Cardiac Cycle

Superior/inferior vena cava

Where oxygen-poor blood from upper and lower body moving to right atrium

Right atrium, tricuspid

Oxygen-poor blood from vena cava moves to __ __, permitting opening of the __ valve

right ventricle, tricuspid

Oxygen-poor blood from right atrium moves to __ __, permitting closing of the __ valve

pulmonary artery, pulmonary

Oxygen-poor blood from right ventricle moves to __ __, permitting closing of the __ valve

Vein

Oxygen-rich blood returns from lungs thru pulmonary __

Left atrium, mitral

Oxygen-rich blood from pulmonary vein moves to __ __, permitting opening of the __ valve

Left ventricle, mitral

Oxygen-rich blood from left atrium moves to __ __, permitting closing of the __ valve

Aortic valve, aorta

Oxygen-rich blood from left ventricle moves to __ valve, opening of this valve allows entry to __ and spread blood thru body

Systole

Heart contraction, pumping/ejecting of blood (systole vs diastole)

Diastole

Heart relaxation, filling of blood (systole vs diastole)

Late diastole

• Atria and ventricles are relaxed and AV valves are open

• Fluid flows passively from atria into ventricles

• Ventricular filling

(cardiac cycle)

Atrial systole

• Atrial contraction pushes small amount of additional blood into ventricles

(cardiac cycle)

Isovolumic Ventricular Contraction

• Ventricles start to contract and generate enough pressure to close AV valves (“lub”)

• Semilunar valves remain closed

• Pressure builds in ventricles without changing volume

(cardiac cycle)

Ventricular Ejection (ventricular systole)

• When pressure in ventricles exceeds pressure in arteries, semilunar valves open and blood is ejected

(cardiac cycle)

Isovolumic Ventricular Relaxation

• Ventricular pressure falls below artery pressure

• Snaps semilunar valves closed (“dub”)

• Without change in volume since both sets of valves are closed

(cardiac cycle)

Systemic arteries, pulmonary vein, umbilical vein

(3) vessels carrying oxygenated blood

Systemic veins, pulmonary artery, umbilical artery

(3) vessels carrying deoxygenated blood

Pressure, higher, lower, pressure, resistance

Fluid (i.e. liquids, gases) flows down __ gradients

• Blood flows from a __ to a __ pressure (lower vs higher)

• Flow is proportional to __ and inversely proportional to __

Contraction, relaxation

Pressure gradients are generated by cardiac __ and __ (actions)

Cardiac Output

Volume of blood pumped to the entire body, per unit of time

Units: L/min

stroke volume x heart rate

Cardiac output = ?

Stroke volume (SV)

How much blood ejected per beat

EDV - ESV

Stroke volume = ?

EDV, ESV

__ is the amount of blood in ventricle when it is full

__ is the amount of blood left in ventricle after it ejects blood

Ejection Fraction (EF)

Percent of blood in ventricle ejected each beat

SV / EDV x 100

Ejection fraction = ?

EF, low contractility, increased afterload

A low __ can mean decreased ability to squeeze (__ __) OR

Heart pushing against increased resistance (__ __load)

• EF and systolic heart failure

Atrioventricular (AV) Valves

Tricuspid and mitral/bicuspid (valve type)

Semilunar Valves

Pulmonary and aortic (valve type)

Lub

AV valves (mitral and tricuspid) close (lub vs dub)

Dub

Semilunar valves close (lub vs dub)

Stenosis

Blood being forced through stiff/narrowed valve (turbulent flow)

Regurgitation

Backward flow through valve that hasn’t closed completely (turbulent flow)

Openings between chambers

Septal defects, patent ductus arteriosus leads to backflow (turbulent flow)

Normal EKG

Aortic stenosis

Mitral regurgitation

Aortic regurgitation

Mitral stenosis

Patent ductus arteriosus (heart defect)