CET Cardiac Anatomy & Physiology 3 — Questions and Answers
Question 1: Which vessel carries oxygenated blood from the lungs to the heart?
- Pulmonary artery
- Superior vena cava
- Pulmonary vein (Correct answer)
- Coronary sinus
Correct answer: Pulmonary vein
The pulmonary veins (four total) return oxygenated blood from the lungs to the left atrium.
Question 2: The Bundle of His divides into which two structures?
- SA node and AV node
- Left and right bundle branches (Correct answer)
- Purkinje fibers and intercalated discs
- Left circumflex and LAD arteries
Correct answer: Left and right bundle branches
The Bundle of His splits into the left and right bundle branches, which conduct impulses down the interventricular septum.
Question 3: What is the normal intrinsic firing rate of the AV node?
- 60–100 bpm
- 40–60 bpm (Correct answer)
- 20–40 bpm
- 100–150 bpm
Correct answer: 40–60 bpm
The AV node has an intrinsic escape rate of 40–60 bpm and serves as a backup pacemaker if the SA node fails.
Question 4: Which chamber of the heart has the thickest myocardial wall?
- Right atrium
- Left atrium
- Right ventricle
- Left ventricle (Correct answer)
Correct answer: Left ventricle
The left ventricle has the thickest walls because it must generate enough pressure to pump blood through the systemic circulation.
Question 5: The T wave on an ECG represents which electrical event?
- Atrial depolarization
- Ventricular depolarization
- Ventricular repolarization (Correct answer)
- Atrial repolarization
Correct answer: Ventricular repolarization
The T wave reflects ventricular repolarization, during which the ventricular myocardium resets for the next contraction.
Question 6: Which autonomic nervous system division increases heart rate?
- Parasympathetic
- Somatic
- Sympathetic (Correct answer)
- Enteric
Correct answer: Sympathetic
Sympathetic stimulation releases norepinephrine, which binds to beta-1 receptors and increases heart rate and contractility.
Question 7: The interventricular septum primarily separates which two chambers?
- Left and right atria
- Left and right ventricles (Correct answer)
- Left atrium and left ventricle
- Right atrium and right ventricle
Correct answer: Left and right ventricles
The interventricular septum is the muscular wall that divides the left and right ventricles.
CET Cardiac Anatomy & Physiology 3
Which vessel carries oxygenated blood from the lungs to the heart?