Pars intermedia: Difference between revisions

Latest revision as of 14:11, 21 February 2025

Pars Intermedia[edit]

Diagram of the pituitary gland showing the pars intermedia.

The pars intermedia is a part of the pituitary gland, which is an important endocrine organ located at the base of the brain. The pituitary gland is divided into three distinct parts: the anterior pituitary (adenohypophysis), the posterior pituitary (neurohypophysis), and the pars intermedia.

Structure[edit]

The pars intermedia is a thin layer of tissue situated between the anterior and posterior lobes of the pituitary gland. It is often considered a part of the anterior pituitary due to its embryological origin from the Rathke's pouch.

Histologically, the pars intermedia is composed of basophilic cells and colloid-filled cysts. These cysts are remnants of the Rathke's pouch and are characteristic of this region.

Function[edit]

The primary function of the pars intermedia is the production of melanocyte-stimulating hormone (MSH). MSH is involved in the regulation of skin pigmentation in some animals, although its role in humans is less clear. In humans, the pars intermedia is often rudimentary and its function is not as prominent as in other species.

Clinical Significance[edit]

In some animals, the pars intermedia plays a significant role in the regulation of melanin production and can affect skin color changes. Disorders of the pars intermedia can lead to conditions such as Cushing's disease in horses, where there is an overproduction of hormones due to pituitary dysfunction.

In humans, the pars intermedia is not commonly associated with major endocrine disorders, but its role in the overall function of the pituitary gland is still a subject of research.

Related Pages[edit]

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-'''Pars intermedia''' is a part of the [[pituitary gland]] that is situated between the [[anterior pituitary]] and the [[posterior pituitary]]. It is also known as the intermediate lobe of the pituitary gland. The pars intermedia is responsible for the production of [[melanocyte-stimulating hormone]] (MSH), which plays a crucial role in the pigmentation of the skin and hair in mammals.
+== Pars Intermedia ==
-==Structure==
+[[File:Gray1181.png|thumb|right|Diagram of the pituitary gland showing the pars intermedia.]]
-The pars intermedia is a thin layer of tissue that separates the anterior and posterior lobes of the pituitary gland. It is composed of [[melanotrophs]], which are cells that produce and secrete MSH. The pars intermedia is more prominent in animals than in humans, where it is often rudimentary or absent.
-==Function==
+The '''pars intermedia''' is a part of the [[pituitary gland]], which is an important endocrine organ located at the base of the brain. The pituitary gland is divided into three distinct parts: the [[anterior pituitary]] (adenohypophysis), the [[posterior pituitary]] (neurohypophysis), and the pars intermedia.
-The primary function of the pars intermedia is the production and secretion of MSH. This hormone stimulates the production and release of melanin, the pigment responsible for the color of the skin, hair, and eyes in mammals. MSH also has effects on appetite and sexual behavior, although these functions are less well understood.
-==Clinical significance==
+== Structure ==
-Abnormalities in the pars intermedia can lead to a variety of medical conditions. For example, [[Cushing's disease]] in dogs is often caused by a tumor in the pars intermedia. This results in an overproduction of MSH, leading to symptoms such as darkening of the skin and hair loss. In humans, a rare condition known as [[Nelson's syndrome]] can occur following the surgical removal of the adrenal glands, leading to an overproduction of MSH and darkening of the skin.
+The pars intermedia is a thin layer of tissue situated between the anterior and posterior lobes of the pituitary gland. It is often considered a part of the anterior pituitary due to its embryological origin from the [[Rathke's pouch]].
+[[File:Pituitary_gland_histology_2014.jpg|thumb|left|Histological section of the pituitary gland showing the pars intermedia.]]
+Histologically, the pars intermedia is composed of basophilic cells and colloid-filled cysts. These cysts are remnants of the Rathke's pouch and are characteristic of this region.
+== Function ==
+The primary function of the pars intermedia is the production of [[melanocyte-stimulating hormone]] (MSH). MSH is involved in the regulation of skin pigmentation in some animals, although its role in humans is less clear. In humans, the pars intermedia is often rudimentary and its function is not as prominent as in other species.
+== Clinical Significance ==
+In some animals, the pars intermedia plays a significant role in the regulation of [[melanin]] production and can affect skin color changes. Disorders of the pars intermedia can lead to conditions such as [[Cushing's disease]] in horses, where there is an overproduction of hormones due to pituitary dysfunction.
+In humans, the pars intermedia is not commonly associated with major endocrine disorders, but its role in the overall function of the pituitary gland is still a subject of research.
+== Related Pages ==
-==See also==
 * [[Pituitary gland]]
 * [[Anterior pituitary]]
 * [[Posterior pituitary]]
 * [[Melanocyte-stimulating hormone]]
-* [[Cushing's disease]]
+* [[Rathke's pouch]]
-* [[Nelson's syndrome]]
 [[Category:Endocrine system]]
 [[Category:Pituitary gland]]
-{{stub}}