This is a great outline and you may download and print
these two pages to study from
RESPONSE TO INJURY
Inflammatory and repair processes
Inflammation – most injuries promote an inflammatory response. A cut
produces four symptoms: heat, redness, swelling and pain.
The injury will tear
cells, releasing their contents. This signals an inflammatory
response. Injured cellssignal nearby blood vessels to dilate,
increasing blood flow to site. The remainder of the process will
be covered in physiology
Repair – 2 ways
replacement of destroyed tissue by new tissue
proliferation of a fibrous connective tissue called scar tissue
TISSUES THROUGHOUT LIFE
EPITHELIAL TISSUE THINS
AMOUNT OF COLLAGEN DECLINES
TISSUE REPAIR LESS EFFICIENT
WOUNDS HEAL SLOWLY
BONE, MUSCLE AND NERVOUS TISSUES ATROPHY
THESE ISSUES MAY BE DUE TO POOR DIGESTION OR POOR CIRCULATION IN ADDITION
TO THE NATURAL AGING PROCESS
What you need to know:
Here's a video that I made for you with many of the
slides that I'll use on the exam
This is an excellent video covering the 4 tissue
types as well as membranes. His objectives are the same as yours.
Cell to Cell Junctions You need to know
This chart has links to each tissue type. When
you look at a tissue, ask yourself the following questions: which of the 4
tissue types am I looking at? Then:
What is the cellularity? (how
many cells are there)
How much matrix is there?
What does the matrix look like?
Are there fibers?
Where are the nuclei?
Click on any of the links below to find
out more and to see slides
Gap junctions are intercellular channels some 1.5–2nmin
diameter. These permit the free passage between the cells of ions and small
molecules (up to a molecular weight of about 1000daltons).
They are cylinders constructed from 6 copies of transmembrane
Because ions can flow through them, gap junctions permit
changes in membrane potential to pass from cell to cell.
(cardiac) muscle flows from cell to cell through the heart providing the
rhythmic contraction of theheartbeat.
At some so-calledelectrical
synapsesin the brain, gap
junctions permit the arrival of an action potential at the synaptic
terminals to be transmitted across to the postsynaptic cell without the
delay needed for release of aneurotransmitter.
As the time ofbirthapproaches,
gap junctions between the smooth muscle cells of the uterus enable
coordinated, powerful contractions to begin.
Several inherited disorders of humans such as
certain congenital heart defects and
certain cases of congenital deafness
have been found to be caused by mutant genes encodingconnexins.
Desmosomes are localized patches that hold two cells tightly
together. They are common in epithelia (e.g., the skin). Desmosomes are
filamentsof keratin in the
diseasein which the patient
has developed antibodies against proteins (cadherins)
in desmosomes. The loosening of the adhesion between adjacent epithelial
cells causes blistering.
cancers of epithelia. However, the cells of carcinomas no longer have
desmosomes. This may partially account for their ability tometastasize.