Quiz 3 Flashcards
Cardiac cycle is
all the events associated with one heart beat caused by a wave of depolarization through the heart. starts in the atria- brief pause- followed by the ventricles
contraction of the ventricles is
systole
relaxtion of the ventricles is
diastole
Na+ into cells is
depolarization (towards positive lead)
K+ out of cells is
repolarization (away from positive lead)
cardiac depolarization starts in the
right atrium (SA node)
bundle brances
depolariation continues to the ventricles from the atria through bundle brancjes
Explain why HR differs between pre-exercise and post-excercise sitting states
excercise: Hr Increases bc body needs more O2 and nutrients to be delivered
post exercise: body works to repay O2 debt, removes metabolic waste products, restores homeostasis (EPOC: post excercise oxygen consumption)
differences in HR with respuratory cycle
inhalation: decreased thoracic pressure causes increased venus return to the heart and increased HR
exhalation: increased thoracic pressure, decreased venus return to heart and HR
Duration between systole and diastole during post excercise is
shorter
ECG intervals during excercise causes
reduction in interval durations, particualrly RR intervals
is amplitude of waves consistent in different cardiac cycles
yes
effect of para and symp activity on the heart
PARA: decreases heart contractility and conduction velocity
SYMP: Increases heart contractility and conduction velocity
waves representing the atria contracting (before the ventricles)
P waves
Which EKG waves represent the largest movement of sodium ions
QRS complex