Anatomy Chapter 18 Flashcards
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Questions and Answers

What is the function of the coronary circulation?

Provide a blood supply to the heart

What is the ligament arteriosum?

A remnant of the ductus arteriosus

What chamber of the heart exits into the pulmonary trunk?

Right ventricle

Identify the ear-like flaps that are attached to the top chambers of the heart.

<p>Auricle</p> Signup and view all the answers

The first branch off the arch of the aorta is the brachiocephalic artery in both the sheep and the human.

<p>True</p> Signup and view all the answers

The base of the heart is located at the bottom of the heart.

<p>False</p> Signup and view all the answers

Which of the following would increase cardiac output?

<p>Epinephrine</p> Signup and view all the answers

Which of the following would decrease stroke volume?

<p>Increasing afterload</p> Signup and view all the answers

Calculate stroke volume.

<p>Subtract the ESV from the EDV</p> Signup and view all the answers

Which of the following descriptions does not describe atrioventricular (AV) valves?

<p>Formed from pocket-like cusps</p> Signup and view all the answers

Which statement regarding cardiac muscle structure is accurate?

<p>Myofibrils of cardiac muscle tissue vary in diameter and branch extensively.</p> Signup and view all the answers

What does the interatrial septum do?

<p>Divides the two atria of the heart</p> Signup and view all the answers

What do atrioventricular valves do?

<p>Control blood flow into the ventricles</p> Signup and view all the answers

What is an electrocardiogram?

<p>A test that records the electrical activity of the heart</p> Signup and view all the answers

What does tachycardia mean?

<p>A faster than normal heart rate</p> Signup and view all the answers

Why is a patent ductus arteriosus a cause for concern?

<p>The higher pressure in the aorta will push extra blood through the ductus arteriosus into the child's pulmonary circulation.</p> Signup and view all the answers

Which of the following abnormalities is not a direct result of right ventricular failure?

<p>Pulmonary edema</p> Signup and view all the answers

Which statement is correct regarding the ventricles?

<p>True</p> Signup and view all the answers

Cardiac tamponade results in ineffective pumping of blood by the heart. This is because the excessive amount of fluid in the pericardial cavity will ______.

<p>prevent the heart from filling properly with blood</p> Signup and view all the answers

What is the epicardium?

<p>Serous layer covering the heart muscle</p> Signup and view all the answers

What is myocardium?

<p>Heart muscle</p> Signup and view all the answers

What is endocardium?

<p>The inner lining of the heart</p> Signup and view all the answers

What is the parietal layer?

<p>The outermost layer of the serous pericardium</p> Signup and view all the answers

The parietal pericardium ________.

<p>lines the internal surface of the fibrous pericardium</p> Signup and view all the answers

Pectinate muscles are found in the ________.

<p>atria only</p> Signup and view all the answers

The foramen ovale ________.

<p>connected the two atria in the fetal heart</p> Signup and view all the answers

Which is NOT a vessel that brings blood directly into the right atrium?

<p>Pulmonary vein</p> Signup and view all the answers

Which valve is located between the right atrium and ventricle?

<p>Tricuspid valve</p> Signup and view all the answers

The role of the chordae tendineae is to open the AV valves at the appropriate time.

<p>False</p> Signup and view all the answers

What does the aortic semilunar valve do?

<p>Prevents backflow into the left ventricle</p> Signup and view all the answers

What does the tricuspid valve do?

<p>Prevents backflow into the right atrium. Atrioventricular (AV) valve with three flaps</p> Signup and view all the answers

What does the mitral (bicuspid) valve do?

<p>Prevents backflow into the left atrium. Atrioventricular (AV) valve with two flaps</p> Signup and view all the answers

What does the pulmonary semilunar valve do?

<p>Prevents backflow into the right ventricle</p> Signup and view all the answers

Which chamber of the heart has the highest probability of being the site of a myocardial infarction?

