Card Set Information
Why is arteriole systole and recoil important?
allows for distension during systole
pushes blood through the body during relaxation
***Generally all vessels have a normal state of tone
What autonomics innervate arteries and arterioles?
What is the diff. b/t basal tone and resting state?
Resting State takes into consideration minor help from SNS
What is the diff. b/t active vasoconstriction/vasodilation?
increase in diameter due to SNS
decrease in diameter due to SNA
What is the diff. b/t passive vasodilation/vasoconstriction?
return to state after active vasoconstriction
return to state after active vasodilation
What is the role of SNS and Adenosine in vessel tone?
active vasoconstriction/passive vasodilation
active vasodilation/passive vasoconstriction
What is the role of Vasopressin and Angiotensin II?
***increased resistance, decreased flow
What happens to vessels in warm/cold states?
What is the role in increased endothelin?
What is the role of Nitric Oxide?
***decreased resistance, increased flow
What are the three intrinsic factors of vascular tone?
What are the two extrinsic factors of vascular tone?
What do extrinsic factors affect most, pressure or flow?
Pressure > flow
What is active hyperemia?
Increased metabolites = vasodilation = increased blood flow = high oxygen = vasoconstriction
Occlusion (clot, block, pinch, etc.)
After an occlusion is removed, what happens to blood flow in Reactive Hyperemia?
Blood flow is greater than before because of the vasodilation that occured to compensate for the occlusion
What happens to the hyperemic response if you have an occlusion present for longer?
It is longer and the peak of Blood flow is higher
What are 5 important vasodilators?
K, H, Adenosine, NO, CO
, Lactic Acid
What gases are important in vasoconstriction?
Changes that automatically occur when BP changes
: Vasodilation to increase flow and decrease resistance
: Vasoconstriction to decrease flow and increase resistance
What organs participate in
Brain, Heart, Kidney, Skeletal muscle
Out of the smooth muscles around vessels and the precapillary sphinctors, which ones are affected by the SNS?
Smooth muscles around vessels
What are three reasons for why capillaries are good for diffusion?
Slow velocity of flow
What is the main hormone that widens capillaries and relaxes precapillary sphinctors?
What vessel contains
Where do the movements of
out of capillaries
: into capillaries
What is the P
at the arteriole/venous end?
: 37 mmHg
: 17 mmHg
What does a negative and positive number tell us when caculating capillary fluid movement?
Negative = reabsorption (in)
Positive = filtration (out)
Where will fluid flow in case of hemorrhage and why?
Reabsorb into capillaries to replace lost fluid
What is the general net outward/infward capillary filtration?
Outward = 11 mmHg
Inward = 9 mmHg
***2 leftove for Lymphatic system
Is there more lymph return in the pulmonary or systemic circulation?
What are the five systems that increase venous return? (BRSSP)
Skeletal muscle pump
Sympathetic vasoconstriction (kinins)
Pressure from cardiac contraction (CO)