Chapter 1 Flashcards
Explain blood flow through the heart and to the body ?
Superior / inferior vena cava -> right atrium -> tricuspid valve -> right ventricle -> pulmonary circuit -> pulmonary trunk -> pulmonary arteries -> lungs -> pulmonary veins -> left atrium -> bicuspid valve / mitral valve -> left ventricle -> aortic valve -> aorta -> ascending / descending valve -> body
Pulmonary Circuit
Pulmonary trunk -> Pulmonary arteries -> lungs -> Alveoli / capillary beds (Gas exchange 0 -> pulmonary veins
Systemic circuit
Ascending / Descending aorta -> capillary beds (gas exchange occurs ) -> cells (take up o2 and give up co2) -> superior / Inferior vena cava
Explain Gas exchange in lungs
Alveoli are covered by capillary beds. Oxygen from alveoli moves into fluid interstitial space of lungs and then gets absorbed by blood stream and enters he RBC, o2 and co2 move through diffusion (from high to low concentration). Each RBC has hemoglobin molecules ad those bind the iron to the oxygen.
Why is blood pressure low in pulmonary circuit ?
Blood pressure is low in the pulmonary circuit to allow time for o2 diffusion and its binding to the hemoglobin molecules in blood
Why is blood pressure high in systemic circuit?
Blood pressure is high in systemic circuit to allow o2 delivery to all the cells of the body.
Why are two separate pumps required ?
Due to two different blood pressures and adequate functioning of both circuits, two separate pumps (right and left ventricles ) are required
Describe heart sounds
Heart sounds are lub dub, which come from valve opening and closing
Lub - tricuspid and mitral valves closing
Dub - aortic and pulmonary valve closing
Between lub dub occurs systole phase (heart contracting) and between dub lub occurs diastole phase (heart relaxing).
What is the sequence of the valves closing and opening
Aortic and pulmonary trunk valves are closed when tricuspid and bicuspid / mitral valves are open and vice versa
What are arteries and arterioles
Arteries carry oxygenated blood away from the heart with high pressure and low volume. Arteries are very elastic because they have elastin proteins present in the wall.
Arterioles are smaller and more vasoconstricted, have higher resistance and less elasticity
How does elasticity balance blood pressure
More elasticity balances more pressure, the more arteries stretch the higher blood pressure is and that gets detected by baroreceptors which further regulates blood pressure.
Veins and venules
Carry deoxygenated blood towards the heart. Have low blood pressure and higher blood volume. They have valves to prevent back flow.
Venules are very small veins with no valves
Thermoregulation done through blood vessels ?
Vasoconstriction - traps heat
Vasodilation - releases heat and cools off
