blood flow and pressure Flashcards
(22 cards)
arterial system
Delivers high blood pressure, oxygenated blood to periphery
Layers of connected and smooth tissue
No gas exchange because of thickness
Elastic contents
Venous system
Capillaries feed deoxygenated blood into the venous system
Eventually blood from the upper and lower portions of the body empty into the superior and inferior vena cava
Low pressures
define Blood pressure
Forced of the blood during ejection from the left ventricle
Propagates a wave of pressure through the arterial system
define MAO
The average arterial pressure during a single cardiac cycle
MAP formula
MAP = DBP + [0.33*(SBP - DBP)]
define TPR
Total resistance to blood flow by the entirety of the systems vasculature
calculate TPR
MAP= Qx TPR
what happens to systolic blood pressure at steady state
Increase before plateauing
Primarily due to the increase Q required to support exercising muscles
what happens to diastolic blood pressure at steady state
Stays the about the same & can even slightly decrease in healthy or trained individual
Due to vasodilation to working muscles (decreased resistance)
MAP during exercise
Increase slightly
b/c increase in Q being offset by peripheral vasodilation
Describe pressure and resistance
Vessel radius is the critical determinate and this can be greatly influenced by vasodilation or constriction
Describe the controllers of blood flow
Blood pressure regulation = vasoconstriction
Oxygen delivery = vasodilation
how does vasoconstriction work
-whole body sympathetic nerve activity increases
- release ATP, norepinephrine,
Sympatholysis
Function reduction of sympathetic vasoconstriction in contracting skeletal muscles
Sympathetic cholinergic nerve fibers release acetylcholine that dilates vessels
Decrease in local tissue PO2 and increase in CO2 and Nitric Oxide released from arteriole membrane dilate vessels
Describe how blood flow is controlled during exercise
Vasoconstriction of arterioles (increases blood pressure)
Sympathetic cholinergic
Decreases in local tissue
Sub maximal training adaptions
HR increase and SV
Redistribution of blood to working muscles
Vasoconstriction in non working
Increase in systolic BP followed by a plateau
Diastolic BP remain constant
Increase preload
CAO2 constant
CvO2 decrease then stabilize
% SaO2 constant
A-Vo22 difference will increase then stabilize
maximal training adaptions
Increase systolic BP , blood flow, preload, HR, Q
TPR is at its lowest in skeletal muscles
a-VO2 difference will continue to increase until max
CaO2 should remain constant
CvO2 will decrease
Describe the chronic adaptations of the cardiovascular system to exercise and exercise training
Heart size
1. Larger internal cavity eccentric- increase EDV
2.Greater wall thickness (concentric)- increase contractility
The degree of change depends on the precise overload the myocardium undergoes
Endurance athletes undergo more eccentric cardiac hypertrophy- sarcomeres laid down in series
What happens to total peripheral resistance during exercise?
decreases
How would describe what happens between vasodilation and vasoconstriction during exercise?
Increases heart mass and volume, cavity size, wall thickness
What substance is crucial for vasodilation?
Acetylcholine
What happens to the heart (specifically) after exercise training?
Increase in size
