1. Which vitamin is crucial for calcium absorption and synthesized in the skin upon sun exposure?

A. Vitamin A
B. Vitamin C
C. Vitamin D
D. Vitamin E

Correct answer: C

Rationale: The correct answer is C: Vitamin D. Vitamin D is crucial for calcium absorption as it helps the body absorb calcium from the diet. When the skin is exposed to sunlight, it produces vitamin D. This is why sunlight is often referred to as the 'sunshine vitamin.' Vitamin A (choice A) is important for vision and immune function, but not specifically for calcium absorption. Vitamin C (choice B) is essential for collagen production and immune function, but not directly related to calcium absorption. Vitamin E (choice D) is an antioxidant that helps protect cells from damage, but it is not primarily involved in calcium absorption like vitamin D.

2. Which part of the heart generates the QRS complex on an ECG?

A. Sinoatrial node (SA node)
B. Atrioventricular node (AV node)
C. Bundle of His
D. Ventricular muscle cells

Correct answer: D

Rationale: The correct answer is D, ventricular muscle cells. The QRS complex on an ECG represents the depolarization of the ventricles. This electrical activity is generated by the spread of impulses through the bundle branches and Purkinje fibers to the ventricular muscle cells. The SA node (option A) is responsible for initiating the electrical impulse in the heart, but it does not directly generate the QRS complex. The AV node (option B) delays the impulse to allow for proper coordination of atrial and ventricular contractions. The Bundle of His (option C) and its branches facilitate the conduction of the electrical signal from the AV node to the ventricles but do not generate the QRS complex directly.

3. Which type of muscle is found in the walls of hollow organs, such as the stomach and intestines, and is responsible for involuntary contractions to propel substances through the organs?

A. Cardiac muscle
B. Smooth muscle
C. Skeletal muscle
D. Striated muscle

Correct answer: b

Rationale: The correct answer is B: Smooth muscle. Smooth muscle is found in the walls of hollow organs like the stomach and intestines. It is responsible for involuntary contractions to move substances through these organs. Unlike skeletal muscle (answer C) and cardiac muscle (answer A), smooth muscle is not under voluntary control. Striated muscle (answer D) is a term that refers to both skeletal and cardiac muscle due to their striped appearance under a microscope, but smooth muscle does not have this striped appearance.

4. Following a successful heart transplant surgery, the patient's body will need to take medications to:

A. Suppress the immune system and prevent rejection of the new heart.
B. Reduce overall blood pressure.
C. Dissolve any remaining blood clots.
D. Stimulate the growth of new heart tissue.

Correct answer: A

Rationale: The correct answer is A: 'Suppress the immune system and prevent rejection of the new heart.' After a heart transplant surgery, the body's immune system may recognize the new heart as a foreign object and try to attack it, leading to rejection. To prevent this, patients need to take medications that suppress the immune system, helping the body accept the new heart. These medications are crucial to ensure the success and longevity of the transplanted organ by reducing the risk of rejection. Options B, C, and D are not directly related to the post-heart transplant medication regimen and do not address the primary concern of preventing rejection.

5. What is the name of the white blood cells that attack foreign invaders?

A. Phagocytes
B. Lymphocytes
C. Platelets
D. Red blood cells

Correct answer: A

Rationale: Rationale: Phagocytes are a type of white blood cell that plays a crucial role in the immune system by engulfing and digesting foreign invaders such as bacteria, viruses, and other harmful substances. They are part of the body's innate immune response and are essential for protecting the body against infections. Lymphocytes, on the other hand, are another type of white blood cell involved in the adaptive immune response, producing antibodies and coordinating immune responses. Platelets are cell fragments involved in blood clotting, while red blood cells are responsible for carrying oxygen to tissues.