What Is the Posterior Pituitary?
The posterior pituitary gland is a collective term for the middle and nerve parts of the pituitary. In the posterior lobe, ependymal cells and glial cells and many myelinated nerve fibers can be seen. These fibers come from the hypothalamus-pituitary bundle and enter the posterior lobe through the funnel handle. The fibers are tightly parallel in the stalk, dispersed after entering the back leaves, and the ends are juxtaposed into a ring. The posterior leaf can secrete two hormones, namely antidiuretic and oxytocin.
- Chinese name
- Posterior pituitary
- Foreign name
- posterius pituitarium
- The posterior pituitary gland is a collective term for the middle and nerve parts of the pituitary. In the posterior lobe, ependymal cells and glial cells and many myelinated nerve fibers can be seen. These fibers come from the hypothalamus-pituitary bundle and enter the posterior lobe through the funnel handle. The fibers are tightly parallel in the stalk, dispersed after entering the back leaves, and the ends are juxtaposed into a ring. The posterior leaf can secrete two hormones, namely antidiuretic and oxytocin.
Overview of the posterior pituitary
- 1 leaf of pituitary. It consists of the nerve part and the middle part. The upper end is connected to the lower thalamus and is composed of glial and nerve fibers. The posterior pituitary can secrete antidiuretic hormone and oxytocin. Can increase blood pressure, reduce urine output and uterine muscle contraction. If the posterior pituitary dysfunction, antidiuretic hormone secretion decreases, the urine output increases, and pituitary diabetes insipidus occurs.
Posterior pituitary
- The pituitary is also known as the "pituitary" or "pituitary". It is located in the pituitary fossa of the skull base saddle and is connected to the hypothalamus by the pituitary stem. Can be divided into two major parts of the pituitary and neural pituitary. The pituitary gland can be divided into the distal part, the nodule part, and the middle part, and the neural pituitary gland can be divided into the nerve part, the funnel stem, and the median bulge. The funnel handle and the median hump are collectively called the funnel, and the funnel and nodule form the pituitary handle. The distal part is generally called the anterior lobe, and the middle part and the nerve part are collectively called the posterior lobe. The pituitary gland can secrete a variety of hormones and has important functions. The functions of the anterior pituitary and posterior pituitary are:
- 1. Anterior pituitary: eosinophils and basophils. (1) Eosinophils are divided into two types: a kind of growth hormone cells can secrete growth hormone (see "growth hormone" for details). Another type of prolactin cell can secrete prolactin, which promotes the growth of the breast and the secretion of milk. (2) There are three types of basophils: Gonadotropin cells can secrete gonadotropins (see "gonadotropin" for details). Thyroid-stimulating hormone cells can secrete thyroid-stimulating hormone and promote the proliferation and secretion of thyroid epithelium. Adrenocorticotropic hormone cells can secrete adrenocortical hormones, which mainly act on the adrenal glands and strengthen the secretion of glucocorticoids and sex hormones.
- 2. Pituitary posterior lobe: (1) cells in the middle can secrete melanocyte stimulating hormone, and have the function of promoting melanin synthesis by skin melanocytes. (2) The structure of the nerve is similar to that of the nerve tissue, and is composed of a large number of myelinated nerve fibers, glial cells, connective tissue and blood vessels. It is closely related to the hypothalamus in structure and function. The nerve department does not have a secretory function, but a place for storing hormones. It stores two hormones-antidiuretic hormone (also called vasopressin) and oxytocin, which are secreted by the hypothalamus and transported to the nerve department. Antidiuretic hormones have the effect of promoting blood pressure and antidiuresis. Oxytocin has the effect of promoting uterine contraction and breast lactation.