What is the main function of the nervous system?

Correct Answer: C

Rationale: The main function of the nervous system is to control and coordinate body activities by transmitting signals between different parts of the body and responding to internal and external stimuli. This allows for the regulation of body temperature, movement, sensory perception, and various other functions necessary for homeostasis. Choices A, B, and D are incorrect as they do not align with the primary role of the nervous system. Transporting blood is mainly carried out by the circulatory system, protecting the body from infection is a function of the immune system, and digesting food is the role of the digestive system.

Correct Answer: A

Rationale: The larynx, also known as the voice box, is a crucial structure in the respiratory system. It is located in the upper part of the trachea and houses the vocal cords. The larynx plays a key role in producing sound and protecting the trachea by closing during swallowing to prevent food from entering the airway. This makes the larynx the correct answer in this context. The trachea (Choice B) is a respiratory structure that connects the larynx to the lungs, allowing air to pass through. The pharynx (Choice C) is a shared pathway for both air and food, located at the back of the throat. The esophagus (Choice D) is part of the digestive system, responsible for transporting food from the mouth to the stomach. Therefore, Choices B, C, and D are not located in the respiratory system.

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: B

Rationale: The correct answer is B: Absorbing water and forming solid waste. The large intestine plays a crucial role in absorbing water from the remaining indigestible food matter and forming solid waste (feces) to be excreted from the body. This process helps in maintaining the body's fluid balance and eliminating waste efficiently. Choices A, C, and D are incorrect because the large intestine is not primarily responsible for absorbing nutrients, breaking down fats, or secreting digestive enzymes. These functions are mainly carried out in the small intestine.

Correct Answer: B

Rationale: The correct answer is B: Insulin. Insulin, produced by the pancreas, is the hormone responsible for lowering blood glucose levels. It achieves this by promoting the uptake of glucose into cells, thereby reducing the concentration of glucose in the bloodstream. Choice A, Glucagon, is actually a hormone produced by the pancreas that works to raise blood glucose levels by stimulating the liver to release stored glucose. Choice C, Cortisol, is a hormone produced by the adrenal glands, not the pancreas, and is involved in stress response and regulation of metabolism. Choice D, Melatonin, is a hormone produced by the pineal gland that regulates sleep-wake cycles and is not directly involved in blood glucose level regulation.

Correct Answer: C

Rationale: The main function of the nervous system is to control and coordinate body activities by transmitting signals between different parts of the body and responding to internal and external stimuli. This allows for the regulation of body temperature, movement, sensory perception, and various other functions necessary for homeostasis. Choices A, B, and D are incorrect as they do not align with the primary role of the nervous system. Transporting blood is mainly carried out by the circulatory system, protecting the body from infection is a function of the immune system, and digesting food is the role of the digestive system.

Correct Answer: B

Rationale: The correct answer is B: 'To pump blood throughout the body.' The primary function of the heart in the circulatory system is to pump blood, which carries oxygen and nutrients, throughout the body. Choice A, 'To filter blood,' is incorrect as the heart does not filter blood; that is primarily done by the kidneys. Choice C, 'To absorb oxygen,' is incorrect as the lungs are responsible for oxygen absorption. Choice D, 'To remove carbon dioxide,' is incorrect as the lungs facilitate the removal of carbon dioxide from the body.

Correct Answer: A

Rationale: Tendons are fibrous connective tissues that attach muscles to bones, allowing the transmission of forces generated by muscles and facilitating movement at joints. Ligaments, on the other hand, connect bones to other bones, providing stability. Cartilage is a firm, flexible connective tissue found in joints and the respiratory tract. Fascia surrounds muscles, groups of muscles, blood vessels, and nerves, offering support and protection. Therefore, the correct answer is tendons as they specifically connect muscles to bones.

Correct Answer: B

Rationale: The correct answer is B: 'To break down food.' The stomach plays a crucial role in the digestive system by breaking down food using gastric acid and digestive enzymes. This process transforms the food into a semi-liquid mixture known as chyme, which is further digested in the small intestine. Choices A, C, and D are incorrect because the stomach does not primarily absorb nutrients, produce bile, or store waste. These functions are carried out by other organs in the digestive system such as the small intestine, liver, and large intestine, respectively.