Exam 12: April 10-14 Flashcards
what are the types of hypotension?
hemorrhage and shock
what is hemmorrhage?
loss of plasma fluids
what is shock?
visceral bleeding
is hypertension chronic?
yes
patients are consistently higher than steady state
what is hypertension caused by?
usually due to increased peripheral resistance
somewhere out in the circulatory system we have increased resistance
resistance means we have something preventing flow from happening
we have lots of tubing in our body and the resistance can be anywhere out in the system and if have a problem at any point then the heart will have to work harder to push past it
do we know specifically what causes hypertension?
no, the cause is often unknown
most of the time we can’t find where in the system that problem is
the small vessels are hard to pinpoint so we never actually try to resolve the underlying cause, we just treat the symptoms and try to lower BP so you can’t stop treatment or else the symptoms will come back
what organ is often associated hypertension?
kidneys
the blood gets filtered in the kidneys so if there’s a problem there, it can raise the blood pressure
kidneys make erythropoietin, EPO. EPO binds to recpetors in the bone marrow which makes RBC’s. However if too much EPO is produced by the kidneys, we will have too many RBC’s being produced. If we increase the RBC level above 45%, the plasma component of the blood will have to decrease and the blood will become more viscous. Viscosity is the resistance of flow, so the more viscous the blood, the more it resists the convective flow of the cardiovascular system (increases peripheral resistance) , and the heart has to work harder to pump the blood throughout the body, creating hypertension.
what does hypertension lead to?
ventricular hypertrophy
what is ventricular hypertrophy?
hypertension often leads to ventricular hypertrophy
you can get a quick response to raise BP through sympathetic but there isn’t an equivalent parasympathetic response to drop it back down
we don’t want our heart to sustain high BP because we need a bigger muscle with bigger volume and bigger pressure sustained
bigger heart creates 2 problems:
what two problems does ventricular hypertrophy lead to?
1) imposing on the lungs
2) heart binds on itself
how does ventricular hypertrophy impose on the lungs?
if you expand your heart, it’s not in an area that can be expanded
if you double your heart, it’s limited by your rib cage and you’ll be imposing on your lungs
individuals with heart conditions first go to their doctors thinking they have a pulmonary condition because their lungs can’t expand as far since their heart has taken over the space; shortness of breath is a common symptom
how does ventricular hypertrophy cause the heart to bind on itself?
when we try to squeeze in 3D, having too much tissue there can start binding on itself
for most people, making a bigger bicep isn’t a problem but ask some of the people at the Arnold to scratch their opposite shoulder and they can’t because their muscle is too big and it gets bound up; same thing goes for our heart
getting a bigger heart is good for a little but then problems start happening
what are the three components of the blood?
1) plasma
2) hematocrit
3) erythrocytes
how much of the blood is plasma?
55%
is plasma liquid of non-cellular?
plasma is he liquid part of the blood
our endocrines move through the plasma
plasma is 90% water which is what the endocrines move through
what happens if plasma levels drop?
plasma is the liquid portion of the blood used to transport endocrines and other things
if the amount of plasma drops then it’ll be harder to transport cellular components
what if there is too much plasma in the blood?
if you get too watery then you lose cellular function of components traveling through plasma
what are the components of plasma?
1) albumin
2) immunoglobulin
3) fibrinogen
what is albumin?
a component of plasma
helps us maintain oncotic blood pressure
volume is set by amount of water that’s there; the amount of albumin in the blood, draws water into the blood vessels via osmolarity
to change the amount of water in this area use osmolarity
albumin sets the right osmolarity so that the movement of water in our blood isn’t too much or too little
since the albumin controls the oncotic pressure (how much water goes into the blood & how much water goes out of the blood), the albumin can control BP. If a lot of water goes into the blood, the n in our PV = nRT equation will go up. Assuming that the V (size of our vessel) remains the same, this will increase the pressure and since the albumin controls this movement of water, it in turn controls the BP.
what is immunoglobulin?
a components of plasma
aka antibodies
also help maintain oncotic pressure = osmotic pressure in the circulatory system specifically
hyperthyroidism is caused by an antibody!
they are why we get shots to avoid diseases so that our immune system creates the immunoglobulin necessary
what is fibrinogen?
a component of plasma
fibrous protein that is inactive (“ogen”)
we want it moving around inactive so that when we need it, it’s there and accessible and we can activate it at the time and place needed
this is key for preventing blood loss
what are the functions of plasma?
