1. How Many Times Does the Heart Contract in an Average Lifetime?

Chapter 15 Cardiovascular System

I. Overview

A. Basics

1. How many times does the heart contract in an average lifetime?

2. How much blood does the heart pump through the body each day?

3. Identify the two circuits of the cardiovascular system.

B. Size & Location

1. How large is the average heart?

2. Locate the smallest cavity in which the heart is located.

3. Where is the base of the heart located? Where is the apex located?

4. What portion of the heart is left of the midline?

II. Anatomy of the heart

A. Coverings of the heart

1. Identify the outermost layer of the pericardium.

• This layer is composed of what type of tissue?

• This layer makes attachments to which structures of the body?

2. Identify the middle layer of the pericardium.

• This layer is composed of what type of tissue?

3. Identify the innermost layer of the pericardium

• This layer is composed of what type of tissue?

• What is the major function of the middle & innermost layers of the pericardium?

• Identify the potential space between the middle & inner pericardium

What is found within this space?

B. Wall of the heart

1. Name the outermost layer of the heart wall.

• How does this layer relate to the pericardium?

2. Name the middle layer of the heart wall.

• Which tissue comprises this layer?

3. Name the inner layer of the heart wall.

• This layer is composed of what type of tissue?

• Why is this layer important?

C. Heart Chambers

1. Identify the upper two chambers of the heart.

• Which chamber receives blood from the lungs?

• Which chamber receives blood from the systemic circulation?

• What structure separates the two upper chambers?

• Name the “ear-like” pouches that increase the volume of these upper chambers.

2. Identify the lower two chambers of the heart.

• Which chamber pumps blood to the lungs?

• Which chamber pumps blood to the systemic circulation?

• What structure separates the lower two chambers?

• Which chamber has a thicker wall? Why?

D. Blood Vessels of the Heart

1. Name two blood vessels that return blood from systemic circulation to the heart.

• Is this blood oxygenated or deoxygenated?

2. Which blood vessel returns deoxygenated blood from the coronary circulation to the heart?

• The three blood vessels above empty into which heart chamber?

3. Identify the blood vessel that conveys blood from the heart to the lungs.

• Is this blood oxygenated or deoxygenated?

• Which chamber does this blood leave from?

4. Name the blood vessels that return blood from the lungs to the heart.

• Is the blood within these vessels oxygenated or deoxygenated?

• Which chamber does this blood empty into?

5. Name the blood vessel that conveys blood from the heart to systemic circulation?

• Is this blood oxygenated or deoxygenated?

• Which chamber does this blood leave from?

• Name each section of this vessel as it leaves the heart.

E. Valves

1. Atrioventricular (AV) Valves

a. Identify the two AV valves

• Valve that guards the right AV orifice:

• Valve that guards the left AV orifice:

b. Name the tendinous chords that anchor the cusps of AV.

c. Which muscles contract, preventing the AV cusps from prolapsing into the atria?

d. When are the two AV valves open? When are they closed?

2. Semilunar Valves

a. Identify the two semilunar valves

• Valve at the base of the aorta:
• Valve at the base of the pulmonary trunk:

b. Briefly describe the structure of semilunar valves. How do they differ from AV valves?

c. When are semilunar valves open? When are they closed?

F. Pathway through the heart.

Trace the pathway of blood as it travels from systemic circulation through the heart. Include

each chamber, valve, and blood vessel.

III. Cardiac Cycle

A. Cardiac Cycle

1. (Ventricular) Systole

• Describe the actions of ventricles during ventricular systole.

• What occurs within the atria during ventricular systole?

• Which valves are open during ventricular systole? Which are closed?

2. (Ventricular) Diastole

• What occurs within the ventricles during ventricular diastole?

• Describe the action of the atria during ventricular diastole.

• What percent of blood enter the ventricles before the atria contract?

• Which valves are open during ventricular diastole? Which are closed?

B. Lubb Dupp

1. What actions within the heart creates the Lubb Dupp sound?

• Lubb = sound of ______valve

• Dupp = sound of ______valve

2. Identify the four places where the heart valves may be best heard with a stethoscope.

• Pulmonary-

• Aortic-

• Tricuspid-

• Bicuspid-

C. Cardiac Conduction System

1. What type of tissue is responsible for conducting the electrical impulses within the heart?

2. Nodes

1. Which node is considered the pacemaker of the heart?

• How often does this node initiate an electrical impulse?

• Does the rate of this pacemaker correspond to the heart rate? Why or Why not?

1. Which node bridges the atrial syncytium to the ventricular syncytium?

• Where is this node located?

3. Fibers

1. Which fibers convey electrical impulses to the left & right atria from the pacemaker?

1. Large bundle of fibers that conduct impulses down the interventricular septum:

• This bundle divides into left and right ______on the interventricular septum

• Fibers that initiate ventricular syncytium at the apex of the heart are ______

• Why is it important that contraction of the ventricles begin at the apex?

• Cardiac muscles are arranged in a ______pattern, which maximizes the efficiency of ventricular contractions.

