Heart and Circulation Flashcards
What is the main difference between the arterial system and veinous system ?
Arterial- arteries here to generate resistance to flow (conductance)
Veinous- Veins here to hold large capacity of blood
What is microcirculation ?
Where transfer of nutrients and waste occurs
How much blood is in each system (pulmonary, systemic and heart) at one time ?
Systemic- 84%
Pulmonary- 9%
Heart- 7%
Which of ventricles or atria is more of a pumping force ?
Ventricles (atria contribute just a little to ventricle filling, mostly a passive process)
Where is the location of the heart ?
Centrally in the chest, between lungs and pleura, in middle mediastinum. Surrounded by pericardial sac of fibrous tissue, which is lined by serous membrane which secretes lubricating fluid.
What is the purpose of the lubricating fluid secretes by the membrane lining the pericardiac sac ?
Helping heart beat without generating too much effort
What are possible disadvantages of too muscular a heart ?
Hypertrophy/cardiomyopathy
What are the main characteristics of the heart ?
Muscular, yet able to transmit waves of contraction
Continuously beating
Only allows blood flow in one direction (valves)
Does not allows coagulation (thanks to endothelium)
Remains in a lubricated potential space to allows expansion and contraction
What are the auricles of the heart ?
Appendanges to both right and left atrium
Which chamber is not visible in the sternocostal surface ?
Left atrium.
What are the different surfaces of the heart ?
Sternocostal (anterior) Diaphragmatic (inferior) base (superior)
Which chamber mainly makes up the inferior diaphragmatic surface ?
Left ventricle
Which chamber mainly makes up the base of the hear ?
The left atrium
What is the entire path of the blood ?
Deoxygenated blood into right atrium –> Tricuspid valve –> Right ventricle –> pulmonary trunk –> R and L pulmonary arteries –> lung capillaries –> L, R, superior and inferior pulmonary veins –> L atrium –> Mitral valve –> L ventricle –> Aorta –> Arteries –> Arterioles –> Capillaries –> Venules –> Veins –> Vena Cava –> Back to start
Why doesn’t all blood get ejected (only 50-60% ejected) from left ventricle to the aorta upon contraction ?
To keep reservoir (in case of increased tissue demands) and because ejecting all would create surface tension between ventricle walls.
How does the heart get supplied ?
Coronary arteries –> coronary veins –> venae cavae –> back to start
How is the fetal heart different to adult heart ?
Foramen Ovale connects R atrium to L atrium allowing oxygenated blood coming from mother to bypass non-functioning fetal lungs.