what is the function of parathyroid hormone

HESI A2

Anatomy HESI A2

1. What is the function of parathyroid hormone?

A. Increasing energy levels
B. Stimulating cell reproduction
C. Speeding up metabolism
D. Activating vitamin D

Correct answer: D

Rationale: The correct answer is D. Parathyroid hormone plays a crucial role in activating vitamin D. This activation occurs in the kidneys, where parathyroid hormone stimulates the conversion of inactive vitamin D to its active form. Active vitamin D is essential for maintaining proper levels of calcium and phosphorus in the body, which are important for bone health and other physiological functions. Choices A, B, and C are incorrect because parathyroid hormone is not involved in increasing energy levels, stimulating cell reproduction, or speeding up metabolism. Its primary function is related to calcium and phosphorus homeostasis through the activation of vitamin D.

2. What is the primary function of the skin in the integumentary system?

A. Regulating body temperature
B. Protecting the body from external damage
C. Producing red blood cells
D. Producing hormones

Correct answer: B

Rationale: The primary function of the skin in the integumentary system is to protect the body from external damage. The skin acts as a barrier against pathogens, UV radiation, and physical trauma. While the skin does help regulate body temperature by sweating and vasodilation, its main role is protection. Skin does not produce red blood cells; this is the function of the bone marrow. Hormones are primarily produced by endocrine glands, not the skin.

3. How does the circulatory system work with the digestive system?

A. The circulatory system removes undigested solids from the body.
B. The circulatory system filters and collects digested materials.
C. The circulatory system moves absorbed nutrients through the body.
D. The circulatory system releases enzymes that control digestion.

Correct answer: C

Rationale: The circulatory system works with the digestive system by transporting absorbed nutrients through the body. After digestion occurs in the digestive system, nutrients are absorbed into the bloodstream. The circulatory system then carries these nutrients to cells throughout the body where they are used for energy, growth, and repair. This process ensures that the necessary nutrients are delivered to where they are needed in the body. Choices A, B, and D are incorrect because the circulatory system is not responsible for removing undigested solids, filtering and collecting digested materials, or releasing enzymes that control digestion. These functions are primarily carried out by the digestive system.

4. Which is a secondary defense for the body against pathogens?

A. Tears
B. Urine
C. Inflammation
D. Mucus

Correct answer: C

Rationale: Inflammation is a secondary defense mechanism for the body against pathogens. When tissues are injured or infected, inflammation occurs as a protective response involving increased blood flow, white blood cell migration, and tissue repair. This process helps contain and eliminate pathogens, preventing them from spreading further in the body. Tears (Choice A) are a primary defense containing lysozyme and other antimicrobial agents. Urine (Choice B) is typically considered a non-specific defense mechanism due to its flushing action in the urinary tract. Mucus (Choice D) acts as a physical barrier and traps pathogens, also considered a primary defense mechanism.

5. What is the primary function of the lymphatic system?

A. Transport oxygen to cells
B. Remove carbon dioxide from the body
C. Produce hormones
D. Transport nutrients

Correct answer: B

Rationale: The correct answer is B: Remove carbon dioxide from the body. The primary function of the lymphatic system is to return excess tissue fluid to the bloodstream and assist in the body's defense against infections by filtering out harmful pathogens and foreign particles. Choices A, C, and D are incorrect because transporting oxygen to cells is mainly done by the circulatory system, hormone production is primarily carried out by endocrine glands, and nutrient transport is also a function of the circulatory system and the digestive system, not the lymphatic system.