test 1 Flashcards
Cardiovascular Parts
heart = pump
blood vessels = tubes
blood = fluid
Cardiovascular Job
delivers oxygen and nutrients
removes carbon dioxide and wastes
Anatomy of heart
2 small chambers (right +left atrium)
2 large chambers (right + left ventricle)
What are the 4 main tubes of the heart?
- vena cava
- pulmonary artery
- pulmonary vein
- aorta
How does blood flow through the heart?
arteries = away from heart veins = back to heart
What is the pulmonary circulation order in the right side of the heart?
deoxygenated blood returns to the heart via the superior & inferior vena cava -> right atrium -> tricuspid valve -> right ventricle -> pulmonary valve -> pulmonary arteries -> lungs
What is the systemic circulation order in the left side of the heart
oxygenated blood from the lungs returns to the heart via the pulmonary veins -> left atrium -> bicuspid/mitral -> left ventricle -> aortic valve ->aorta -> systemic arteries
parts of the cardiac conduction system
- sinoatrial node (SA)
- atrioventricular node (AV)
What does the SA node do?
located in the upper posterior portion of the right atrium, contains pacemaker cells that demonstrate rhythmicity
How does the cardiac conduction system work?
SA node depolarizes -> AV node depolarizes -> Bundle of His -> Bundle Branches -> Purkinje system
What do cardiomyocytes do?
the cells that contract, “slow twitch”, lot of mitochondria
Vasculature of the Cardiovascular system
- Arteries (away)
- arterioles (control the flow)
- venules (collect blood)
- veins (back)
What happens during the Cardiac Cycle?
- mid to late diastole = both AV valves open, aortic valve is shut
- late diastole = atria contract
- systole = aortic valve opens
- early diastole = aortic valve closes; AV valves open
what is stroke volume?
- volume of blood pumped in one heartbeat
- end Diastolic volume - end systole volume = stroke volume
What is ejection fraction?
- % of end diastolic volume pumped out of the left ventricle
- stroke volume/EDV = ejection fraction
Cardiac output (Q)
- total volume of blood pumped per minute
- Q = heart rate* stroke volume
Systolic BP
- highest pressure in artery
- generally 110 to 120
Diastolic BP
- lowest pressure in artery
- generally 70 to 80
Mean arterial pressure
- average pressure over the cardiac cycle
- 2/3 DPB + 1/3 SBP
What is the cardiac output during rest and exercise?
rest = 5 L/min exercise = 25 L/min
what is cardiovascular drift?
Cardiac responses to exercise demonstrate a “drift” after prolonged exercise at moderate-high intensity
What are the causes of cardiovascular drift?
hypovolemia and hypothermia
What is heart rate max?
max heart rate a human can achieve
-220 - age = max HR
What is preload?
The degree to which the myocardium is stretched before it contracts.
what is afterload?
The pressure against which the heart must pump blood. Determined by the peripheral resistance of the large arteries.
General Hemodynamics
blood flow (all tissues require)
pressure (heart contracts)
resistance (force that opposes flow)
What are the hemodynamic symbols?
Q with a dot = blood flow
delta P = pressure gradient
R = vasoconstriction or vasodilation
What happens to blood pressure during exercise?
SBP increases, DBP may decrease, MAP increases
Control of heart rate during exercise
- sinus rhythm (generated by SA node) 100 bpm
- parasympathetic (rest) = 60 bpm
- sympathetic (exercise)
What is in blood?
plasma = 55%
erythrocytes = 45%
platelets and leukocytes = <1%
hematocrit = % of total volume of red blood cells
what does blood do during exercise?
transport nutrients
temperature regulation
acid-base (pH) balance
What is the Fick Principle
O consumption = (amount going in - amount going out)*blood flow rate
