the heart Flashcards
what is cardiac arrest
-medical emergency where the heart stops besting leading to a cessation of blood flow to the brain, cpr used to manually preserve brain function until blood flow is restored
briefly describe the heart
-muscular organ located in the chest cavity slightly left of the midline, about the size of the fist and has four chambers
what are the four chambers of the heart
-2 atria-right atrium and left atrium
-2 ventricles-right ventricle and left ventricle
function of right atrium
-right atrium receives deoxygenated blood from the body through superior and inferior vena cava
function of the left atrium
-receives oxygenated blood from the lungs via pulmonary veins
function of the right ventricle
-pumps deoxygenated blood to the lungs through the pulmonary artery
function of the left ventricle
-pumps oxygenated blood to the body through the aorta
what does a valve do and name the four valves of the heart
-valves ensure unidirectional flow of blood, these include the tricupsid valve, pulmonary valve, mitral valve, aortic valve
location of the tricupsid valve
-between the right atrium and right ventricle
location of pulmonary valve
-between the right ventricle and pulmonary artery
location of the mitral valve
-between left atrium and left ventricle
location of aortic valve
-between left ventricle and aorta
endocardium
-inner layer lining the chambers and valves
myocardium
-thick muscular middle layer responsible for pumping action
pericardium
-double walled sac surrounding the heart, providing protection and anchoring within the chest consists of fibrous pericardium(outer layer, epicardium) and serous pericardium(inner layer) which further divides into the parietal and visceral layers
function of the sinoatrial node
-located in the right atrium ,
-natural pacemaker, generates electrical impulses that initiate each heartbeat, impulses cause the atria to contract which pushes the blood into the ventricles
function of the atrioventricular node
-located in junction between atria and ventricles
-av node receives impulse from sa node , briefly delays impulse allowing ventricles to fill with blood from atria before contracting
function of bundle of his
-after av node impulses travel to bundle of his, pathway of fibres located in interventricular septum, bundle splits into left and right bundle branches that run down both sides of the septum
function of purkinje fibres
-bundle branches divide into purkinje fibres which spread throughout the ventricles , rapidly conduct electrical impulses causing ventricles to contract and pump blood to the lungs and rest of the body
