Which hormone is primarily responsible for regulating calcium levels in the blood?

A. Motor neurons: Motor neurons carry impulses away from the central nervous system to muscles and glands. They are responsible for initiating movement and responses, not for transmitting sensory information to the CNS.

B. Sensory neurons: Sensory neurons transmit nerve impulses from sensory receptors in the peripheral nervous system to the central nervous system. They convey information about touch, pain, temperature, and other stimuli for processing and response.

C. Glial cells: Glial cells support and protect neurons, maintain the extracellular environment, and assist with nutrient supply. They do not directly transmit nerve impulses but are essential for proper neuronal function.

D. Interneurons: Interneurons are located within the central nervous system and connect sensory and motor neurons. They process information and coordinate responses but do not transmit impulses from the PNS to the CNS.

A. Insulin: Insulin is produced by the beta cells of the pancreas and regulates blood glucose levels. It promotes the uptake of glucose into cells and its storage as glycogen, playing a central role in energy metabolism.

B. Epinephrine: Epinephrine is synthesized in the adrenal medulla and functions in the fight-or-flight response. It increases heart rate, blood pressure, and blood glucose levels to prepare the body for rapid activity.

C. Growth hormone (GH): Growth hormone is secreted by the anterior pituitary gland. It stimulates growth of bones and tissues, promotes protein synthesis, and regulates metabolism, affecting multiple organ systems throughout the body.

D. Cortisol: Cortisol is produced by the adrenal cortex in response to ACTH from the anterior pituitary. It regulates metabolism, supports the stress response, and influences immune and anti-inflammatory functions.