Question

Angiotensin DIRECTLY causes the release of which of the following from the adrenal cortex? A. Renin B. Aldosterone C. Calcitonin D. Thyroxine

Short answer

B. Aldosterone

Step-by-step solution

Understand the Question

The question asks about a substance that angiotensin directly causes to be released from the adrenal cortex. The adrenal cortex is a key part of the endocrine system involved in steroid hormone production.

Identify the Function of Angiotensin

Angiotensin is a peptide hormone that plays a critical role in regulating blood pressure and fluid balance. It acts mainly through the renin-angiotensin system.

Examine the Functions of Given Options

Review each option: A. Renin: An enzyme released by the kidneys, not the adrenal cortex.B. Aldosterone: A hormone produced by the adrenal cortex that regulates sodium and potassium levels.C. Calcitonin: A hormone released by the thyroid gland that lowers blood calcium levels.D. Thyroxine: A hormone produced by the thyroid gland involved in metabolism regulation.

Determine the Correct Answer

Among the given options, Aldosterone is the only hormone that is directly released from the adrenal cortex in response to angiotensin.

Key concepts

angiotensin

Angiotensin is a peptide hormone that plays a crucial role in regulating blood pressure and fluid balance. It is part of the renin-angiotensin system, which involves a chain reaction of enzymes and hormones.

Angiotensin is initially produced as angiotensinogen by the liver. When blood pressure drops, the kidneys release an enzyme called renin. Renin converts angiotensinogen into angiotensin I. Angiotensin I is then converted to angiotensin II by the enzyme ACE (angiotensin-converting enzyme), primarily in the lungs.

Angiotensin II has several important functions:

• It causes blood vessels to constrict, which increases blood pressure.
• It signals the adrenal cortex to release aldosterone, which helps regulate sodium and water balance.
• It stimulates the release of antidiuretic hormone (ADH) from the pituitary gland, which also helps in water retention by the kidneys.

Understanding angiotensin’s role helps us to appreciate why it directly influences aldosterone secretion.

aldosterone secretion

Aldosterone is a steroid hormone produced by the adrenal cortex. Its primary function is to regulate electrolyte and water balance. When you understand aldosterone’s role, it becomes clear why angiotensin is crucial in its secretion.

Here's how it works:

• When angiotensin II levels rise, they stimulate the adrenal cortex to secrete aldosterone.
• Aldosterone then acts on the kidneys to increase sodium reabsorption into the bloodstream.
• This process also leads to the retention of water, which helps maintain or increase blood pressure.
• Consequently, potassium is excreted to maintain electrolyte balance.

Understanding aldosterone secretion and its regulation by angiotensin II is crucial, especially in the context of treating conditions like hypertension and heart failure.

By managing aldosterone levels, doctors can effectively control blood pressure and fluid balance. This also demonstrates the interconnectivity of the body’s hormonal and cardiovascular systems.

endocrine system

The endocrine system consists of glands that secrete hormones directly into the bloodstream. These hormones regulate a wide range of bodily functions, from metabolism to growth to mood.

Understanding the endocrine system involves recognizing how interconnected and finely tuned this network is.

Key Players:

• The adrenal glands, which secrete hormones like aldosterone and cortisol.
• The thyroid gland, which produces hormones that regulate metabolism.
• The pituitary gland, often called the ‘master gland’ because it controls other endocrine glands.

The adrenal cortex, part of the adrenal glands, produces steroid hormones including aldosterone. Angiotensin II directly stimulates the adrenal cortex, leading to aldosterone secretion.

This complex interaction highlights the precision of the endocrine system.

It’s fascinating to see how hormone pathways like the renin-angiotensin-aldosterone system can have systemic effects, from blood pressure regulation to electrolyte balance.

The endocrine system's efficiency and adaptability make it essential for maintaining homeostasis in the body.