Cardiovascular System Flashcards
what is anterior to the mediastinum
sternum
what is lateral to the mediastinum
pleurae of lungs
what is posterior to the mediastinum
vertebrae T4 - T11
what is superior/inferior to the mediastinum
superior = thoracic inlet
inferior = diaphragm
what is contained within the mediastinum
- heart
- great vessels
- trachea
- oesophagus
- thoracic duct
- thymus
- azygos venous system
- nerves
- lymph nodes
what is the function of the pericardium
- protect & anchor the heart
- prevent friction
- prevent overfilling with blood
list the layers of the heart wall in order
- pericardium
- epicardium / serous pericardium
- myocardium
- endocardium
what are the surfaces of the heart
- sternocostal
- diaphragmatic
- left & right pulmonary
what vertebrae is posterior to the heart in a CT
T7
what is another name for the pulmonary valve and where is it
right semilunar
between right ventricle & pulmonary artery
what is another name for the aortic valve and where is it
left semilunar
between aorta & left ventricle
what are the valves between atria and ventricles
atrioventricular
what are the valves between the ventricles and lungs/body
pulmonary & aortic
what is another name for the mitral valve and where is it
bicuspid/left atrioventricular valve
what is another name for the tricuspid valve and where is it
right atrioventricular valve
what is a lumen
a cavity within a tubular structure e.g. blood flows to the heart through the lumen of the superior vena cava
what kind of pump is the heart
a dual pump because both sides simultaneously pump equal amounts of blood
what is the path of blood from the LA
LA –> bicuspid valve –> LV –> aortic semilunar valve –> aorta –> systemic circulation
what is the path of blood from the RA
RA –> tricuspid valve –> RV –> pulmonary semilunar valve –> PA –> lungs
what circulation is loaded with O2 and has CO2 removed
pulmonary
what circulation is loaded with CO2 and has O2 removed
systemic, it’s delivering O2 and collecting CO2
what kind of pressure does the pulmonary circulation have
low pressure, whereas systemic has high pressure
what is anastomosis
connection between blood vessels e.g. vein-vein, artery-artery, artery-vein
what proportion of the chest diameter should the cardiac silhouette occupy
< 50%
what is the retrosternal space and why is it important
lucent area between the sternum and heart
if it’s reduced in an xray it indicates an issue
what does parietal mean
top e.g. parietal bone
what does visceral mean
deep e.g. visceral organs
what is a sulcus
depression or groove e.g. the coronary sulcuses
in terms of the atrioventricular valves - why are they tri and bicuspid
tri because the right ventricle’s lumen is semilunar
bi because the left ventricle’s lumen is circular and easier to cover
what are the functions of the heart
- deliver waste back to lungs for removal
- work with other body systems to control rhythm and speed of heart rate
- maintain blood pressure
- pump blood & O2 around body
what is the cardiac intrinsic conduction process
SA/pacemaker –> AV node –> AV bundle of His –> bundle branches –> purkinje fibres
SA causes atrial contraction
purkinje fibres cause ventricular contraction
what is a syncytium
both atrial and ventricular
an arrangement of muscle fibres in which they fuse together to create an interconnected mass
what are the parts of the ECG
P = atrial depolarisation
P-Q = conduction time from atrial to ventricular excitation
QRS = ventricular depolarisation (left first)
R = left S = right
T = ventricular repolarisation
what are the abnormalities that ECGs detect
rate, rhythm, cardiac myopathies
what is the purpose of beta blockers
slowing down the heart rate. it can improve imaging
can also decrease BP
what does cardiac output inform
strength and health of heart
what is the formula for CO
SV * HR
what is normal SV
ml/beat = 70mL
what is the SV formula
EDV - ESV
what is ejection fraction & normal values
SV/EDV
65% - 80%
what is EDV & ESV
amount of blood remaining in each ventricle at the end of either systole or diastole
does ejection fraction change with age and is it better to be higher or lower
no
higher because it indicates the heart is pumping more blood in one pump
what are the factors that affect cardiac output
HR
- autonomic nervous system
- hormones
SV
- EDV
- ESV
what are baroreceptors
cells that respond to changes in BP
how do epinephrine & norepinephrine work on the HR
they promote vasoconstriction, which increases BP
heart contractility
what do calcium channel blockers do
negatively inotropic
blocks Ca channels which decreases HR
how is CO controlled
CO = HR * SV
HR = hormones & autonomic nervous system, sympathetic incr. para decr.
