Nokea
Where is the impulse from the SA node delayed, enabling atrial contraction to complete before the ventricles are stimulated and contract?
- A. AV node
- B. Bundle of His
- C. SA node
- D. Aorta
Correct Answer: A
Rationale: The impulse from the SA node is delayed at the AV node to allow time for the atria to contract before the ventricles. The AV node acts as a gatekeeper, slowing down the electrical signal before transmitting it to the Bundle of His, which then conducts the signal to the ventricles. This delay ensures proper coordination between atrial and ventricular contractions. Choices C and D are incorrect as the SA node does not delay its own impulse, and the aorta is not involved in the conduction system.
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Which heart chamber receives oxygenated blood from the four pulmonary veins and serves as a reservoir during ventricular systole?
- A. Right atrium
- B. Left atrium
- C. Right ventricle
- D. Left ventricle
Correct Answer: B
Rationale: The correct answer is B: Left atrium. The left atrium receives oxygenated blood from the pulmonary veins, acting as a reservoir during ventricular systole. This blood is then pumped into the left ventricle for distribution to the body. The right atrium receives deoxygenated blood from the body via the vena cavae. The right ventricle pumps this blood to the lungs for oxygenation. The left ventricle is responsible for pumping oxygenated blood to the rest of the body. Therefore, the left atrium is the correct choice based on its role in receiving oxygenated blood from the pulmonary veins.
Which surgical procedure involves removing a portion of the lung?
- A. Lobectomy
- B. Pneumonectomy
- C. Tracheostomy
- D. Bronchoscopy
Correct Answer: A
Rationale: The correct answer is A: Lobectomy. A lobectomy involves the removal of a lobe of the lung. This procedure is commonly done to treat lung cancer or other conditions affecting a specific lobe. Pneumonectomy (B) involves the removal of an entire lung, not just a portion. Tracheostomy (C) is the surgical creation of an opening in the windpipe to help with breathing, not a lung removal procedure. Bronchoscopy (D) is a diagnostic procedure to visualize the airways using a flexible tube with a camera, not a lung removal surgery. Therefore, A is the correct choice for removing a portion of the lung.
This is a test that measures the oxygen saturation level in the blood, often used to assess respiratory function.
- A. Pulse oximetry
- B. Spirometry
- C. Arterial blood gas (ABG)
- D. Lung function test
Correct Answer: A
Rationale: The correct answer is A: Pulse oximetry. Pulse oximetry measures oxygen saturation levels in the blood by using a non-invasive method to determine the percentage of hemoglobin carrying oxygen. This test is commonly used to assess respiratory function quickly and efficiently.
Summary of incorrect options:
B: Spirometry measures lung function by assessing airflow and volume.
C: ABG measures oxygen and carbon dioxide levels in the blood.
D: Lung function test is a broad term that can include various tests, such as spirometry and imaging studies.
What is a life-threatening condition where the heart suddenly stops beating?
- A. Cardiac arrest
- B. Myocardial infarction
- C. Heart failure
- D. Atrial fibrillation
Correct Answer: A
Rationale: The correct answer is A: Cardiac arrest. Cardiac arrest is a life-threatening emergency where the heart stops beating suddenly. This leads to the cessation of blood flow to vital organs, causing loss of consciousness and death if not treated immediately with CPR and defibrillation. Myocardial infarction (B) is a heart attack where blood flow to the heart muscle is blocked, leading to tissue damage. Heart failure (C) is a chronic condition where the heart is unable to pump blood effectively. Atrial fibrillation (D) is an irregular heartbeat that can increase the risk of stroke but is not the same as cardiac arrest.
What is a surgical procedure where a blood vessel is grafted to bypass a blocked coronary artery, improving blood flow to the heart muscle?
- A. Coronary artery bypass graft (CABG)
- B. Valve replacement
- C. Angioplasty
- D. Endarterectomy
Correct Answer: A
Rationale: The correct answer is A: Coronary artery bypass graft (CABG). This surgical procedure involves grafting a blood vessel to bypass a blocked coronary artery, improving blood flow to the heart muscle. It is used to treat severe coronary artery disease. Valve replacement (B) is a surgery to replace heart valves, not to bypass blocked arteries. Angioplasty (C) involves inserting a balloon to widen a narrowed artery, not bypassing it. Endarterectomy (D) is a procedure to remove plaque from an artery, not bypassing a blocked coronary artery.