200
the human body houses over ___ different cell types
size, shape, and function
cells vary in this
1/12,000 of an inch to over 1 yard (nerve cells)
cells vary in length from...
specialized function
cell shape reflects its...
fibroblast cells and erythrocyte cells
cells that CONNECT body parts
fibroblast
secretes cable-like fibers
erythrocyte (red blood cell)
carries oxygen in the bloodstream
epithelial cells
cells that COVER AND LINE body organs
epithelial cells
packs together in sheets; intermediate fibers resist tearing during rubbing or pulling
skeletal muscle and smooth muscle cells
cells that MOVE organs and body parts
skeletal muscle and smooth muscle cells
contractile filaments allow cells to shorten forcefully
fat cells
cells that STORE nutrients
fat cells
lipid droplets stored in the cytoplasm
white blood cells (such as the macrophage, a phagocytic cell)
cells that FIGHT DISEASE
white blood cells
digests infectious microorganisms
nerve cells (neurons)
cells that GATHER INFORMATION AND CONTROL body functions
nerve cells
receives and transmits messages to other body structures
oocyte cell and sperm cell
cells of REPRODUCTION
oocyte (female)
largest cell in the body; divides to become an embryo upon fertilization
sperm (male)
built for swimming to the egg for fertilization; flagellum acts as a motile whip
nucleoplasm and cytosol
intracellular fluids
intracellular fluid
interior of the cell; a solution containing gases, nutrients, and salts dissolved in water
extracellular fluid
exterior of the cell; contains thousands of ingredients such as nutrients, hormones, neurotransmitters, salts, and waste products
selectively permeable
the plasma membrane is a ____________________________________ barrier
passive processes and active processes
two basic methods of transport
active processes requires energy
difference between passive processes and active processes
passive processes
substances are transported across the membrane without any input from the cell
active processes
the cell provides the metabolic energy (ATP) to drive the transport process
isotonic, hypertonic, and hypotonic
type of osmosis solutions
isotonic solutions
have the same solute and water concentrations as cells and cause no visible changes in the cell
hypertonic solutions
contains more solutes than the cells do; the cells will begin to shrink
hypotonic solutions
contains fewer solutes (more water) than the cells do; cells will plump
vesicular transport
active transport process
vesicular transport
substances are moved across the cell membrane "in bulk" without actually crossing the plasma membrane
exocytosis (exit) and endocytosis
types of vesicular transport
exocytosis (exit)
bulk items are removed from the cell
endocytosis
bulk items are brought into the cell
phagocytosis and pinocytosis
types of endocytosis
phagocytosis
solids in
pinocytosis
liquids in
tissues
groups of cells with similar structure and function
epithelial, cartilage, dense connective tissue, loose connective tissue
four types of tissue
body coverings, body linings, and glandular tissue
locations of epithelial tissue
protection, absorption, filtration, secretion
functions of epithelial tissue
cover and lines body surfaces
hallmark of epithelial tissues; often form sheets with one FREE SURFACE, the apical surface, and a BASAL-anchored, regenerate easily if well-nourished; anchored surface: the BASEMENT MEMBRANE
avascular
no blood supply
simple or stratified
epithelial cell layers
simple
one layer of epithelial cell tissue
stratified
more than one layer of epithelial cell tissue
squamous, cuboidal, and columnar
shape of epithelial tissue cells
squamous
flattened like fish scales
cuboidal
cube shaped like dice
columnar
shaped like columns
simple epithelia
functions in absorption, secretion, and filtration; very thin (so not suited for protection)
simple squamous epithelium
single layer of flat cells, lines air sacs of the lungs, forms serous membranes (serosae) that line and cover organs in the ventral cavity, functions in diffusion, filtration, or secretion in membranes
LOCATION: usually forms membranes
simple cuboidal epithelium
single layer of cubelike cells, functions in secretion and absorption; ciliated types of propelling mucus or reproductive cells
LOCATION: common in glands and their ducts, forms walls of kidney tubules, covers the surfaces of ovaries
simple columnar epithelium
single layer of tall cells (GOBLET CELLS secrete mucus)
LOCATION: lining of the digestive tract from stomach to the anus, mucous membranes (mucosae) line body cavities opening the exterior, functions in secretion and absorption
pseudostratified columnar epithelium
all cells rest on a basement membrane; single layer, but some cells are shorter than others giving a false (pseudo) impression of stratification
LOCATION: respiratory tract, where it is ciliated and known as the pseudostratified ciliated columnar epithelium
stratified squamous epithelium
most common stratified epithelium, named for cells present at the free (apical) surface, which are squamous, functions as a protective covering where the friction is common
LOCATIONS: the lining of the... skin (outer portion), mouth and esophagus
stratified cuboidal epithelium
two layers of cuboidal cells; functions in protection
stratified columnar epithelium
surface cells are columnar and cells underneath vary in size and shape, functions in protection, both are rare in the human body
LOCATION: found mainly in ducts of large glands
transitional epithelium
composed of modified stratified squamous epithelium, shape of cells depends upon the amount of stretching, functions in stretching and the ability to return to normal shape
LOCATION: the lining of urinary system organs
stratified squamous epithelium, stratified cuboidal epithelium, stratified columnar epithelium
stratified epithelial tissues
glandular epithelia
one or more cells responsible for secreting a particular product
endocrine and exocrine glands
two major gland types that develop from epithelial sheets
endocrine glands
ductless; secretions (hormones) diffuse into blood vessels)
ex.) include thyroid, adrenals, and pituitary
exocrine glands
secretions empty through ducts to the epithelial surface
ex.) include sweat and oil glands, liver, and pancreas (both internal and external)
connective tissue
found everywhere in the body to connect body parts, includes the most abundant and widely distributed tissues
protein, support, binding
functions of connective tissue
variations in blood supply, some types are vascularized, some have poor blood supply or are avascular (none)
characteristics of connective tissue
extracellular matrix
nonliving material that surrounds living cells
ground substance and fibers
2 main elements of the extracellular matrix
ground substance
mostly water, along with adhesion protins and polysaccharide molecules
fibers
collagen (white) fibers, elastic (yellow) fibers, reticular fibers (a type of collagen)
bone (osseous tissue), cartilage, dense connective tissue, loose connective tissue, blood
types of connective tissue from most rigid to softest, or most fluid
bone (osseous tissue)
composed of osteocytes, hard matrix of calcium salts, large number of collagen fibers, and functions to protect and support the body
osteocytes
bone cells sitting in lacunae (cavities)
chondrocyte
cartilage cell
cartilage
less hard and more flexible than bone, found in only a few places in the body, chondrocyte is the major cell type
TYPES: 8 cartilage: most WIDESPREAD type of cartilage, abundant collagen fibers hidden by a glassy, rubbery matrix LOCATION: trachea, attaches ribs to the breastbone, covers ends of long bones, entire fetal skeleton prior to birth; epiphyseal (growth) plates in long bones
elastic cartilage: produces elasticity LOCATION: supports the external ear
fibrocartilage: highly compressible LOCATION: forms cushion-like between vertebrae of the spinal column
dense connective tissue
dense fibrous tissue
dense fibrous tissue
main matrix element is collagen fiber, fibroblasts are cells that make fibers
LOCATIONS: tendons, ligaments, dermis
tendons
attach skeletal muscles to bone
ligaments
attach bone to bone at joints and are more elastic than tendons
dermis
lower lays of the skin
Studied by 41 People