Module 13 Study Guide

Distinguish how valves regulate blood flow through the heart.

1. AV valves (tricuspid + bicuspid) control flow b/w atria + ventricles, preventing backflow during ventricular contractions 2. Semilunar valves (pulmonary + aortic) manage blood flow from ventricles to arteries, preventing backflow during ventricular relaxation; open + close to ensure unidirectional blood flow, maintaining efficient circulation + preventing backward flow

During ventricular systole, which valves are open? a. Tricuspid/Right Atrioventricular Valve b. Aortic Seminlunar Valve c. Bicuspid/Left Atrioventricular/Mitral Valve d. Pulmonary Semilunar Valve

1. Aortic semilunar valve 2. Pulmonary semilunar valve

If an atrioventricular valve prolapses (folds back into the atrium), blood can flow backwards into the atrium as the ventricle contracts. What two structures prevent the atrioventricular valves from prolapsing?

1. Chordae tendinae 2. Papillary muscles

Identify and describe the location, origins, and branches

1. Coronary Artery (LCA): Origin: Arises from left aorta Branches: LAD (anterior septum + left ventricle) + LCx (left atrium + left ventricle) 2. Right Coronary Artery (RCA): Origin: Arises from right aorta Branches: Right marginal artery (right ventricle), PDA (posterior septum + ventricles), atrial branches (right atrium + SA node)

Outline the pattern of blood flow through the heart.

1. Deoxygenated blood returns to right atrium from body 2. Right atrium contracts, sending blood to right ventricle thru tricuspid valve 3. Right ventricle contracts, pushing blood into pulmonary artery via pulmonary semilunar valve 4. Blood travels to lungs, picking up O2 + releasing CO2 5. Oxygenated blood returns to left atrium via pulmonary veins 6. Left atrium contracts, sending blood to left ventricle thru bicuspid (mitral) valve 7. Left ventricle contracts, forcing blood into aorta thru aortic semilunar valve 8. Aorta carries oxygenated blood to body's tissues 9. Deoxygenated blood returns to right atrium, completing cycle

What are the layers of the heart itself?

1. Epicardium (outer) 2. Myocardium (middle, muscular) 3. Endocardium (inner, endothelial)

Describe the general pattern of circulation.

1. General circulation pattern: Deoxygenated blood returns to right atrium 2. Right atrium contracts, sending blood to right ventricle 3. Right ventricle pumps blood to lungs via pulmonary artery 4. Lungs oxygenate blood, which returns to left atrium 5. Left atrium contracts, sending blood to left ventricle 6. Left ventricle pumps oxygenated blood to body via aorta + arteries 7. Oxygen + nutrients are delivered to tissues via capillaries 8. Deoxygenated blood returns to right atrium, completing cycle

Explain the external anatomy of the heart

1. Heart is fist-sized organ in thoracic cavity 2. Enclosed by pericardium 3. Has 4 chambers (2 atria, 2 ventricles) 4. Right atrium receives deoxygenated blood 5. Left atrium receives oxygenated blood 6. Right ventricle pumps blood to lungs 7. Left ventricle pumps blood to body 8. Coronary blood vessels supply heart muscle

Explain the internal anatomy of the heart

1. Layers: Endocardium, Myocardium, Epicardium. 2. Chambers: Atria (receive blood) + Ventricles (pump blood) 3. Valves: AV valves (tricuspid + bicuspid) separate atria + ventricles 4. Semilunar valves (pulmonary + aortic) separate ventricles from arteries 5. Papillary Muscles + Chordae Tendineae prevent valve inversion 6. Conduction System coordinates heart contractions (SA node, AV node, bundle of His, Purkinje fibers)

Describe the pericardium, including its layers, and its functions

1. Protective sac around heart 2. 2 layers: Fibrous pericardium (outer) + serous pericardium (inner); serous pericardium consists of parietal layer (lining fibrous pericardium) + visceral layer (covering heart) 3. Functions: Protect heart, reduce friction w/ lubricating fluid, prevent overexpansion, maintain heart's position

What coronary vessels supply which parts of the heart?

1. Right coronary artery supplies right atrium, right ventricle, part of interventricular septum, atrioventricular node 2. Left coronary artery divides into left anterior descending artery; supplies anterior part of interventricular septum + significant portion of left ventricle + left circumflex artery, supplying left atrium + part of left ventricle

Describe electrical conduction through the heart.

1. SA node initiates impulses in right atrium 2. Atria contract 3. Impulse reaches AV node, briefly delaying to fill ventricles 4. Bundle of His conducts impulse thru septum 5. Bundle branches send impulse to respective ventricles 6. Purkinje fibers distribute impulse, causing ventricles to contract 7. Repolarization follows, preparing for next cycle

What would happen if an AV valve or semilunar valve prolapsed?

1. Valve doesn't close properly 2. Can cause regurgitation (backflow) of blood 3. Specific effects depend on affected valve

What if the valve was stenotic (opening was narrowed)?

1. Valve opening is narrowed 2. Obstructs blood flow 3. Effects depend on valve 4. Can lead to symptoms + complications 5. Treatment may include medication or surgery

What is the order of blood flow through the heart?

1. Vena Cave 2. Right Atrium 3. Right Ventricle 4. Pulmonary Artery 5. Lungs 6. Pulmonary Veins 7. Left Atrium 8. Left Ventricle 9. Aorta 10. Body

Which vessel has the greatest pressure on its walls during ventricular systole?

