Correct Answers
Structure of the human heart ✅-Heart has 4 chambers
-2 atria receive blood from Venous system
-2 Ventricles pump blood to arteries
-2 Sides of heart are 2 pumps separated by muscular septum.
What is the beats per minute of the average heart: ✅75 bpm
What is the ml/beat of the average heart: ✅70 ml/beat
What is the systemic blood pressure value? ✅120 mmhg
What is the pulmonary blood pressure value? ✅12-14 mmhg
Tricuspid valve in the heart ✅squeezes blood into the lower ventricles on the right side
of the heart
Bicuspid valve in the heart ✅squeezes blood into lower ventricles on the left side
When the pressure is greater behind the valve, it will? ✅open
When the pressure is greater in front of the valve it will what? ✅Close
When the pressure is greater in front of the valve, will it ever cause the valve to open in
the opposite direction? ✅No. It is a one-way valve.
What happens during Late Diastole? ✅Both sets of chambers relaxed. Passive
ventricular filling.
What happens during atrial systole- ✅Atrial contraction of forces. A small amount of
additional blood into ventricles.
What is the End-Diastolic volume? ✅The maximum amount of blood. In ventricles
occurs at the end of ventricular relaxation. EDV=135 Ml
What happens during the isovulmetric ventricular contraction: ✅First phase of
ventricular contraction pushes AV valves closed but does not create enough pressure to
open semilunar valves.
, What is ventericular ejection: ✅As ventricular pressure rises and exceeds pressure in
the arteries, the semilunar valves open and blood is ejected.
What is end-systolic volume? ✅Or minimum amount of blood in ventricles, ESV=65 Ml
What happens during Isovolumetric Ventricular Relaxation: ✅As ventricles relax
pressure in ventricles drops, blood flows back into cups of semilunar valves and snaps
them closed.
Produces "DUB" sound.
Cardiac output equation: ✅Cardiac Output (CO)= Heart Rate (HR) x Stroke Volume
(SV)
What is Cardiac Output? ✅Cardiac Output is the amount of blood pumped out by each
ventricle in one minute. Cardiac output is directly related to heart rate and stroke
volume.
What is Heart Rate? ✅Heart Rate (HR) is the number of ties the heart beats in one
minute, averaging 70-75 beats per minute (BPM) in the adult at rest.
What is stroke volume? ✅Stroke Volume (SV) is the amount of blood pumped by each
ventricle with each heartbeat, averaging 70 ml per beat in the adult at rest.
What 3 variables determine stroke volume? ✅-End Diastolic Volume (EDV)= volume of
blood in ventricles at end of diastole
-Total Peripheral Resistance (TPR)- impedance to blood flow in arteries.
-Contractility= strength of ventricular contraction
What increases Contractility? ✅sympathetic activity.
What is the Frank-Starling Law of the Heart? ✅is state of myocardial sarcomeres just
before filing
-actins overlap, actin-myosin interactions are reduced and contraction would be weak.
-there is increasing interaction of actin and myosin allowing more force to be developed.
Venous Return: ✅have thin walls and stretch easily to accomdate more blood without
increased pressure (=higher compliance)
How much of the blood in our body do the veins hold? ✅70% and are thus called
capacitance vessels.
How much pressure is within the vessels? ✅0-10 mm HG pressure.
How much pressure is in the arteries? ✅120 mmhg