Heart and Lungs Flashcards
Describe blood flow starting at the right atrium.
Right atrium, right ventricle, pulmonary artery, lungs, pulmonary ventricle, left atrium, left ventricle, aorta, arteries, capillaries, veins, right atriums.
Describe systolic blood pressure and diastolic pressure
Systolic blood pressure occurs when the left ventricle contracts sending blood into the systemic cycle.
Diastolic blood pressure occurs when the ventricle begins to relax.
Describe arteries
Composed of smooth muscle, connective tissue, elastin to support the enormous pressure from the left ventricle. High pressure, low volume (space). High resistance to flow.
Describe arterioles
Branches of arteries. Have strong resistance to maintain the flow of blood through the body.
Describe veins
Transport blood against the pull of gravity. Special valves make sure blood doesn’t go in the opposite direction. High volume (space), low pressure. No recoil properties.
Where is the tricuspid valve located?
Between the right atrium and right ventricle.
Where is the mitral valve located?
Between the left atrium and the left ventricle.
When do the lub dub sounds in the heart occur?
lub occurs when the AV valve closes, opening of semi.
dub occurs when the semilunar valve closes, opening of AV.
Describe the transmission of electrical signals in the heart.
The SA node sits at the top of the right atrium where it sends an electrical signal to the rest of the heart to contract. The signal is transmitted to the AV node where it is then transmitted via the bundle of his to the ventricles.
Describe the function of baroreceptors in the heart.
Baroreceptors maintain pressure. If the blood pressure decreases then these receptors send signals to the brain to increase pressure. Epinephrine and norephinerphine are released to increase the contractions of the heart to stimulate blood pressure.
What is the equation for Cardiac output?
Cardiac Output = Heart Rate ( Stroke Volume)
What is P’s law?
Flow = change in pressure (pi) (r)^4 / 8nL
notice the importance of the radius, it makes a huge difference.
What are the three layers of the heart?
Endocardium: Inner layer of the heart, covers valves.
Myocardium: larger part of the heart, contractile muscles.
Pericardium: top layer, protective layer.
Relate vasoconstriction and vasodilation to resistance.
Vasoconstriction decreases radius so it increases resistance.
Vasodilation increases radius so it decreases resistance.
What is Resistance proportional to?
1/ r^4
R= 8nL / r^4 (pi)