<p>Left ventricle</p> Signup and view all the answers

If the mitral valve is unable to close properly, ________.

<p>blood could flow back into the left atrium</p> Signup and view all the answers

Which heart chamber receives oxygenated blood from the lungs?

<p>Left atrium</p> Signup and view all the answers

Arterial blood supply to heart muscle is continuous whether the heart is in systole or diastole.

<p>False</p> Signup and view all the answers

The left side of the heart pumps the same volume of blood as the right.

<p>True</p> Signup and view all the answers

Which coronary artery is most responsible for supplying blood to the myocardial tissue of the left atrium?

<p>Circumflex artery</p> Signup and view all the answers

What does it mean that the left ventricle is thicker than the right ventricle?

<p>It pumps blood against a greater resistance</p> Signup and view all the answers

What is the term for pain associated with deficient blood delivery to the heart?

<p>Angina pectoris</p> Signup and view all the answers

What effects does the presence of an incompetent tricuspid valve have?

<p>Reduced efficiency in the delivery of blood to the lungs</p> Signup and view all the answers

What structures connect the individual heart muscle cells?

<p>Intercalated discs</p> Signup and view all the answers

If cardiac muscle is deprived of its normal blood supply, damage would primarily result from ________.

<p>Decreased delivery of oxygen</p> Signup and view all the answers

If the length of the absolute refractory period in cardiac muscle cells was the same as it is for skeletal muscle cells, ________.

<p>Tetanic contractions might occur, which would stop the heart's pumping action</p> Signup and view all the answers

Compared to skeletal muscle, cardiac muscle has gap junctions that allow it to act as a functional syncytium.

<p>True</p> Signup and view all the answers

What does the QRS wave of the electrocardiogram (ECG) represent?

<p>Ventricular depolarization</p> Signup and view all the answers

Which structure receives the depolarization wave from the atria?

<p>AV node</p> Signup and view all the answers

What would happen to the SA node if a chemical blocker was used to reduce transport of Na+ into the pacemaker cells?

<p>The SA node would depolarize more slowly, reducing the heart rate</p> Signup and view all the answers

Electrical impulses pass through the conduction system of the heart in the following sequence:

<p>SA node, AV node, bundle of His, bundle branches, and Purkinje fibers</p> Signup and view all the answers

What does the P wave on an electrocardiogram represent?

<p>Atrial depolarization</p> Signup and view all the answers

In an ischemic heart, the affected cardiac muscle cells are likely to have an altered ______.

<p>Resting membrane potential</p> Signup and view all the answers

Which chambers of the heart contain oxygenated blood?

<p>Left atrium and left ventricle</p> Signup and view all the answers

Which of the following is NOT part of the intrinsic conduction system of the heart?

<p>Atrioventricular (AV) valve</p> Signup and view all the answers

What causes the 'pacemaker potential' of pacemaker cells?

<p>The opening of slow Na+ channels at the end of an action potential</p> Signup and view all the answers

What is the plateau phase of an action potential in cardiac muscle cells due to?

<p>Influx of Ca2+ through slow Ca2+ channels</p> Signup and view all the answers

Besides cardiac muscle, what muscle tissue type is involuntary and displays autorhythmicity?

<p>Smooth muscle</p> Signup and view all the answers

What is the period during the cardiac cycle when the valves leading to and from the ventricles are completely closed?

<p>Isovolumetric contraction phase</p> Signup and view all the answers

At what point in the cardiac cycle is pressure in the ventricles the highest?

<p>Ventricular systole</p> Signup and view all the answers

During which stage are the aortic and pulmonary valves open?

<p>Phase 2b</p> Signup and view all the answers

What causes heart sounds?

<p>Heart valve closure</p> Signup and view all the answers

Which best describes the isovolumetric contraction phase of the cardiac cycle?

<p>As ventricular systole starts, the AV valves are closed and the semilunar valves are closed.</p> Signup and view all the answers

The first heart sound is caused by __________.

