Which hormone is released by the adrenal medulla?

Correct Answer: B

Rationale: The correct answer is B, Adrenaline (also known as epinephrine), which is released by the adrenal medulla during the body's fight-or-flight response. Adrenaline helps prepare the body for action by increasing heart rate, dilating air passages, and mobilizing glucose and fats for energy, among other physiological responses. Choice A, Cortisol, is a steroid hormone released by the adrenal cortex involved in the stress response and regulation of metabolism. Choice C, Insulin, is produced by the pancreas and regulates blood sugar levels. Choice D, Somatostatin, is a hormone that inhibits the release of several other hormones in the body, but it is not released by the adrenal medulla.

Correct Answer: B

Rationale: Vitamin D is crucial for the absorption of calcium in the intestines. It aids in maintaining optimal calcium levels in the body, promoting strong bones and teeth. Without sufficient Vitamin D, the absorption of calcium can be compromised, leading to potential issues with bone health. Choices A, C, and D are incorrect. Vitamin A is essential for vision, skin health, and immune function. Vitamin K is necessary for blood clotting and bone metabolism. Vitamin C is important for collagen synthesis, wound healing, and immune function, but it is not directly involved in calcium absorption.

Correct Answer: A

Rationale: Insulin, produced by the pancreas, is the hormone responsible for regulating blood sugar levels. It works by facilitating the uptake of glucose into cells, helping to lower blood sugar levels. Glucagon, on the other hand, works to increase blood sugar levels by promoting the release of glucose from the liver. Thyroxine is a hormone produced by the thyroid gland that regulates metabolism. Melatonin, a hormone that helps regulate sleep-wake cycles, is not responsible for regulating blood sugar levels. Therefore, the correct answer is insulin.

Correct Answer: A

Rationale: Vitamin A is the correct answer. It is crucial for maintaining healthy skin as it supports skin cell growth, repair, and overall skin health. Additionally, vitamin A plays a role in vision and immune function. Deficiency in vitamin A can lead to skin issues such as dryness and poor wound healing. Vitamin C is known for its role in collagen synthesis and antioxidant properties, while Vitamin D is important for bone health and immunity. Vitamin K is essential for blood clotting, but it is not primarily associated with skin health.

Correct Answer: B

Rationale: Cardiac muscle tissue, represented by choice B, is the correct answer. Cardiac muscle tissue is unique to the heart and responsible for its involuntary contractions that pump blood throughout the body. Smooth muscle (choice A) is found in the walls of hollow organs, skeletal muscle (choice C) is attached to bones for movement, and striated muscle (choice D) is a general term that can refer to both cardiac and skeletal muscle but is not specific to the heart.