▪ cardiac tissue is capable of
autoconduction
▪ cardiac conduction
system (ccs) has own
conduction system – initiates
own pulse without neural
control.
components of cardiac conduction system :
▸sa node
▸av node
▸av bundle
▸purkinje fibers
extrinsic control of the heart
controls of the cardiovascular system include neuronal, humoral, reflex, and chemical regulatory mechanisms. these extrinsic controls regulate heart rate, myocardial contractility, and vascular smooth muscle to maintain cardiac output, blood flow distribution, and arterial blood pressure.
the heart
heart rate
increase work will increase hr
rhr increases with age
mhr = 220 – age
stroke volume
volume of blood pumped per stroke
sv increases with increase rate of work
cardiac output (q)
total volume of blood pumped out in 1 minute
q = hr x sv (average = 60-80ml in adults)
q increases with increase rates of work
blood flow
➠ during rest = 15-20% of resting q
➠ during exercise = increase up to 80%
of q
during exercise in the heat, there is increase blood flow to the skin
blood pressure
pressure exerted by blood against the blood vessels
systolic = highest p in the artery
diastolic = lowest p in the artery
normal bp = 120/80 mmhg
blood
transporting oxygen and nutrients to the lungs and tissues
forming blood clots to prevent excess blood loss
structure and function of the cardiovascular system
► the heart (the pump)
► the vascular system
► the blood
⊳ cardiac muscle is called the
myocardium.