Physiology week3 autonomic system Flashcards
(28 cards)
what nerve is used from brain stem to fibres connecting to SA NODE
vagus
what does the SA node do
act as a pacemaker
can the SA node change due to sympathetic and parasympathetic changes
yes
what can effect inital onset of hr increase
arousal / anticipatory rise
what is the 2 things that effect regulation of stroke volume
end diastolic volume in the ventricles during pre load and aortic pressure
how does arterial pressure effect regulation of stroke volume
increase in cardiac afterload results in a decrease in SV during rest and contractility decreases
how is contractility effect regulation of stroke volume
the increase in contractions due to epe, noepe and SNS
what is starlings law
increased contractility and venous return results in a bigger SV and Q
HOW DOES VENOUS RETURN VARY- 3
vasoconstriction of veins
skeletal muscle pump and constriction
respiratory pump which changes the pressure
and valves
does SV and Q differ between public and athlete
yes
whats the equation for Q - cardiac output
HR X SV
what is systolic pressure
pressure during ventricular contraction
what is disatolic pressure
pressure in arteries during cardiac relaxation
what is pulse pressure
difference between diastolic and systolic
whats equation for MEAN ARTERIAL PRESSURE
DBP+ 0.33 (SBP-DBP)
What factors influence Arterial BP
cardiac output
vascular resistance
whats long term regulator of arterial bp
kidney - blood volme
what is the short term regulation of arterial BP
SNS
Baroreceptors
Increase and Decrease in BP
what are the 2 changes and increase when starting exercise
metabolic need for o2 for muscle and cardiac output due to redistribution of blood
changes in bp and hr is dependent on what (4)
duration, intensity, environment and emotional influence
onset of exercise causes what 4 things
rapid raise in HR,SV OUTPUT
and a plateau in submaximal exercise below lactate
during recovery what decreases
HR, SV, Q
Incremental exercise - increasing over time
causes what
linear increasing work rate HR, and reaches plateau at 100% VO2 max
incremental exercise mean arterial pressure increases along with what
systolic bp not diastolic remains constant