Aorta (vessel leaving a chamber of the heart)

In the pulmonary circuit, __________. a. veins carry deoxygenated blood to the lungs b. body tissues receive oxygenated blood before the blood returns to the right atrium of the heart c. arteries carry deoxygenated blood to the lungs d. arteries carry oxygenated blood to the lungs

Arteries carry deoxygenated blood to the lungs

Why do the atria have thinner walls than the ventricles?

Atria don't have to pump blood very far, just into next chamber; gravity also helps blood flow into ventricles; while atria do have muscular walls, they don't need to be very thick; ventricles need to pump blood to lungs + body, so they need more muscle in their walls

A superficial extension of the aorta near the superior surface of the heart

Auricle

You are examining a heart in the anatomy lab, and you observe evidence of a myocardial infarction (heart attack, loss of cardiac myocytes) along the lateral aspect of the left atrium and ventricle. As a result, you suspect that this individual would have had an obstruction the _____ artery.

Circumflex

Which valves are open when the atria are contracting?

During atrial contraction (atrial systole), atrioventricular (AV) valves (tricuspid + bicuspid) are open to allow blood into ventricles

Which valves are open when the ventricles are contracting?

During ventricular contraction (systole), aortic + pulmonary valves are open

T or F: Neurons from the parasympathetic division are acting on the cardiac muscle in the left ventricle to decrease its strength of contraction

False

The right ventricle ________. a. has thinner muscular walls than does the left ventricle b. pumps blood out of the heart to the systemic circuit c. pumps blood out of the heart through the aortic valve d. receives blood from the left atrium through the right atrioventricular (tricuspid) valve e. is connected to the pulmonary veins

Has thinner muscular walls than does the left ventricle

Identify and describe the great vessels carrying blood immediately to and from the heart and the major vessels of the thoracic, abdominal, and pelvic cavities.

Immediate to + from Heart: 1. Aorta: Carries oxygenated blood from heart 2. Pulmonary Artery: Takes deoxygenated blood to lungs 3. Superior + Inferior Vena Cava: Return deoxygenated blood to heart Thoracic Cavity: 1. Superior Vena Cava: Drains upper body 2. Inferior Vena Cava: Drains lower body 3. Pulmonary Veins: Return oxygenated blood from lungs 4. Azygos Vein: Drains thoracic wall Abdominal and Pelvic Cavities: 1. Abdominal Aorta: Supplies abdominal organs + legs 2. Renal Arteries: Supply kidneys 3. Mesenteric Arteries: Supply intestines 4. Common Iliac Arteries: Supply pelvis + lower limbs 5. Renal Veins: Return blood from kidneys 6. Inferior Mesenteric Vein: Drains lower colon 7. Internal and External Iliac Arteries and Veins: Supply + drain pelvis + legs

Wall of heart muscle tissue between right + left atria

Interatrial septum

Wall of heart muscle tissue between right + left ventricles

Interventricular septum

Heart valves subjected to the greatest amount of pressure are most likely to be involved in valve disorders. This means pressure while it is doing its job preventing back flow, not pressure to open as it normally would. Knowing this, you can assume that the valve most commonly invilved in valve disorders is the _____ valve. This valve prevents backflow into the _____.

Left atrioventricular (AV); left atrium

Which chamber of the heart can generate the greatest pressure because it can contract with the most strength? a. right ventricle b. left ventricle c. right atrium d. left atrium e. both ventricles can generate equal pressure and strength of contraction

Left ventricle

Connect to chordae tendinae + contract to help prevent AV valves from prolapsing

Papillary muscles

You are meditating in your yoga class. As you breath slowly, your heart rate is decreasing. The _____ division of the autonomic nervous system is causing your heart rate to decrease.

Parasympathetic

Parallel muscular ridges in the right atrium

Pectinate muscles

What are the layers protecting the heart?

Pericardium (fibrous + serous layers)

Incompetent valves are valves that leak because they fail to close properly. If the tricuspid valve was incompetent, what chamber of the heart would blood flow back into? a. Left Atrium b. Right Ventricle c. Right Atrium d. Left Ventricle

Right atrium

If prolapse of the right atrioventricular valve occurs, blood would flow back into the _____ (chamber), and less blood would be pumped to the _____ (organ) through the _____ trunk and arteries.

Right atrium; lungs; pulmonary

A blockage in the pulmonary trunk would cause a back-up of blood and limit blood from leaving which chamber of the heart? a. left ventricle b. right ventricle c. left atrium d. right atrium

Right ventricle

How does the autonomic nervous system regulate heart rate + strength of contraction?

Sympathetic branch (SNS) increases both, releasing norepinephrine, while parasympathetic branch (PNS) decreases them, releasing acetylcholine; balance ensures heart adapts to changing demands, such as increased activity (SNS) or rest (PNS)

Blood that is transported to and from all of the tissues of the body (with the EXCEPTION of the lungs) is in the ________. a. pulmonary circuit b. coronary circuit c. hepatic portal circuit d. cardiac circuit e. systemic circuit

Systemic circuit

What is the purpose of the chordae tendineae? a. to keep the atrioventricular valves from prolapsing, preventing regurgitation of blood back into the atria b. to prevent blood from flowing into the pulmonary trunk and aorta c. to keep the atrioventricular valves open during atrial contraction d. to prevent leakage of blood back into the ventricles through the semilunar valves

To keep the atrioventricular valves from prolapsing, preventing regurgitation of blood back into the atria

Ridges of cardiac muscle covered by endocardium located in the walls of the ventricles

Trabeculae carneae