Problem 4 - Campbell Biology

Question

Which hormone is correctly paired with its action? (A) oxytocin-stimulates uterine contractions during childbirth (B) thyroxine-inhibits metabolic processes (C) ACTH-inhibits the release of glucocorticoids by the adrenal cortex (D) melatonin-raises blood calcium level

Step-by-Step Solution

Answer

Option A: oxytocin-stimulates uterine contractions during childbirth.

Step 1: Understand the Question

Identify the hormone and its corresponding action that are correctly paired. There are four options provided.

Step 2: Analyze Option A

Oxytocin is known to stimulate uterine contractions during childbirth. Assess if this pairing is correct.

Step 3: Analyze Option B

Thyroxine is mainly involved in regulating metabolic processes. It typically does not inhibit these processes. Assess this pairing.

Step 4: Analyze Option C

ACTH (Adrenocorticotropic Hormone) actually stimulates the release of glucocorticoids by the adrenal cortex. Therefore, this pairing seems incorrect.

Step 5: Analyze Option D

Melatonin primarily regulates sleep-wake cycles. It does not raise blood calcium levels. Assess this pairing.

Step 6: Conclusion

After analyzing all the options, the correct pairing is determined based on the physiological actions of the hormones.

Key Concepts

Oxytocin

Oxytocin is a hormone produced by the hypothalamus and released by the pituitary gland. It plays a crucial role in childbirth by causing the muscles of the uterus to contract. This helps in labor and the delivery of a baby. Additionally, oxytocin also helps in the ejection of milk during breastfeeding. This hormone is often referred to as the 'love hormone' because it is associated with bonding behavior. For example, it is released when people hug or bond socially.

Thyroxine

Thyroxine, also known as T4, is a hormone produced by the thyroid gland. It is essential for regulating the body's metabolism. Unlike the incorrect pairing mentioned in the exercise, thyroxine does not inhibit metabolic processes; it actually stimulates them. By doing so, thyroxine helps control how the body uses energy. It influences various bodily functions, including heart rate, digestion, and muscle control. If the thyroid produces too much or too little thyroxine, it can lead to conditions such as hyperthyroidism or hypothyroidism.

ACTH

Adrenocorticotropic Hormone (ACTH) is produced by the pituitary gland. It stimulates the adrenal cortex to release glucocorticoids such as cortisol. Cortisol is vital for many functions, including regulating metabolism and the immune response. This hormone directs the adrenal gland to convert proteins and fats into glucose, providing the body with energy. High levels of ACTH can signal the body's stress response, while low levels may lead to adrenal insufficiency.

Melatonin

Melatonin is a hormone secreted by the pineal gland, primarily at night. It plays a key role in regulating the sleep-wake cycle by signaling the body when it's time to sleep. Exposure to light affects its production, with less melatonin produced during daylight hours and more when it is dark. It does not have any role in raising blood calcium levels, as was incorrectly suggested in the exercise. Instead, melatonin's main function is to help you fall asleep and stay asleep, making it a popular supplement for those experiencing sleep difficulties.