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
body fluid
all of the body’s water and dissolved solutes
type of vein that is up to 1 mm in diameter and has one or two layers of smooth muscle in the tunica media with a thin tunica externa
muscular venules
type of vein that has a thin tunica media and externa and relies upon skeletal muscle to act as a pump and drive blood back toward the heart
medium veins
what are the two places that body fluid is distributed between?
intracellular fluid compartment and extracellular fluid compartment
what is the intracellular fluid compartment and how much body fluid is found here?
consists of the cytoplasm and cisternae of organelles about 2/3 (67%) of body fluid is found here
what does the extracellular fluid compartment consist of and how much fluid is found here?
found in blood vessels as plasma, found in interstitial fluid, and Transcellular fluid. about 33% of body fluid is found here
what percent of extracellular fluid is found in blood vessels as plasma?
~20%
what percent of extracellular fluid is found in interstitial fluid?
~78%
what percent of extracellular fluid is found in transcellular fluid and what is transcellular fluid?
~2% - things like synovial fluid and CSF
how much blood is in the systemic veins/venules?
60-64% of blood
how much blood is in systemic arteries/arterioles?
12-15%
how much blood is in pulmonary vessels?
8-12%
how much blood is in the heart?
~8%
how much blood is in the capillary beds?
~5%
what is the purpose of the basement membrane in capillaries?
can restrict the movement of substances through the endothelium, or it can allow substances to leak out
small spaces between endothelial cells
intercellular clefts
what are the different types of capillaries classified on?
the size of intercellular clefts, and how easily substances can cross the capillary
what are the three types of capillaries?
continuous, fenestrated, sinusoidal
has a basement membrane, cells contain fenestrae, leaks fluid and fluid flows more freely
fenestrated capillaries
continuous tube of endothelial cells, average capillary, most restrictive, well-developed basal lamina
continuous capillary
leakiest capillary, poorly developed basal lamina if it has one, large diameters, large intracellular clefts, large fenestrations
sinusoidal capillaries
cells that wrap around continuous capillaries and restrict blood flow by contracting around the capillary
pericytes
type of capillary found in bone, cartilage, brain, connective tissue
continous capillary
type of capillary found in liver, spleen, red bone marrow, and parathyroid gland
sinusoidal capillaries
type of capillary found in glomeruli, villi of small intestines, ciliary bodies, choroid plexus, and endocrine glands
fenestrated capillaries
where are capillaries absent or scarce?
tendons, ligaments, epithelia, cornea, and lens of the eye
what kinds of solutes can pass through continuous capillaries?
glucose
in what type of organs are fenestrated capillaries found?
organs that require rapid absorption or filtration
what are fenestrae?
holes in endothelial cells that are spanned by very thin glycoprotein layer and that allow passage of small molecules
what types of things do sinusoidal capillaries allow to enter the blood stream?
proteins, clotting factor, and new blood cells
collection of capillaries that connects metaarterioles with venules.
capillary bed
control whether blood enters the capillary bed
pre-capillary sphincters
passageway that blood travels through to get from a metarteriole to a venule when it doesn’t enter the capillary bed
thoroughfare channel
how much of a body’s capillaries are shut down at any given time?
3/4
what is the simplest route for blood to flow?
through only one set of capillaries
heart - arteries - arterioles - capillaries - venules - veins - heart
flows through 2 consecutive capillary beds
portal system
point where 2 blood vessels merge
anastomosis
arteriolevenous anastomosis
an artery directly attaches to a vein and bypasses a capillary bed
where is the portal system found?
between the hypothalamus and anterior pituitary, in kidneys, and between intestines to liver
most common type of anastomosis
venous anastomosis
one vein empties directly into another
venous anastomosis
two arteries merge, creating an alternate route of blood supply to the tissues, usually found in joints and coronary circulation
arterial anastomosis
what are the three main routes that substances take to move across capillaries?
endothelial cytoplasm, intercellular clefts, fenestration
what are the three mechanisms to move things across the cellular membrane
diffusion, transcytosis, and bulk flow
movement of substances across cells using vesicles
transcytosis
outward force - force of water out of capillaries and into tissues
filtration
inward force - force that draws water into the capillary and out of tissues
reabsorption
opposing forces involved in capillary dynamics
starling forces
are glucose and oxygen more concentrated in the blood or in the tissues? how does this affect their flow in capillaries?
they are more concentrated in the blood, so they diffuse out of the blood and into the tissues
what are the starling forces?
Blood hydrostatic pressure and plasma colloidal pressure, tissue hydrostatic pressure and tissue colloidal/osmotic pressure
HPc
blood hydrostatic pressure
OPp
Plasma Colloidal Pressure
blood pressure inside the capillary that drives fluid out
blood hydrostatic pressure
what creates the blood hydrostatic pressure?
the pumping of the heart
what is the norm for HPc
32-37 mmHg
what creates OPp
plasma proteins that don’t leave the plasma
what is the pulling force for water and other substances into the capillary and what force does this have to do with?
albumin in plasma colloid pressure
how does albumin work to pull water into the capillaries?
it dilutes water on the inside and causes water to enter the capillary by osmosis
what is the water pressure of the tissue
tissue hydrostatic pressure
why is the tissue osmotic pressure negligible
there is very little albumin in the tissues
Pi
Tissue Hydrostatic pressure
(pi)i
tissue colloidal/osmotic pressure
about how much fluid doesn’t get reabsorbed into the blood stream and where does this fluid go?
10-15% goes into the lymph
when does filtration occur?
when HPc is higher than OPc
why is it common for venous pressure to be lower than arteriole in HPc
further from the heart, filtered out a lot of fluid in the capillaries at the arteriole end, increased friction of the plasma in the capillary as it moves
why is OPc about the same on both the arteriole and venule ends?
proteins haven’t left the blood
when does reabsorption occur?
when OPc is higher than HPc
what are variations in typical capillary fluid dynamics?
glomeruli in the kidneys and the alveolar capillaries in the lungs
about how much fluid that is filtered do capillaries reabsorb?
85%
how does activity or trauma affect filtration?
it increases it
capillaries usually absorb most of the fluid they filter. Where are the exceptions?
in the kidneys - glomeruli, and in the alveolar capillaries in the lungs
accumulation of excess fluid in the tissue
edema
what causes edema to occur?
filtration without adequate reabsorption, fluid accumulates in the tissues
what are the two types of edema
pitting edema and myedema
what causes the pit in pitting edema?
when pressure is applied to the area, it causes reabsorption of the fluid in that area, and the pit is formed
myedema
endocrine disorder (thyroid disease) - connective tissue builds up and capillary dynamics is disrupted
what factors affect edema?
increase in HPc, Decrease in OPc, Increased capillary permeability, increased Hydrostatic pressure
how does an increase in HPc affect edema?
it leads to more filtration, more fluid moves into the tissue, but there isn’t more reabsorption
how does a decrease in OPc affect edema?
fluid is not moving from the tissue into the capillary, accumulates in the tissues. this is based upon the amount of plasma protiens - why starving kids have big bellies
how does increased hydrostatic pressure affect edema?
thrombosis or blockages in a vein, fluid leaks into tissue to decrease pressure of vessel - increases filtration
what causes increased capillary hydrostatic pressure
hypertension
what causes decreased colloid pressure
starvation or liver damage
what causes increased capillary permeability
inflammation
what causes an increase in hydrostatic pressure
thrombosis or a blockage in a vein
