Which part of the brain is responsible for regulating heart rate, breathing, and swallowing?

Correct Answer: C

Rationale: The correct answer is C, the medulla oblongata. This part of the brain, located at the base of the brainstem, is primarily responsible for regulating essential functions like heart rate, breathing, and swallowing. Choices A, B, and D are incorrect. The cerebrum is associated with higher brain functions such as thinking and voluntary movements, the cerebellum controls coordination and balance, and the thalamus serves as a relay station for sensory information. Therefore, the medulla oblongata specifically governs the autonomic functions critical for survival.

Correct Answer: B

Rationale: Corticosteroids, produced by the adrenal cortex, primarily function to control blood pressure and electrolyte balance. One of the key corticosteroids, aldosterone, plays a crucial role in regulating sodium and potassium levels in the body. This regulation is essential for maintaining blood pressure and electrolyte balance. Choices A, C, and D are incorrect because corticosteroids do not primarily regulate insulin sensitivity and blood sugar levels, stimulate the immune system and inflammatory response, or promote growth and development during puberty. While corticosteroids can have effects on insulin sensitivity, immune response, and growth, their major role is in maintaining blood pressure and electrolyte balance.

Correct Answer: C

Rationale: Potassium is essential for muscle function, including muscle contraction. A deficiency in potassium can lead to muscle weakness and cramps. While sodium, calcium, and magnesium are also important minerals for muscle function, potassium is specifically known for its role in preventing muscle cramps by regulating muscle contractions and nerve signals.

Correct Answer: A

Rationale: The correct answer is the sympathetic nervous system. The sympathetic nervous system is responsible for activating the body's response to stress or danger, leading to the 'fight-or-flight' response. It prepares the body for action by increasing heart rate, dilating pupils, and redirecting blood flow to muscles. Choice B, the parasympathetic nervous system, is responsible for the body's 'rest-and-digest' activities, which are opposite to the 'fight-or-flight' response. Choice C, the enteric nervous system, primarily regulates the gastrointestinal system and is not directly involved in the 'fight-or-flight' response. Choice D, the sensory nervous system, transmits sensory information from the body to the central nervous system and is not responsible for the physiological changes associated with the 'fight-or-flight' response.

Correct Answer: A

Rationale: The correct answer is A: Ventral carries motor, dorsal carries sensory information. In the spinal nerve, the ventral root carries motor information from the spinal cord to the muscles, while the dorsal root carries sensory information from the peripheral sensory receptors to the spinal cord. Therefore, other choices are incorrect. Choice B is incorrect as it states the opposite roles of ventral and dorsal roots. Choice C is incorrect as the size comparison between ventral and dorsal roots is not related to their functions. Choice D is incorrect as the terms 'anteriorly' and 'posteriorly' are not commonly used to describe the locations of ventral and dorsal roots in relation to each other.