Lecture 1: Intro to the CVS

Question 1

what is syncope

Answer 1

fainting due to low blood pressure

Question 2

how is pulmonary circulation described

Answer 2

series, blood flows through one capillary system and then the next

Question 3

how is systemic circulation described

Answer 3

parallel, lots of branching and blood flows either through one capillary system or another

Question 4

what is the blood pressure equation

Answer 4

blood pressure = cardiac output x peripheral resistance

Question 5

when measuring blood pressure, how do you know you’ve reached systolic blood pressure

Answer 5

when you start hearing sounds

Question 6

when measuring blood pressure, how do you know you’ve reached diastolic blood pressure

Answer 6

when you stop hearing sounds

Question 7

function of aorta

Answer 7

stretch and recoil to store energy from the heart contractions

Question 8

function of arteries

Answer 8

distribute, adjust volume

Question 9

function of arterioles

Answer 9

regulate blood flow into capillaries, set resistance and blood pressure

Question 10

function of capillaries

Answer 10

exchange

Question 11

function of venules

Answer 11

collect blood, some exchange

Question 12

function of veins

Answer 12

reservoir for blood, muscle pump (contains 64% of blood in body)

Question 13

composition of an artery from innermost to outermost

Answer 13

• 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

Question 14

what does the cross section of the right heart look like

Answer 14

crescent, thin wall

Question 15

what does the cross section of the left heart look like

Answer 15

circular, thick wall

Question 16

what is systole

Answer 16

ventricle contraction, blood ejected

Question 17

what is diastole

Answer 17

ventricle relaxation, blood fills ventricles

Question 18

what is the apex beat

Answer 18

at systole, the apex of the heart moves forward and strikes the chest wall

Question 19

when do valves open and close

Answer 19

• open when pressure is high on inflow side

- close when pressure is higher on outflow side

Question 20

features of atrioventricular valves

Answer 20

• close during systole
• have papillary fibres to prevent prolapse
• responsible for S1 or “lub” sound

Question 21

features and examples of semilunar valves

Answer 21

• eg aortic and pulmonary
• close during diastole
• reponsible for S2 or “dub” sound

Question 22

what do the kidneys control

Answer 22

• blood volume

- concentration of salts, ions and electrolytes

Question 23

what is glomerular filtration rate

Answer 23

• fluid entering all Bowman’s capsules in both kidneys

- measured in ml / min

Question 24

what is hypoxia

Answer 24

insufficient oxygen supply to a region

Question 25

what is anoxia

Answer 25

no oxygen supply to a region

Question 26

what is hypoxaemia

Answer 26

insufficient oxygen supply to whole system

Question 27

what can cause hypoxaemia

Answer 27

- low haemoglobin - tissue consumption is too much for blood flow - lung failure of gas exchange or issue in breathing

Question 28

what is ischaemia

Answer 28

insufficient blood flow to a region

Question 29

what causes ischaemia

Answer 29

- vessel constriction, closure or clogging - insufficient blood volume eg in haemorrhage - insufficient pressure generation from heart

Question 30

what is angina pectoris

Answer 30

- chest pain due to over exertion of damaged heart tissue | - caused by ischaemia of heart tissue due to an obstruction of a coronary artery

Question 31

what is a myocardial infarction

Answer 31

- death of one region in the heart - causes sudden crushing pain - results from occlusion of a coronary artery

Question 32

treatment of myocardial infarction

Answer 32

- immediate reperfusion, eg PCI | - drug treatments are morphine, oxygen, nitrates and aspirin (MONA)

Question 33

what is heart failure

Answer 33

- aka pump failure - heart pumps out insufficient blood - symptoms are fatigue, dyspnoea and oedema - generally results from myocardial infarctions

Question 34

what is shock

Answer 34

- critically low perfusion | - affects cerebral and renal function

Question 35

what is syncope

Answer 35

- fainting due to insufficient blood flow to the brain | - often caused by heart malfunctions eg shock or arrhythmia