CV System and Disorders- Week 4 Set 1 Flashcards
Layer outside the heart, protective layer
protective layer
Pericardium
Middle muscle layer of heart
Myocardium
Inner protective layer of the heart
Endocardium
The first arteries in the heart that receive oxygen
Coronary arteries
Why are the Coronary arteries the first arteries in the heart that receive oxygen?
heart needs adequate oxygen so it can pump blood to the rest of the body.
Main functions of the Circulatory System
Transport and Temperature regulation
What does the circulatory system transport?
- 02 2. Nutrients 3. Hormones 4. Immune Substances 5. Electrolytes 6. Waste
Waste from the circulatory system is filtered by what organs?
a. Kidneys b. Excretory Organs
How many chambers in the heart?
four
What are the four chambers of the heart called?
right atrium, right ventricle, left atrium, left ventricle.
How many valves does the heart have
four
What is the function of heart valves
keep blood moving in the correct direction
How do heart valves keep blood moving in the correct direction?
Open only one way and only when needed
What are the valves of the heart called?
Tricuspid, mitral, pulmonary and aortic valves.
What do valves have tha topen and close once during each heartbeat?
flaps, called leaflets or cusps
Circulation of Blood thru the Heart: Step 1
02 poor blood returns from body to heart
Circulation of Blood thru the Heart: Step 2- after 02 poor blood returns from body to heart
Heart: Step 2- after 02 poor blood returns from body to heart
blood fills R atrium
Circulation of Blood thru the Heart: Step 3- after blood fills R atrium
blood flow to R ventricle
Circulation of Blood thru the Heart: Step 4- after blood flow to R ventricle
blood pumped to the lungs via pulmonary arteries
Circulation of Blood thru the Heart: Step 5- after blood pumped to the lungs via pulmonary arteries
ungs refresh the blood with a new supply of oxygen
Circulation of Blood thru the Heart: Step 6- after lungs refresh the blood with a new supply of oxygen
blood returns from the lungs and enters the left atrium
Circulation of Blood thru the Heart: Step 7- after blood returns from the lungs and enters the left atrium
blood flows from left atrium to the left ventricle
Circulation of Blood thru the Heart: Step 8- after blood flows from left atrium to the left ventricle
Blood is pumped through the main artery (aorta)
Circulation of Blood thru the Heart: Step 9- after Blood is pumped through the main artery (aorta)
supply tissues throughout your body with oxygen
Order of valves
(Superior vena cava) tricuspid, pulmonary (pulmonary vein) mitral, aortic (aorta)
Contraction of heart
systole
Relaxation of heart
diastole
Electrical impulses begin in… and travel to….
right atrium, in the sinus node through pathways to ventricles
What do the electrical impulses of the conduction system do?
deliver signal for the heart to pump
Initial stretching of the cardiac myocytes (muscle cells) prior to contraction, related to ventricular filling. The amount the ventricles stretch at the end of diastole (EDV).
Preload
Imagine balloon- once it is blown up, what does this represent?
Preload
In what condition would we want to increase preload?
hypovolemic shock
Why do you want to increase preload in hypovolemic shock?
There is not enough fluid in the body and therefore not enough pressure for preload
How can you increase preload?
give fluids via IV or give meds to stimulate sns
How do IV fluid help to increase preload?
increase blood volume> increase preload
What meds help increase preload?
vasopressors
How do vasopressors to help to increase preload?
cause vasoconstriction- increase venous return to heart
Why would you need to decreased fluid preload?
fluid overload
What condition often causes fluid overload?
HF
What can you do to decrease preload?
give diuretics or nitro
How do vasodilators cause a decrease in preload?
pulls fluid out of blood volume via renal system
How does nitro cause a decrease in preload?
widening of vessels decreased venous return to heart
Is the force or load against which the heart must contract to eject blood
OR the pressure the ventricles must work against in order to get semilunar valves open so blood can leave ventricle and can go to either lungs or the body.
Afterload
Things that increase afterload
Vasoconstriction, pulmonary hypertension, valve stenosis
How does vasoconstriction increase afterload?
increases pressure to overcome
How does pulmonary hypertension increase afterload?
increases pulmonary vascular resistance- increase work load on right ventricle
How does valve stenosis increase afterload?
valve narrowing- working very hard to get blood throughout the body.
Things that decreased afterload
vasodilators
How do vasodilators decreased afterload
decrease resistance
Strength of cardiac cells to contract/shorten
Cardiac contractility
Amount of blood pumped by (each) ventricle with each beat
Stroke Volume (SV)
What effects SV
cardiac contractility, preload and afterload
What is normal SV?
70ml/ventricle
The amount of blood the heart pumps throughout the body per min
Cardiac Output
How do you calculate cardiac output?
HRxSV=CO
What is the normal amount of cardial output?
approx. 5 L/ventricle/min
1 beat= 70ml, 72 bpm
The max amount of blood that can be pumped out by the heart above the normal volume
Cardiac Reserve
When is cardiac reseve used?
exercise, stress, ect
Cardiac output for increased age
300 % extra work 15L/min
Cardiac output for young adult
500% extra work -25 L/min
Cardiac output for athletes
600-700% extra work -30-35 L/min
Same as the stroke volume just as a percentage
Ejection Fraction
What is normal Ejection Fraction?
<55%
How to calculate Ejection Fraction?
cross multiply
70 = x 130 100(%)
answer 53.84%
Valve that is narrowed and doesn’t open properly
Heart Valve Stenosis
What happens to the valves in Heart Valve Stenosis?
thicken, stiffen or fuse together
How does Heart Valve Stenosis effect the heart?
Heart has to work harder to pump blood through the valve- reduced 02 to body
backflow of blood caused by failure of the heart’s mitral valve to close tightly
Heart Valve regurgitation
What are other names for Heart valve regugitation?
Heart Valve Insufficiency or incompetence
What is the difference between valve stenosis and valve regurgitation?
Stenosis-Ridged, stuck, cant open
Regurgitation- Leaky, floppy allow blood backwards, doesn’t close all the way
What is the purpose of heart valves?
keep blood moving through the heart in the right direction
Problems with the mitral valve?
stenosis, regurgitation or prolapse
Problems with the aortic valve?
stenosis, age related
Blood is prevented from flowing backward in the veins by…
one-way valves
Blood flow through the capillary beds is controlled by……
precapillary sphincters
How do precapillary sphincters work?
Increase and decrease flow depending on the body’s needs
What activates precapillary sphincters?
Nerve and hormone signals.
Circulation of the blood in the smallest blood vessels
Microcirculation
Where is Microcirculation found
within organ tissues
What are the different types of microvessels?
1.terminal arterioles, 2.metarterioles, 3.capillaries, and 4.venules
Carry oxygenated blood to the capillaries
Arterioles
Blood flows out of the capillaries through what?
venules
Where does blood go once it leave through venules?
veins
other than blood microcirculation also includes?
lymphatic capillaries and collecting ducts
Main functions of the microcirculation
Delivery of O2, nutrients and removal of CO2
Regulate blood flow and tissue perfusion
What does microcirculation effect by regulating blood flow and tissue perfusion?
BP and edema (imflammation)
Lymphatic System returns what?
Venous blood
How many people in the US have some form of heart disease?
1 out of 2
Venous or arterial? pulses
arterial
Venous or arterial? deoxygenated
venous
Venous or arterial? 1. Gets back through lymph systems of peripheral vascular system
venous