4. List the order of the cardiac conduction system of the heart.

D. Electrocardiogram (ECG/EKG)

1. What activity of the heart is measured by an ECG?

2. Draw a typical cardiac cycle as shown on an ECG. Indicate each of the waves.

3. Describe the event that occurs during the p wave

4. Describe the major event that occurs during the QRS complex

5. What event occurs during the t wave?

6. What minor event is not visible because it is hidden by the QRS complex?

7. Define the following arrhythmias:

1. Tachycardia

1. Bradycardia

1. Atrial flutter

1. Atrial fibrillation

1. Ventricular fibrillation

E. Regulation of the Cardiac Cycle

1. Where is the cardiac control center located?

2. Cardioinhibitor Reflex Center

1. Which nerves conveys impulses from the cardioinhibitor reflex center to the heart?

1. What neurotransmitter is released by fibers within this nerve?

1. What affect do these neurotransmitters have on the heart?

1. Do these fibers transmit sympathetic or parasympathetic impulses to the heart?

3. Cardioaccelorator Reflex Center

1. Which nerves convey impulses this reflex center to the heart?

1. What neurotransmitter is released by fibers within this nerve?

1. What affect do these neurotransmitters have on the heart?

1. Do these fibers transmit sympathetic or parasympathetic impulses to the heart?

4. Baroreceptors

1. Baroreceptors are sensitive to what type of stimulus?

1. Identify two major baroreceptor locations within the blood vessels.

1. Describe how baroreceptors interact with the two reflex centers above to regulate blood pressure.

IV. Blood Vessels

A. Overview

1. List the general order of blood vessels as they convey blood away from the heart to the body,

then back to the heart.

B. Arterial Walls

1. Inner Layer

1. Name the innermost layer of the arterial wall.

1. Describe the type of tissue that makes up this layer.

1. How can this layer help regulate blood pressure and blood clotting?

2. Middle Layer

1. Name the middle layer of the arterial wall.

1. Describe the tissues in this layer. Provide the name and function.

3. Outer Layer

1. Name the outer layer of the arterial wall.

1. What tissue is found in this layer?

1. What are Vasa Vasorum?

C. Capillaries

1. Describe the tissue that comprises capillaries.

1. What are slits?

1. What are sinusoids, and where are they found?

1. What are precapillary sphincters?

D. Veins

1. Describe 4 ways in which veins differ from arteries in the following areas:

1. Tunica media –

1. Lumen-

1. Tunica interna-

1. Blood capacity-

V. Blood Pressure

A. Overview

1. What units are used to measure blood pressure?

1. Define systolic blood pressure

1. Define diastolic blood pressure

B. Factors that influence blood pressure

1. Heart Actions
2. Define stroke volume

1. What is the average stroke volume for an adult male?

1. Define cardiac output

1. How is cardiac output calculated?

1. How does changing the cardiac output affect blood pressure?

1. Blood Volume
2. What is the average blood volume of an adult male?

1. How does changing blood volume change blood pressure?

1. Peripheral Resistance
2. What is peripheral resistance?

1. What effect do vasoconstriction and vasodilation have on peripheral resistance?

1. Viscosity
2. Define viscosity

1. Name two factors of the blood that change blood viscosity.

1. Describe how some types of anemia may result in low blood pressure.

C. Control of blood pressure

1. Explain how changes in each of the following may alter blood pressure:
2. Cardiac output
3. Peripheral resistance
4. Stroke volume

1. Define preload

1. What is the Frank-Starling Law of the heart?

VI. Venous Return

A. Why do heart contractions contribute very little to venous return?

B. Identify 4 factors that influence blood return within the veins

1.

2.

3.

4.

VII. Systemic Arteries

1. Aortic Root
2. Name the swelling at the base of the aortic root

1. What chemoreceptors are found within the aortic root

1. Which blood vessels arise from the aortic root?

1. Principal branches of the aorta
2. List the sections of the aorta as it leaves the heart and continues down into the abdomen

1. List in order the three principle branches that arise from the aortic arch?

1. Arteries to Head and Neck
2. Common carotid arteries
3. Carotid Sinus

• Where is the common carotid sinus located?

• What chemoreceptors are found in this area?

• What condition commonly occurs near this site?

1. Internal carotid arteries
2. What percent of blood is supplied to the brain by these arteries

• Name three arteries that arise from the internal carotid arteries, and indicate the structures they supply blood to.

1. –
2. –
3. –

1. External carotid arteries
2. Name three arteries that arise from the external carotid arteries, and indicate the structures they supply blood to.
3. –
4. –
5. –
6. Circle of Willis
7. What is an alternative name for the circle of Willis?

• Define anastomosis

1. Vertebral arteries
2. Describe the unique path taken by the vertebral arteries towards the brain.

1. What percent of blood is provided to the brain by vertebral arteries?

1. The left and right vertebral arteries merge to form the ______artery.

1. Thoracic Aorta
2. Name three arteries that arise from the thoracic aorta, and indicate the structures they supply blood to.

1. Abdominal Aorta.
2. Name eight branches from the abdominal aorta, and indicate the structures they supply blood to.

• ______artery (trunk).
• ______

• ______

• ______

• ______

• ______arteries – supply the gonads

1. ______a.a. supply testes in males

1. ______a.a. supply ovaries in females

• ______

• ______

1. Arteries of upper limbs
2. List the order of the major arteries of the upper limbs as they arise from the aortic arch.

1. Arteries of lower limbs

1. List the order of the major arteries of the lower limbs as they arise from the abdominal aorta.

VIII. Systemic Veins

A. Veins that drain the head and neck

1. What are venous sinuses?

1. Which veins drain the blood from venous sinuses?

1. The face and scalp are drained by which blood vessels?

B. Hepatic Portal Vein (HPV)

1. Define a portal system.

2. What type of blood is conveyed by the hepatic portal vein?

3. Name 4 tributaries of the HPV, and indicate which organs they receive blood from.

4. Which blood vessel returns blood from the liver to the inferior vena cava?