A&P 2 Chapter 20 Homework
The structure that permits blood flow from the right atrium to the left atrium in the fetal circulation is the?
foramen ovale
Cardiac muscle cells and skeletal muscle cells differ in a few ways. Which of the following is not one of them? - Cardiac muscle cells branch. - Cardiac muscle cells have a single, centered nucleus. - Cardiac muscle cells lack transverse tubules. - Skeletal muscle cells lack intercalated discs. - Cardiac muscle cells are smaller in size.
Cardiac muscle cells lack transverse tubules
The property of heart muscle to contract in the absence of neural or hormonal stimulation is called?
automaticity
Which of the following would not increase heart rate? - beta blocking drugs - faster depolarization of the pacemaker potential - increased sympathetic stimulation of SA node - increased levels of epinephrine - decreased parasympathetic stimulation of nodal fibers
beta blocking drugs
The volume of blood ejected from each ventricle during a contraction is called the?
stroke volume
The contraction phase of the cardiac cycle is called?
systole
Tetanic muscle contractions don't occur in a normal cardiac muscle because?
the refractory period lasts until the muscle relaxes
If the connection between the SA node and AV node becomes blocked?
the ventricles will beat more slowly
Passive refilling of the heart occurs during which phase of the cardiac cycle?
ventricular diastole
The relaxation phase of the cardiac cycle is called?
diastole
The volume of blood remaining in the ventricle as ventricular diastole begins is called the __________?
end-systolic volume