The human heart

Heart Chambers

4 chambers (two atria and two ventricles)

Chambers expansion

Upper chambers are the Atria (receive blood). Lower chambers are the ventricles (pump blood out)

Lub sound

First and longer sound) caused by closing of the Atrioventricular valve (AV); (cystole contraction)

Dub sound

(Second and shorter sound) caused by closing of the semilunar valves when the ventricles relax; (Diastole relaxation)

Sonoatrial (SA) node

right atrium, hearts primary pacemaker, generates signal that starts the heartbeat

Atrioventricular (AV) node

between atria & ventricles, relay station that delays signal for atria to fully empty b4 ventricles contract

Bundle of His (AV Bundle)

After AV node, impulses travel down bundle into septum between the ventricles

Purkinje fibers

spreads out signal throughout ventricular muscle, causing ventricles to contract and pump blood out of heart

Pulmonary Circulation

carry deoxyginated blood from heart to lungs

Systemic circulation

carry oxygenated blood from heart to rest of body

Arteries

carries blood away from the heart

Arterioles

carries blood away from arteries

Veins

carries blood toward heart

Venules

carries blood toward veins

Capillaries

connects arterioles and venules

55% Plasma

primarily water but also contains dissolved proteins; transports blood cells and platelets through the body that binds to oxygen in lungs

Erythrocytes (Red Blood Cells)

red disc-shaped that contains hemoglobin and transports CO2 back to lungs

Leukocytes (White Blood Cells)

identify and fights off infections, bacteria, and viruses

Thrombocyts (Platelets)

smaller cell fragments that work as a clotting factor in the plasma

Detect with ECG (Electrocardiogram)

used to diagnose heart rhythm issues and damage

Murmurs

Abnormal sounds detected between the lub and dub. Caused by defective valves that allowed back flow

Ventricular Fibrillation

When ventricles twitch rapidly and chaotically instead of contracting normally

Myocardial Infarction

commonly known as heart attack. when blood flow to the myocardium is blocked

Systole

heart ventricles contract and push blood out

Diastole

heart ventricles relax and refill