Adrenocorticotropic Hormone (ACTH) | Adrenal Gland

Summary

This video explains the role of adrenocorticotropic hormone (ACTH), focusing on how it stimulates the adrenal glands, specifically the cortex, to release vital hormones. ACTH is triggered by stress signals and released from the anterior pituitary. These hormones include mineralocorticoids like aldosterone, which regulate blood pressure, glucocorticoids like cortisol, which aid in energy metabolism and immune suppression, and androgens, which contribute to sexual characteristics. The script delves into the complex interactions between these hormones and the body’s stress response, highlighting how they help the body manage stress and maintain homeostasis.

Takeaways

• 😀 ACTH stands for Adrenocorticotropic Hormone, which is vital for the body’s stress response.
• 😀 ACTH is released from the anterior pituitary gland and stimulates the adrenal cortex to release hormones.
• 😀 The adrenal glands are located atop the kidneys and are responsible for producing important hormones.
• 😀 The term 'tropic' means that ACTH is a hormone that stimulates other glands to release hormones.
• 😀 ACTH is triggered by stress-inducing stimuli such as anxiety, fear, pain, or rage, which activate the hypothalamus.
• 😀 The hypothalamus sends signals to the anterior pituitary, prompting it to release ACTH into the bloodstream.
• 😀 ACTH stimulates the adrenal glands to release three primary hormones: mineralocorticoids, glucocorticoids, and androgens.
• 😀 Mineralocorticoids, such as aldosterone, help regulate sodium levels and blood pressure during stress.
• 😀 Glucocorticoids, like cortisol, aid in glucose metabolism, provide energy, and suppress inflammation.
• 😀 Androgens, such as DHEA, play a role in sexual characteristics but are less involved in the immediate stress response.
• 😀 Glucocorticoids have a feedback mechanism that helps regulate ACTH production, ensuring balance in the stress response.

Q & A

What is Adrenocorticotropic Hormone (ACTH)?

Adrenocorticotropic Hormone (ACTH) is a hormone released from the anterior pituitary gland that stimulates the adrenal cortex to release various hormones, including aldosterone, cortisol, and androgens, particularly in response to stress.

What does the term 'tropic' mean in the context of ACTH?

'Tropic' refers to a hormone that targets another gland and stimulates it to release other hormones. In the case of ACTH, it stimulates the adrenal cortex to release more hormones.

Where is ACTH produced, and what triggers its release?

ACTH is produced in the anterior pituitary gland, which is located at the base of the brain. Its release is triggered by signals from the hypothalamus in response to stressors like fear, pain, anxiety, or physical stress.

How does ACTH affect the adrenal glands?

ACTH stimulates the adrenal cortex to release various hormones, including mineralocorticoids, glucocorticoids, and androgens, which are involved in managing stress responses, regulating blood pressure, and modulating immune function.

What role do the adrenal glands play in the body?

The adrenal glands, located on top of the kidneys, are responsible for producing and releasing hormones that help regulate stress responses, blood pressure, metabolism, and immune function.

What is the function of aldosterone, and how does it relate to ACTH?

Aldosterone, a mineralocorticoid hormone, is released from the adrenal cortex in response to ACTH. It promotes sodium reabsorption in the kidneys, increasing blood volume and blood pressure, which helps the body manage stress.

What is cortisol, and how does it contribute to the stress response?

Cortisol is a glucocorticoid hormone released by the adrenal cortex in response to ACTH. It plays a key role in carbohydrate metabolism, increasing glucose availability for energy. It also helps suppress the immune system and inflammation during stress.

What are androgens, and what role do they play in the body?

Androgens are hormones that contribute to male sexual characteristics. They are released from the adrenal cortex and play a role in masculinization. Examples include dehydroepiandrosterone (DHEA).

How does negative feedback regulate ACTH levels?

When cortisol and other glucocorticoid levels rise, they signal back to the pituitary gland to inhibit further release of ACTH, maintaining a balanced level of these hormones in the body.

Why is the adrenal cortex specifically important when discussing ACTH?

The adrenal cortex is the outer layer of the adrenal glands and is where ACTH acts to stimulate the release of essential hormones like aldosterone, cortisol, and androgens, which are crucial in responding to stress.