1) transport
2) maintain BP
3) maintain pH
4) immunity
5) clotting
how does plasma help with transport?
transporting ions, oxygen, cellular components, and heat
this is why individuals that have pale skin and you can tell what’s going on with their temperature; if someone is cold they get pastier but if they’re warm, blood goes to the surface and they become more pink in the skin
in our extremes, when we’re too warm or cold, we raise HR to cool or heat areas of our body
what happens when people have pale skin?
plasma helps with transport
individuals that have pale skin and you can tell what’s going on with their temperature; if someone is cold they get pastier but if they’re warm, blood goes to the surface and they become more pink in the skin
how does plasma maintain blood pressure?
albumin helps us make sure we don’t overload amount of water
our V plays into pressure
how does plasma maintain pH?
albumin is critical for this process
immunoglobins play a distant second role in this process
how does plasma help with clotting?
it prevents blood from exiting blood vessels thorough fibrinogen
what is hematocrit?
the part of the blood made of red blood cells but it also includes the buffy white coat = leucocytes and platelets
what percentage of the blood of erythrocytes?
45%
how much of the blood is the white layer? what is in the white layer?
<1%
leucocytes = WBC and platelets
what are leucocytes?
WBC
it’s really just a catch-all category for anything that’s not RBC
what are platelets?
they work with fibrinogens to prevent blood loss
if you damage a blood vessel, platelets limit how much blood exits the system
platelets are highly derives cells that are often referred to as not being cellular because they’re lost so much of their cellular activity
what are the components of the hematocrit?
1) erythrocytes
2) leucocytes
3) platelets
when do people need blood transfusion?
if you don’t have the right amount of RBC, that is why we give people a whole blood transfusion rather than just an IV drip
how big are RBC?
they’re small
5-7 micrometers
why do you want RBC to be small?
RBC go through capillaries one at a time so the bigger the RBC are, the bigger the capillaries are and the bigger the capillaries, the slower diffusion is
you want RBC to be as small as possibly
how are RBC so small?
RBC have no nucleus or organelles to keep them as small as possible
what do RBC sacrifice because they’re so small?
they don’t have organelles so they lose mitochondria!
this limits ATP production so they’ll be making ATP only with anaerobic glycolysis (aerobic glycolysis would make NADH and there’s no TCA/ETC to use it because those are only in the mitochondria)
however, they don’t really have a need for ATP because they aren’t making new proteins since they don’t have a nucleus
they also don’t have to move on their own because they’re getting moved by convective flow of the heart
what is the shape of RBC?
biconcave ellipse shape
to get a RBC through a vessel better, you want a small diameter and to do that you can compress it into a cylinder so RBC are actually biconcave ellipse shaped
you don’t want RBC to be round
why do RBC have the shape that they do?
they are biconcave so that we can maximize surface area in the smallest space and depressions increase SA while maintaining minimum width = helps with diffusion
what are RBC packed with?
RBC are packed with hemoglobin!
what does hemoglobin do?
Hb does primary function of RBC which is transport
plasma does transport but that transport is an issue in terms of endocrines because it’s polar and some of the things we need to transport are non polar
well we need to transport oxygen which is a nonpolar components! The amount of oxygen that can be free in plasma is super low so you need to give it a plasma binding protein that is in a cell aka Hb
what is the function of RBC?
transport of O2, CO2, H+ and CO
what does Hb carry?
it carries CO2 waste and helps move H+ so it impacts pH levels
Hb also binds CO and binds at the same spot on Hb as O2
what’s the lifespan of an RBC?
120 days!! fast turnover rate
why do RBC have a short life span?
in order to have these super high levels of Hb in RBC, they had to lose their nucleus and organelles = no ATP or protein production
when Hb breaks down, we don’t get any more because we don’t have protein production
what is erythropoiesis?
the making of RBC
where does erythropoiesis occur?
in the bone marrow
what is the rate of RBC production?
you make 2-3 million RBC per second
you need lots of supplies or else that rate drops of
what does erythropoiesis need?
1) Fe
2) vitamin B12
3) folic acid
4) erythropoietin
why does erythropoiesis need iron?
Fe is necessary for Hb
you need 4 Fe per Hb
why does erythropoiesis need erythropoietin? (EPO)
EPO is made by the kidney and goes and binds to receptors in the bone marrow and causes bone marrow to make RBC
what makes erythropoietin?
it’s a protein made by the kidneys and it’s an endocrine
what do high EPO levels mean?
high EPO levels means bone marrow will make more RBC