Nokea
Which hormone, produced by the thyroid gland, regulates calcium levels in the blood by enhancing calcium absorption in the intestines and reducing calcium loss in the kidneys?
- A. Calcitonin
- B. Parathyroid hormone (PTH)
- C. Thyroxine
- D. Insulin
Correct Answer: A
Rationale: Calcitonin is the hormone produced by the thyroid gland that regulates calcium levels in the blood. It enhances calcium absorption in the intestines and reduces calcium loss in the kidneys. Parathyroid hormone (PTH) operates oppositely to calcitonin by increasing calcium levels in the blood. Thyroxine is a thyroid gland hormone that primarily regulates metabolism, not calcium levels. Insulin, produced by the pancreas, is responsible for controlling blood sugar levels, not calcium levels. Therefore, the correct answer is Calcitonin as it specifically targets calcium regulation in the body.
You may also like to solve these questions
Which of the following is an example of a nosocomial infection?
- A. The common cold contracted from a family member
- B. A urinary tract infection (UTI) acquired during a catheterization
- C. A fungal skin infection from contaminated soil
- D. Food poisoning from undercooked chicken
Correct Answer: B
Rationale: A nosocomial infection, also known as a healthcare-associated infection (HAI), is an infection that is acquired in a healthcare setting. In this case, a UTI acquired during a catheterization procedure is a classic example of a nosocomial infection. Catheterization involves the insertion of a tube into the urinary tract, which can introduce bacteria into the urinary system and lead to an infection. Nosocomial infections are a significant concern in healthcare settings due to the potential for increased morbidity, mortality, and healthcare costs.
Let's review the other options:
A) The common cold contracted from a family member - This is not a nosocomial infection as it is acquired outside of a healthcare setting.
C) A fungal skin infection from contaminated soil - This is not a nosocomial infection as it is acquired from environmental exposure, not in a healthcare setting.
What is the involuntary muscle tissue found in the walls of blood vessels and organs like the stomach and intestines?
- A. Skeletal muscle
- B. Cardiac muscle
- C. Smooth muscle
- D. Striated muscle
Correct Answer: C
Rationale: Smooth muscle is the correct answer. It is the involuntary muscle tissue found in the walls of blood vessels and organs like the stomach and intestines. Smooth muscle is responsible for various involuntary movements in the body, such as peristalsis in the digestive system and regulating blood flow in blood vessels. Skeletal muscle is voluntary and attached to bones for movement. Cardiac muscle is specific to the heart and not found in blood vessel walls or organs like the stomach and intestines. Striated muscle refers to both skeletal and cardiac muscle due to their striped appearance under a microscope, but it does not specifically describe the involuntary muscle tissue in the walls of blood vessels and organs as asked in the question.
What is the main component of stomach acid?
- A. Hydrochloric acid
- B. Bicarbonate
- C. Bile salts
- D. Enzymes
Correct Answer: A
Rationale: Stomach acid, also known as gastric acid, is primarily composed of hydrochloric acid. Hydrochloric acid plays a crucial role in the digestive process by helping to break down food and kill bacteria in the stomach. Bicarbonate is a base that helps neutralize stomach acid in the small intestine, but it is not the main component of stomach acid. Bile salts are produced by the liver and stored in the gallbladder, aiding in the digestion and absorption of fats, but they are not the main component of stomach acid. Enzymes are proteins that help catalyze chemical reactions in the body, including the breakdown of food molecules during digestion, but they are not the main component of stomach acid.
What is the function of arrector pili muscles?
- A. To control sweat production
- B. To contract and cause goosebumps
- C. To produce sebum
- D. To sense touch
Correct Answer: B
Rationale: The correct function of arrector pili muscles is to contract and cause goosebumps. These small muscles are attached to hair follicles in mammals. When they contract, they cause the hair to stand on end, resulting in goosebumps. This physiological response is often triggered by cold temperatures or emotional states like fear, helping mammals conserve heat or appear larger in threatening situations. Choices A, C, and D are incorrect. Arrector pili muscles are not involved in controlling sweat production (Choice A), producing sebum (Choice C), or sensing touch (Choice D).
What is the structure that surrounds individual muscle fibers, providing support and aiding in the transmission of force generated during muscle contraction?
- A. Tendon
- B. Endomysium
- C. Perimysium
- D. Epimysium
Correct Answer: B
Rationale: The endomysium is the connective tissue layer that surrounds individual muscle fibers, providing support and aiding in the transmission of force generated during muscle contraction. It is crucial for maintaining the structural integrity of muscle fibers and facilitating the transmission of force within them. Tendons (option A) connect muscles to bones, perimysium (option C) surrounds bundles of muscle fibers known as fascicles, and epimysium (option D) encases the entire muscle. The endomysium specifically targets the structure that directly supports and aids in force transmission within individual muscle fibers, making it the correct answer in this context.