Chap 4 tissues Flashcards
Tissues
fabric or group of cells with similar structure and function
primary types of tissues
epithelium (covering
connective (support)
Muscle (movement)
Nervous (control); signaling
how do you identify tissues?
- cells
- ECF (extracellular fluid); ground substance
- fibers
biopsy
living tissue
autopsy
determing cause of death after death
epithelial tissues
sheet of cells that cover all free body surfaces (inside and out) forming an interface between two environments
line internal tubes, form organs
what are the functions of epithelial tissues?
- protection
- absorption
- filtration
- secretion
- sensory reception
what are the special characteristics of epithelial tissues?
- cellularity
- specialized contacts
- polarity
- supported by connective tissue
- avascular but innervated
- regeneration
cellularity
tightly packed cells
desmosomes
confers strength
anchoring junctions between cells that provide structural strength
apical surface
(free surface) surface that is in contact with air or opening
basal surface
(bound surface) usually bound to connective tissue
apical surface special structural features
surface area is increased
microvilli
cillia
microvilli
fingerlike extensions that increase the surface area, which increases absorption and secretion
may create adhesion points for secreted mucus
cillia
microtubules (hair like) project from cell membrane as hairs that move in one direction
nicotine decreases cilliary action
lateral cell junctions
desmosomes
tight junctions
gap junctions
tight junctions
rivets that seal extracellular space
gap junctions
allow substances to leak between cells
what makes up the basal surface?
basal lamina
basement membrane
basal lamina
noncellular, adhesive sheet of glycoproteins secreted by epithelial tissue
functions of basal lamina
selective filter
scaffold to which epithelial cells can grow upon
basement membrane
just beneath the basal lamina
reinforces epithelial sheet and defines epithelial boundary
how to classify epithelium tissue?
1st name is the # of cell layers
2nd name is the shape of cells
cell layers
simple - one layer
stratified - more than one layer
pseudostratified - looks like multiple but only one
shape of cells
squamos - flat; nucleus - flat and disc like
cuboidal - cube shaped; nucleus - large and round
columnar - column like; nucleus - oval
glands
one or more epithelial cells organizes to secrete a particular product
secretory pathway
RER –> golgi –> vesicles –> exocytosis
2 major gland types
endocrine glands
exocrine glands
endocrine glands
ductless
secretions are hormones
hormones
manurfactured to react with a specific target organ and or cells
exocrine glands
secrete products to a body surface (skin surface, body cavities, or passages leading to outside)
unicellular exocrine glands
single goblet cell secretes mucin
multicellular exocrine glands
sweat and oil glands
connective tissue classes
- connective tissue proper
- cartillage
- osseous tissue (bone)
- blood
functions of connective tissue
- binding
- protection
- insulation
- transportation
structural elements of connective tissue
- cells
- ECM (extracellular matrix); made up of fibers and ECF
connective tissue cell types
fibroctye, can become fibroblasts
chondrocyte, (chondro=cartillage)
osteocyte
red blood cells/ white blood cells
ECM (extracellular matrix) composed of…
ground substance (ECF)
ffibers
composition of ECF
water
adhesion proteins/ desmosomes
polysaccharide molecules
types of fibers
collagen fibers (strength)
elastic fibers (recoil)
reticular fibers (fine collagen but give more)
muscle tissue function
produce movement
contain internal protein microfilaments for contraction
types of muscle tissue
skeletal muscle - attached to skeleton
cardiac muscle - branched
smooth muscle - organs
nervous tissue cell types
neuroglia
neurons
neuroglia
nerve support cells
all kinds of functions to support the neurons.
dont do electrical signals
functions of neurons
irriatability - can sense and respond
conductivity - send impulses to other areas of body
structrual components of neurons
dendrites - multiple, reciever
cell body
axon - 1, sender
axonal terminals - endpoint of axon
types of tissue repair
external defenses
internal defenses
external defenses of tissue repair
mechanical
chemical
microbiological
mechanical defenses of external tissue repair
skin
mucus membranes - collects things
chemicals defenses of external tissue repair
fatty acids - lower pH on skin, bacteria doesnt like acidity
enzymes (lysozyme & pepsin) - digestive enzymes
stomach acid
vaginal secretions
urine
internal defenses of tissue repair
inflammatory response
immunity repsonse
inflammatory response
nonspecific - chemicals and WBC
develops quickly
immunity response
specific - like antibodies
takes longer
2 ways tissue repair occurs
regeneration
fibrosis
regeneration
replacement of destroyed tissue with same kind of tissue
fibrosis
replacement of destroyed tissue with fibrous connective tissue
scar tissue
steps of tissue repair
inflammation
organization
regeneration and fibrosis
Inflammation
injured tissue cells, macrophages, mast cells, and other release inflammatory chemicals (histamines)
WBCs (neutrophils & monocytes) and plasma fluid rich in clotting proetines, antibodies and other substances seep into injured area
excess fluid, damaged cells, and other debris are evnetually removed by lymphatic vessels and/or phagocytized by macrophages
histamine functions
causes capillaries to dilate and become very leaky (permeable)
leads to redness, heat, swelling and pain (pain comes from fluid pressure on nerves)
functions of clotting proteins
clotting proteins form clot
stops loss of blood
holds edges of wound together
isolates injured area
clot eventually turns to scab after being exposed to air and drying
organization
starts before inflammatory response is complete
granulation tissue forms
macrophages digest blood clot and collagen fiber deposit continues
once enought matrix has accumulated, fibroblasts revert to resting stage or undergo apoptosis
granulation tissue
pink tissue found in wounds
fibroblasts secrete growth factors and new collagen fibers bridge the gap and pull wound together
apoptosis
programmed cell death
steps of regeneration and fibrosis
surface epithelium continues to grow under scab
fibrous tissue beneath matures and contracts until it resembles skin
end result is fully regenerated epithelium and underlying area of scar tissue
the thin white scar is collagen fiber
regenerative capacity of different tissues, from best to worst
- epithelial tissues, bone, areolar, and flood forming tissue
- smooth muscles and dense reular connective tissue
- skeletal muscle and cartillage
- cardiac muscle and nervouse tissue have no regeneration
