calciferol is controlled by

HESI A2

Anatomy HESI A2

1. Which gland controls Calciferol?

A. Thyroid
B. Pituitary
C. Parathyroid
D. Hypothalamus

Correct answer: C

Rationale: Calciferol, commonly known as Vitamin D, is regulated by the parathyroid gland, not the thyroid, pituitary, or hypothalamus. The parathyroid gland plays a crucial role in maintaining calcium and phosphorus balance in the body by regulating the production of calcitriol, the active form of Vitamin D. This hormone helps in the absorption of calcium from the intestines and its reabsorption in the kidneys to maintain proper calcium levels in the blood. Therefore, the correct answer is the Parathyroid gland (Choice C). Choices A, B, and D are incorrect as they do not have a direct role in controlling Calciferol.

2. Which system does the gall bladder belong to?

A. endocrine system
B. urinary system
C. digestive system
D. nervous system

Correct answer: C

Rationale: The gall bladder is part of the digestive system. Its primary function is to store and concentrate bile produced by the liver and release it into the small intestine to aid in the digestion of fats. This process facilitates the breakdown and absorption of fats from the food we consume. Choices A, B, and D are incorrect as the gall bladder is not associated with the endocrine, urinary, or nervous systems.

3. Which enzyme functions to break down lactose, a specific sugar found in milk and dairy products?

A. Catalase
B. Lipase
C. Protease
D. Lactase

Correct answer: D

Rationale: Lactase is the enzyme responsible for breaking down lactose, a sugar present in milk and dairy products. When lactase breaks down lactose, it splits it into two simpler sugars, glucose, and galactose, which can then be absorbed and used by the body. Catalase is involved in breaking down hydrogen peroxide into water and oxygen. Lipase breaks down fats into fatty acids and glycerol. Protease breaks down proteins into amino acids. Therefore, choices A, B, and C are incorrect for the specific breakdown of lactose.

4. How does the lymphatic system work with the circulatory system?

A. The circulatory system produces red blood cells for the lymphatic system.
B. Lymph draws excess fluid from the cells and deposits it into the blood vessels.
C. The heart regulates the production of lymph in the lymph glands.
D. White cells from the lymphatic system eliminate excess red blood cells.

Correct answer: B

Rationale: The lymphatic system works with the circulatory system by draining excess fluid and waste products from the spaces between cells, known as interstitial fluid. This excess fluid, now called lymph, is then transported back into the blood circulation through lymphatic vessels. This process helps maintain fluid balance in the body and supports the circulatory system in regulating blood volume and pressure. Choice A is incorrect because the circulatory system does not produce red blood cells for the lymphatic system. Choice C is incorrect as the heart does not regulate lymph production in lymph glands. Choice D is incorrect as white cells from the lymphatic system do not eliminate excess red blood cells. Therefore, the correct answer is B, as lymph draws excess fluid from the cells and deposits it into the blood vessels, aiding in maintaining proper fluid balance and supporting the circulatory system.

5. Which type of muscle tissue is under voluntary control?

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

Correct answer: C

Rationale: Skeletal muscle is under voluntary control, allowing conscious regulation for activities like walking and lifting. This type of muscle is attached to bones and is responsible for movement in the body. Smooth muscle (Choice A) is involuntary and found in organs like the stomach and intestines. Cardiac muscle (Choice B and D) is also involuntary and specific to the heart, contracting rhythmically to pump blood, but it is not under conscious control.