Which of the following lobes of pituitary atrophies during fetal development and is smaller is adults ?

Options

A. Pars distalis
B. Pars intermedia
C. Adenohypophysis
D. Neurohypophysis

Answer

To answer the question, "Which of the following lobes of the pituitary atrophies during fetal development and is smaller in adults?", we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Structure of the Pituitary Gland**: The pituitary gland is divided into three lobes: the anterior lobe (adenohypophysis), the middle lobe (also part of the adenohypophysis), and the posterior lobe (neurohypophysis).

2. **Identify the Function of Each Lobe**:
- The **anterior lobe** (pars distalis) produces several hormones including growth hormone, prolactin, and adrenocorticotropic hormone.
- The **middle lobe** (pars intermedia) primarily secretes melanocyte-stimulating hormone (MSH), which is involved in skin pigmentation.
- The **posterior lobe** (pars nervosa) stores and releases hormones like oxytocin and vasopressin that are produced in the hypothalamus.

3. **Determine Which Lobe Atrophies**: During fetal development, the middle lobe (pars intermedia) is known to atrophy and becomes smaller in adults. This lobe degenerates significantly as the individual matures.

4. **Conclude the Answer**: Based on the information gathered, the lobe of the pituitary that atrophies during fetal development and is smaller in adults is the **pars intermedia**.

### Final Answer:
The correct answer is **pars intermedia** (option no. 2).

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