Which hormone is released by the adrenal glands in response to stress?

Correct Answer: C

Rationale: Adrenaline is the correct answer. It is released by the adrenal glands in response to stress to prepare the body for the 'fight or flight' response. Adrenaline increases heart rate, dilates airways, and mobilizes energy stores to help the body deal with the perceived threat. Insulin (Choice A) is produced by the pancreas to regulate blood sugar levels, not in response to stress. Cortisol (Choice B) is another hormone released by the adrenal glands in response to stress, but it primarily helps regulate metabolism and immune response. Glucagon (Choice D) is also produced by the pancreas to increase blood sugar levels when they are low, not by the adrenal glands in response to stress.

Correct Answer: B

Rationale: The correct answer is B: Ball-and-socket joint. A ball-and-socket joint, like the ones found at the shoulder and hip, allows for a wide range of motion. These joints provide multidirectional movement due to the rounded end of one bone fitting into the cup-like socket of another bone, enabling flexion, extension, abduction, adduction, and rotation. Choice A, Hinge joint, is incorrect because hinge joints allow movement in one plane, like a door hinge, and do not provide the wide range of motion seen at the shoulder and hip. Choice C, Pivot joint, is incorrect because pivot joints allow rotation around a single axis, such as the neck, and do not provide the same range of motion as ball-and-socket joints. Choice D, Saddle joint, is incorrect as saddle joints allow movement in multiple directions but are not as versatile or allow as wide a range of motion as ball-and-socket joints.

Correct Answer: B

Rationale: The correct answer is B. Arteries carry oxygenated blood away from the heart to the rest of the body, delivering nutrients and oxygen to the tissues. Veins, on the other hand, carry deoxygenated blood back to the heart. Capillaries are where the exchange of gases, nutrients, and waste products occurs between the blood and tissues. Lymphatic vessels are responsible for transporting lymph, which is a clear fluid containing white blood cells and waste products, and play a key role in the immune system.

Correct Answer: B

Rationale: The iris is the correct answer as it controls the amount of light that enters the eye by adjusting the size of the pupil. The cornea is responsible for focusing light onto the retina, the retina detects light at the back of the eye, and the lens helps in further focusing light onto the retina. The iris, through changing the size of the pupil, regulates the amount of light reaching the eye, making it the part that controls the entry of light.

Correct Answer: B

Rationale: The cerebellum is responsible for coordinating voluntary muscle movements. It plays a crucial role in motor control, helping to maintain balance, posture, and coordination of voluntary movements. The medulla oblongata is involved in regulating basic life functions such as breathing and heart rate. The thalamus serves as a relay center for sensory information, while the hypothalamus is primarily involved in regulating various physiological processes like body temperature, hunger, and thirst. Hence, the correct answer is the cerebellum as it is specifically associated with voluntary muscle coordination, unlike the other brain regions listed.