What is the primary role of the large intestine?

Correct Answer: B

Rationale: The correct answer is B: To absorb water. The primary role of the large intestine is to absorb water from indigestible food matter. This absorption process helps in forming solid waste for excretion. Nutrient absorption primarily occurs in the small intestine, not the large intestine. Breaking down food and secreting digestive enzymes are functions primarily associated with the stomach and small intestine.

Correct Answer: B

Rationale: The correct answer is B: Triceps brachii. The triceps brachii muscle is responsible for extending the elbow joint. It is located on the back of the upper arm and acts in opposition to the biceps brachii, which is responsible for elbow flexion. The deltoid muscle is primarily responsible for shoulder abduction, not elbow extension. The pectoralis major muscle is involved in movements of the shoulder joint, not the elbow.

Correct Answer: A

Rationale: The correct answer is A: To control breathing and heart rate. The medulla oblongata is a vital part of the brainstem responsible for regulating essential functions such as breathing, heart rate, and blood pressure. These functions are crucial for maintaining life, and the medulla oblongata plays a key role in ensuring the body's survival. Choices B, C, and D are incorrect because regulating body temperature is primarily controlled by the hypothalamus, coordinating voluntary movements is associated with the cerebellum and motor cortex, and processing sensory information is related to the thalamus and sensory cortex, not the medulla oblongata.

Correct Answer: A

Rationale: The correct answer is Vitamin C. Vitamin C is essential for the synthesis of collagen, a protein crucial for maintaining the structure and integrity of skin, blood vessels, and bones. It plays a key role in the hydroxylation of proline and lysine residues in collagen synthesis, which is necessary for the stability and strength of collagen fibers. Choice B: Vitamin D is essential for bone health and calcium absorption but is not directly involved in collagen synthesis. Choice C: Vitamin B12 is important for red blood cell formation and neurological function but is not directly related to collagen synthesis. Choice D: Vitamin K is necessary for blood clotting and bone metabolism but does not play a direct role in collagen synthesis.

Correct Answer: B

Rationale: Vitamin K is essential for the synthesis of proteins involved in blood clotting. These proteins help in the coagulation process, ensuring that wounds can heal properly by preventing excessive bleeding. Without sufficient Vitamin K, the blood clotting process may be impaired, leading to potential health risks. Vitamin D is important for bone health, Vitamin C is essential for the immune system and collagen production, and Vitamin B12 plays a role in red blood cell production and nerve function, but they are not directly involved in the blood clotting process.

Correct Answer: B

Rationale: White blood cells, also known as leukocytes, play a crucial role in the immune system by primarily fighting off infections caused by pathogens like bacteria, viruses, and other invaders. They help the body recognize and destroy these harmful agents, contributing to the body's defense mechanisms against diseases. Choice A is incorrect because the primary function of red blood cells, not white blood cells, is to carry oxygen. Choice C is incorrect as the transportation of nutrients is mainly carried out by the bloodstream as a whole, not specifically by white blood cells. Choice D is incorrect as the process of blood clotting is primarily managed by platelets in the blood, not white blood cells.

Correct Answer: A

Rationale: The liver's main role in digestion is to produce bile, a substance that aids in the breakdown and absorption of fats in the small intestine. Bile emulsifies fats, helping enzymes break them down into smaller molecules for easier absorption in the digestive tract. Therefore, the correct answer is A: 'To produce bile.' Storing glucose, secreting digestive enzymes, and detoxifying harmful substances are functions of the liver, but they are not primarily related to digestion.

Correct Answer: B

Rationale: The correct answer is the Adrenal gland. The Adrenal glands, situated on top of the kidneys, are responsible for producing adrenaline. Adrenaline is a hormone that prepares the body for the fight-or-flight response during stress. Choice A, the Thyroid gland, is responsible for producing hormones that regulate metabolism, not adrenaline. Choice C, the Pituitary gland, regulates many of the body's functions by producing various hormones but is not responsible for adrenaline production. Choice D, the Pineal gland, produces melatonin, a hormone that regulates sleep-wake cycles, and is not responsible for adrenaline production.

Correct Answer: B

Rationale: The correct answer is B: To secrete digestive enzymes. The pancreas plays a crucial role in digestion by secreting digestive enzymes that break down carbohydrates, fats, and proteins in the small intestine. These enzymes help in the process of breaking down food particles into smaller molecules that can be easily absorbed by the body for nutrients. Choices A, C, and D are incorrect as the primary function of the pancreas is not to absorb nutrients, produce bile, or store glucose in digestion.