Question

Which is steroid hormone? (a) GH (b) Insulin (c) Aldosterone (d) Epinephrine

Short answer

The steroid hormone among the provided options is (c) Aldosterone.

Step-by-step solution

Identify the nature of GH

GH, or Growth Hormone, is a peptide hormone. It is produced by the pituitary gland and is not a steroid hormone.

Identify the nature of Insulin

Insulin is also a peptide hormone. It is produced by pancreatic beta cells and is not a steroid hormone.

Identify the nature of Aldosterone

Aldosterone is a steroid hormone. It is produced in the outer section (cortex) of the adrenal glands and plays an important role in maintaining sodium balance in the body.

Identify the nature of Epinephrine

Epinephrine, also known as adrenaline, is a hormone and neurotransmitter. It is a catecholamine, not a steroid hormone. It's produced by both the adrenal glands and certain neurons.

Key concepts

GH (Growth Hormone)

GH, also known as Growth Hormone, is a fascinating substance that plays a crucial role in the body. It's a peptide hormone, meaning it's made up of amino acids strung together in a specific sequence. This hormone is produced by the pituitary gland, a pea-sized gland located at the base of the brain.

GH's main function is to stimulate growth, cell reproduction, and regeneration in the body. It works directly by affecting cells and indirectly by promoting the production of another growth-related molecule called IGF-1 (Insulin-like Growth Factor 1).

Here's what GH does:

• Promotes bone growth, especially during childhood and adolescence
• Increases muscle mass and strength
• Enhances fat metabolism, reducing overall body fat
• Supports critical bodily functions like metabolism and muscle and tissue repair

Vice versa, a deficiency in GH can lead to growth-related issues such as dwarfism in children, while excessive GH can result in gigantism or acromegaly in adults.
Understanding the pivotal role GH plays helps us appreciate the complex network of hormones in our body and how they integrate to sustain life.

Insulin

Insulin is a vital peptide hormone essential for regulating metabolism and energy utilization in the body. It is secreted by beta cells in the pancreas. Like GH, insulin is also composed of chains of amino acids, categorizing it as a non-steroid hormone.

Insulin primarily helps to regulate glucose levels in the blood. After you eat, your blood glucose levels rise, prompting your pancreas to release insulin. Here's how it works:

• Facilitates the uptake of glucose by cells so they can use it for energy
• Signals the liver to store glucose in the form of glycogen for later use
• Prevents the body from using fat as its primary source of energy when adequate glucose is present

If insulin levels or function are impaired, it can lead to diabetes mellitus, a serious condition wherein the body cannot properly utilize sugar.

Therefore, understanding insulin's mechanism is key to grasping how the body maintains its internal balance and supports cellular energy needs.

Aldosterone

Aldosterone is a crucial steroid hormone produced in the adrenal cortex, the outer part of the adrenal glands located above the kidneys. As a steroid hormone, its structure is derived from cholesterol, differing fundamentally from peptide hormones like GH and insulin.

Aldosterone plays a significant role in ensuring the body's salt and water balance. It mainly influences the kidneys, helping to regulate blood pressure by adjusting sodium and potassium levels. Here's what aldosterone does:

• Increases sodium reabsorption in the kidneys, promoting water retention and increasing blood volume
• Encourages the excretion of potassium, maintaining electrolyte balance
• Helps control blood pressure and balance of fluids and electrolytes

Disruption in aldosterone production can cause health problems like Addison's disease (insufficient production) or Conn's syndrome (overproduction).

Understanding aldosterone's role sheds light on the importance of hormonal balance and its effects on long-term health and well-being.

Epinephrine

Also known as adrenaline, epinephrine is a hormone and neurotransmitter that triggers your body's "fight-or-flight" response. Produced by the adrenal medulla, this exciting hormone is a catecholamine, not a steroid hormone.

When you're faced with stress or danger, your adrenal glands rapidly release epinephrine into your bloodstream. Here’s how epinephrine helps your body cope:

• Increases heart rate and strength of heart contractions, boosting blood supply to muscles and the brain
• Promotes the breakdown of glycogen to glucose in the liver, providing a quick energy source
• Expands the air passages of the lungs, facilitating increased oxygen intake
• Redirects blood flow to major muscle groups, preparing you for quick action

This fast-acting mechanism enables you to respond effectively to immediate threats, enhancing performance and survival.

Thus, epinephrine plays a pivotal role in enabling rapid and effective responses to acute stress, showcasing the dynamic nature of hormonal responses in the body.