overview of cardiovascular system

Question 1

what does the cardiovascular system consist of

Answer 1

heart- pump
blood vessels- distribution
blood- higher pressure means faster delivery of nutrients
double circulation- blood passes through heart twice
-pulmonary=
oxygenation/removing CO2
-systemic= distribution, gas exchange, waste removal

Question 2

why is it called a closed circulatory system

Answer 2

blood remains in vessels, doesnt come in direct contact with tissues

Question 3

how does blood respond to change andchange direction

Answer 3

constriction or dilation of vessels

Question 4

why is pulmonary circulation at lower pressure than systemic circulation

Answer 4

ensure effective gas exchange and not damage pulmonary capillaries

Question 5

what does pulmonary and systemic circulation do

Answer 5

pulmonary- oxygenation, CO2 removal

systemic- distribution, gas exchange, waste removal

Question 6

what is peripheral resistance

Answer 6

blood pressure decreases further away from heart due to friction with blood vessel walls

Question 7

why do arteries have muscular walls

Answer 7

to maintain and regulate blood flow

Question 8

describe veins in carrying blood

Answer 8

carries blood at lowest pressure, has valves to prevent back flow

Question 9

components of the heart

Answer 9

pericardium- fibrous and serous layers
epicardium
myocardium- myocytes
chambers
valves
aorta, vena cava, pulmonary vein/artery

Question 10

what is the epicardium

Answer 10

layer of endothelial cells covering the surface of the heart

Question 11

what valves are present in the heart

Answer 11

atrioventricular (separate atrium and ventricle)- tricuspid and bicuspid

semilunar

Question 12

what is the heart muscle made of

Answer 12

cardiomyocytes or myocardial fibres

Question 13

what are fibres formed from and why

Answer 13

individual cells joined end to end by specialised junctions (intercalated discs), ensure tight interactions and mediate electrical coupling

Question 14

what is contraction dependent on

Answer 14

calcium signalling

Question 15

what is a sarcomere and describe its structure

Answer 15

sarcomere= unit of muscle that contracts

thick filament- myosin
thin filament- actin

A band- length of myosin
I band- section with only thin filament
H band- zone of only thick filament, no actin

M line- middle of sarcomere
Z line- end of each sarcomere

Question 16

what is the cardiac pacemaker and what does it do

Answer 16

sinoatrial node

-intrinsic waves of excitation spread from SA node to AV node to myocytes to bundle of HIS and purkinje fibres

Question 17

what controls sinoatrial activity

Answer 17

autonomic nervous system signals

Question 18

what makes up the nervous system

Answer 18

central and peripheral

Question 19

what does the peripheral nervous system divide into

Answer 19

somatic- control of skeletal muscles, conscious

autonomic- involuntary, organ function

Question 20

what does the autonomic system divide into

Answer 20

sympathetic- increases heart rate, fight or flight, noradrenaline and adreno receptors

parasympathetic- decreases heart rate, rest and digest, acetylcholine and muscarinic receptors

Question 21

what is systole and diastole

Answer 21

systole- contraction of heart muscle

diastole- relaxation

Question 22

cardiac cycle

Answer 22

ventricular filling- AV valves open, then atrial systole

ventricular systole- increased ventricular pressure closes AV valve, ventricle contract and opens semi lunar valves

Question 23

what is action potential generated by and how is it monitored

Answer 23

generated by contractions of myocytes

detected by ECG (electrocardiogram)

Question 24

how to read a ECG trace

Answer 24

P wave- SA node depolarisation
QRS complex- ventricular depolarisation
T wave- ventricular repolarisation

Question 25

what do all blood vessels have and what is its function

Answer 25

inner lumen lined with single layer of endothelial cells that regulate interactions with blood and movement of cells in/out of circulation

Question 26

structure of arteries and veins and how they differ

Answer 26

same structures but different amount and organisation endothelium (tunica intima) smooth muscle and elastin (tunica media) connective tissue/nerve fibres- tunica adventitia

Question 27

structure/features of capillaries

Answer 27

-found at terminal ends of arterioles connecting with venules to forma capillary bed -tubes of endothelium and pericytes distributed around them -continuous, fenestrated, sinusoidal

Question 28

what are pericytes

Answer 28

contractile muscle like cells

Question 29

name and explain the 3 types of capillaries

Answer 29

continuous- cells joined by tight interactions fenestrated- small gaps/pores interrupting tight interactions sinusoidal- larger gaps between cells

Question 30

structure/features of veins

Answer 30

-large veins have thick intima and adventitia and thin media, contains elastic fibres and smooth muscle -smaller veins have thin adventitia and media, multiple layers of muscle, valves -flexible and contain most of the bodies blood volume -unidirectional flow by valves and compression of neighbouring tissues

Question 31

what are venules

Answer 31

smallest vein and receives blood from capillary

Question 32

structure/features of different sized arteries

Answer 32

-large arteries have lots of elastin to help vessels recoil with high pressure -muscular arteries have layers of smooth muscle with some elastin -arterioles have little smooth muscle -smaller muscular arteries have the highest wall:lumen ratio, contribute to vascular resistance

Question 33

what is an arrhythmias

Answer 33

abnormalities in heart rate/rhythm -linked to abnormal control of excitation/depolarisation often, cardiac arrest

Question 34

what is hpertension

Answer 34

elevated resting blood pressure -damages blood vessels and leads to other conditions

Question 35

what is myocardial ischaemia

Answer 35

reduced flow of blood in coronary arteries -blocked arteries, heart attacks

Question 36

what is heart failure

Answer 36

heart unable to produce/maintain enough output to satisfy organs/tissue

Question 37

hypertension treatments

Answer 37

lifestyle changes diuretics- reduce blood volume calcium channel blockers- reduce heart rate/vasoconstriction/stroke volume ACE inhibitors sympathetic nervous regulators

Question 38

treatments for angina and ischaemic heart disease

Answer 38

lifestyle changes nitrates- release NO into smooth muscle and dilates blood vessels beta blockers- decrease heart rate and cardiac output calcium channel blockers- decrease heart rate and reduce vascular resistance statins- reduce cholesterol

Question 39

treatments for myocardial ischaemia

Answer 39

surgery- bypass graft, angioplasty aspirin, heparin- reduce formation of thrombi/break up thrombus

Question 40

what is thrombus

Answer 40

blood clot

Question 41

what is myocardial ischaemia

Answer 41

when blood flow through coronary arteries is decreased, can develop as arteries become blocked

Question 42

what is an angioplasty

Answer 42

procedure to widen blocked/narrowed coronary arteries