Heart

Veins

Blood from body flows into heart

Arteries

Blood from heart flows into body

Right side of heart

Carries deoxygenated blood to lungs

Left side of heart

Carries oxygenated blood to body

(1/15) BLOOD FLOW:Return of Blood to Heart

Superior vena cava receives deoxy blood from upper body, Inferior vena cava receives deoxy blood from lower body

(2/15) BLOOD FLOW: Blood enters first chamber from SVC and IVC

Right atrium receives deoxy blood from vena cava

(3/15) BLOOD FLOW:First AV Valve

Deoxygenated blood from right atrium enters through the right AV tricupsid valve

(4/15) BLOOD FLOW: First Ventricle

Deoxygenated blood enters through right AV valve and enters right ventricle, which pumps the blood superior

(5/15) BLOOD FLOW:First Semilunar valve

Deoxygenated blood from right ventricle is pumped up the pulmonary semilunar valve

(6/15) BLOOD FLOW:First trunk

Deoxygenated blood pumped from pulmonary semilunar valve moves up the pulmonary trunk

(7/15) BLOOD FLOW: First arteries

Deoxygenated blood moves up the pulmonary trunk and divides into left and right pulmonary arteries

(8/15) BLOOD FLOW: Pulmonary Circulation

Deoxygenated blood goes to left lung and right lung, releases CO2 and picks up O2

(9/15) BLOOD FLOW: Blood comes back to heart

Oxygenated blood comes back to heart through left and right pulmonary veins

(10/15) BLOOD FLOW: Second chamber

Oxy blood from pulmonary veins enters left atrium

(11/15) BLOOD FLOW: Second AV valve

Oxy blood from left atrium goes down through left AV mitral valve

(12/15) BLOOD FLOW: Second ventricle

Oxy blood goes through mitral valve and enters the left ventricle

(13/15)BLOOD FLOW:Second semilunar valve

The left ventricle pumps oxy blood through aortic semi lunar valve

(14/15) Second artery

Oxy blood goes through the aortic semi lunar valve and enters the aorta

(15/15) BLOOD FLOW: Systemic Circulation

The aorta releases the oxy blood through the aortic branches, and travels to body tissues where it delivers the oxy blood and collects CO2

(1/3) Pacemaker Potential:SA Node Cell Stimulation of Heartbeat

Sodium channels open and depolarizes. T calcium channels then open and calcium enters, helping reach threshold (-40mV)

(2/3) Main Depolarization: SA Node Cell Stimulation of Heartbeat

Threshold is reaches and causes L calcium channels to open and rapidly enter cell, and depolarize

(3/3) Repolarization: SA Node Cell Stimulation of Heartbeat

L calcium channels close and calcium decreases, K channels open and K leaves the cell and repolarizes (-60mV)

Conduction System: (1/7) Atrial Depolariziation and Ventricular Filling

SA node fires action potential and spreads across atrial muscle cells and then travels to AV node

Mechanical Events:(1/7)Atrial Depolariziation and Ventricular Filling

SA node action potential stimulates atrial muscle cells to depolarize and begin contraction. Ventricles relaxed as atria fill them. AV valve open

ECG:(1/7) Atrial Depolariziation and Ventricular Filling

P wave

Conduction System: (2/7)Atrial Contraction and Ventricular Filling

Impulse is delayed at AV node, then travels through AV bundle, Bundle branches, and purkinje fibers

Mechanical Events: (2/7)Atrial Contraction and Ventricular Filling

Atria contracts and finish pushing blood into relaxed ventricles. AV valve open

ECG: (2/7)Atrial Contraction and Ventricular Filling

Between P and Q

Conduction System: (3/7)Ventricular Depolarization

Impulse arrives at ventricular cardiomyocytes

Mechanical Events: (3/7)Ventricle Depolarization

Fast sodium channels open and rapidly enter cell, depolarizes from -90 to -30mV, close, then Calcium channels open and enter cell. AV valve closes when ventricular pressure exceeds atrial pressure.

ECG: (3/7)Ventricular Depolarization

QRS complex

Conduction System: (4/7)Isovolumetric Contraction

Currently in plateu phase, calcium channels open and enters cell and K+ channels open and leaves cell

Mechanical Events:(4/7) Isovolumetric Contraction

Actin and myosin interact and cardiomyoctes contract, causing ventricular pressure to rise, all valves are closed

ECG: (4/7)Isovolumetric Contraction

Beginning of ST

Conduction System: (5/7)Ventricular Ejection

Ventricles remain depolarized, still in plateu

Mechanical Events: (5/7)Ventricular Ejection

Ventricles contract and squeeze blood through semilunar valves. Ventricular pressure > arterial pressure, cause semilunar valves to open

ECG: (5/7)Ventricular Ejection

ST segment

Conduction System: (6/7)Ventricular Repolarization

Ca channels close, K channels open and K leaves the cell and repolarizes

Mechanical Events: (6/7)Ventricular Repolarization

Ventricular contraction weakens, Arterial pressure rises above ventricular pressure and semilunar valves close

ECG: (6/7)Ventricular Repolarization

T wave

Conduction System: (7/7)Isovolumetric Relaxation

Ventricles return to RMP

Mechanical Events: (7/7)Isovolumetric Relaxation

Ventricles relax and pressure decreases, Ca is removed and cross-bridge cycling stops, all valves close

ECG:(7/7) Isovolumetric Relaxation

After T wave

Flow Equation

F= Pressure Diff / R

Cardiac Output equation

CO= HR x SV

Stroke Volume Equation

SV= EDV-ESV

Ejection Fraction Equation

EF= SV/EDV

Cardiac Output

amount of blood pumped by 1 ventricle per minute

Stroke volume

amount of blood ejected by 1 ventricle during 1 heartbeat

Ejection fraction

percentage of the ventricular blood that is ejected during one contraction

Preload

how much the cardiac muscle is stretched before contraction, determined by EDV

Frank starling law

The more cardiac stretch during filling, the stronger the contraction

Contractility

strength of contraction, determined by the calcium released during action potential

Afterload

resistance the ventricle must overcome to eject blood

Increase in preload

increase EDV, increase stretch, increase contractility, decrease ESV, increase SV, increase CO

Increase in contractility

increase in calcium, increase contractility, decrease ESV, increase SV, increase CO

Increase in Afterload

increase resistance, increase ESV, decrease SV, decrease CO

B1 adrenergic blocked

decrease HR, decrease contractility, decrease SV, decrease CO

Atrophine

blocks muscarinic receptors, increase HR and CO

P wave

atrial depolarization

QRS complex

ventricular depolarization

T wave

ventricular repolarization

Flow using resistance equation

Flow= 1/R