circulatory system Flashcards
what do the cardiovascular and lymphatic system do
Transport fluid through body. Distribution of gases and molecules, chemical signaling, thermoregulation, mediate inflammation and defense response.
pulmonary and systemic circulation
right atrium – right ventricle – lungs – left atrium – left ventricle – body – back to RA
pulmonary circulation
to lungs to be oxygenated
systemic circulation
supplies the rest of body with oxygenated blood
systole and diastole
systole = contraction. diastole = relaxation
walls of heart. 3 layers
epicardium, myocardium, endocardium
epicardium
external layer
myocardium
middle layer, cardiac muscle, pumps most of blood, very strong
endocardium
internal, endothelium of blood vessels connecting w the heart
great vessels
superior vena cava. pulmonary trunk, divides into L&R arteries. pulmonary veins x4. inferior vena cava
valves
atrioventricular (between atrium and ventricle) there’s a L&R one. left = mitral valve. right = tricuspid valve. Semilunar (blood leaving left and right ventricles), left = aortic. right = pulmonary
conduction system in heart
impulse starts at SA node, causing both atria to contract. travels to AV node at AV septum. travels down right and left bundles in interventricular septum. spreads out to myocardium through conducting fibres. both ventricles contract
arterial supply and venous drainage components
blood vessels, arteries, artery branches, tone
naming branches
Bifurcate (splits into 2) or trifurcate. Terms like ‘common’ or ‘trunk’ indicates the artery will divide
arteries
Often part of neurovascular bundle, high pressure, named by anatomical position, round lumen, carry oxygenated blood, typically deeper than veins.
tone
smooth muscle in arterioles can contract. vasodilation or vasoconstriction
vasodilation
relaxation of muscle, increase blood flow.
vasoconstriction
contraction of muscle, reduce blood flow. The muscle contraction can help prevent blood loss during injury.
anastomoses
arteries connect together without intervening capillary network. This provides alternative routes for blood flow for the blood if a blockage occurs. alternative routes called collateral circulation
end arteries
the only arterial blood supply to given area (no collateral vessels). Untreated occlusion of an end artery results in infarction of territory.
infarction
Infarction = irreversible cell death due to lack of oxygen (hypoxia).
where does systemic arterial blood enter first
aorta
aorta : elastic recoil
Receives blood at high pressure during systole, elastic walls expand under pressure. Elastic recoil maintains peripheral flow during distole, aorta has many branches supplying whole body
branches of aorta
1) brachiocephalic trunk 2) left common carotid artery 3) left subclavian artery