

sensory touch receptors associated with nerve endings

layers of epidermis (superficial - deep)

corneum/ cornified (horny) layer; (thick skin only) lucidum/ clear layer; granulosum/ grainy layer; spinosum/ spiny layer; basale/ basal layer

Thick skin

palms, fingertips, soles of feet

Thin skin

covers most of body, strata's are thinner

TERM

Basale/ basal layer

DEFINITION

deepest layer of epidermis; one row of actively mitotic stem cells; some newly formed cells become part of the more superficial layers; (10-25%) melanocytes and some dendritic cells

TERM

Spinosum/ spiny layer

DEFINITION

several keratinocyte layers, cells contain thick bundle of intermediate filaments made of pre-keratin; abundant melanosomes and dendritic cells

TERM

Granulosum/ grainy layer

DEFINITION

4-6 cell layers thick, begin to develop keratin, functions as an external water barrier; organelles deteriorating and cells stain dark

TERM

Lucidum/ clear layer

DEFINITION

only found in thick skin; thin, translucent band superficial to the stratum granulosum; a few rows of flat, dead keratinocytes

TERM

Corneum/ cornified/ horny layer

DEFINITION

20-30 layers of dead cells, outermost layer, protect against abrasion and penetration, protects internal cells from harsh environment, water loss, and from chemical, biological, and physical assaults

TERM

Dermis

DEFINITION

deep to epidermis, dense irregular connective tissue, consists of 2 layers (papillary and reticular); contains nerves, blood & lymphatic vesicles, hair follicles, oil and sweat glands

Dermis cell types/fibers

fibroblasts, mast cells, WBC, Macrophages/ collagen, elastin

Papillary layer (dermis)

superficial, thin; loose areolar connective tissue; exhibits dermal papillae that protrude toward the epidermis above and form dermal ridges (enhance gripping ability, contribute to sense of touch, pattern is fingerprints)

Dermal papillae

peg like protrusions, indent overlaying epidermis, may contain capillary loops or nerve endings and Meissner's corpuscles

Reticular layer

deep, thicker layer; dense irregular connective tissue; contains cutaneous plexus

skin color

three pigments contribute to skin color; melanin (only pigment made in skin), carotene, hemoglobin

melanin

two forms (reddish-yellow to brownish-black); color differences due to amount and form; produced in melanocytes; same relative number in all people; freckles and pigmented moles are local accumulations of melanin;

sun exposure stimulates melanin production

carotene

yellow to orange pigment; most obvious in palms and soles; accumulates in stratum corneum and hypodermis; can be converted to vitamin A for vision and epidermal health

hemoglobin

pinkish hue of fair skin due to blood cells

cyanosis

blue skin color - low oxygenation of hemoglobin

erythema

redness may indicate blushing, fever, hypertension, inflammation, allergies

pallor or blanching (Pale)

may indicate fear, anger, emotional stress, anemia, and low blood pressure

jaundice

liver disorder, yellow bile pigments accumulate in blood and are deposited into tissues

bronzing

metallic appearance, Addison's disease, adrenal disease, can also be pituitary gland tumor that secret melanocyte stimulation hormones

black-and blue marks

Bruises forms when blood escapes from circulation and clots beneath the skin called hematomas

TERM

hair

DEFINITION

dead keratinized cells of hard keratin; not found on palms, soles, lips, nipples, portions of external genitalia

hair functions

warn of insects on skin, physical trauma, prevent heat loss, sunlight protection

hair pigments

melanins (yellow, rust, brown, black); trichosiderin in red hair; gray/white hair: decreased melanin production, increased air bubbles in shaft

TERM

hair follicle

DEFINITION

consists of heavily keratinized cells; inner epithelial root sheath and outer peripheral connective sheath; hair bulb; is richly vascularized, has many nerve fibers

TERM

arector pili muscle

DEFINITION

smooth muscle pull the follicles upright producing goose bumps, and propel sebum to the skin surface when contracted, involuntary

hair bulb

expanded deep end of hair surrounded by a hair follicle receptor (root hair plexus); contains sensory nerve endings (touch receptors) and a hair matrix (actively dividing area) with stem cells and melanocytes

root hair plexus

a special group of nerve fiber endings that serves as a very sensitive mechanoreceptor for touch sensation; each hair plexus forms a network around a hair follicle and is a receptor that sends and receives nerve impulses to and from the brain when the hair moves

hair structure

consisting of several layers, starting from the outside: the cuticle, which consists of several layers of flat, thin cells laid out overlapping one another as roof shingles; the cortex, which contains the keratin bundles in cell structures; the medulla, a disorganized and open area at the fiber's center

vellus hair

pale, fine body hair of children and adult females

terminal hair

coarse, long hair of eyebrows, scalp; at puberty, appear in axillary and pubic regions of both sexes also face and neck of males

alopecia

the partial or complete absence of hair from areas of the body where it normally grows; baldness

nails

protective cover for distal, dorsal surface of fingers and toes; contain hard keratin

nail functions

keeps Meissner's (light touch) and Pacinian/lamellar (vibration and pressure) corpuscles at right distance beneath epidermis to work properly

