Lecture 2- CVS anatomy Flashcards
outline the cardiac cycle
- Deoxygenated blood from the body enters the heart via the right atria.
- When the pressure is sufficient the tricuspid valve opens and the blood enters the right ventricle
- Deoxygenated blood is pumped from the right ventricle into the pulmonary artery via the pulmonary valve
- Blood pumped to the lungs and oxygenated
- Oxygenated blood returned to the heart via the pulmonary vein into the left atria
- When the pressure in the left atria exceed that of the ventricles, the mitral valve (bicuspid) opens and allows blood to flow into the left ventricle
- This blood is ejected out of the left ventricle via the aortic valve and into the aorta
- Once in the aorta the oxygenated blood is pumped to both superior (above the heart) and inferior tissue (below the heart)
- Tissue uses up oxygen during respiration
- Deoxygenated blood full of CO2 is then returned to the heart via the inferior and superior vena cava into the right ventricle
methods of cardiac imaging
- X-ray (not great because soft tissue - Ultrasound (echocardiogram) - Cardiac MRI - CT (recommended)
MRI is the best at
looking at soft tissue (especially if contrast enhanced)
CT scan are great for
visualising bone and vasculature
Arterio-venous structure/ connections
Arteries —> capillaries —> veins (return to heart to be oxygenated by the lungs)
layers of the blood vessels (outside to inside)
tunica externa, tunica media, tunica intima, basement membrane
features of large arteries
elastic e.g. aorta
medium arteries
distributing– muscular
small arteries
arterioles- resistance vessels control blood pressure
features of veins
have valves to ensure unidirectional blood flow
deeper veins run through
muscle- helps venous return- squeezing the veins
left side of the heart has
much thicker muscle layer–> needs to pump with greater foce
where is pressure lowest in the heart
the right atrium (0-8)
where is prevue greater
the aorta (110-130)/ (70-80)
role of chordae tendineae and papillary muscle
The papillary muscles are muscles located in the ventricles of the heart. They attach to the cusps of the atrioventricular valves (also known as the mitral and tricuspid valves) via the chordae tendineae and contract to prevent inversion or prolapse of these valves on systole (or ventricular contraction).