Test 2 Flashcards
ischemia
loss of blood to an area
Hypoxia
oxygen deprivation
how does hypoxia cause cellular injury?
Oxygen is the final electron acceptor in the electron transport chain which makes ATP, without the final electron acceptor, the cell cannot make enough ATP
What are the 7 causes of cellular injury?
toxins, foreign invaders, immunological reactions, genetic defects, nutritional balances, physical agents, aging
how do toxins cause cellular injury?
impede enzymes, affect membranes and metabolism
how do foreign invaders cause cellular injury?
they can produce toxins, or disrupt cellular function on their own
how do immunological reactions cause cell injury?
through responses to foreign invaders and through autoimmune diseases
how do genetic defects cause cell injury?
mistakes in DNA code for the wrong proteins and the wrong proteins are produced
how does aging cause cell injury?
alters ability to replicate, divide, or repair
what two things can cause an irreversible cell injury?
inability to disrupt mitochondrial function, and disruption of the cellular membrane
progression in how tissues respond to injury
Cellular Swelling, Hydropic Degeneration, Lipid Degeneration, Necrosis
what occurs during cellular swelling and why?
Na/K pumps need ATP to work. When they don’t work, Na accumulates inside the cell, and due to osmosis, water follows and also accumulates inside the cell. Reversible
what occurs during hydropic degeneration and why?
Cells need to do something with excess water inside the cell, so they channel the water to the smooth ER which puts them in vacuoles that detach from the smooth ER
vacuolization
vacuoles fill the cell and push organelles to the side
what happens during lipid degeneration and why?
Smooth ER is dealing with excess water and loses it’s primary function - lipid metabolism. lipid accumulates in the vacuoles with the water. All organelles are pushed to the sides and the vacuole resembles a mature adipocyte
necrosis
abnormal cell death that occurs with disease or injury - irreversible
What are the steps to necrosis?
pyknosis, dissolution of the plasma membrane, karyosis
condensation of nuclear material into a tight, dense spot
pyknosis
what is the problem with dissolution of the plasma membrane?
internal and external parts of the cell mix and cellular contents are released
occurs when the nuclear membrane breaks down and all that is left of the cell is fragments
karyosis
what does the fate of necrotic tissue depend upon?
the number of cells involved and the types of cells
what are the 5 fates of necrotic tissue?
phagocytosis, slough it off, scar it over, encapsulate it in connective tissue, or calcify it
what is the most popular way that the body deals with things it can’t get rid of?
calcification
how does calcification occur in the body?
change the pH in an area, calcium precipitates out and a calcium wall is formed
efferent vessels
arteries
afferent vessels
veins
smallest vessels
capillaries
layer closest to the blood that lines the interior of blood vessels
tunica interna
made of simple squamous epithelium, very smooth, acts as a selectively permeable barrier, can cause vessels to contract or dilate
tunica interna
made of smooth muscle, collagen, and elastic tissue, can change the diameter of a blood vessel in order to maintain blood pressure
tunica media
made of loose connective tissue, connects vessel with external environment, and contains a set of vessels that nourish the vessel
tunica externa or adventitia
vasa vasorum
set of vessels that nourish the tunica externa
changing the diameter of a blood vessel
vasomotion
simple squamous epithelium overlying a basement membrane and a sparse layer of loose connective tissue. what is it and where is it found?
tunica interna
how does the tunica interna function in dilation or constriction of the vessel
it secretes chemicals that cause the vessels to dilate or constrict
when tissue around a vessel is inflamed, what do endothelial cells produce that induce leukocytes to adhere to their surface? This causes leukocytes to congregate in tissues where their defensive actions are needed
cell-adhesion molecules
what layer of the vessel wall strengthens blood vessels and prevents blood pressure from rupturing them?
tunica media
distributing arteries
distribute blood from conducting arteries to the body parts
type of artery that is in control of how much blood is getting to the organ
resistance arteries
type of artery that connects arteries to capillaries and contains pre-capillary sphincters.
metarterioles
channel that blood moves through to get to veins from the arteries
thoroughfare channel
weak point in an artery or heart wall
aneurysm
this occurs when blood builds up between the layers of the arteries and separates them
dissecting artery
largest type of artery
conducting artery
what are some examples of a conducting artery?
aorta, common carotid, subclavian, pulmonary trunk, and common iliac arteries
internal elastic lamina
layer of elastic tissue at the border between interna and media in conducting arteries
where is the external elastic lamina in conducting arteries?
at the border between media and externa
what is the advantage of conducting arteries expanding during systole and recoiling during diastole?
it lessens fluctuations in blood pressure
what are examples of distributing arteries?
brachial, femoral, renal, and splenic
what type of artery is an arteriole?
a resistance artery
what are the most common sites for aneurysms?
abdominal aorta, renal arteries, and arterial circle at the base of the brain
baroreceptors - what are they and what arteries are they found in?
sense changes in pressure. they are in the carotid sinus - internal carotid artery
chemoreceptors - what are they and what arteries are they found in?
sense chemical changes - changes in pH, CO2, and oxygen. transmits signals to the brain stem. Found in common carotid arteries, and aortic bodies
veins that have smooth muscle in all tunics and can collapse or expand
large veins - 10 mm or larger
veins that have a thin tunica media and the tunica interna forms venous valves
medium veins - up to 10 mm
smallest veins, sometimes more porous than capillaries
venules