TERM

Meissner's corpuscle

DEFINITION

a sensory nerve ending that is sensitive to mechanical stimuli (light touch); found in the dermis in various parts of the body

TERM

Pacinian (lamellar) corpuscle

DEFINITION

a sensory nerve ending in the skin responsible for sensitivity to vibration and pressure

Sudoriferous (sweat) glands

found on alll skin surfaces except nipples and parts of external genitalia with about 3 million per person; types - eccrine, apocrine, sebaceous, ceruminous, mammary

TERM

Eccrine glands (=everywhere)

DEFINITION

all over body; function is thermoregulation; small coiled tubular glands; secret salt solution into ducts that empty through pores to surface of skin

Apocrine sudiferous glands

larger glands found in axillary and anogenital areas with ducts that lead to hair follicles; may function as sexual scent glands; secrete sweat with proteins and fatty substances; feed bacteria on the skin causing BO

Ceruminous glands

modified apocrine glands; found in ear; secrete earwax (cerumin)

Mammary glands

modified apocrine glands; secrete milk; contains complex proteins, lipids, carbohydrates, calcium and other minerals, and vitamins

TERM

Sebaceous glands

DEFINITION

occur over entire body except palms and soles; secret oily sebum which empty into hair follicles

Sebum

softens skin and hair, prevents water loss, acts as a bactericidal agent, activated at puberty

6 functions of integument

protection, temperature regulation, sensory reception, vitamin D synthesis (metabolic), blood reservoir, excretion

protection

resistance to abrasion, trauma, dehydration, and infection; chemical barriers-sebum, defenses, acid mantel, UV shield of melanin; physical barriers - hardened keratinized and lipid-rich surface; biological barriers- dendritic cells, macrophages and DNA

temperature regulation

vasculature and sweat glands

sensory reception

cutaneous sensory receptors respond to temp, touch, pressure, and pain

metabolic

vitamin D synthesis- required for calcium absorption in intestine

blood reservoir

extensive vascular supply of dermis allows skin to act as a ______ ______

excretion

sweat contains small amounts of wastes

Cutaneous sensory receptors

respond to stimuli from outside the body; includes Meissner's (tactile) corpuscles and Pacinian (lamellar) corpuscles

skin cancer

most skin tumors are benign (not cancerous) and do not metastasize (spread); risk factors 1. overexposure to UV radiation 2. frequent irritation of skin; prevention by limiting sun exposure and some skin lotions contain enzymes that can repair damaged DNA

Three forms of skin cancer

basal cell, squamous cell, and melanoma

Basal cell carcinoma

least malignant, and moat common, stratum basal cells proliferate, invading the dermis and hypodermis. Occurs in sun exposed areas of the face, shiny domelike, slow growing, metastasis is rare, cured by surgery

Squamous cell carcinoma

second most common, arises form keratinocyte's if the stratum spinosum, scaly reddened papule, head scalp ears lip and hands, grows fast will metastasize if not treated by surgery or radiation

Melanoma

cancer of melanocytes, dangerous, highly metastatic and resistant to chemo, account to 2-3% of skin cancers, spreading brown/black mole, chance of survival poor if over 4mm thick.

ABCDE rule

used for recognizing melanoma: asymmetry, border irregularity, color, diameter, evolution

Rule of nines

used to estimate the volume of fluid lost in adult burn patients, divides the body into 11 areas, each accounting for 9% of the total body area.

Burns

tissue damage caused by heat, electricity, radiation, certain chemicals; denatures proteins and kills cells; immediate threat is dehydration and electrolyte imbalance; can lead to renal shutdown and circulatory shock; classified according to severity and depth

First degree burn

only epidermis is damaged, symptoms- redness, swelling and pain

2nd degree burn

epidermis and upper region of the dermis affected, symptoms- same as first with the addition of blisters, regeneration within 3-4 weeks

3rd degree burns

full thickness burns, entire thickness of skin is affected, appears gray or white, cherry red or blackened, initially little edema, nerve ending destroyed there is little pain until regeneration, treated with grafting