Week 7- Cardiovascular system Flashcards
Describe the pulmonary circuit of the circulatory system
heart lungs heart
systemic veins bring low 02 blood from body to heart
Pulmonary arteries brings low o2 blood from heart to lungs
Describe the systemic circuit of the circulatory system
heart body heart
Pulmonary vein brings 02 blood back to heart from lungs
systemic arteries bring high 02 blood to body from heart
Systole
contraction
blood goes out
diastole
Ventricles filling with blood
relaxation
As a pump, what is the purpose of the right side of the heart?
Receive blood from body
Give blood to lungs
As a pump, what is the purpose of the left side of the heart?
Remove blood from lungs
give blood to body
What results from left ventricular failure (left sided heart failure)
Blood will back up in lungs (where it received blood from)
What results from Right ventricular failure (right sided heart failure)
Blood will back up in the body(where they received blood from)
What is the significance of the coronary arteries?
Supplies blood to heart
Differentiate between a myocardial infarction (heart attack) and myocardial ischemia
infarction-
sudden death of patch of myocardium because of complete obstruction to coronary circulation(no 02 getting to cardiac muscle)
ischemia- chest pain from PARTIAL obstruction of coronary blood flow
Describe the heart’s conduction system—what are the specialized areas that send signals from start point to end point of the system
1-Sa node(in right atrium) will send signal and cause both of atrium to contract
2-Av node then receives the signal
3- signal bundles up in av bundle
4- signal travels down bundle branches(L and R) down the intraventricular septum of heart
5- signal will go back up perkiinje fibers on outside of heart walls (on both sides)
Relate the conduction system with the cardiac cycle
Follows cardiac cycle-allows it to be stimulated
Atria will contract first-while ventricle are in diastole
then ventricle will contract-while atria are in diastole
What does an ECG record?
electrocardiogram
measures electrical signal going to the heart
Describe what the P wave, QRS complex and T wave represent on an ECG.
p-atrial depolarization
qrs- ventricular depolarization
t-ventricular repolarization- relax
What is the heart rate determined by?
SA node
However many fires per minute makes it a beats per minute
What is the sinus rhythm?
Normal heartbeat triggered by SA node
What is an arrhythmia?
any abnormal rhythm
What is tachycardia?
high heart rate
100 or over
What is Bradycardia?
lower heart rate
less then 60
What is the cardiac cycle? What specific events occur during the cardiac cycle?
All events associated during one heartbeat
Atrial systole – atria contract which sends blood to the ventricles while the ventricles are relaxed (in diastole)
Followed by Ventricular Systole – ventricles contract while atria are relaxed (in diastole)
How do the valves function during the cardiac cycle?
Atrial systole-
When AV valves are open, semilunar valves are closed
Ventricular systole
When semilunar valves are open, av valves are closed
Define Cardiac Output (CO).
amount of blood ejected from a ventricle per minute
What determines CO—what is the equation for
CO?
Heart rate X stroke volume
(BPM X milliliters per beat)
How will HR or blood volume changes impact CO?
If HR or BV go up- CO goes up
if hr or bv go down- co goes down
How do the sympathetic and parasympathetic divisions affect HR?
S- increases HR
P-slows heart rate
What hormones can increase HR?
epinephrine
norepinephrine
thyroxine
What is stroke volume and how is it determined?
how many milliliters per beat
End diastolic volume - end systolic volume
What is the ESV (end systolic volume) and the EDV (end diastolic volume)?
ESV- how much is left in ventricle after contraction
EDV- how much is in ventricle before contraction
Where is the cardiac center located in the brain?
medulla
What do the proprioceptors detect
inform cardiac center about changes in activity,
HR increases before metabolic demands of muscle
arise
What do the baroreceptors detect?
signal cardiac center
blood pressure decreases, signal rate drops, cardiac center increases heart rate
if blood pressure increases, signal rate rises, cardiac center decreases heart rate
What do Chemoreceptors detect
more important in respiratory control than cardiac control
sensitive to blood pH, CO2 and O2 levels
Differentiate between blood flow and perfusion
BF- amount of blood goes through blood vessels to cells to deliver oxygen ( ml/min)
Perfusion-flow per given volume (ml/min/g)
in general, how do pressure and resistance affect blood flow?
P-Greater the pressure = increased flow
decreased pressure = decrease flow
R- greater resistance= decrease flow
decrease resistance = increase flow
Define blood pressure
Generated by heart
Pressure created by left ventricle
Pressure exerted against bv walls
What are diastolic and systolic pressure?
D- amount of pressure on arterial wall during left ventricle relaxation
S-amount of pressure generated on arterial wall during left ventricle contraction
How do CO and Blood volume affect blood pressure
Blood volume-
Greater blood volume = greater blood pressure
lower blood volume = lower blood pressure
CO-
Greater CO = greater CO
lower CO = lower CO
Describe how the peripheral resistance factors affect BP vessel radius/diameter
Vessel radius/diameter-
Increased diameter = decreased resistance(increase blood flow & decrease blood pressure)
Decreased diameter- = increase resistance (increase Blood pressure and decrease flow)
Describe how the peripheral resistance factors affect BP (viscosity
Thickness of blood
increase thickness- decrease flow- increase pressure
decrease thickness- increase flow- decrease pressure
Describe why each of the following hormones would be released and HOW they each affect BP—how can they save us??
(angiotensin II)
save you from low BP
goal is to increase bp to normal
promotes release of ADH and aldosterone
Describe why each of the following hormones would be released and HOW they each affect BP—how can they save us??
aldosterone
save you from low BP
goal is to increase bp to normal
Describe why each of the following hormones would be released and HOW they each affect BP—how can they save us??
ANP/BNP,
save you from high bp
goal is to lower bp to normal
Describe why each of the following hormones would be released and HOW they each affect BP—how can they save us??
ADH
save you from low BP
goal is to increase bp to normal
Describe why each of the following hormones would be released and HOW they each affect BP—how can they save us??
epinephrine and norepinephrine
peripheral vasoconstriction
Does the Parasympathetic Nervous System affect blood vessel diameter?
NO
What is the overall effect of the Sympathetic Nervous System (SNS) on blood vessel diameter, blood pressure and CO?
stimulates most to constrict- but skeletal and cardiac to dilate
would mean that it decrease blood pressure
What are the mechanisms that will help venous blood return to the heart?
pressure gradient
Gravity
skeletal muscle pump
thoracic (respiratory) pump
