BPK 105 Study Guide - Midterm Guide: Posterior Pituitary, Anterior Pituitary, Capillary
27 Apr 2018
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Module 6 - Objectives - Part 4
● Compare and contrast how the hypothalamus controls hormonal release from
the anterior and posterior pituitary.
Pituitary and Hypothalamus
- The pituitary gland is also called the hypophysis
. It is a small gland about the size of a
pea (figure 10.12, top
). It rests in a depression of the sphenoid bone inferior to the
hypothalamus of the brain.
- The hypothalamus is an important autonomic nervous system and endocrine control
center of the brain located inferior to the thalamus.
- The pituitary gland lies posterior to the optic chiasm and is connected to the
hypothalamus by a stalk called the infundibulum.
- The pituitary gland is divided into two parts: The anterior pituitary is made up of
epithelial cells derived from the embryonic oral cavity; the posterior pituitary is an
extension of the brain and is composed of nerve cells. The hormones secreted from
each lobe of the pituitary gland are listed in table 10.2.
- Hormones from the pituitary gland control the functions of many other glands in the
body, such as the ovaries, the testes, the thyroid gland, and the adrenal cortex (figure
10.12, bottom
).
- The pituitary gland also secretes hormones that influence growth, kidney function, birth,
and milk production by the mammary glands.
- Historically, the pituitary gland was known as the body’s master gland
because it
controls the function of so many other glands. However, we now know that the
hypothalamus controls the pituitary gland in two ways: hormonal control and
direct innervation.
Hormonal Control of the Anterior Pituitary
- Neurons of the hypothalamus produce and secrete neuropeptides that act on cells of
the anterior pituitary gland (figure 10.13).
- They act as either releasing hormones or inhibiting hormones.
- Each releasing hormone stimulates the production and secretion of a specific hormone
by the anterior pituitary, whereas each inhibiting hormone decreases the secretion of a
specific anterior pituitary hormone.
- Releasing and inhibiting hormones enter a capillary bed in the hypothalamus and are
transported through veins to a second capillary bed in the anterior pituitary.
Document Summary
Compare and contrast how the hypothalamus controls hormonal release from the anterior and posterior pituitary. The pituitary gland is also called the hypophysis . It is a small gland about the size of a pea (figure 10. 12, top ). It rests in a depression of the sphenoid bone inferior to the hypothalamus of the brain. The hypothalamus is an important autonomic nervous system and endocrine control center of the brain located inferior to the thalamus. The pituitary gland lies posterior to the optic chiasm and is connected to the hypothalamus by a stalk called the infundibulum . The pituitary gland is divided into two parts: the anterior pituitary is made up of epithelial cells derived from the embryonic oral cavity; the posterior pituitary is an extension of the brain and is composed of nerve cells. The hormones secreted from each lobe of the pituitary gland are listed in table 10. 2.
