A + P: Integumentary System

Integumentary system structures

skin, sweat glands, oil glands, hair, nails

functions of the integumentary system

protects underlying structures, maintains body temperature, cutaneous sensations, metabolic functions, blood reservoir, excretion

what are the 3 parts of the skin

epidermis, dermis, hypodermis

the epidermis is primarily composed of

keratinized stratified squamous epithelium

5 distinct layers of the epithelium (superficial to deep)

stratum corneum, stratum lucidum, stratum granulosum, stratum spinosum, stratum basale

where can you find stratum lucidium

only in the palms and soles of feet

four cell types in the epidermis

keratinocytes, melanocytes, dendritic (langerhans) cells, tactile (merkel) cells

thin, translucent band of skin, superficial to the stratum granulosum

stratum lucidum

a few rows of flat, dead kerantinocytes

stratum lucidum

describe stratum corneum

20-30 layers of dead cells, essentially flat membranous sacs with keratin, glycolipids in extracellular space

describe stratum granulousum

typically five layers of flattened cells, organelles deteriorating; cytoplasm full of lamellar granules (release lipids) and keratohyalin granules

describe stratum spinosum

several layers of keratinocytes unified by desosomes. Cells contain thick bundles of intermediate filaments made of pre- keratin

describe stratum basale

deepest epidermal layer; one row of actively mitotic stem cells. see occasional melanocytes and dendritic cells

what epidermis layer produces two daughter cells

stratum basale

what layer of the epidermis is known as the prickly layer

stratum spinosum

keratinization begins in what layer of the epidermis

stratum granulosm

what is water resistant in the granulosum and slows water loss

glycolipid

cells above what layer in the epidermis die

stratum granulosum

what layer in the epidermis is known as the horny layer

stratum corneum

two layers of the dermis

papillary and reticular layer

what kind of tissue makes up the papillary layer of the dermis

areolar

what kind of tissue makes up the reticular layer of the dermis

dense irregular type

cells that make up the dermis

fibroblasts, macrophages, mast cells, and white blood cells

in what layer of the dermis are collagen fibers abundant

reticular

t/f: the dermis does not contain nerve fibers or blood vessels

false

what layer is areolar connective tissue with collagen and elastic fiber and blood vessels

papillary layer

superficial peglike projections

dermal papillae

what is the role of Meissner’s corpuscles

light touch receptors near the surface of the skin.

raised dermis that helps form fingerprints and keeps the epidermis attached.

dermal ridges

fingerprint ridges that improve grip and touch

friction ridges

the reticular layer makes up how much of the dermis

80%

what kind of lines are made up of collagen and lie parallel to the skin surface (important to suregons)

cleavage lines

dermal folds at or near joints

flexure lines

official word for stretch marks

striae

fluid filled pocket that separates the epidermal and dermal layers

blister

3 main pigments that contribute to skin color

melanin, carotene, hemoglobin

color of melanin

reddish- yellow to brownish- black

color of carotene

yellow to orange pigement

where is carotene most obvious

palms and soles

what migrates to keratinocytes to form pigment shields for nuclei

melanin

what color does hemoglobin give off

pinkish to red

what is cyanosis and what color does it give off

low oxygenation of hemoglobin; blue skin color

examples of erythema

fever, hypertension, inflammation, allergy

explain pallor (blanching)

unusual paleness of the skin

examples of pallor

anemia, low blood pressure, fear, anger

jaundice is due to a

liver disorder

example of bronzing

inadequate steroid hormones in Addisons disease

clotted blood beneath skin

bruises

dead keratinized cells of hard keratin is known as

hair

the 4 appendages of the epidermis are

hair, nails, sudoriferous (sweat) glands, sebaceous (oil) glands

3 parts that make up hair are

hair shaft, hair root, hair bulb

part of hair that projects above skin surface

hair shaft

part of hair embedded in skin

hair root

the enlarged, rounded base of a hair follicle located deep in the skin. (growth region)

hair bulb

the layer of actively dividing cells inside the hair bulb inside stratum basale

hair matrix

is a small projection of connective tissue that sits inside the hair bulb.

hair papilla

is a tiny smooth muscle attached to a hair follicle

arrector pili

what part of the hair is resonsible for goose bumps

arrector pili

hair fold down from the epidermal surface into dermis

hair follicle

outer peripheral connective tissue that forms a fibrous sheath

follicle wall

the glassy membrane makes up what part of the hair follicle

follicle wall

t/f: epithelial root sheaths consist of external and internal parts

true

heavily keratinized protective layer of the hair root

cuticle

several epithelial layers in the hair root

cortex

soft keratinized cells in the hair root

medulla

base of follicle is the

hair bulb

what part of the follicle contains the hair matrix

hair bulb

where does rapid cell division and hair growth happen (stratum basale)

hair matrix

what part of the hair houses melanocytes for hair color

hair matrix

hair papilla

dermal tissue with blood and nerve supply

vellus hair

pale, fine body hair of children and adult females

terminal hair

coarse, long hair of eyebrows, scalp

terminal hair appears in the _________ and ______ regions

axillary and pubic

hair thinning in both sexes after age 40

alopecia

official name for sweat glands

sudoriferous glands

two main types of sweat glands

eccrine and apopcrine

most numerous sweat glands

eccrine glands

eccrine sweat glands

abundant on palms, soles, and forehead

what sweat glands secretion is 99% water, salts, vitamin c, antibodies, dermcidin, metabolic waste

eccrine

apocrine glands are confined to what areas

axillary and anogenital

t/f: apocrine glands are larger than eccrine glands

true

what ducts begin functioning at puberty

apocrine glands

modified apocrine glands

ceruminous and mammary glands

glands that line external ear canal

ceruminous glands

sebaceous glands are _____ glands

oil

sebaceous glands are stimulated by ________, especially androgens

hormones

what gets secreted by sebaceous glands that softens the hair and skin

sebum

3 types of protective borders in integumentary system

chemical, physical, biological

list two types of chemical barriers in the skin

skin secretions and melanin

physical barriers of the skin include:

keratinized stratum corneum of the epidermis

biological barriers of the skin

dendritic cells, macrophages, DNA

the small amount of water that is continuously lost through the skin by evaporation, even when you are not actively sweating

insensible perspiration

the sweat you can actually see or feel

sensible perspiration

what happens to the dermal blood vessels in cold environments

they constrict

what cutaneous sensations are located in dermal papillae and sense light touch

tactile (meissners) corpuscles

what cutaneous sensations are located in the deep dermis and sense deep pressure

Lamellar corpuscles

free nerve endings are located in the dermis part of the nervous system and detect…

temperature, touch, and pain

metabolic function of skin

synthesis of vitamin D

explain the function of blood reservoir in skin

up to 5% of bodys blood volume

explain excretion as a skin function

nitrogenous wastes and salts in sweat