Anatomy Ch 6 - The Integumentary System

cutaneous membrane

another name for the integument

dermatology

the scientific study of and treatment of the skin

trauma, harmful chemicals, pollutants, microbes, dehdration

the skin protects against these thigs:

true

true/false: the skin is made up of epithelial, connective, muscular and nervous tissue

epidermis and dermis

these two make up the cutaneous membrane

epidermis

keratinized stratified squamous epithelium

dermis

areolar+dense irregular connective tissue and smooth muscle tissue

subcutaneous

areolar and adipose connective tissue and blood vessels make up this layer

protection, heat regulation, absorption, secretion, excretion, sensation

6 functions of the integument

UV rays, infection, abrasion, dehydration; prevents chemicals from getting into deeper tissue

skin protects our bodies from…

maintaining 98.6 degree F via homeostasis; subcutaneous insulates

skin regulates heat by…

whatever you put on it, Vitamin D, water, lotion, etc

skin absorbs…

water, salts, urea via sweat

skin secretes…

sebum (iols)

skin excretes…

presure, pain, temperature

skin senses…

5

number of layers in the epidermis

basale/germinativum

layer of cuboidal/low columnar cells on the basement membrane separating the epidermis from the connective tissue of the dermis; contains 3 different types of cells

keratinocytes

keratin-making cells located throughout all epidermal strata

keratin

tough, insoluble protein that helps give skin strength and make it water resistant and prevent dehydration

melanocytes

melanin-making cells that have long/branch-like processes; production of melanin in response to UV light exposure

merkel cells

aka Tactile cells; when compressed, release chemicals that stimulate nerve endings, which provides infor about the stimulus

stratum spinosum

multiple layers of polygonal keratinocytes; aka spiny layer

stem cells in the stratum basale get pushed up towards the stratum spinosum

how are new cells formed in the stratum spinosum?

desmosomes

these bind keratinocytes together in the stratum spinosum

langerhans cells

aka epidermal dendritic cells; fight infection in the epidermis

3-5

number of layers of keratinocytes located within the stratum granulosum

keratinization

begins in the granulosum layer

keratinization

keratinocytes fill up with protein, causing the nucleus+organelles to die, killing the cell; dead cells reach the epidermis and strengthen it

stratum lucidum

the clear layer; 2-3 layers; found only in thick skin located in the palms and soles

eleidin

found in the stratum lucidum; protects skin form UV light

stratum corneum

visible cells of the skin that are 20-30 layers thick; dead, scaly and anucleate

2 weeks

how long it takes new skin cells to become part of the stratum corneum

2 weeks

how long skin cells stay in the stratum corneum before being sloughed off

stratum corneum

thickness and the anti-bacterial protein found in sweat from the exocrine glands help prevent bacterial growth in this layer

stratum lucidum

this layer is missing from thin skin

thick skin

0\.4-0.6 mm, all 5 strata layers, located on palms and soles, and only contains sweat glands

thin skin

0\.075-0.150 mm, 4/5 strata layers, located all over the body, and contains hair follicles, sebaceous and sweat glands

hemoglobin

red pigment

melanin

black, brown, tan, yellow-brown pigment

carotene

yellow/orange pigment

carotene

gets converted to Vitamin A which helps with vision; can be acquired from yellow/orange veggies; reduces potentially dangerous molecules called free radicals which allows the immune cell number to increase

stratum corneum

carotene accumulates in this layer

amino acids

instead of using UV light, sunless tanners use an ingredient that binds with ____ _____ in the cells of the superficial layer of skin

nevus

mole; an overgrowth of melanin-forming cells in one area; harmless

freckles

localized areas of increased melanocyte *activity;* affected by sun exposure and heredity

capillary hemangioma

strawberry colored birthmarks; benign tumor caused by increased number of blood vessels; present at birth but disappear

cavernous hemangioma

port-wine stains caused by large blood vessels; may last a lifetime

friction ridges

whorls pattern; formed from large folds and valleys of the dermis/epidermis

friction on contact

fingerprints are flexible and unique but their shape allows for

dermis

layer beneath the epidermis; 0.5-3.0 mm thick

collagen, elastic, and reticular fibers

connective tissues found in the dermis

papillary and reticular

layers of the dermis

papillary dermis

areolar CT, contains dermal papillae and epidermal ridges that increase surface area and connect epidermis to the dermis

dermal papillae

this feature of the papillary dermis contain capillaries for nutrients as well as sensory nerve endings

reticular dermis

dense irrgular CT; hair follicles, sebaceous and sweat glands, nerves, blood vessles

parallel

surgical cuts made ____ to cleavage lines will minimize scarring

perpendicular

surgical cuts made ____ to cleavage lines will increase scarring

absorbs

keratin _____ water

subcutaneous layer

pads+protects the body, acts as an energy reservoir and provides thermal insulation; allows for independent movement of skin and muscle

areolar and adipose CT and blood vessles

tissues that form the subcutaenous layers

dermis; epidermis

collagen in found in the _____while kertain is found in the _____

basale layer

you shouldn’t pop blisters because you risk introducing bacteria into this layer

pacinian corpuscle

mechanoreceptor that is sensitive to high frequency vibration and deep pressure

true

true/false: the basale layer is close to blood vessels

spinosum

starshaped cells are located in the stratum _____

granulosum

the darkest and grainy layer is the stratum _____

lipids

vesicles of ____ accumulate to make the the granulosum layer grainy and stain it

cyanosis

bluish tint caused by darker hemoglobin because of a lack of oxygen

jaundice

yellowing of skin because of liver failure

tumor

overgrowth of cells

vitiligo

auto-immune disease that causes a depletion of pigment in the skin

basal cell carcinoma

originates in the stratum basale; rarely fatal; most common skin cancer; usually occurs on the face

squamous cell carcinoma

develops in the keratinocytes of stratum spinosum; non fatal but can be agressive; red, scaly lesions

melanoma

most dangerous skin cancer that forms in the melanocytes, usually in a preexisting mole; good survival rate when detected early

dermal innervation

distribution of nerve fibers

detect touch

merkel cells and meissner’s corpuscles

bare nerve endings

pain caused by…

detect pressure

lamellated or Pacinian corpuscles

plexus

network

bruise

ruptured blood vessel

hematoma

deep bruise

vasodilation

the dilatation of blood vessels, which decreases blood pressure.

vasoconstriction

the constriction of blood vessels, which increases blood pressure.

lanugo

baby hair

vellus

peach fuzz (on face, neck, arms, legs, trunk)

terminal

regular pigmented hair

33 mm/day

daily growth of hair

pheomelanin

orange melanin

eumelanin

brown/black melanin

aging

loss of melanocytes

grey

a very small amount of pigment in hair

white

no pigment at all in hair

anagen stage

active phase of hair where normal growth occurs

catagen stage

transition phase when the hair stops growing and detaches from the base of the follicle; can be caused by stress

telogen stage

resting phase when growth stops and club hair is completely formed

sympathetic neurons

work automatically; you don’t have to think about it; help with fight or flight responses

sebaceous glands

type of holocrine gland that secretes sebum

arrector pili muscle

contract consistently to push oil out of sebaceous glands

sebum

inihibits bacteria growth and lubricates

dandruff

dried oil and dead skin cells; cradle cap in babies