Ch 18 quiz

hemmorhage with a large loss of blood causes...

a lowering of blood pressure due to change in cardiac output

which of the following is a chronotropic agent that decreases heart rate

acetylcholine

the ___ carry blood away from the heart

arteries

what hormone is released to decrease blood pressure

atrial natriuretic peptide (ANP)

what occurs at the area labeled D on the graph

av valve opens

which wave on the electrocardiogram ECG represents ventricular depolarization

QRS

what occurs at B on the graph

semilunar valve closes

the right and left atria depolarize and contract following the arrival of the action potential from the

sinoatrial SA node

the volume of blood ejected from each ventricle during a contraction is called the

stroke volume

cardiac output is increased by

sympathetic stimulation

Archie has a resting heart rate of 145 bpm this condition is called

tachycardia

what occurs at the circle labeled 4 on graph

isovolumetric vetricular contraction

if the SA node is not functioning an ECG will show

no p waves with a HR between 40-60 bpm

thick projections of muscle in the ventricles that anchor chordae tendineae are called

papillary muscles

what occurs at the circle labeled 5 on the graph

peak systolic pressure

what is found between the visceral pericardium and the parietal pericardium

pericardial fluid

hypertension increases ____ causing stroke volume to ____

preload;increase

which of the following vessels carry oxygenated blood

pulmonary vein

the left ventricular wall of the heart is thicker than the right in order too

pump blood with great force

calculate the cardiac output of a patient with a heart rate of 100 bpm and a stroke volume of 75 mL

750 ml/mm

determine the mean atrial pressure (MAP) given systolic pressure of 130 mm Hg and diastolic pressure of 70 mm Hg

90 mm Hg

which valve is situated between the left atrium and left ventricle

bicuspid valve (mitral)

An increase in the rate of action potentials from baroreceptors will trigger a reflex to

both decrease heart rate and decrease pressure

the long plateau phase of the cardiac muscle action potential is due to

calcium influx as those channels remaining open

normal heart sounds are caused by which of the following events

closure of the heart valves

which of the following stimuli is detected by a chemoreceptor

decreased blood oxygen concentration

the aorta receives the full force of blood exiting the heart during ventricular systole. which of the following statements best describes the adaptive anatomy of the aorta

elastic fibers are extensive in the tunica media of the aorta and dampen the pulse pressure generated by the heart

Compared to skeletal muscle, cardiac muscle ________.

has gap junctions that allow it to act as a functional syncytium

The frank-starling law states that if other factors are constant, a _______

higher stroke volume will produce a higher end diastolic volume

What ion movement changes the membrane potential in a contractile cell from negative to positive?

influx of sodium ions