Tissues Flashcards
what are the four primary types of tissue in the human body?
connective
epithelium
muscle
nervous
define tissues
group of cells with similar structure and function
where can you find epithelium tissue?
body linings and coverings
glandular tissue
functions of the epithelium
secretion
absorption
filtration
protection
how are epithelium classified?
number of layers (first name) and shape of the cell (last name)
squamous
flat squished cells with a flat nucleus
allows for materials like oxygen to easily move across
fast absorption and diffusion
cuboidal
cube like cells
circular nucleus
absorption of nutrients and secretion
columnar
tall thick cells
ellipse nucelli
absorbs nutrients and produce secretions
simple
one layer
stratified
more than one layer
avascular
no blood supply
how does the epithelium get the materials they need?
from the connective tissues surrounding them
characteristics of epithelium
cells fit close together and form sheets
selective permeability
regenerate if well nourished
appical
upper side of tissue
located outside body or whatever internal cavity it is lining
basal
rests on basements membrane
inner side of tissue
simple epithelia
forms membranes that line body cavities
lines lungs and capillaries
simple cuboidal
common in glands and ducts
forms walls of kidney tubules
covers the ovaries
simple columnar
lines digestive tract
includes mucus producing goblet cells
pseudostratified columnar epithelium
single layer with some shorter cells
may be ciliated in the respiratory tract
may function in absorption of secretion
stratified squamous
protective covering where friction is common
located in the skin, mouth and esophagus
transitional epithelium
shape of cells depends on amount of stretching
lines organs of the urinary system
glandular epithelium
endocrine gland (secretes hormones, ductless bc secretions diffuse into blood vessel) and exocrine glands (secrete sweat and oil, secretions empty through ducts to the epithelial surface)
gland
organ specialized in secreting substances
epithelium
primary tissue
covers the surface of the body and lines body cavities, ducts and vessels
selective permeability
barrier allows some substances through and excludes others based on what the cell needs
functions of connective tissue
binds body tissue together
supports the body
provides protection
extracellular matrix
nonliving material that surrounds living cells
what are the main elements of extracellular matrix?
ground substance and fibers -
collagen (white)
elastic (yellow)
recticular
ground substance
mostly water, adhesion proteins and polysaccharide molecules
name the 8 types of connective tissue
dense connective (fibrous tissue)
loose connective (aerolar)
loose connective (adipose)
hyaline cartilage
bone (osseous)
blood (vascular)
fibrocartilage
elastic cartilage
bone (osseous tissue)
composed of osteocytes in lacunae cavities
hard matrix of calcium salts and collagen fibers
used to support and protect the body
erythropoiesis
hyaline cartilage
glassy, most common type of cartilage provides support, rich ground substance with starchy proteoglycans
composed of collagen fibers and rubbery matrix
located in larynx, fetal, skeleton and joints
elastic cartilage
found where strength and stretchability is needed
found in external ear and epiglottis
provides elasticity
chondrocytes (cartilage cells)
fibrocartilage
forms cushion like discs between vertebrae to keep bones from grinding together
highly compressible, shock absorbs
thick fibers of collagen
good at withstanding pressure
dense connective tissue
dense fibrous tissue
main matrix is collagen fibers
tendons ligaments and forms dermis
thicker/arranged erratically
tendons
attaches skeletal muscle to bone
ligaments
attaches bone to bone at joints
dermis
lower layers of skin
irregular/regular dense connective tissue
irregular dense connective tissue are nonparallel and found where tension may be exerted in areas
loose connective tissue (areolar)
most common and widely distributed connective tissue
soft and pliable like cobwebs
fibroblast cells
soak up excess fluid, lots of room for edema, swelling, etc.
found under epithelial tissue wrapped around organs
edema
swelling caused by too much tissues
loose connective tissue (adipose)
contain liquid deposits filled with fat
adipocytes share airy disposal of fibers
insulates body against heat loss
serves as a site for fuel storage
protects some organs
organelles get pushed to side
loose connective vs dense connective tissue
loose connective has fewer fibers and more ground substance
dense connective tissue has more fibers and less ground substance
blood (vascular)
surrounded by fluid matrix called plasma with protein fibers floating around it
functions in transport
recticular tissue
like areolar tissues but with a woven mess of reticular fibers rather than collagen and elastic
provides soft internal framework of spleen, lymph nodes and bone marrow
supports developing blood cells
what are the three types of muscle tissue?
skeletal
cardiac
smooth
which of the 3 muscle tissue types is voluntary?
skeletal
irritability
ability to react to stimuli
skeletal muscle
attached to skeleton
contracts on bones and joints to produce movement and facial expressions
long, striated, cylindrical
multinucleated
cardiac muscle
only found in the heart wall
as contracts it acts as a pump to propel blood through blood vessels
striated, short cells
one nucleus per cell
branched shape allows for cells to fit closely together to form intercalated discs
smooth muscle
not striated
long with tapered ends
one nucleus per cell
found in hollow organs (stomach, uterus, blood vessels)
spindle shaped cells
nervous tissue
composed of nerves and neuroglia
sends impulses to other areas of the body
which muscle tissue type contracts the slowest?
smooth muscle tissue
neuroglia
type of supporting cell that insulates, protects and supports neurons in the structures of the nervous system
what are the hallmarks of connective tissue?
extracellular matrix and varying vascularity
areola
small open space
how do some of the connective tissues vary in blood supply?
cartilage connective tissues don’t have any nerves or blood
dense connective has poor blood supply
some connective tissues are well vascularized
what do all four primary tissue types have in common?
all tissues have a matrix
how does a neurons structure determine its function?
a neurons long processes allows a single neuron to conduct an impulse to distant body locations
which fiber type provides strength to connective tissues?
collagen fibers
intercalated discs
specialized connections for communication between cardiac muscle cells containing gap junctions and desmosomes
goblet cells
simple glands that produce mucus
basement membrane
thin layer of extracellular material to which epithelial cells are attached in mucosa surfaces
mucous membrane
forms the linings of body cavities open to the exterior
ex: digestive, respiratory, urinary, reproductive tracts
serous membrane
membrane that lines a cavity without an opening to the outside of the body
(excludes joint cavities)
desmosomes
anchoring junctions prevent cells from being pulled apart
gap junctions
allow for communication between cells
tight junctions
binds cells into leak proof sheets
regeneration
replacement of destroyed tissues by the same kind of cells
fibrosis
repair by dense connective tissue by formation of scar tissue
when does fibrous usually occur?
depending on the type of tissue and severity of it
what are the three events of tissue repair in order?
capillaries become permeable
granulation tissue forms
regeneration of surface epithelium
granulation tissue
delicate pink tissue composed of new capillaries
capillaries become permeable
blood clot forms
granulation tissue forms
wound begins to shrink
regeneration of surface epithelium
scab detaches
which tissue types regenerate poorly?
skeletal, cardiac and nervous tissue within brain and spinal cord
which tissue types regenerate well?
fibrous connective tissue, bone and epithelial tissue (skin and mucous membranes)
endocrine system
secretes hormones
ductless since secretions diffuse into blood vessels
exocrine system
secrete sweat and oil
secretions empty through ducts of the epithelial surface
major connective tissue from most rigid to most fluid
bone
cartilage
dense connective tissue
loose connective tissue
blood
