Patho Test 2 lect. 1 Flashcards
Hemodynamics is concerned with the _______ generated by the ______ and the resulting _______ of blood through the cardiovascular system
Hemodynamics is concerned with the forces generated by the heart and the resulting motion of blood through the cardiovascular system
What are 4 disorders that arise from a disruption of normal blood flow?
circulatory, cerebral, renal , and maternal
What is Om’s Law?
Q = P/R
What does P, in OM’s law mean?
pressure difference from a to b
What does R, in OM’s law mean?
resistance
True or False, Q in Om’s law = blood flow
TRUE
True or False, blood moves from areas of low P to high?
FALSE, blood moves from high P to low P
What is resistance determined by?
vessel length, radius, viscosity
If vessel LENGTH increases or decreases, what will happen to RESISTANCE?
L ^ = ^ R, v L = vR
IF RADIUS increases or decreases, what will happen to RESISTANCE?
r^ = vR, v r= ^R
If VISCOSITY increases or decreases, what will happen to RESISTANCE?
V^ = ^R, vV = R v
TRUE or FALSE, 99% of blood is made up of WBCs
FALSE, RBC
RBCs and plasma= _____
RBCs and plasma = Hct
IF you increase RBCs, what will happen to viscosity?
Increase
IF you decrease RBCs, what will happen to viscosity?
Decrease
What does TPR mean?
total resistance throughout vascular system
What does SVR mean?
resistance peripheral to heart and lungs
What does increased SVR lead to and why?
HTN, increases work of heart to eject blood, CO
What does decreased SVR lead to and why?
Shock, spread over larger areas (SLOWS)
Measure of distance traveled in a given amount of time
Velocity
What is laminar flow? And give examples.
layer levels of blood movement through smooth vessels (Core center, sides, wall flow)
Give 2 examples of Turbulent flow, a flow created by cross flow to laminar
Bruit, thrills
Place in order the most dynes/cm? Aorta, capillary, vena cava
Aorta (170,000 dynes/cm), vena cava 21,000 dynes/cm, capillary (6 dynes/cm)
What is a dyne?
Unit of force. The force required to cause a mass of one gram to accelerate at a rate of one cenitmeter per second squared.
Wall tension allows an aorta of 1cm to sustain an internal pressure of 100 mmHg, using which structures?
elastin, collagen, and smooth muscle
Wall tension allows a capillary w/ a radius of .000001cm to sustain an internal pressure of 100 mmHg with only _________
a single endothelial cell layer
What things have an effect on pressure?
size, internal pressure
What is hydrostatic pressure?
pressure created by fluid, movement of blood from aorta to capillary
What is colloids and what is colloid pressure?
Colloids are big, heavy weighted plasma proteins. If you put something heavy in the liquid you will sink/get sucked in
_________ has some exerting positive pressure on the blood vessel
Interstital fluid
True or False, without proteins you can maintain pressure.
FALSE, w/out protein you can not maintain pressure, and will have swelling
What is autoregulation?
The intrinsic ability of an organ to maintain constant blood flow despite changes in perfusion pressure. Ex: if I get up fast, there is a gravity pull, which will pull blood from the brain to compensate
Define resitance
arterioles resistance to ventricular contraction and ejection of blood
______ = cardiac output (L/min) 5-6
FLOW
What is the formula for MAP?
MAP = CO X SVR
What is the formula for CO?
CO = SV + HR
What is the short-cut formula for estimating MAP?
ADD diastolic and systolic BP and divide by 2
What does SVR stand for?
Systemic vascular resistance
What is SVR dependent on?
elasticity and diameter of vessels
What is CO and how what is that dependent on?
Volume and rate, preload and afterload
What is MPAP
Mean pulmonary arterial pressure
What kinds of things contribute to the cardiac/blood flow dynamic?
strucutre of the vessels, vascular factors ( how fast the blood is moving), neurohumoral factors (renin/angiotensin or nateuretic hormones)
What does nateuretic hormones do?
blocks sodium
What does aldosterone do?
Helps take up sodium
If you body needs to absorb fluid, which one (aldosterone or naterurtic )will be utilized?
Aldosteron
If you are fluid overloaded, the body will block what?
Nateuretic
Someone with HTN, will that increase or decrease flow?
Decrease flow? b/c you have more resistance
As resistance goes higher, will go up or down?
Down
True or False, Kidneys are totally dependent on blood flow?
TRUE
What is the fxn of kidneys?
To filter blood of wastes, electrolytes, ect.
IF cardic output decrease, what will happen to kidneys?
Kidney fxn will decrease
True or False, If you are in shock/bleeding, you want to add Na & water and tighten vessels
TRUE
True or False, if you had an infarction, it is a good idea to add Na and H20
False, adding more fluid, will cause the heart to work harder and fail more
What can cause alterations in blood flow?
Obstruction, hypertension, stress, inflammation
What are examples of obstruction and occlusion?
thrombi, emboli, vasospasm, inflammation, arterio/athersclerosis, valvular disease, infarction
True or False, Vasospasm means shut down
TRUE
What can an emboli be made of?
blood, amniotic fluid, air, fat
What is the difference between MI and CVA?
CVA- brain attack, no blood flow to the tissue of the brain, MI- no blood flow to the tissue of the heart
True or False, as you get older, you your arteries are less elastic and flexible?
TRUE
What happens to the coronary arteries as you get older?
Decreased blood flow
What happens to the Vavles as you get older?
become rigidity and thickened
True of False, as you get older, you have decreased compliance, but increased contractility and c.o.
False, aging = decreased compliance, contractility, and c.o.
What is preload?
