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Flashcards in The Heart Deck (19):

What is the outer layer of the heart called

Fibrous pericardium
Made of dense connective tissue
Helps protect heart and anchors it


What are the inner layers of the pericardium

Visceral pericardium inner
Outer parietal layer


What does the heart muscle wall contain

Epicardium outer layer
Myocardium middle layer composed of cardiac tissue
Endocardium inner layer of squamous epithelium tissue


What divides the heart into two sections



Where is the pulmonary semi lunar valve

Between the right ventricle and pulmonary artery, allows blood to flow from heart to lungs


Where is the mitral valve

(Bicuspid valve) between left atrium and left ventricle


Where is the aortic semilunar valve

Between the left ventricle and aorta, which carries blood from heart to rest of body


Where is the tricuspid valve

Between the right atrium and right ventricle


How does blood become oxygenated

Blood leaves the heart though the right ventricle past the pulmonary semi lunar valve into the lungs through the pulmonary artery, picks up oxygen, carbon dioxide leaves


How does blood re enter the heart after being oxygenated

Blood enters the left atrium which has lower pressure than the pulmonary vein, the atrium contracts increasing its pressure, blood passes down through the mitral valve to the left ventricle


How does oxygenated blood leave the heart

Left ventricle contracts to increase pressure, mitral valve closes to prevent backflow forcing blood to leave through the aortic semilunar valve through the aorta


How does deoxygenated blood re enter the heart

Enters through superior and inferior vena cava into right atrium, atrium contracts increasing pressure above ventricle, blood flows into ventricle through tricuspid valve


What is systole

High pressure caused by ventricular or atrial contraction


What is diastole

Ventricles relax to receive blood from atria


What do pacemaker cells do

Keep heart beating at correct rhythm and ensure each cardiac muscle cell contracts in coordination with others


What does the sino atrial node do

Acts as a pacemaker, sends action potentials across atrial walls causing contraction until they reach the av node


What does the atrioventricular node do

Signal gets delayed by av node so atria finish contracting before ventricles contract, signal moves down bundle of his


What happens to the signal at the purkyne fibres

Signal reaches bottom of heart at purkyne fibres which cause ventricles to contract from the bottom up


What is fibrillation

Uncoordinated contraction