Problem 20 - Objective Biology for NEET

Question

Neurohypophysis consist of (a) Pars distalis (b) Pars intermedia (c) Pars nervosa (d) All of these

Step-by-Step Solution

Answer

The correct answer is (c) Pars nervosa.

Step 1: Understanding the Terminology

Firstly, it's important to understand the terminology used in the question and options. The 'neurohypophysis' is a component of the pituitary gland, which is an endocrine gland that regulates a wide range of bodily functions. The terms 'Pars distalis', 'Pars intermedia', and 'Pars nervosa' are all components of the pituitary gland. 'Pars distalis' and 'Pars intermedia' are associated with the anterior pituitary (Adenohypophysis), while 'Pars nervosa' is associated with the posterior pituitary or Neurohypophysis.

Step 2: Select the Correct Option

After understanding the terminology, it's clear that option (c) 'Pars nervosa' is the only part that's associated with Neurohypophysis. The other parts 'Pars distalis' and 'Pars intermedia' are associated with the other part of the pituitary gland, called the anterior pituitary or Adenohypophysis. Therefore, option (a) and (b) are not parts of the Neurohypophysis, which makes the option (d) incorrect as well.

Key Concepts

Pituitary Gland

The pituitary gland is a small, pea-sized organ located at the base of the brain. It is often referred to as the "master gland" because it regulates a multitude of hormonal functions throughout the body. The pituitary gland is part of the endocrine system, which plays a pivotal role in maintaining bodily homeostasis. It is divided into two main parts: the anterior pituitary (Adenohypophysis) and the posterior pituitary (Neurohypophysis).
The anterior pituitary is responsible for producing and secreting hormones like growth hormone (GH), thyroid-stimulating hormone (TSH), and adrenocorticotropic hormone (ACTH). The posterior pituitary, on the other hand, stores and releases hormones produced by the hypothalamus, such as oxytocin and vasopressin (also known as antidiuretic hormone, ADH).

• Located in the brain beneath the hypothalamus
• Composed of anterior and posterior sections
• Controls various hormonal activities

Understanding the function of the pituitary gland is crucial, as it affects numerous aspects of health and development.

Pars Nervosa

The Pars Nervosa is a component of the Neurohypophysis or posterior pituitary gland. It is primarily used for the storage and release of two major hormones: oxytocin and vasopressin. These hormones are not produced by the Pars Nervosa itself but are synthesized in the hypothalamus before traveling down nerve fibers to be stored.
When needed by the body, these hormones are released into the bloodstream from the Pars Nervosa. Vasopressin helps regulate the body's retention of water by increasing the permeability of the kidney's collecting ducts. Oxytocin plays a critical role in social bonding, sexual reproduction, and during and after childbirth.

• Located in the posterior pituitary
• Involved in hormone storage and release
• Works in coordination with the hypothalamus

The Pars Nervosa is essential in why the neurohypophysis is important for body's overall fluid balance and reproductive functions.

Endocrine System

The endocrine system consists of glands that release hormones directly into the bloodstream, which are then carried to organs and tissues throughout the body to exert their functions. This system regulates a multitude of processes, including growth, metabolism, and mood.
The pituitary gland is a central component of the endocrine system, interacting with various other glands such as the thyroid, adrenals, and reproductive organs. This system works on a feedback loop mechanism, meaning it relies on signals to maintain balance within the body's internal environment.

• Composed of multiple hormone-releasing glands
• Regulates critical physiological processes
• Operates through a feedback mechanism

Understanding the endocrine system is crucial for grasping how hormonal imbalances can affect physical and mental health. This intricate network ensures that everything from our metabolism to our mood is tightly regulated and in harmony.