Cardiovascular System Design Flashcards
Explain the five main functions of the cardiovascular system and how each contributes to homeostasis
- Transports O2, CO2, nutrients, & waste around the body
- Mixing of body fluids, pH, ionic composition, & osmolarity regulation
- Thermal regulation
- Hormone delivery
- Defense against infection
Identify the major body fluid compartments and approximate volume of each
Circulating plasma compartment (non-cellular formed materials) = 3L
Interstitial compartment = 12L
Intracellular compartment = 30L
Explain the function of pulmonary and systemic circulations, and how they function in series
Systemic blood flows entirely into and out of the pulmonary circulation, driven by the right heart pump (IVC goes into right heart).
Blood is driven into the systemic circulation by the left heart pump. Remember that the heart is a muscle.
Diagram the blood flow pathways between the heart and other major body organs, and through the heart itself
Aorta, arteries, organs, veins, IVC, right atrium
SVC & IVC –> right atrium –> tricuspid valve –> right ventricle –> pulmonary valve –> pulmonary arteries –> pulmonary veins (oxygenated, returning from lungs) > left atrium –> bicuspid/mitral valve –> left ventricle –> aortic valve –> aorta
Describe the relative blood flow and distribution in the major organs in the resting state
Organs that need a high rate of blood flow like kidneys and skin get more flow, but receive less Oxygen (for consumption) for their energy needs. The inverse is true for organs with high energy needs like the brain (less flow) since it needs lots of Oxygen for its high metabolic function.
State the relationship between cardiac output, heart-rate and stroke volume; given two values, calculate the unknown quantity.
What is normal cardiac output?!
CO (ml-beat/min) = HR (beat/min) x SV (ml)
Normal CO = 5L/min
Compare and contrast the major methods for blood pressure measurement
Auscultatory method of measuring blood pressure = indirect method
Artery or venous catheter measurement: gives a direct method of measuring blood pressure
Pulmonary artery catheterization directly measures pulmonary venous and left atrium
Ventricular systole
When the heart is at its most contracted = ejecting blood = peak pressure
Ventricular diastole
When the heart is at its most expanded = filling blood = minimum pressure
State Starling’s law of the heart
Cardiac output is almost entirely determined by the rate of blood return by the veins. Therefore, stroke volume is directly proportional to ventricular end-diastolic volume.
1) Give the 2 equations for pulse pressure, PP =
2) What is pulse pressure determined by?
PP = Systolic pressure - diastolic pressure
1) PP = SP - DP
2) PP = SV/C
SV = stroke volume
C = compliance
In resting young adults, PP = 40 mmHg; since 120-80=40
Pulse pressure reflects the volume ejected by the left ventricle (stroke volume).
Pulse pressure increases when the capacitance of the arteries decreases, such as with aging.
Given arterial systolic and diastolic pressures, estimate mean arterial pressure (MAP).
MAP = average pressure over the entire cardiac cycle
MAP = DP + (1/3)PP
MAP = DP + (1/3)(SP - DP)
DP = diastolic pressure PP = pulse pressure
Arterial vs venous system
Arterial system = high pressure & flow velocity & less blood in it
Venous system = low pressure & flow velocity & more blood in it
Define mean arterial pressure
The mean arterial pressure (MAP) is the average blood pressure in an individual. It is defined as the average arterial pressure during a single cardiac cycle.
When does a decrease in pressure occur in the cardiovascular system?
The decrease in pressure at any level of the cardiovascular system is caused by the resistance of the blood vessels (ΔP= QxR). The greater the resistance is, the greater the decrease that decrease in pressure is.
