Lecture 1: Intro to the CVS Flashcards
what is syncope
fainting due to low blood pressure
how is pulmonary circulation described
series, blood flows through one capillary system and then the next
how is systemic circulation described
parallel, lots of branching and blood flows either through one capillary system or another
what is the blood pressure equation
blood pressure = cardiac output x peripheral resistance
when measuring blood pressure, how do you know you’ve reached systolic blood pressure
when you start hearing sounds
when measuring blood pressure, how do you know you’ve reached diastolic blood pressure
when you stop hearing sounds
function of aorta
stretch and recoil to store energy from the heart contractions
function of arteries
distribute, adjust volume
function of arterioles
regulate blood flow into capillaries, set resistance and blood pressure
function of capillaries
exchange
function of venules
collect blood, some exchange
function of veins
reservoir for blood, muscle pump (contains 64% of blood in body)
composition of an artery from innermost to outermost
- tunica intima (made up of endothelium, basement membrane and lamina propria)
- tunica media (made of smooth muscle and elastic fibres)
- tunica adventitia (made of connective tissue)
- if it is a large vessel, has vasa vasorum on the outside for blood supply
what does the cross section of the right heart look like
crescent, thin wall
what does the cross section of the left heart look like
circular, thick wall
what is systole
ventricle contraction, blood ejected
what is diastole
ventricle relaxation, blood fills ventricles
what is the apex beat
at systole, the apex of the heart moves forward and strikes the chest wall
when do valves open and close
- open when pressure is high on inflow side
- close when pressure is higher on outflow side
features of atrioventricular valves
- close during systole
- have papillary fibres to prevent prolapse
- responsible for S1 or “lub” sound
features and examples of semilunar valves
- eg aortic and pulmonary
- close during diastole
- reponsible for S2 or “dub” sound
what do the kidneys control
- blood volume
- concentration of salts, ions and electrolytes
what is glomerular filtration rate
- fluid entering all Bowman’s capsules in both kidneys
- measured in ml / min
what is hypoxia
insufficient oxygen supply to a region
what is anoxia
no oxygen supply to a region
what is hypoxaemia
insufficient oxygen supply to whole system
what can cause hypoxaemia
- low haemoglobin
- tissue consumption is too much for blood flow
- lung failure of gas exchange or issue in breathing
what is ischaemia
insufficient blood flow to a region
what causes ischaemia
- vessel constriction, closure or clogging
- insufficient blood volume eg in haemorrhage
- insufficient pressure generation from heart
what is angina pectoris
- chest pain due to over exertion of damaged heart tissue
- caused by ischaemia of heart tissue due to an obstruction of a coronary artery
what is a myocardial infarction
- death of one region in the heart
- causes sudden crushing pain
- results from occlusion of a coronary artery
treatment of myocardial infarction
- immediate reperfusion, eg PCI
- drug treatments are morphine, oxygen, nitrates and aspirin (MONA)
what is heart failure
- aka pump failure
- heart pumps out insufficient blood
- symptoms are fatigue, dyspnoea and oedema
- generally results from myocardial infarctions
what is shock
- critically low perfusion
- affects cerebral and renal function
what is syncope
- fainting due to insufficient blood flow to the brain
- often caused by heart malfunctions eg shock or arrhythmia