<p>Closure of the atrioventricular valves</p> Signup and view all the answers

Which of the following terms is correctly matched to its description?

<p>Quiescent period: period of total heart relaxation</p> Signup and view all the answers

As soon as ventricular pressure falls below atrial pressure, the AV valve will open and ventricular filling will begin.

<p>True</p> Signup and view all the answers

An abnormal P wave could be indicative of ______.

<p>Enlarged atria</p> Signup and view all the answers

What does ischemia mean?

<p>Heart muscle is deprived of oxygen</p> Signup and view all the answers

What is the quiescent period?

<p>Total heart relaxation</p> Signup and view all the answers

What does infarction refer to?

<p>Death of heart muscle cells</p> Signup and view all the answers

What is ectopic focus?

<p>An abnormal pacemaker</p> Signup and view all the answers

What does fibrillation mean?

<p>A condition of rapid and irregular or out-of-phase contraction of heart muscle cells</p> Signup and view all the answers

During the isovolumetric relaxation phase of the cardiac cycle, AV, aortic, and pulmonary valves are closed.

<p>True</p> Signup and view all the answers

Which of the following receive(s) blood during ventricular systole?

<p>Both the aorta and pulmonary trunk</p> Signup and view all the answers

When are the atrioventricular (AV) valves closed?

<p>When the ventricles are in systole</p> Signup and view all the answers

What happens during the period of ventricular filling?

<p>Blood flows mostly passively from the atria through the atrioventricular (AV) valves into the ventricles</p> Signup and view all the answers

The second heart sound is heard during which phase of the cardiac cycle?

<p>Isovolumetric relaxation</p> Signup and view all the answers

Which of the following would cause a DECREASE in cardiac output (CO)?

<p>Decreasing thyroid function (thyroxine)</p> Signup and view all the answers

Which of the following INCREASES stroke volume?

<p>Exercise</p> Signup and view all the answers

What best describes afterload?

<p>Back pressure exerted by arterial blood</p> Signup and view all the answers

As your skeletal muscles contract during physical activity, what happens to preload?

<p>Preload would be increased, which would result in a larger cardiac output</p> Signup and view all the answers

Increasing end-diastolic volume (EDV) or end-systolic volume (ESV) will increase stroke volume.

<p>False</p> Signup and view all the answers

Which of the following descriptions of cardiac pacemaker cells is INCORRECT?

<p>Rapid depolarization is due to Na+ influx</p> Signup and view all the answers

What could hypercalcemia cause?

<p>Prolonged T wave</p> Signup and view all the answers

Which of the following cannot trigger tachycardia?

<p>Increased vagal tone</p> Signup and view all the answers

What does a patent ductus arteriosus permit?

<p>Blood to flow from the aorta into the pulmonary trunk</p> Signup and view all the answers

What does the Frank-Starling Law state?

<p>A higher end diastolic volume will produce a higher stroke volume</p> Signup and view all the answers

What is the expected heart rate when a heart is removed from a living body?

<p>100 beats / minute</p> Signup and view all the answers

What is a correct statement about cardiac output?

<p>A slow heart rate increases end diastolic volume, stroke volume, and force of contraction.</p> Signup and view all the answers

If the vagal nerves to the heart were cut, the result would be that ______.

<p>The heart rate would increase by about 25 beats per minute</p> Signup and view all the answers

How does norepinephrine act on the heart?

<p>Causing threshold to be reached more quickly</p> Signup and view all the answers

What is cardiac reserve?

<p>Difference between resting and maximal cardiac output</p> Signup and view all the answers

What does bradycardia mean?

<p>An abnormally slow heart rate</p> Signup and view all the answers

What does vagal tone refer to?

<p>Heart rate at rest under both autonomic divisions signaling</p> Signup and view all the answers

What happens during hemorrhage with a large loss of blood?

