Histology Flashcards
what is histology
study of tissues
what is tissue def
group of cells with similar struct;ure, function, and embryologic origin. or collection of cells and cell products that perform specific limited functions
what are the three germ layers
ectoderm
mesoderm
endoderm
what does ectoderm become
epithelium and nervous tissue
what does mesoderm become
muscle, connective tissue and epithelium tissue
what does endoderm become
epithelium tissue
what do all cells carry out?
complete dna insturctions for all body structures and functions
is the genome identical within an organism
yes (minus mutations)
what does it mean that cells are specialized
they are desinged for differenent functions
what does differentiation depend on
which genes are active and which are inactive
Active vs inactive (protein activity)
Active- proteins produced
Inactive- proteins suppressed
heterochromatin def
dna that is highly folded
this is linked to inactive genes
euchromatin def
dna that is less folded
this is linked to active genes
what are the 4 classes of tissues
epithelial
connective
muscle
nervous
epithelial tissue main function
line/protect surfaces
connective tissue main function
play a variable role in support
muscle tissue main function
to generate movement
nervous tissue main function
to communicate with electiricity
what layer does epithelial tissue form from
all 3 germ layers
what layer does connective tissue form from
mesoderm
what layer does muscle tissue form from
mesoderm
what layer does nervous tissue form from
ectoderm
List the types of epithelial tissue
simple squamous
simple cubodial
simple columnar
psudostratified columnar
stratified squamous - dry and wet
list the types of connective tissue
loose (areolar)
adipose
dense, regular
dense, irregular
hyaline cartilage
compact bone
list the types of muscle tissue
skeletal
cardiac
smooth
list the four types of tissues
epithelial tissue
connective tissue
muscle tissue
nervous tissue
coagulation def
clotting
what do damaged / dead cells do
release chemicals
what 2 chemicals can dead cells release
histamin and heparin
histamin does what
increase blood flow and increase permeability of blood vessels
vasodialation def
increase blood flow
heparin does what
is a anticoagulent
mast cells do what
release more inflamatory chemicals (like histamin and herapin)
what does inflammation represent usually
an increase in blood flow to promote repair
what comes with inflammation
swelling, redness, heat, pain, sometimes pus,
what is the positive of pain
it reduces activity in the area to promote repair
what has high regeneration
epithelial, bone, some connective tissue
what has low regeneration
smooth muscle, and dense regular CT
what has very low regeneration
skeletal muscle, cartilage
what has no regeneration
cardiac muscle, neurons
what is scar tissue
Connective tissue replacement of damaged tissue
what does collagen mainly do
holding things together or filling space
What are the 3 impacts of age on tissues
increased likelihood of damage
decreased ability to repair
increased rates of cancer
increased likelihood of damange because of why
thinner epithelium/CT
or decreased elastin and collagen
thinner or weaker bones
neuropathy
what is neuropathy
a decrease in sensation due to degeneration of peripheral nerves
what are peripheral nerves
axons
what is the decreased ability to repair associated with
a decrease in energy consumption and a decreased blood flow
pressure sores indicate what
decreased blood flow because of continuous pressure
increased rates of cancer with age are because of what
because cancer results from accumulated damage to DNA and is also largely related to time and exposure
