Lecture 13: Organization of the Cardiovascular System

3 parts of circulatory system:

heart, vasculature, blood.

Role of vasculature in circulatory system:

perfusion.

Perfusion is:

delivery of blood per time per gram of tissue (mL/min/g).

3 types of blood vessels:

arteries, capillaries, veins.

Blood vessel that serves as vessels of exchange:

capillaries.

Capillaries exchange blood between:

air, cells.

3 anatomic features of the heart:

two-pumps;
great vessels;
two pairs of valves.

Right pump receives:

deoxygenated blood from the body, and brings it to lungs.

Right pump is the pump for __________ circulation.

pulmonary.

Left pump receives:

oxygenated blood from lungs, and brings it to body.

Left pump is the pump for __________ ciruclation.

systemic.

Both pumps have ___ chambers.

2.

Receiving chambers:

atriums (superior chambers).

Propelling chambers:

ventricles (inferior chambers).

Atrium contractions contribute very little to:

the propulsion of blood from the heart.

There are ___ pairs of valves.

2.

Atrioventricular (AV) valves lie between:

atrium and ventricles.

Right atrioventricular (AV) valve is aka:

tricuspid valve.

Left atrioventricular (AV) valve is aka:

mitral or bicuspid valve.

Semilunar valves lie between:

ventricle and arterial trunks.

2 semilunar valves:

pulmonary and aortic.

Pulmonary valve lies between:

right ventricle and pulmonary trunk.

Aortic valve lies between:

left ventricle and aorta.

Pairs of valves serve to direct blood into the __________ and prevent inappropriate __________.

heart; backflow.

Pairs of valves ensure __________ flow.

unidirectional.

There are no valves between __________ and __________.

veins, atria.

Atrial pressure is not much __________ than venous pressure.

higher.

The __________ __________ becomes partially compressed during atrial contraction.

venae cavae.

Flow of blood starts in __________ half of heart (O2-__________ blood).

right; O2-poor.

Pulmonary capillaries exchange O2-__________ to O2-__________ blood.

poor to rich.

Blood returns to left half of heart (O2-__________ blood) from the pulmonary circulation.

O2-rich.

Systemic circulation starts from __________ then __________ __________.

aorta then branching arteries.

Systemic capillaries gas exchange O2-__________ to O2-__________ blood.

rich to poor.

Systemic circulation ends with __________ __________ to __________ __________.

systemic veins to vena cavae.

The blood returns to the right half of the heart from the left via __________ __________ to __________ __________.

vena cavae to right atrium.

__________ __________ __________ carries blood from the digestive tract to the liver so absorbed nutrients can be processed.

hepatic portal vein.

Hepatic portal vein carries blood from the __________ __________ to the __________.

digestive tract to the liver.

Blood flow is dependent on __________ __________ and __________.

pressure gradients; resistance.

__________ __________ is the difference in pressure between the beginning and end of the vessel.

pressure gradient (ΔP).

Heart is responsible for creating the __________ pressure.

high.

Pressure drops along the length of a blood vessel due to __________ __________.

frictional losses.

Driving pressure occurs along the __________ axis of a vessel.

longitudinal.

Driving pressure causes blood to flow between __________ __________.

two points.

In circulation, driving pressure is the difference between __________ and __________ ends of the systemic circulation.

arterial, venous.

Transmural pressure occurs along the __________ axis of a vessel.

radial.

Transmural pressure is the difference in pressure across the __________ of a vessel.

wall.

Transmural pressure is the difference of pressure in the vessel vs in the __________.

tissue.

Transmural pressure governs vessel __________, which determines __________.

diameter, resistance.

Hydrostatic pressure occurs along the __________ axis of a vessel.

height.

Hydrostatic pressure is related to the effect of __________on the blood and proportional to its __________.

gravity, density.

__________ __________ is the flow of blood delivered by the heart.

cardiac output.

Cardiac output is dependent on __________ __________ and __________ __________.

heart rate (HR);
stroke volume (SV).

Cardiac output is the amount of blood (__________) pumped per unit time (__________).

liters per minute.

stroke volume measures __________ per __________.

liters per beat.

Resistance (R) is the opposition to blood flow due to friction between:

the fluid & vessel wall.

Resistance (R) is an inverse relationship between __________ and __________.

flow; resistance.
F = 1/R

As resistance increases, flow __________.

decreases.

3 factors that determine resistance:

vessel radius,
vessel length,
blood visocity.

Blood viscosity is determined by:

number of circulating RBCs.

Blood flow is __________.

laminar (smooth).

Blood travels in __________ __________.

concentric rings.

The blood velocity of each ring increases to a __________ at the center.

v_max

The blood velocity of each ring is __________ at the wall of the vessel.

v₀

Laminar flow is __________.

silent.

Turbulent flow produces __________.

murmurs.

Blood pressure is __________due to pump activity of the heart.

pulsatile (throbbing).

Systolic pressure is the __________ pressure.

maximum.

Diastolic pressure is the __________ pressure.

minimum.

Systolic and diastolic pressure is measured in the __________.

arteries.

__________ pressure is the pressure difference between systolic and diastolic pressure.

pulse.

Mean arterial pressure (MAP) is the average pressure that:

drives blood forward.

Mean arterial pressure (MAP) is roughly equivalent to:

diastolic pressure + 1/3 pulse pressure.

Roughly 2/3 of cardiac cycle is spent in __________ while 1/3 is in __________.

2/3: diastole;
1/3: systole.

Both Pulse pressure and MAP __________ with increasing distance from the heart.

decline.

__________ is the blood pressure cuff that measures blood pressure indirectly.

sphyngmomanometer.

__________ sounds are used to determine the blood pressure.

Korotkoff.

Korotkoff sounds appear when pressure in artery is:

greater than pressure in cuff.

Korotkoff sounds disappear when cuff no longer:

exerts pressure.

SA (sinoatrial) node is a specialized region in the __________ __________ __________ near the opening at the __________ __________ __________.

right atrial wall;
superior venae cava.

AV (atrioventricular) node is located at the base of the __________ __________ near the __________.

right atrium;
septum.

AV node is __________ the junction of the __________ and __________.

above;
atrium & ventricles.

Bundle of His (atrioventricular bundle) is a tract of cells that originate at the __________ __________.

AV node.

Bundle of His is AKA __________ __________.

atrioventricular bundle.

Bundle of His divides into:

two branches (left and right).

Bundle of His divides and projects to the __________.

apex.

Purkinje fibers are terminal fibers that extend from the:

Bundle of His.

Purkinje fibers project from __________along __________ __________ towards __________.

apex;
ventricular walls;
atria.

SA node is the __________ of the heart.

pacemaker.

Other nodes (than SA) have their own natural __________ rates, but rate is directed by __________ __________.

slower;
SA node.

If the SA node is damaged, the __________ node sets the pace.

fastest.

Once initiated in the SA node, an __________ spreads throughout the rest of the heart.

AP.

Heart beats rhythmically as a result of __________ spread across the __________ __________.

AP;
muscle membranes.

Two types of muscle cells:

nodal (autorhythmic);
contractile.

__________ cells are specialized cells that initiate and conduct APs.

nodal (autorhythmic).

Nodal (autorhythmic) cells display __________ activity.

pacemaker.

__________ cells are 99% muscle cells.

contractile.

Contractile cells do the __________ of pumping.

mechanical.

Contractile cells do NOT:

initiate their own AP.

Pacemaker potential is due to 3 ions:

Na+, K+, and Ca2+.

I_f currents are dependent on __________ channels that activate at __________ potentials.

HCN;
hyperpolarizing.