Heart Flashcards
describe what is double circulation
- blood passes through the heart twice in a complete circuit
- consists of systemic and pulmonary circulation
- systemic: oxygenated blood from heart to other parts of body and returns deoxygenated blood back to heart
- pulmonary: deoxygenated blood from heart to lungs and return oxygenated blood to heart
what are the advantages of double circulation
- keep oxygenated and deoxygenated blood separated, improving efficiency of o2 distribution
- slow blood flow in pulmonary circulation ensures adequate gaseous exchg at lungs
name the parts of the heart
4 chambers + 4 B.V.+ 4 valves + 1 structure
- chambers: left atrium, left ventricle, right atrium, right ventricle
- aorta, pulmonary artery, pulmonary vein, vena cava
- semi-lunar valves in aorta and pulmonary artery (aortic and pulmonary valves), atrioventricular valves (LHS- bicuspid, RHS-tricuspid)
- median septum
median septum
1. function?
2. describe and explain the symptoms of someone with hole in the heart disease/ atrial septal defect/ ventricle septal defect
- separates oxygenated (LHS) and deoxygenated (RHS) blood
- mixing of blood betw LHS and RHS
- reudced o2 to respiring tissues
- P in LHS lower than healthy person
- P in RHS higher that healthy person
- rate/distance of blood travelled by blood decreaes
- heart contracts more strongly, easily tired
describe:
1. general flow of blood in heart
2. deoxygenated blood (RHS of heart)
3. oxygenated blood (LHS of heart)
- vein—>atrium—>ventricle—> artery (VAVA)
- venae cavae–> right atrium–>right ventricle–> pulmonary artery
- pulmonary vein –> left atrium–> left ventricle–> aorta
state the 4 stages of the cardiac cycle
atrial diastole, atrial systole, ventricular systole, ventricular diastole (*both atria and both ventricles work simultaneously)
describe what happens during atrial diastole in terms of blood flow & pressure and valve movement
- whole heart relaxed
- deoxygenated blood enters right atrium from vena cava
- oxygenated blood enters left atrium from pul. vein
- low pressure, heart is relaxed
- cuspid valves are open
describe what happens during atrial systole in terms of blood flow & pressure and valve movement
- both atria contract simultaneously
- blood pushed into ventricles
- higher P in atria
- cuspid valves remain open (P atria > P ventricle, correct flow of blood)
describe what happens during ventricular systole in terms of blood flow & pressure and valve movement
- both ventricles contract simultaneously
- SLVs open, blood flows from left v. to aorta, and from right v. to pul. artery
- P in ventricles > P in atria, cuspid valves close to prevent backflow into atria
- chordae tendinae prev. valves from inverting into atria
describe what happens during ventricular diastole in terms of blood flow & pressure and valve movement
- ventricles relax, P ventricles decrease
- P aorta and P pul.artery > P ventricle (slightly)
- SLV valves close to prevent backflow into ventricles
- cuspid valves open (P ventricle now < P atria)
coronary artery
1. describe and locate coronary artery
2. state function of coronary artery
- small blood vessel, wraps around heart (ext surface)
- bring oxygenated blood to heart
coronary heart diseases
1. when does it occur?
- when coronary arteries are blocked/narrowed, reducing supply of oxygenated blood to heart muscles
causes of CHD: atherosclerosis
1, what are causes atherosclerosis? how does it happen? (3)
- fatty substances deposit on inner arterial wall, build up of plaque
- lumen of artery narrows, B.P increases
- arterial wall becomes rougher, increase chances of thrombosis occurring (blood clots form)
what are the effects of coronary heart diseases/atherosclerosis?
- chest pain/discomfort (angina pectoris), insufficient o2 and GAA for aerobic respiration of heart muscles
- heart attack (almost complete blockage), insufficient o2 and GAA causes heart muscles to die, heart stops pumping
