Interactive Physiology
The Study of the Heart
Answer Sheet

Study Questions on Anatomy Review: The Heart

1. What's the difference between the blood in the right side of the heart and the left side of the heart? The right atrium receives oxygen-poor blood from Systemic veins. The left atrium receives Oxygenated blood from the pulmonary veins.

2. a. Where does the blood go that is pumped out of the right heart? Out the right heart to lungs.

b. Where does the blood go that is pumped out of the left side of the heart? Out the left heart to Body Tissues

c. What happens to the blood in the lungs In the lungs it receives on right Oxygne-poor blood/carbon dioxide rig blood. In the left lungs it receives Oxygen/eliminates Carbon dioxide.

3. What is the pulmonary circuit and the systemic circuit?
The Pulmonary circuit consists of blood vessels that carry blood to/from the lungs where carbon dioxide is unloaded from blood and oxygen is picked up; right side of heart pumps blood through pulmonary circuit. The Systemic circuit consists of blood vessels that carry blood to and from Body Tissues where oxygen and nutrients are released fm blood & carbon dioxide and other wastes are picked up;
Left side of heart pumps blood through systemic circuit.

4. What three structural features are found on histological images of cardiac muscle?
Nucleus
Interrelated disc -regions where plasma memo of adjacent cardiac cells interlock; it contains
Desmosomes & Gap Junctions. Cardiac Myofibril-bundles of contractile myofilament actin & myosin.

5. What are the names of the two types of cell junctions in cardiac muscle cells?
Desmosomes
Gap Junctions

6. What is the function of desmosomes?
Prevent cells from separating during contraction. Cell junction between adjacent cardiac cells.

7. What is the function of gap junctions?
Allows ion to pass freely from cell to cell. Passage way between adjacent cardiac cells.

Study Questions on the Cardiac Action Potential:

1. What two cell types are involved in producing a coordinated heart contraction?
Cardiac autorhythmic cells and cardiac contractile cells.

2. Before cardiac auto rhythmic and contractile cells depolarize, what is the charge inside and outside the cell.
Positive out, negative in.

3. When cardiac auto rhythmic and contractile cells depolarize, what happens to the charge inside and outside the cell.
Charge becomes negative outside, positive inside.

4. When cardiac autorhythmic and contractile cells repolarize, what happens to the charge inside and outside the cell.
Charge becomes positive outside, negative inside

5. What is responsible for reestablishing ion levels in autorhythmic cells?
Ionic pumps actively transport calcium back to the extracellular space during repolarization. Na+/K+ pumps also pump sodium out and potassium in.

6. Match the following events in autorhythmic cells:
A. Repolarization: ___Y___
B. Pacemaker Potential: __X____
C. Depolarization and reversal of the membrane potential: ___Z___
x. due to influx of sodium
y. due to efflux of potassium
z. due to influx of calcium

7. Are neurotransmitters involved in the transmission of depolarization from one cardiac muscle cell to another?
No.

Study Questions on the Intrinsic Conduction System:

1. List the structures from top to bottom.

3. What is the purpose of the intrinsic conduction system of the heart?
It sets the basic rhythm of the heart

4. What type of cells are present in the intrinsic conduction system of the heart?

Autorhythmic cardiac cells

5. Explain the difference between the electrical and mechanical events which occur within the heart, and explain the cell types that carry out each. Which occurs first, the electrical or mechanical events? Electrical events are act. pots. which spread from the autorhythmic cells of the intrinsic conduction systole to contractile cells. Mechanical events are a subsequent contraction of the contractile cells that cause the