Problem 40 - Objective Biology for NEET

Question

Diuresis is reduced by (a) Oxytocin (b) Prolactin (c) Luteinizing hormone (d) Vasopressin

Step-by-Step Solution

Answer

The hormone that reduces diuresis is Vasopressin (d).

Step 1: Understanding Hormones

A hormone is a chemical messenger that is produced by certain cells and transported by the bloodstream to affect other parts of the body. There are four hormones listed in this exercise: Oxytocin, Prolactin, Luteinizing hormone, and Vasopressin. Each one of them has a different role or function in the body.

Step 2: Oxytocin Influence

Oxytocin is known as the love hormone because it is released when people snuggle up or bond socially. Other than this, it plays a role in childbirth and breastfeeding. It doesn't have any known direct influence on Diuresis.

Step 3: Prolactin Influence

Prolactin is a hormone released by the pituitary gland and primarily functions to help women produce milk after childbirth. Prolactin doesn't have a significant effect on diuresis.

Step 4: Luteinizing Hormone Influence

The Luteinizing hormone plays a vital role in sexual development. It is responsible for triggering ovulation in females and testosterone production in males. It doesn't significantly influence diuresis.

Step 5: Vasopressin Influence

Vasopressin, also known as antidiuretic hormone (ADH), is a hormone released to help regulate the body's retention of water. It directly acts on the kidneys and other parts of the body, reducing urine output, making the urine more concentrated, hence reducing diuresis.

Key Concepts

Antidiuretic Hormone (ADH)

Antidiuretic hormone, also known as ADH or vasopressin, plays a crucial role in maintaining the body's water balance. It is produced by the hypothalamus and stored in the pituitary gland. The main function of ADH is to conserve water by reducing the amount of water excreted in urine. This hormone achieves this by acting on the kidneys, prompting them to absorb more water from the filtering blood and concentrate the urine.
When the body is dehydrated, or when blood volume is low, ADH levels increase. This leads to less urine production and helps maintain blood pressure. On the other hand, when there is excess water in the body, ADH levels decrease, leading to increased urine production.

• Produced in response to low blood volume or high blood osmolality.
• Acts on kidneys to reduce urine output.
• Helps maintain fluid balance and blood pressure.

ADH is essential for preventing diuresis, which refers to increased urine production. Disorders in ADH secretion can lead to conditions like diabetes insipidus, where the body cannot adequately conserve water.

Hormone Functions

Hormones are vital biochemical substances that help regulate bodily functions by transmitting messages from one part of the body to another. Each hormone has a specific role essential for maintaining homeostasis, which is the stable condition of internal health.

• Hormones like insulin regulate blood glucose levels.
• Thyroid hormones influence metabolism rates.
• Sex hormones control reproductive functions.
• Cortisol helps in stress response and inflammation control.

Each hormone functions through specific receptors that only respond to certain signals. When a hormone binds to its receptor, a signal is sent to the target cells, resulting in a particular action or process. This targeted action ensures that hormones effectively manage various physiological activities
and maintain the body’s balanced state. Without hormones, such regulation would be impossible, leading to imbalance and disease.

Pituitary Gland Regulation

The pituitary gland, often termed the "master gland," plays a pivotal role in regulating the endocrine system. Located at the base of the brain, it influences many processes by releasing hormones that control other glands in the endocrine system.
The pituitary gland is divided into the anterior and posterior lobes, each responsible for different hormone secretions.

• The anterior lobe produces hormones like growth hormone, ACTH, TSH, and prolactin.
• The posterior lobe stores and releases hormones like oxytocin and vasopressin (ADH).

Hormones secreted by the pituitary gland regulate various bodily functions, including growth and metabolism, thyroid function, water balance, and reproduction.
For instance, vasopressin is stored in the posterior lobe, and its release is triggered by signals of low blood volume or high solute concentration, underscoring its role in fluid homeostasis.
The pituitary gland receives signals from the hypothalamus, a region of the brain that helps maintain the equilibrium of hormonal secretions. This close connection between the hypothalamus and the pituitary gland ensures a finely tuned regulation of hormone levels throughout the body. This intricate system underscores its importance in maintaining overall health and well-being.