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made of 2 parts:
cutaneous membrane, or skin,
& accessory structures

6 integument functions

1. cover & protect
2. maintain body temperature
3. produce Vitamin D upon UV-ray exposure
4. detects sensory information
5. nutrient storage (fat, glucose, water, salt)
6. excretes waste

3 skin layers

2 cutaneous layers:
epidermis [epithelial tissue] & dermis [connective]
1 underlying tissue:
subcutaneous tissue [connective];
aka hypodermis


outer-most layer of skin;
epithelial tissue; has 5/4 layers or keratinocytes, macrophages, and melanocytes;

stratum corneum

outermost layer of epidermis; made of flattened, dead, keratinocytes; these cells slough off, mostly into bath or dust


skin cell that produces keratin
(vast majority of skin cells)


hard, waterproof protein found in epidermis, hair, and nails;

stratum lucidum

epidermal layer deep to the s. corneum;
5th layer found only in thick skin on palmar & plantar regions

stratum granulosum

epidermal layer deep to the s. corneum/s. lucidum;
keratinization (cell hardening) occurs here

stratum spinosum

epidermal layer deep to the s. granulosum;
contains live keratinocytes and macrophages to defend from pathogens

stratum germinativum

deepest epidermal layer; aka stratum basale;
keratinocytes undergo contstant mitosis here; cells then ascend through the epidermal layers until sloughed; melanocytes found here;


pigment that determines skin color; protects skin from UltraViolet rays (from sun or lightbulbs); produced in melanocytes in s. germinativum;


melanin-producing cell found in s. germinativum;


red-pigmented protein found in red blood cells; red when bound to O2; gives pink undertone in light-skinned people


rash of itchy wheals (raised hives); an acute allergic reaction




redness of skin; no raised wheals;
often from injury, infection, and inflammation, or blushing


yellowish pigment found in epidermis


fibrous connective tissue deeper than epidermis; contains accessory structures of skin;
provides nutrients to epidermis


column of dead, compacted keratinocytes produced in hair follicle; protects scalp and orifices; provides sensory information

hair follicle

tubelike pocket of epidermal cells that extends into dermis, where hair is produced

hair shaft

visible portion of hair

hair root

portion of hair inside the follicle below the epidermis

sebaceous gland

sebum (oil) gland of skin; often empties into hair follicle

ceruminous gland

found in external auditory canal; prodcues cerumen


ear wax;
protects eardrum (eg, trauma, infection, and dehydration

sudoriferous gland

sweat gland; produces sweat to cool body via evaporation

subcutaneous layer

connective adipose tissue layer deep to dermis; connects dermis to underlying muscle tissue; insulates and cushions; aka hypodermis;
no major organs: IDEAL for INJECTIONS (Sub-Q injections)

skin sensory receptor

provide Central Nervous System (brain & spinal cord) information from environment about touch & pressure, temperature, and pain


sheet of dead, compacted keratinocytes produced in; nail root; protects fingertips


superficial band of epidermis covering nail bed, made of keratinocytes

vitamin D

produced in skin upon UltraViolet radiation (light);
aka sunshine vitamin


blood vessels increase in size & bloodflow (eg, skin when body is hot); contributes to sweat & heat loss


blood vessels decrease in size & bloodflow (eg, skin when body is cold)

thin skin

skin type covering most of the body;
only has 4 layers, no s. lucidum

thick skin

skin type covering only on palmar & plantar regions;
has 5 layers, including s. lucidum

dermal papillae

folds, or ridges, of dermis into overlying epidermis;
contributes to fingerprints;
blood vessels and nerves inside;

4 tissue types

1. epithelial
2. connective
3. muscle
4. nervous

epithelial tissue

avascular cellular tissue that covers surface of body and lines internal organs;
cells are polar, attached to something, and regnerate when damaged

epithelial tissue functions

protects body, controls permeablity, senses environement, and secretes substances

germinative cell

stem cell, one which divides regularly

cell junction

form tight bonds with other cells or extracellular material;
3 types (strongest to weakest):
1. desmosomes
2. gap junctions
3. tight junctions


large complex of molecules, which are strongest intercellular junction; anchors cell

epithelial classes

layers [simple or stratified] & shape [squamous, cuboidal, columnar, (transitional)]


epithelium only 1-cell thick


epithelium more than 1-cell thick


flat, thin epithelial cell; looks "squashed" or like a fried egg


epithelial cells that look like cubes when cut


tall, slender epithelial cells


stratified epithelium with cells that stretch; ex, urinary bladder

exocrine gland

epithelial tissue that produces secretions onto epithelial surfaces

endocrine gland

epithelial tissue that releases hormones into blood

merocrine secretion

secretions released by vesicle exocytosis;
eg sweat

apocrine secretion

secretions released by shedding cytoplasm, or "pinching off top" of cell;
eg, milk

