Problem 145 - Objective Biology for NEET

Question

Assertion: Oxytocin is called 'birth hormone'. Reason: In female it stimulates a vigorous contraction of smooth muscle of uterus at the time of child birth.

Step-by-Step Solution

Answer

Both the assertion and the reason are correct, and the reason correctly explains why Oxytocin is referred to as the 'birth hormone'.

Step 1: Understanding the Assertion

The first step is to understand and assess the given assertion. What does it mean by terming Oxytocin as 'birth hormone'? Oxytocin is mammalian neurohypophysial hormone. It not just induces labor, but also helps the body in several post labor tasks.

Step 2: Understanding the Reason

The next step is to understand the reason behind the assertion. Oxytocin indeed stimulates the contraction of the uterus, which is an important biological event for the process of childbirth.

Step 3: Linking the Assertion and Reason

Finally, verification is needed by linking the assertion and the reason. From the above steps, it can be concluded that the assertion is correct because Oxytocin plays a crucial role in child birth, and hence can be called a 'birth hormone'. For similar reasons, the reason is also correct because it accurately describes the function of Oxytocin in relation to childbirth.

Key Concepts

Birth Hormone

Oxytocin, often referred to as the 'birth hormone,' plays a significant role in the reproductive process. This hormone is synthesized in the hypothalamus and released by the posterior pituitary gland, also known as the neurohypophysis. It is essential not just during childbirth but also during other stages of reproduction.

• Oxytocin triggers the onset of labor, making it crucial for the birthing process.
• Besides childbirth, it aids in lactation by promoting milk ejection.

Understanding oxytocin's vital functions help us appreciate why it has earned the title 'birth hormone.' Its influence spans beyond just childbirth, impacting various physiological and emotional aspects of reproduction.

Uterine Contraction

Uterine contractions are a core part of the childbirth process, and oxytocin is the chief hormone responsible for initiating these contractions. During labor, oxytocin binds to specific receptors on the uterus, leading to powerful muscle contractions necessary for delivering the baby.

• These contractions start slowly but gradually intensify, helping open the cervix.
• Oxytocin-induced contractions also assist in pushing the baby through the birth canal.

The hormone's role is to ensure these contractions are consistent and strong enough to facilitate a smooth labor process. Without oxytocin, the effectiveness and regularity of uterine contractions would be compromised, making it a key player in childbirth.

Childbirth Process

The childbirth process, also known as parturition, is a complex sequence driven by hormones, including oxytocin, which is central to initiating and managing labor. Childbirth involves several stages:

• The early phase, where contractions begin mildly and irregularly.
• The active phase, marked by stronger and regular contractions opening the cervix.
• The finale, where the baby and placenta are delivered.

Each stage relies on hormonal control to progress smoothly. Oxytocin ensures uterine contractions remain steady and helps in the expulsion of the placenta after the baby's delivery. Understanding each phase reveals the meticulous balance oxytocin maintains during the entire childbirth process.

Neurohypophysial Hormone

Oxytocin belongs to a group of hormones known as neurohypophysial hormones, which are synthesized in the hypothalamus and stored in the posterior pituitary gland. These hormones play crucial roles in various bodily functions. Apart from oxytocin's involvement in childbirth:

• Another key neurohypophysial hormone is vasopressin, which regulates water balance and blood pressure.
• Oxytocin also influences social bonding and stress management.

The synthesis and release of neurohypophysial hormones highlight the interaction between the nervous and endocrine systems, making them essential for maintaining homeostasis and facilitating critical life processes. This dual role emphasizes the importance of neurohypophysial hormones in regulating both physiological and behavioral functions.