Vessels of the Systemic Circulation

Question 1

Capillaries in terms of velocity and CSA and purpose

Answer 1

velocity decreased, large CSA, thin walls and slow blood flow help exchange substances

Question 2

Veins in terms of CSA and velocity

Answer 2

closer to the heart number of veins decreases and CSA decreases so velocity increases

Question 3

veins are the primary _ vessels

Answer 3

capacitance!

Question 4

Central venous pressure =

Answer 4

right atrial pressure

Question 5

what is central venous pressure determined by?

Answer 5

venous return, pumping ability of right side of heart

Question 6

venous return is increased when

Answer 6

increase in blood volume, increase large venous vessel tone, dilation of arterioles

Question 7

Explain how cough or straining might effect venous return

Answer 7

increased pressure transmitted from intra to extra thoracic arteries = increase in arterial BP (initially see increased SV and CO but then will have decreased venous return and decreased BP)
increased pressure is NOT transmitted from intra to extra thoracic veins (valves prevent back flow, venous return is diminished)
once stop coughing see decreased BP