holocrine secretion

secretions released by cell bursting;
eg sebum

serous gland

secretes watery serous solution, used for lubrication (reduce friction)

mucous gland

produces thick, slippery mucous; also used for lubrication and as "fly paper" to catch debris

mixed gland

secretes both serous fluid & mucus

connective tissue

tissue with more matrix than cells; tissue characteristics depends on matrix; tissue with "more stuff than cells"


extracellular parts of connective tissues;
determines function of tissue;
"stuff outside connective cells";
eg, in bone: calcium phosphate, in blood: water, in adipose tissue: fat

connective tissue functions

support and protect (bone/cartilage)
transport materials (blood)
energy storage (adipose)
defense (lymph)

connective tissue types

connective tissue proper, ie loose & dense;
fluid connective tissues, ie blood & lymph
supportive connective tissues, bone & cartilage

connective tissue proper

loose & dense tissues comprise this class of connective tissue;
adipose, or fat, tissue is loose;
tendons & ligaments are dense

fluid connective tissue

blood & lymph comprise this class of connective tissue

supportive connective tissue

bone & cartilage comprise this class of connective tissue

connective tissue cell types

1. fibroblasts: form matrix
2. macrophages: devour pathogens
2. mast cells: release histamine (inflammation) and heparin (blood thinner)


strong, yet flexible protein; most-produced protein in body; found extensively in connective tissues (bone, skin, etc)


stretchy, but elastic, protein; found extensively in connective tissue (skin)

ground substance

clear, colorless, viscous (thick) substance;
fills spaces between cells;
slows pathogen movement

reticular fiber

thin collagen-like fiber; form supportive networks in a variety of tissues


fatty tissue; type of loose connective tissue that stores energy, insulates and cushions the body


dense connective tissue that attaches muscles to bones


dense connective tissue that attaches bones to bones


dense connective tissue deep to the epidermis (epithelial layer)


strong connective tissue, more flexible than bone; found on bone ends, trachea, intervertebral discs, etc.


stongest cartilage type; reduce friction upon bone to bone contact; functions as protective padding; found between vertebrae (intervertebral discs) and pad the knee (meniscus)

elastic cartilage

most-flexible cartilage type; found in external ear (pinna) and top of larynx (epiglottis)

hyaline cartilage

"in-between strength" cartilage; more flexible than fibrocartilage, but stronger than elastic cartilage; found at the tips of bones

muscle tissue

tissue that contracts; produces force, movement, and heat; 3 types: skeletal, cardiac, smooth

skeletal muscle

attached to skeleton;
moves body and creates most body heat;
striated (striped) in appearance

cardiac muscle

found in heart; moves blood;
involuntary; striated (striped) in appearance

smooth muscle

found in walls of tubular organs; involuntary; smooth (not striped) in appearance

nervous tissue

tissue made of neurons and neuroglia; receives sensory impulses (electrical signals) from the environment, analyzes the data (in brain/spinal cord), and directs motor output


specialized cell for electrical communication (aka, nerve impulses); basic building block of the nervous system; aka nerve cell


supporting cells of the nervous system; perform wide array of functions in brain/spinal cord; "nerve glue"


long extensions of the cell membrane;
receive electrical impules from other neurons, sending info to the cell body

cell body

part of cell containing nucleus;
in neurons, this part summates ("adds up") electrical impulses arriving from dendrites


long extension of neuron cell membrane that conveys electrical impulse away from cell body to another cell; "A"xons send impulses "A"way


where an axon communicates with a dendrite (or other cell) using electrical and chemical signals

cutaneous membrane

covers and protects body; aka skin

mucous membrane

lines cavities exposed to outside world; secretes protective, lubricating mucous; found in nose, lungs, intestines, etc

serous membrane

thin membrane covering internal body cavities; secretes serous fluid that keeps the membrane lubricated


serous membrane covering lungs and pleural cavity


serous membrane lining the heart and the pericardial cavity abdominal organs and the abdominopelvic cavity; covers a "ton" of organs


serous membrane lining the abdominopelvic cavity and organs

synovial membrane

found in joint cavities; secretes "eggy" fluid that lubricates the joint


tissure response to injury;
signs & symptoms: swelling, redness, heat, pain;
aka inflammatory response


