Overview of The Function of The Cardiovascular system Flashcards
What does the blood flow sytsem of the CVS carry?
If the pumps are in series (right and left ventricle) what does this imply?
Output must be equal
Why are most vascular beds in parallel?
Ensures all tissues get blood,
Allows regional redirection of blood
Can send different proportions of blood to match specific requirements to different parts of the body.
Give an example of when there are local regions of vessels being in series
Blood flow system between liver and gut
Hypothalamus releasing hormones which travel directly to the anterior pituitary
Why does the skin receive more oxygen than it uses?
Thermoregulation
Which organs receive less of the percentage cardiac output than percentage oxygen consumption?
How do you calculate flow?
How is difference in pressure calculated?
Pressure difference = Mean Arterial Pressure –
Central Venous Pressure
Affects all tissues
How is the resistance calculated?
Controlled by radius4
Decreasing radius by half increases resistance to the power 4, 16 fold
Selectively redirects flow
Which vessels can affect resistance and influence blood distribution?
Arterioles
How does the size of blood vessels change?
Arteries - arterioles - capillaries
How does the size of the veins change?
Capillaries - venules - veins
What are elastic arteries?
What are muscular arteries?
What are resistance vessels?
What are exchange vessels?
What are capacitance vessels?
Are valves active or passive?
Passive
What separates the ventricles?
Interventricular septum
What vein enters the right atrium?
Vena cava
What is the mitral valve?
Valve between left atrium and left ventricle
Has two tapered cusps
Define the tricuspid valve?
Valve at the opening of right atrium into right ventricle
Resembles mitral valve in structure but consists of three triangular membranous flaps (also called right atrioventricular valve)
Define chordae tendinae
tendons that connect papillary muscles to tricuspid valve and mitral valve
Define papillary muscle
Muscles located in ventricles of heart
Attach to cusps of atrioventricular valves via chordae tendineae and contract to prevent inversion or prolapse of valves on systole (ventricular contraction)
