Blood

Which right flow tube radius resulted in the fastest flow rate?

5.0 mm

Calculate the cardiac output if heart rate (HR) is 90 beats per minute, stroke volume (SV) is 110 ml/beat, end diastolic volume (EDV) is 140 ml, and end systolic volume (ESV) is 30 ml.

9.9 L/min - Cardiac output is the product of heart rate times stroke volume.

___ ______ electrical link(s) between atria and ventricles

AV bundle

___ _____ delay(s) occurs here while atria contract

AV node

Which of these structures conduct(s) action potentials the slowest? A) Bundle branches B) AV bundle C) AV node D) Purkinje fibers

AV node - Action potentials slow down as they pass through the AV node. This gives the atria time to finish contracting before the ventricles are depolarized.

Which event does not happen during ventricular diastole? A) The second sound of the heart is heard. B) Atrioventricular valves close because of the contracting ventricles. C) Blood flows from the atria into the ventricles. D) Blood is pushed into the ventricles by the contracting atria.

B) Atrioventricular valves close because of the contracting ventricles.

Which of the following statements most accurately defines what is happening during the second phase of ventricular systole of the cardiac cycle? A) All four valves of the heart are closed. B) Pressure in the ventricles is rising, but not enough to open the semilunar valves. C) Blood is being ejected from the ventricles through open semilunar valves. D) Due to the pressure generated by the contracting ventricles, the second sound of the heart can be heard.

C) Blood is being ejected from the ventricles through open semilunar valves.

In the non-exercising heart, which event of the cardiac cycle lasts the longest? A) ventricular systole B) atrial systole C) atrial diastole D) ventricular diastole

C) atrial diastole

______ ________ is the volume of blood per minute pumped out by one ventricle

Cardiac output (CO)

These activities change heart rate by changing the balance of parasympathetic and sympathetic stimulation of the heart. Sort each of the activities according to whether it decreases or increases heart rate.

Decrease- Lying Down,Digesting Increase- Standing Up, Fright or Anger, Exercise - The balance between parasympathetic and sympathetic stimulation to the heart controls heart rate. Increased parasympathetic activity decreases heart rate, and sympathetic activity increases heart rate.

_________ ________ ______ is the volume of blood in one ventricle before contraction

End diastolic volume (EDV)

_______ _______ _______ is the volume of blood in one ventricle after contraction

End systolic volume (ESV)

_________ ___________ is the number of heart beats per minute

Heart rate (HR)

_____ ______ convey(s) the impulse throughout the ventricular walls

Purkinje fibers

__ _____ set(s) the pace for the entire heart

SA node

Which part of the intrinsic conduction system normally initiates the depolarizing impulse that causes a heartbeat?

SA node - Like the rest of the intrinsic conduction system, the SA node contains pacemaker cells that spontaneously depolarize. The cells within the SA node, however, depolarize faster than the other cells within the system. This causes action potentials to initiate in the SA node rather than in any of the other structures.

Arrange the elements of the intrinsic conduction system in the order that a depolarizing impulse travels during a normal heartbeat.

SA node --> internodal pathways --> AV node --> AV bundle --> bundle branches --> purkinje fibers

________ _________ is the volume of blood per heart beat pumped out by one ventricle

Stroke volume (SV)

________ ______ is the volume of blood per minute flowing into one atrium

Venous return (VR)

______ ______ convey(s) the impulse down the interventricular septum

bundle branches

An increase in sympathetic stimulation of the heart would increase stroke volume by increasing __________.

contractility - Increased sympathetic activity increases heart contractility. This causes cardiac fibers to contract more forcefully at all levels of preload. Regardless of end diastolic volume, this mechanism increases stroke volume by reducing end systolic volume

The volume in the pump when the pump piston is all the way down represents the _______.

end systolic volume

Increase in stroke volume is a result of _______.

increased contractility of the heart, increased EDV and increased preload

_______ _________ link(s) between the SA node and AV node

internodal pathways

An increase in venous return _______.

occurs during exercise

When the flow tube radius increased, _______.

resistance decreased and pump rate increased to maintain pressure

The flow rate in this activity _______.

stayed constant, because pump rate decreased as the stroke volume increased

Which of the following stayed constant throughout this activity?

stroke volume

Which variable was altered in this activity?

stroke volume