Is how much the ventricular wall stretch. It is the amound of blood in the ventricle before it contacts/ejects. It’s the gas in the tank
Increased preload is seen in:
increased circulating vol. (too much vol.), mitral insufficiency, aortic insufficiency, heart failure, and vasoconstrictor use (e.g. dopamine)
Decreased preload is is seen in :
shock ( where the vol. drops), decreased circulating vol. ( bleeding, 3rd spacing), mitral stenosis, vasodilator use (NTG), asynchrony of atria and ventricles
What is 3rd spacing?
interstitial space- someone has cardiac surgery, from the surgery you get inflammation, which pulls in a lot of cells and fluids in. The surgery causes damage to blood vessels and arterials, which leaks protein, blood, & water into peritneal cavity. Days later, when the lymph & blood vessels have closed, the fluid will go back in. BIG PICTURE: you have a leak, the more fluid will fill your body… looks like shock, but just have shifted where the fluid is. Decrease Bp, CO, & urine output
What is NTG?
Nitroglycerine, a vasodilator, give it b/c coronary artery is so constricted causes lack of blood flow to tissues
Do pulmonary arteries take oxygenated or deoxygenated blood?
Deoxygenated
What does P , A, L, R mean ?
P = pulmonary, A = arteriole, L = left, R = Right
What does Afterload mean?
Resistance the blood in the ventricle must overcome ot force the valves open and eject contents to circulation
People on Beta blockers have a higher or lower HR and BP?
Lower
What is a Hemodynamic Monitoring?
It is a mechanical setup by inserting a cardiac cath in to the person, connected to a mointor to give you hemodynamic perameters
What kind of people will get put on hemodynamic monitoring?
trauma , MI, cardiac surgery pt.
Why do you need a pressure pushing down on the cath?
So you don?t filll up the whole line with blood, if you don?t have pressure pushing down on it.
What percent is CO increased in pregnant women and why?
30-60% b/c heart is pumping for 2 bodies
Does SV stay up throughout the entire pregnancy?
No. It is initially up in the 1st tri, then down in 2nd and 3rd
If RBC mass is increased, why does it lead to dilution?
b/c extra with extra flow, you have extra water. So, you have more blood vol. not more concentration
Why is it good that vascular resistance goes down during pregnancy?
Because you have all these increases in blood vol. you want it to easily flow throughout the body.
What is PIH?
Pregnancy Induced Hypertension
TRUE or FALSE, Gestational HTN occurs outside of pregnancy?
FALSE, Only HTN occures during pregnancy
What is chronic hypertension?
Already have HTN prior to pregnancy
What does it mean that PIH is considered a progressive manifestation of a single process with one etiology?
There is a flow that starts with elevated Bp > preeclampsia> elcamspia
What does M and M stand for?
Morbidity and Mortality
True or False, everyone is at risk for preeclampsia/eclampsia
TRUE
Maternal immunologic intolerance, abnormal placental implantation, genetic, nutritional, environmental factors, cardiovascular and inflmmatory changes are all causes of what?
Preeclampsia/eclampsia
What are some pregnancy-associated risk factors?
chromosomal abnormalites, hydatidiform mole, hydrops fetalis, multifetal pregnancy, oocyte donation, structural congenital anomlalies, and urinary tract infections
First -time father and having fathered a preeclamptic pregnancy in another woman are risk factors for what?
Preeclampsia/eclampsia
What are maternal specific risk factors for preeclampsia/eclampsia?
Older than 35, younger than 20, black, fam hx of preeclampsia, nulliparity, hx of preeclampsia, med conditions ( gestational diabetes, obestiy, chronic HTN, stress)
Gina comes into the community clinic with a BP of 140/90 for the first time, no proteinuria. Post-partum, her BP returns to normal. What is this a diagnosis of?
Gestational HTN
What are the 2 classifications of Chronic HTN
BP 140/90 or greater before pregnancy or dx before 20 weeks GA OR HTN first dx after 20 weeks GA and persistent after 12 weeks postpartum
Whats the difference between gestational HTN and preeclampsia?
Presence of leaking of protein in kidney, from 20 weeks to 1-3 days postpartum
Becky comes into the clinic with BP less than 160/100, MILD edema, proteinurua trace/1+, and minimal liver enzymes. What is her dx?
MILD Preeclampsia
Tiffany comes into Memorial hospital, with a BP over 160/110, has marked edema, proteinuria 2+, headache, visual distrubances, abdominal pain, only 399 Ml of urine in the past 24 hrs,and liver enzymes. What is her dx?
Severe Preeclampsia
What is the difference between Eclampsia and preeclampsia?
Neuro effects (CNS effects, seizures, coma)
What is the pathophysiology cause of eclampsia?
Placental Ischemia, which causes damage> inflammation > forms endothelin and thromboxane> more sensitive to Angiotensin, which increases Na and H20 = edema, effects the blood vessels, which causes the BP to go up
What are the clinical manifestations of Pre/elampsia?
BP greater than or equal to 140/90, edema, proteinuria greater than equal to 300mg/24 hr, SBP up 30, 15 mmhg Dbp, headaches, visual changes, abdominal pain, seizures, coma
What is HELLP syndrome?
a group of symptoms in pregnant women, H Hemolytic anemia, EL elevated liver enzymes, and LP Low platelet count
What are treatments for Pre/Eclampsia?
Rest, delivery, decrease Na intake, increase IV water, Left sidelaying, Hydralazine ( vasodilator), Lasix, Labetalol (vasodilator), Nifedipine
What is the action of Mag sulfate?
anticonvulsant, increases conc. & osmotic pressure, Helps with movement
Why do you need to watch for muscle weakness in Mag Sulfate?
It can lead to paralysis