presnece of harmful pathogen

cancer rate

1 in 4 (25%) of people in US develop cancer;
#2 cause of death,
cigarette smoking causes ~450,000 deaths including 50,000 from secondhand smoke


basic unit of life (of structure and function);
smallest living thing

cell theory

cells all:
1. make up all living things
2. are basic unit of life
3. come from another cell that divided
4. maintain homeostasis


science that investigates formation, structure, and function of cells

cell membrane

thin, flexible, phospholipid bilayer;
isolates inside of cell;
regulates what enters and exits cell;
senses environment;
supports sturcutres in and on cell


watery solution (cytosol) plus organelles;
minerals, gases, and organic molecules are suspended and react/interact here;
found between cell membrane and nucleus


watery-fluid portion of cytoplasm;
contains nutrients, ions (high K+ low Na+), and wastes


property of cell membranes: some substances pass through, others cannot


region within the nuclear envelope containing chromosomes (DNA); resposible for mitosis / meiosis; "control center" of the cell

number of chromosomes

46, in humans


structure inside the nucleus, where ribosomes are made


tiny cell structure, which perform specific cell function(s)


performs cellular respiration, which produces ATP (pure energy); "powerhouse" of the cell

Golgi apparatus

flatened sacs of membrane that modify, store, and route cell products; aka Golgi body


small particle in cell that assembles proteins; made of RNA and protein


oval membrane sacs, containing digestive enzymes

endoplasmic reticulum

network of membrane tubules; modifies proteins, synthesizes lipids, and transports them throughout cell

smooth endoplasmic reticulum

endoplasmic reticulum WITHOUT ribosomes attached

rough endoplasmic reticulum

endoplasmic reticulum WITH ribosomes attached


short, hair-like projections of cell membrane; move materials outside a cell: "cilia sweep snot"


long, tail-like projection of cell; provide motility (ie, moves cell); only in sperm (in humans)


cell division into two nearly identical daughter cells; both cells contain 46 chromosomes


sex-cell division; daughter cells contain only 23 chromosomes


movement of molecules from highly concentrated area to less concentrated area; ex, Kool-Aid spreads out in water, CO2 and O2 diffuse out of and into blood

concentration gradient

difference between area of high concetration of a given molecule versus another area of lower concentration


diffusion of water through a selectively permeable membrane; ex, water spreads into Kool-Aid

osmotic pressure

force of a concentration gradient of water;
force caused by movement of water from area of high concetration to low concetration

hydrostatic pressure

force needed to block osmosis;
eg, in body, heart provides this pressure

isotonic solution

solution whose solute concentration is equal to that inside a cell; thus, no osmosis

hypotonic solution

solution with less solutes than cell;
cell swells, due to osmosis

hypertonic solution

solution with more solutes than cell;
cell shrivels, due to osmosis


using pressure to force a solution through a filter; ex, blood pressure filters blood plasma in the kidneys


allows some things to pass through, while prevent other things passage; ex, coffee filter, water filter

active transport

molecule movement requiring energy (ATP); usually moving molecules across cell membrane from low concentration to high concentration-against diffusion;
ex, Na+-K+ exchange pump, and amino acid absorption in small intestine

passive transport

type of molecular transport requiring no energy (ATP);
eg absorbing water

facilitated diffusion

passive movement of molecules across cell membranes through protein channels/carriers; requires no energy, diffusion provides the force; ex, glucose-transporters that allow glucose from the blood to enter cells


process by which cell takes in material by infolding the cell membrane: ex, phagocytosis and pinocytosis


process by which a cell engulfs foreign substances or other cells; "cell eating"; white-blood cells, called phagocytes, engulf pathogens


process by which certain cells engulf and incorporate droplets of fluid; "cell drinking"


materials are released from the cell


total number of particles in a solution;
(eg, sugar, Na+, Cl-, amino acids)


moves 2+ substances in same direction at same time; performed by protein


moves 2+ substances in opposite directions at same time; performed by protein


anything that has mass (weight) and takes up space; made of atoms;
3 familiar forms: solid, liquid, gas;


ability to put matter into motion (aka produce work); using energy releases heat


smallest part of element that has the same chemical properties (ex, properties of rock, metal, etc.); made of nucleus & electron cloud;
contains 3 subatomic particles:
protons, neutrons, electrons


central portion of atom where protons and neutrons are found

electron cloud

region around atomic nucleus where electrons are likely to be found


positively charged subatomic particle found in nucleus; (p+); change the number of protons, change the element


uncharged subatomic particle found in nucleus; (n0); change the number of neutrons, get a radioactive isotope


atom's central region, made up of protons and neutrons

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