Which part of the brain controls balance and coordination?

Correct Answer: A

Rationale: The correct answer is the cerebellum. Located at the back of the brain, the cerebellum plays a crucial role in controlling balance, coordination, and fine motor movements. It receives information from the sensory systems, the spinal cord, and other parts of the brain to coordinate voluntary movements and maintain posture. Damage to the cerebellum can result in issues with balance, coordination, and muscle tone. The cerebrum is responsible for higher brain functions like thinking and problem-solving, the medulla oblongata controls vital autonomic functions like breathing and heartbeat, and the brainstem serves as a pathway for neural fibers traveling to and from the brain.

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: The correct answer is a hinge joint. The elbow joint is a hinge joint that allows for flexion and extension movements, much like the movement of a door hinge. This type of joint permits movement in one plane, similar to the action of opening and closing a door. The other choices are incorrect: A) Ball and socket joints allow for a wide range of motion in multiple directions, such as the hip and shoulder joints. C) Pivot joints allow rotation around a single axis, like the joint at the top of the neck that allows the head to turn from side to side. D) Saddle joints are found in the thumb and have a biaxial range of motion allowing flexion, extension, adduction, abduction, and circumduction.

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.