<p>A lowering of blood pressure due to change in cardiac output</p> Signup and view all the answers

Which of the following is NOT an age-related change affecting the heart?

<p>Thinning of the valve flaps</p> Signup and view all the answers

When released in large quantities, thyroxine causes a sustained increase in heart rate.

<p>True</p> Signup and view all the answers

If blood volume decreased dramatically due to massive bleeding, the autonomic nervous system will attempt to maintain cardiac output by increasing the heart rate.

<p>True</p> Signup and view all the answers

Suppose a patient develops a myocardial infarction that disables the sinoatrial node. Would the heart still pump blood to the aorta and the pulmonary trunk?

<p>True</p> Signup and view all the answers

What structure is most responsible for the synchronized contraction of cardiac muscle tissue?

<p>Gap junctions</p> Signup and view all the answers

Trace the pathway of stimulation through the heart. Which of these pathways shows stimulation in the correct order?

<p>AV node, AV bundle, interventricular septum, subendocardial conducting network</p> Signup and view all the answers

Study Notes

Coronary Circulation and Cardiac Anatomy

  • Coronary circulation provides essential blood supply to the heart muscle.
  • The ligament arteriosum is a remnant of the ductus arteriosus, linked to fetal circulation.
  • Right ventricle is responsible for pumping blood into the pulmonary trunk.

Heart Structure

  • Auricles are ear-like flaps attached to the atria, aiding in expansion.
  • The interatrial septum divides the two atria, ensuring separate blood flow.
  • Pectinate muscles are specific to the atria, providing structural support.

Valvular Function

  • Atrioventricular (AV) valves prevent backflow into the atria during ventricular contraction; includes the tricuspid and mitral valves.
  • Semilunar valves (aortic and pulmonary) ensure blood does not flow back into the ventricles after ejection.
  • Chordae tendineae help maintain valve positions but do not actively open AV valves.

Cardiac Cycle

  • Stroke volume calculation is key: subtract end-systolic volume (ESV) from end-diastolic volume (EDV).
  • Ventricular systole occurs when pressure in the ventricles rises, ejecting blood into the aorta and pulmonary artery.
  • Isovolumetric contraction phase features all valves closed while ventricles contract, raising pressure without volume change.

Electrical Activity

  • SA node serves as the natural pacemaker, initiating electrical impulses, followed by the AV node and subsequent pathways.
  • The QRS wave on an electrocardiogram (ECG) represents ventricular depolarization.
  • Abnormalities, such as enlarged atria or altered resting membrane potential, can indicate underlying heart issues.

Cardiac Output and Regulation

  • Cardiac output can increase due to factors like epinephrine or physical exercise.
  • Afterload refers to the resistance the heart must overcome to eject blood, influenced by arterial pressure.
  • Frank-Starling Law indicates that increased end-diastolic volume leads to higher stroke volume.

Heart Conditions and Responses

  • Myocardial infarctions commonly occur in the left ventricle due to its thicker muscle and higher workload.
  • Bradycardia describes a heart rate slower than normal, potentially harmful if severe.
  • Autonomic responses adjust heart rate based on blood volume changes or external stimuli such as hormones.

Miscellaneous Terms

  • Angina pectoris is pain due to reduced blood flow to cardiac tissue.
  • Fibrillation is described as chaotic heart muscle contractions, leading to ineffective pumping.
  • Cardiac reserve indicates the capacity for increased output beyond resting levels during physical activity.

Summary of Cardiovascular Dynamics

  • Blood flow dynamics involve continuous supply under varying heart states; contraction phases influence blood movement significantly.
  • Gap junctions in cardiac muscle tissue ensure synchronized contractions, essential for effective heart function.
  • Thyroxine can significantly impact heart rate when released in high quantities, leading to sustained increases.

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Test your knowledge of the heart's anatomy with these flashcards focusing on coronary circulation, ligaments, and heart chambers. Ideal for students studying human anatomy or preparing for exams.

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