Mechanical Events of Heart

Question 1

(): period of heart relaxation

Answer 1

Diastole

Question 2

() cycle: blood flow through heart during one complete heartbeat

Answer 2

Cardiac

Question 3

() systole and diastole are followed by ventricular systole and diastole

Cycle represents series of pressure and blood volume changes
Heart beats around avg. = () times per minute
Cardiac cycle lasts about 0.8 seconds

Answer 3

Atrial
75

Question 4

() Diastole
Pressure is low; 80% of blood passively flows from atria → ventricles through AV valves (SL valves closed)

During atrial systole (P wave), atria contract, pushing remaining 20% of blood into ventricle
(/) volume (EDV): volume of blood in each ventricle at end of ventricular diastole

Answer 4

Ventricular
End diastolic

Question 5

Beginning of Ventricular ()
() relax; ventricles begin to contract

Rising ventricular pressure causes closing of () valves
-First heart sound

()
contraction phase is split-second period when ventricles are completely closed (all valves closed), volume remains (), ventricles continue to contract

When ventricular pressure exceeds pressure in large arteries, () valves are forced open
Pressure in aorta reaches about 120 mm Hg

Answer 5

Systole
Atria
AV
Isovolumetric
constant
SL

Question 6

Rapid ()
Ventricular ()
SL valves open and blood leaves ventricles into the Aorta & Pulmonary ()
AV still closed at this time
Represented by “() wave” of EKG

Answer 6

ejection
Systole
Trunk
T

Question 7

() relaxation:
() Ventricular ()
Ventricles began relaxing

() systolic volume (ESV): volume of blood remaining in each ventricle after systole (not all blood leaves)

Ventricular pressure drops causing () of blood from aorta and pulmonary trunk that triggers closing of SL valves
() heart sound

Answer 7

Isovolumetric
Early
Diastole
End
backflow
Second

Question 8

(): period of heart contraction

Answer 8

Systole