Unit 4 - A & P Assignment - Cardiovascular System

Question 1

Diagram to identify structure and function of the cardiovascular system

Answer 1

Question 2

Pathway of Blood Through the Heart

The heart is actually (one, two, or three) pumps?

Answer 2

Two pumps, the right side of the heart pumps to/from the lungs (pulmonary circuit) and the left side of the heart pumps to/from the rest of the body (the systemic circuit)

Question 3

Pathway of Blood Through the Heart

Which chamber receives blood from the superior and inferior venae cavae?

Answer 3

Right atrium, the right atrium receives oxygen-poor blood from the systemic circuit

Question 4

Pathway of Blood Through the Heart

Which heart chamber receives blood from the pulmonary veins?

Answer 4

Left atrium, receives oxygenated blood from the pulmonary veins

Question 5

Pathway of Blood Through the Heart

Which heart chamber pumps oxygen-poor blood out the pulmonary trunk?

Answer 5

Right ventricle, pumps oxygen-poor blood out the pulmonary trunk to the lungs

Question 6

Pathway of Blood Through the Heart

Which chamber pumps oxygenated blood out the aorta to the systemic circuit?

Answer 6

Left ventricle, pumps oxygenated blood out the aorta to the entire body (systemic circuit)

Question 7

Action Potentials in Autorhythmic Cells

Action potentials generated by the autorhythmic cells spread to the contractile cells through what structures in the membrane?

Answer 7

Gap junctions

Action potentials generated by the autorhythmic cells spread waves of depolarization to contractile cells through gap junctions. If the depolarization causes the contractile cells to reach threshold, they will in turn generate an action potential.

Question 8

Action Potentials in Autorhythmic Cells

One of the changes that occurs in the pacemaker potential (unstable resting membrane potential) in the SA node (an autorhythmic cell) is a decreased efflux of what ion?

Answer 8

Potassium

If there is a decreased efflux of potassium while there is a normal influx of sodium, the inside of the cell would become less negative. Thus, threshold would be reached. The ability of these autorhythmic cells to spontaneously depolarize is what results in the pacemaker potential.

Question 9

Action Potentials in Autorhythmic Cells

When threshold is reached at the SA node (an autorhythmic cell), what channels open causing further depolarization of the membrane?

Answer 9

Fast calcium

Unlike nerve cells or cardiac muscle cells, fast calcium channels are responsible for the depolarization phase of the autorhythmic cell action potential. When the fast calcium channels open, calcium rushes into the cell making it less negative (or more positive).

Question 10

Action Potentials in Autorhythmic Cells

Repolarization of an autorhythmic cell is due to the opening of which channels?

Answer 10

Voltage-gated potassium channels

Opening of voltage-gated potassium channels causes positive potassium ions to move out of the cell. This efflux of potassium causes the cell to become more negative inside thus, repolarizing the cell.

Question 11

Action Potentials in Autorhythmic Cells

In order to cause cardiac muscle contraction, the contractile cells must also depolarize. What causes the depolarization of the contractile cells?

Answer 11

The flow of positive ions from adjacent cells

The flow of positive ions from the autorhythmic cells (or adjacent cells) brings the membrane to threshold initiating depolarization of the contractile cell.

Question 12

Intrinsic Conduction System of the Heart

Which part of the conduction system initiates the depolarizing impulse, which spreads throughout the heart?

Answer 12

SA node

SA Node spontaneously depolarizes, causing the wave of depolarization that spreads through the rest of the conduction system and heart

Question 13

Intrinsic Conduction System of the Heart

What does the ECG wave tracing represent?

Answer 13

Electrical activity in the heart

The ECG waves show the depolarization and repolarization in various areas of the heart.

Question 14

Intrinsic Conduction System of the Heart

What does the QRS complex represent in the ECG wave tracing?

Answer 14

Ventricular depolarization

The QRS complex represents depolarization in the ventricles, which have greater mass than the atria

Question 15

Intrinsic Conduction System of the Heart

Contraction of the atria results from which wave of depolarization on the ECG tracing?

Answer 15

P wave, represents atrial depolarization, which leads to atrial contraction.

Question 16

Intrinsic Conduction System of the Heart

Which part of the intrinsic conduction system delays the impulse briefly before it moves on to the ventricles?

Answer 16

AV node, slows down the impulse giving the atria time to contract before the ventricles contract.

Question 17

Sympathetic and parasympathetic influences on cardiac output

Answer 17

Question 18

Wiggers diagram to identify specific events during the cardiac cycle

Answer 18

Question 19

Diagram to identify factors that affect mean arterial pressure

Answer 19

Question 20

Arterial Baroreceptor Reflex

If blood pressure is increased at the arterial baroreceptors, what would happen with the activity level of the parasympathetic nervous system (PNS) and sympathetic nervous system (SNS)?

Answer 20

Increased PNS activity and decreased SNS activity

The PNS activity would increase and the SNS activity would decrease in an attempt to lower blood pressure.

Question 21

Arterial Baroreceptor Reflex

What would cause vasodilation of arterioles?

Answer 21

Decreased activity of the sympathetic nervous system

Results in decreased activity of vasomotor fibers, resulting in vasodilation.

Question 22

Arterial Baroreceptor Reflex

Where are the sensors for the arterial baroreceptor reflex located?

Answer 22

Carotid sinus and aortic arch

The sensors are the arterial baroreceptors themselves, located at the carotid sinus and aortic arch. They detect changes in blood pressure by the degree of stretch on the blood vessel.

Question 23

Arterial Baroreceptor Reflex

Stimulation of the adrenal medulla would result in which of the following?

Answer 23

An increase in heart rate and contractility

Epinephrine and norepinephrine are released from the adrenal medulla and act as part of the sympathetic nervous system, increasing heart rate and contractility. Epinephrine and norepinephrine have other effects that would also increase blood pressure.

Question 24

Arterial Baroreceptor Reflex

A decrease in blood pressure at the arterial baroreceptors would result in which of the following?

Answer 24

An increase in heart contractility

Sympathetic nervous system activity would be increased because of the low blood pressure. Sympathetic fibers go to the ventricles of the heart and increase their contractility. An increase in contractility would increase stroke volume which would lead to an increase in cardiac output and blood pressure.

Question 25

Diagram to identify the components of blood

Answer 25

Question 26

Diagram to identify steps that occur during a coagulation response

Answer 26