The thymus gland secretes hormones called:
A.
Thyroxines; control metabolism.
B.
Melatonins; control circadian rhythms.
C.
Thymosins; control production and differentiation of white blood cells.
D.
Prostaglandins; control strength.
The Correct Answer and Explanation is:
The correct answer is C. Thymosins; control production and differentiation of white blood cells.
Explanation:
The thymus gland is a crucial component of the immune system, primarily responsible for the development and maturation of T lymphocytes (T cells), which are a type of white blood cell essential for adaptive immunity. Located in the mediastinum, the thymus plays a pivotal role in the development of T cells from progenitor cells that originate in the bone marrow.
The thymus gland secretes several hormones known collectively as thymosins. These hormones are vital for the regulation of T cell development and differentiation. Thymosins support the maturation of T cells into functional immune cells that can recognize and combat pathogens, including viruses and bacteria, as well as other foreign substances. This process is crucial for establishing a functional and effective immune response.
During fetal development and early childhood, the thymus is particularly active, ensuring that a robust T cell repertoire is generated. As a person ages, the size and activity of the thymus decrease, a process known as thymic involution. However, the role of thymosins remains significant throughout life for maintaining immune system balance.
Here’s a brief overview of why the other options are incorrect:
- A. Thyroxines; control metabolism: Thyroxine (T4) is a hormone produced by the thyroid gland, not the thymus. It is crucial for regulating metabolism, growth, and development.
- B. Melatonins; control circadian rhythms: Melatonin is a hormone produced by the pineal gland, not the thymus. It regulates sleep-wake cycles and circadian rhythms.
- D. Prostaglandins; control strength: Prostaglandins are a group of lipid compounds that have diverse roles in the body, including influencing inflammation and pain. They are not produced by the thymus and do not specifically control strength.
In summary, thymosins, secreted by the thymus gland, are critical for the proper development and differentiation of T cells, making option C the correct answer.