Intro to the Heart Flashcards
What are the 4 chambers of the heart?
Which vessels exit out of the different chambers?
Why are the pressures in these different vessels important clinically?
Why is the vena cava and central venous pressure important?
Chambers: right and left atria and ventricles
Right atrium = superior and inferior vena cava
Left atrium = pulmonary vein
Right ventricle = pulmonary artery
Left ventricle = aorta
Pressures can act as markers for diseases e.g. hypertension:
Vena cava = central venous pressure (gives an idea of the venous pressure around the body) = e.g. sepsis (too low pressure can result in death)
Pressure in aorta = disease marker e.g. hypertension
Pressure in pulmonary artery = disease marker e.g. hypertension
What are the capacities of the different chambers?
What are the pressures of the different main vessels of the heart?
Left atrium = 100mL
Right atrium = 110mL
Left ventricle = 150mL
Right ventricle = 175mL
Aorta = 100-120mmHg
Pulmonary artery = 10-20mmHg
Vena cava = 5-10mmHg
Pulmonary veins = 10-15mmHg
What is the blood flow through the heart? Annotate on the diagram:
Label the valves of the heart:
What disease conditions affect the heart valves?
Stenosis = hardening of the valves; treated usually by replacing the valve
Regurgitation = if the valves do not close properly, there is backflow which reduces the efficiency of the heart and affects blood pressure
How does the heart conduct electricity?
What are the different components of the heart responsible for the electrical conductance of the heart?
Not cardiac muscle cells, instead has specialised cadiac cells called nodal cells and fibrous tract cells
Made up of nodal cells:
SAN = pacemaker of the heart; located in the upper right wall of the atrium at the opening of the superior vena cava
AVN = pacemaker activity also, has slow calcium mediated action potential
and tract cells:
Intranodal tracts
Bundle of His = splits into two branches made of specialised myocytes allowing for electrical conductance to spread
Purkinje fibres = specialised conducting fibres
What is the blood flow around the heart?
What are the names of the arteries and where are they located?
What are the names of the veins and where are they located?
Right coronary artery, left circumflex, left anterior descending
Coronary sinus, great cardiac vein, middle cardiac vein
Disease conditions of the blood supply to the heart?
What are the uses of the ECG?
Myocardial infarction (leads to necrosis of the cardiac muscle) and angina (blood supply to the heart is restricted) - often causes by blockages in these vessels
Can find where the myocardial infarction is specifically by looking at the electrical activity of the heart
What are anti-hypertensives?
What are the names of some antihypertensives and how do they work?
Class of drugs used to treat hypertension (high BP)
Atenolol = beta blocker
Amlodipine = Ca2+ channel blocker (act as vasodilators - routinely used for hypertension)
Losartan = angiotensin receptor blocker (angiotensin = vasoconstrictor)
Ramipril = ACE inhibitor (also prevent vasoconstriction)
Chlorthalidone - thiazide-like diuretic (reduce BP by reducing blood volume)
