Introduction

1. What are the basic functions of the circulatory system?

• transport substances throughout the body

  • Oxygen

  • Nutrients

  • waste

• helps regulate temperature and pH

• supports the immune system

•  maintains fluid balance

Heart Anatomy

1. Where is the heart located within the chest?

• The heart is located in the chest slightly left of center.

2. What is the pericardium?  

• The pericardium is a protective sac around the heart.

3. The walls of the heart contain myocardium and endocardium.  What is the specific function of these layers of the heart wall?

• myocardium (muscular layer) responsible for the heart's pumping action

• endocardium (lining) of the heart chambers and valves, providing a smooth surface for blood flow.

Chambers and Great Vessels

1. How are the atria different from the ventricles in terms of their size, location, and function?

• Atria are smaller, upper chambers that receive blood

• ventricles are larger, lower chambers that pump blood out.

2. How is pulmonary circulation different from systemic circulation?  Which side of the heart drives the two different circulations?

• Pulmonary circulation carries blood to the lungs for oxygenation

• systemic circulation delivers oxygenated blood to the body.

• right side of the heart drives pulmonary circulation

• left side drives systemic circulation.

3. What path does the blood follow through the heart and lungs starting with the right atrium?

• Blood flows from the right atrium to the right ventricle, then to the lungs for oxygenation, returning to the left atrium, then to the left ventricle, and finally to the body.

Heart Valves

1. How many valves are in the heart?  Name them.

• four valves in the heart:

  • tricuspid valve

  • pulmonary valve

  • mitral valve (bicuspid)

  • and aortic valve.

2. What is the function of the AV valves?  When are they open and closed?

• AV valves (tricuspid and mitral) prevent backflow of blood into the atria during ventricular contraction.

• open during heart relaxation (diastole) and closed during ventricular contraction (systole).

3. What is the function of the semilunar valves? When are they open and closed?

• Semilunar valves (pulmonary and aortic) prevent blood from flowing back into the ventricles after contraction.

• They are closed during diastole and open during ventricular contraction (systole).

Physiology of the Heart

1. How are cardiac muscle cells different from skeletal muscle cells?

• Cardiac muscle cells have unique properties like automaticity and conductivity, allowing them to contract without nerve stimulation.

2. What two systems act to regulate heart activity?

• The autonomic nervous system and the endocrine system regulate heart activity.

3. What is the function of the sinoatrial (SA) node in heart function?  Where is it located?

• The SA node initiates the heartbeat and is located in the right atrium.

4. What is the function of the atrioventricular (AV) node in heart function?  Where is it located?

• The AV node delays the electrical impulse to allow atria to contract before ventricles and is located in the lower part of the right atrium.

5. What is the function of the atrioventricular (AV) bundle in heart function?  Where is it located?

• The AV bundle conducts the impulse from the AV node to the ventricles and is located in the interventricular septum.

6. What is the function of the Purkinje fibers in heart function?  Where are they located?

• Purkinje fibers distribute the impulse throughout the ventricles and are located in the walls of the ventricles.

7. How is systole different from diastole?

• Systole is the contraction phase, diastole is the relaxation phase.

Cardiac Output

1. What does cardiac output measure?

• Cardiac output measures the volume of blood pumped by the heart per minute.

2. What factors contribute to cardiac output?

• Heart rate and stroke volume.

3. What are some factors that can increase cardiac output?

• Exercise, sympathetic stimulation, and certain hormones (e.g., epinephrine) can increase cardiac output.

4. What are some factors that can decrease cardiac output?

• Factors like dehydration, heart disease, and certain medications can decrease cardiac output.

Blood Vessels

1. What are the five types of vessels the blood travels in throughout the body?

• Blood travels through arteries, arterioles, capillaries, venules, and veins.

2. How are arteries similar to veins?

• Arteries and veins both transport blood around the body.

3. How are arteries different from veins?

• Arteries carry oxygenated blood away from the heart, veins carry deoxygenated blood back to the heart.

Physiology of Circulation

1. What are the vital signs?

• Vital signs include temperature, pulse rate, respiration rate, and blood pressure.

2. What is blood pressure?

• Blood pressure is the force exerted by blood against the walls of blood vessels.

3. How is the systolic pressure different from the diastolic pressure?

• Systolic pressure is the pressure during ventricular contraction

• Diastolic pressure is the pressure during ventricular relaxation.

4. How do vasoconstriction and vasodilation help regulate blood pressure?

• Vasoconstriction narrows blood vessels, increasing blood pressure.

• Vasodilation widens blood vessels, decreasing blood pressure.

5. What are some factors that can increase blood pressure?

• Factors like stress, obesity, and high salt intake can increase blood pressure.

6. What are some factors that can decrease blood pressure?

• Factors like dehydration, bleeding, and shock can decrease blood pressure.

Homeostatic Imbalances (describe/define each)

1. myocardial infarction

• Death of heart muscle due to blocked blood flow.

2. Fibrillation

• Abnormal heart rhythm causing rapid, irregular contractions.

3. Tachycardia

• Abnormally fast heart rate.

4. Bradycardia

• Abnormally slow heart rate.

5. Hypertension

• High blood pressure.

6. Hypotension

• Low blood pressure.

7. orthostatic hypotension

• Sudden drop in blood pressure upon standing.

8. circulatory shock

• Inadequate blood flow to meet body's needs.