Which gland is known as the 'master gland' of the body?

Correct Answer: C

Rationale: The pituitary gland, often referred to as the 'master gland,' controls the release of hormones from other endocrine glands in the body. It secretes various hormones that regulate many bodily functions, making it a central and vital component of the endocrine system. The thyroid gland (Choice A) regulates metabolism, the adrenal gland (Choice B) produces hormones like adrenaline, and the pineal gland (Choice D) secretes melatonin, but none of these glands are considered the 'master gland' that controls the functions of other endocrine glands.

Correct Answer: B

Rationale: White blood cells, also known as leukocytes, play a crucial role in the immune system by primarily combating infections. These cells can identify and destroy pathogens, such as bacteria and viruses, helping the body defend against illnesses and maintain overall health. Red blood cells are responsible for oxygen transport, platelets aid in blood clotting, and plasma carries various components throughout the circulatory system, but none of these functions involve fighting infections like white blood cells do.

Correct Answer: B

Rationale: The gallbladder's main function is to store and concentrate bile produced by the liver. Bile is essential for the digestion and absorption of fats in the small intestine. Therefore, the correct answer is B, as the gallbladder acts as a reservoir for bile rather than producing it. Choices A, C, and D are incorrect because the gallbladder does not produce bile, detoxify harmful substances, or regulate blood sugar in the digestive system.

Correct Answer: B

Rationale: Tendons are the correct answer. They are strong connective tissues that connect muscles to bones, allowing movement when muscles contract. Ligaments connect bones to other bones, providing joint stability. Cartilage is a firm, flexible connective tissue present in joints and the outer ear. Fascia is a connective tissue that surrounds muscles, blood vessels, and nerves, offering support and protection. Therefore, the correct tissue type that connects muscles to bones is tendons.

Correct Answer: B

Rationale: Adrenaline, also known as epinephrine, is released during the body's fight-or-flight response. This hormone prepares the body for rapid action by increasing heart rate, dilating airways, and redirecting blood flow to essential organs in response to stress or danger. Insulin is not released during the fight-or-flight response; its primary role is to regulate blood sugar levels. Thyroxine is a hormone produced by the thyroid gland that regulates metabolism, and cortisol is released in response to stress to regulate various bodily functions, but adrenaline is the hormone specifically associated with the fight-or-flight response.