hemodynamics Flashcards
in diastole which valves are open
mitral and tricuspid valves (AV valves)
___ % of heart’s blood volume flows passively into the ventricles
80%
atrial systole adds ___% more to the ventricular blood volume
this is referred to as the” “
20%
atrial kick
ventricular systole which valves causes the first heart sound (S1)
closure of the tricuspid and mitral valves
which valves causes the second heart sound (S2)
closure of the pulmonic and aortic valves
autonomic nervous system has 2 divisions:
SNS and PSNS
Sympathetic nerves originate int he spinal cord between ___ and ___
L2 and T1
sympathetic nerves supply____
atria and ventricles
which neuro-transmitters area released with SNS stimulation
epinephrine and nor-epinephrine
Parasympathetic nerves arise from _____
vagal nuclei in the medulla
parasympathetic nerves supply
SA nodes, the atrial muscles, the AV node, and only very minimal influence on the HIS-purkinje fibres
PSNS effects are ___
supraventricular
which neuro-transmitter is released with PSNS (vagal) stimulation
acetylcholine
the primary intracellular electrolyte is
K+
the primary extracellular electrolytes are
Na+ and Ca++
2 main hormones that assist with homeostasis are
aldosterone and ADH
aldosterone is secreted by
adrenal cortex
aldosterone promotes
retention of Na+ and water
ADH (anti-diuretic hormone) is secreted by
posterior pituitary gland
ADH causes
decrease in urine volume, increase in urine concentration
3 main receptors that assist in cardiac function and homeostasis
osmoreceptors
pressoreceptors
chemoreceptors
osmoreceptors detect low osmolarity will cause
decrease in ADH, increase in urine output
osmoreceptors detect high osmolarity will cause
increase in ADH, decrease in urine output
pressorreceptors are sensitive to changes in
BP, HR and CO
increase in BP, HR and CO will cause pressoreceptors to
PSNS stimulation
& decrease in aldosterone, increase in urine output, decrease in BP
decrease in BP, HR and CO will cause pressoreceptors to
SNS stimulation
& increase in aldosterone, decrease in urine output, increase in BP
chemoreceptors are responsive to
low O2 levels
severe drops in CO and arterial BP
drop in CO and low PO2 levels will cause chemoreceptors to
stimulate SNS, release nor-epinephrine and epinephrine to increase HR, cause vasocontriction
drop in CO and low PO2 levels will ALSO cause chemoreceptors to
stimulate the respiratory centre to increase O2 intake
