Chapter 18 IP2

Which of the following graphs depict the cardiac cycle of an individual with chronic hypertension in which blood pressure is 140/90?

-The graph for aortic pressure must show an increase throughout ventricular ejection. -The graphs for aortic and ventricular pressure must show an increase.

Arrange these elements of the intrinsic conduction system in the order that a depolarizing impulse travels during a normal heartbeat. Rank from first to last. Do not overlap any tiles.

1) SA node 2) Internodal pathways 3) AV node 4) AV bundle 5) Bundle branches 6) Purkinje fibers

Match the cardiac components in the left column to the blanks near their functions on the right. 1. Convey(s) the impulse down the interventricular septum 2. Set(s) the pace for the entire heart 3. Electrical link(s) between atria and ventricles 4. Convey(s) the impulse throughout the ventricular walls 5. Delay(s) occurs here while atria contract 6. Link(s) between the SA node and AV node

1. Bundle branches 2. SA node 3. AV bundle 4. Purkinje fibers 5. AV node 6. Internodal pathways

Match the term in the left column to the blanks near their definition on the right. 1. the volume of blood per minute flowing into one atrium 2. the volume of blood per heart beat pumped out by one ventricle 3. the number of heart beats per minute 4. the volume of blood per minute pumped out by one ventricle 5. the volume of blood in one ventricle before contraction 6. the volume of blood in one ventricle after contraction

1. Venous return (VR) 2. Stroke volume (SV) 3. Heart rate (HR) 4. Cardiac output (CO) 5. End diastolic volume (EDV) 6. End systolic volume (ESV)

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

9.9 L/min

Which of these structures conduct(s) action potentials the slowest? AV bundle AV node Bundle branches 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 of the following can be heard with a stethoscope most easily? Closing of atrioventricular valves Contraction of atria Blood flow into aorta Isovolumetric contraction

Closing of atrioventricular valves

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.

Decreases heart rate: -digesting a meal -lying down Increases heart rate: -exercise -fright or anger -standing up

​Identify the phases of the cardiac cycle by dragging the appropriate labels to their respective targets.

In order left to right: ventricular filling isovolumetric contraction ventricular ejection isovolumetric relaxation

Predict the changes in heart rate, stroke volume, and cardiac output for each of the following conditions by filling out the table below.

Increased sympathetic activity: Increase HR, SV, CO Increase Preload: No change in HR, increase SV and CO Increased exercise: Increase HR, SV, CO Increase contractility: No change in HR, increase SV and CO (HR= heart rate, SV= stroke volume, CO= cardiac output)

A person notices his or her heart beat because he or she senses blood being pumped by the heart. Excessive caffeine intake can lead to irregular heart rhythms (arrhythmias) that patients perceive as "skipped beats." Given that caffeine is a stimulant, which of the following mechanisms best explains the reason for the feeling that the heart skipped a beat? Action potentials propagate into the ventricles before the contractile cells have repolarized from the previous heartbeat. Spontaneous action potentials in the SA node overlap such that the repolarizing phase of one action potential cancels out the depolarizing phase of the next. Purkinje fibers initiate spontaneous action potentials, which cause the ventricles to contract early. Action potentials are not delayed sufficiently at the AV node.

Purkinje fibers initiate spontaneous action potentials, which cause the ventricles to contract early.

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.

The beginning of the QRS complex of the electrocardiogram (ECG) immediately precedes which of the following events? closing of the atrioventricular valves blood ejection from the ventricles closing of the semilunar valves atrial contraction

closing of the atrioventricular valves

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

contractility

Arrange these images of the phases during the cardiac cycle in order starting with atrial contraction.

diagram answers can be found in another quizlet using the link https://quizlet.com/282113049/mastering-a-and-p-chapter-14-flash-cards/

Place the appropriate valve position for the atrioventricular valves (AV) and semilunar valves for each phase of the cardiac cycle on the left side of the heart.

left to right: atrioventricular (AV) valves - closed, closed, closed, open semilunar (SL) valves- closed, open, closed, closed diagram answers can be found in another quizlet using the link https://quizlet.com/282113049/mastering-a-and-p-chapter-14-flash-cards/

As part of a blood drive on campus for the American Red Cross, you and your friends have just donated 500 mlml of blood. You are now relaxing at the student lounge, waiting for A&P lab to begin. Unfortunately, even though you are thirsty, you haven't bothered to buy yourself a drink. Other than a little soreness of the skin and tissue around your median cubital vein, you feel fine. How has your 500 mlml decrease in blood volume most likely affected your cardiac output, heart rate, and stroke volume?

no change in cardiac output, increased heart rate, decreased stroke volume

The anatomy of the intrinsic conduction system causes contraction of the ventricles to begin at the apex and move superiorly. Why is this important?

so blood is forced upward, toward the semilunar valves Beginning contraction at the apex causes blood to be forced upward, through the semilunar valves, and into the aorta and pulmonary trunk. This makes ventricular ejection more efficient, much like squeezing a tube of toothpaste up from the bottom is more efficient at dispensing the toothpaste than is squeezing from the top.

The tiles below are pieces of a normal ECG tracing representing a little less than two heartbeats at a resting rate of 80 bpmbpm. Arrange the tiles in their correct order.

use link to see what image should look like https://session.masteringaandp.com/problemAsset/2009948/13/IP_EAH_MAP_Part-E-WAR-10.png