B3W1 Organization of Cardiovascular System Flashcards
Main Organs of the Cardiovascular System
Heart, Blood, Lungs, and interconnected vessels
Arteries
Move Blood away from the heart
“A” for Away
Veins
Move Blood towards the heart
“V” V arrow pointing to the heart
Ways to categorize the circulatory system
Pulmonary Vs. Systemic
Arterial High Pressure Vs. Veinous Low Pressure
Arterial Blood Flow Resistance Vs. Veinous Storage
Location of 2/3rds of blood at any given time
Within the veins
Role of the Cardiovascular system
Maintain homeostasis by delivering “good” things and removing “bad” things from organs, temperature regulation, endocrine signaling, and mediation of immune and inflammatory responses
“Good” Things in blood
Glucose
Oxygen
Hormones
Immune Cells
“Bad” Things in blood
CO2
Metabolites
Systole
Contraction of Cardiac Muscle
Diastole
Relaxation of Muscle Contraction
Pattern of Blood flow
Right Atrium -> Tricuspid Valve -> Right Ventricle -> Pulmonary Semilunar Valve -> Pulmonary Arteries -> Lungs -> Pulmonary Veins -> Left Atrium -> Bicuspid Valve -> Left Ventricle -> Aortic Semilunar Valve -> Aorta -> Systemic Circulation -> Vena Cava
R -> Lungs -> L Right of body to left lungs are in the middle
A -> V “A” Points up “V” Points down
Tri -> Semilunar -> Bi -> Semilunar
Breakdown of Artery offshoots
Aorta -> Arteries -> Arterioles -> Capillaries
Breakdown of Vein offshoots
Venules -> Veins -> Superior/inferior Vena Cava
Pressure Volume Loops
Show the amount of blood in the left ventricle as it changes with pressure
Another Name for the Pulmonary Semilunar Valve
Mitral Valve
Another Name for the Aortic Semilunar Valve
Aortic Valve
What causes the opening of valves within the heart?
Pressure differences between the two sides of a valve
Steps of a Pressure Volume Loop
Mitral Valve opens and blood fills the left ventricle -> Around when Left Ventricular Volume equals 120 mL -> Mitral Valve Closes and the left ventricle undergoes an isovolumetric contraction which while maintaining the volume greatly increases pressure to about 80 mmHg -> Aortic Valve opens and the blood from the left ventricle enters the Aorta -> As blood moves from the ventricle into the aorta the ventricle contracts so strongly that the pressure continues to increase up to about 130 mmHg while volume decreases -> After 130 mmHg of pressure the pressure within the ventricle decreases and volume continues declining -> leads to closing of the aortic valve and end of systole
Structure of Vessels
Inner-Endothelial Cell
Middle-Smooth Muscle
External-Connective Tissue and Blood Supply for larger vessels
Arteries and Veins contain all three
Venules and Arterioles lack external layer
Capillaries only contain endothelial cells
Equation for Blood flow
Flow=Change in Pressure/Resistance
Vessel Resistance in Series
Resistance is added from the summation of groups of vessels in a sequential order
Vessel Resistance in Parallel
Resistance is added as 1/Resistance of a single vessel which are parallel to one another
Cardiac Output
Cardiac Output = Stroke Volume * Heart Rate
Stroke Volume
Is the amount of blood that is expelled from the left ventricle during a contraction
Poiseuille’s Law
Flow = Change in pressure * ((PiRadius^4)/(8Viscosity*length)
Changes in Blood Flow According to Poiseuille’s Law
Increase Flow Rate
- Increase Pressure Change
- Increase Radius
- - Largest effect on flow due to the ^4
Decrease Flow Rate
- Increase Viscosity
- Increase Length
Laminar Flow
Flow within a cylinder moves fastest at the center and slower at the periphery
Turbulent Flow
Flow that becomes noisy due to inconsistent viscosity or areas of high resistance
Driving pressure exceeds the flow and reaches critical velocity
Common Site of Turbulent Flow
Aortic Arch
Sites of Branching
Bifurcation Sites
Three Pressure Sources in Circulatory Systen
Driving Pressure
Transmural Pressure
Hydrostatic Pressure
Driving Pressure
Pressure from the pumping of the heart
P(x1-x2)
Transmural Pressure
Pressure caused by the changes of the vessel wall, such as tension and radius
T=P*r
Hydrostatic Pressure
Pressure caused by gravity in relation to a person’s position in space or on a column of fluid
Pressure felt strongest at whatever level is the lowest
Mean Arterial Pressure
Average arterial pressure that takes into account that only 1/3 of time is spent in systole
Mean Arterial Pressure vs. Pulse
Systolic Blood Pressure-Diastolic Blood Pressure = Pulse P about 40 mmHg
Mean Arterial Pressure = Diastolic Blood Pressure + 1/3(Systolic Blood Pressure-Diastolic Blood Pressure)
Vessel Compliance
How much a vessel can expand with pressure
C=Volume/Pressure
High Compliance
Larger distension of vessel
Low Compliance
Low Distension of vessel
Bernoulli effect
Liquid moves due to a pressure and energy gradient
From high to low energy
Pressure decreases as the speed of a fluid increases