SV = EDV, ESV
what is the Frank-Starling principle
ventricular output increases as pre-load (end diastolic pressure) increases e.g. more return = more contraction
name main arteries & veins
diagram
what are the 3 layers of blood vessels
tunica externa –> tunica media –> tunica intima
where are the smooth muscle/elastic fibres in blood vessels
between tunica media & intima
what increases resistance in arteries
size of lumen (smaller = more resistance)
which has valves? arteries, veins, or both?
veins have valves so that blood doesn’t flow backward because they transport blood at a low pressure
what is the property of blood in terms of directional flow
flows from high pressure point to low pressure point
what is the purpose of artierioles
reducing pressure before it gets to capillaries so they don’t burst, and gas exchange can occur
what is deep vein thrombosis
accumulation of blood in veins that forms clots. clots can dislodge and create blockages
what is the pressure of blood in decreasing order
elastic arteries –> muscular arteries –> arterioles –> capillaries –> venules –> veins –> venae cavae
what affects blood flow
vessel radius, blood viscosity, vessel length
what is standard BP
120/80 mmHg
when is systolic pressure measured
peak measured during ventricular systole
when is diastolic pressure measured
min BP at the end of ventricular diastole
hypotension bp
90/60 mmHg
hypertension bp
140-159/90-99 mmHg
low bp
< 90/60 mmHg
normal bp
< 120/80 mmHg
elevated bp
120-129/80-89 mmHg
high bp stage 1
130-139/80-89 mmHg
high bp stage 2
> 140/90 mmHg
hypertensive crisis
> 180/120 mmHg
what’s more important? systolic or diastolic?
systolic because it’s indicative of contraction
why do we feint with low bp
easier for heart to perfuse the brain when the whole body is on the same plane
what is the difference between the cardiovascular & lymphatic system
cardio transports, lymph is part of immune system
cardio is closed, lymph is open
cardio has a pump, lymph doesn’t
cardio has red blood cells, lymph is plasma
heart pumps 20L, 17L returned, 3L is lymph system
what is prospective ecg gating
image at specific point in cardiac cycle
what is prospective ecg gating
imaging performed consistently
what nerve controls heart rate
cranial nerve 10 e.g. vagus
what is the purpose of baroreceptors
sense changes in blood pressure
what is the purpose of chemoreceptors
sense changes in concentrations of O2 & CO2
how does Na affect BP
more Na retention in kidneys = more water retention = inc blood vol = inc BP
what is a heart attack
myocardial infarction
what is myocardial infarction
when blood flow to the heart is completely blocked, and heart muscle cells die. often the result of thrombosis
what level of occlusion causes asymptomatic CAD
<50% narrowing, but still symptomatic in vigorous exercise
what is atherosclerosis & it’s risk factors
slow progressive disease where plaque builds in the arteries
risk factors are age, smoking, obesity, high cholestrol, high BP
what does ischemic heart disease look like on an angiogram
areas have no blood flow, and heart can build more branches to supply blood
what is angina
blocking or constriction of a blood vessel in the heart e.g. coronary artery that results in chest pain
what is an aneurysm
bulging in the blood vessel that is > 50% of it’s normal diameter
often asymptomatic and at risk of bursting
what is heart failure
- muscle is pumping blood as well as it should
- harder to fill chambers
- venous pressure goes up causing back pressure through the venous system
- high pressure in capillaries forces water into tissues
how do you tell which side of the heart is failing
left = pulmonary congestion & oedema because the left veins drain the lungs
right = congestion & oedema of lower extremities because the right side veins drain the abdomen, ankles etc
what is systolic dysfunction
left side heart failure
- poor LV contraction
- defect is with relaxation of LV and delayed filling
- causes are myocardial infarction
- lung congestion
what is diastolic dysfunction
right side heart failure
- RV fails due to left side heart failure or respiratory disease
- congestion/oedema of lower extremities
what is cardiomyopathy & the 3 types
disease of the heart muscle that makes it harder to pump blood to the rest of the body
dilated: dilation of all 4 chambers
hypertrophic: muscle thickens
restrictive: restricted filling because LV is hypertrophic
what are the two categories of heart failure
systolic & diastolic
how is cardiac failure assessed
plain radiographs, echocardiogram, doppler, radionucleotide ventriculography
what is valvular heart disease & the most common valve
disease or damage of heart valves
aortic because it’s the area with the most pressure
what are some diseases of the valves
stenosis = valves is narrowed and stiff so can’t fully open
regurgitation = valve is leaky
prolapse = the valve slips out of place
what can valvular heart disease lead to
heart failure, sudden cardiac arrest, death
how do you diagnosis valvular heart disease
murmurs through auscultation
echocardiography
what are symptoms of valvular heart diseas
whoosing heart murmur
angina
abdominal swelling
dyspnea
how is valvular heart disease treated
drugs, surgery, artificial valve replacement
what is congenital heart disease
heart structure defects present at birth e.g. atrial septal defect
patent foramen ovale (fossa ovalis is not closed)
what are the pericardial diseases
acute pericarditis
constrictive pericarditis
what is acute pericarditis
infection
what is constrictive pericarditis
stiffer & thicker than normal, calcification in CTs
what is pericardial effusion
accumulation of fluid in pericardium as a result of inflammation
what is cardiac tamponade
extreme pericardial effusion e.g. lots of fluid in pericardial space
