Structure and function of pituitary gland

Endocrine and exocrine glands serve very different purposes in the body. Endocrine glands Endocrine glands are part of your endocrine system. They make hormones and release them into your bloodstream. These hormones control a number of important functions in your body, such as: • your growth and development • metabolism • mood • reproduction Your endocrine glands include: • • • • • There are also organs that contain endocrine tissue and act as glands. These include the: • • • • Exocrine glands Your exocrine glands produce other substances — not hormones — that are released through ducts to the exterior of your body, such as sweat, saliva, and tears. The substances released by your exocrine glands play important roles in your body. They do things like help regulate your body temperature, protect your skin and eyes, and even help mothers feed babies by producing breast milk. Your exocrine glands include: • salivary • sweat • • sebaceous • lacrimal Lymph nodes are often referred to as glands, but they’re not true glands. They’re part of your You have glands throughout your body, all varying in size and function. Here are a few examples of these glands and what they do. Thyroid gland Your thyroid gland is located in the front of your neck, just below your larynx. It measures approximately two inches and has a shape similar to a butterfly. It secretes hormones that affect virtually every tissue in your body. Thyroid hormones regulate your metabolism, heart, and digestive functi...

Learning Objectives By the end of this section, you will be able to: • Explain the interrelationships of the anatomy and functions of the hypothalamus and the posterior and anterior lobes of the pituitary gland • Identify the two hormones released from the posterior pituitary, their target cells, and their principal actions • Identify the six hormones produced by the anterior lobe of the pituitary gland, their target cells, their principal actions, and their regulation by the hypothalamus The hypothalamus–pituitary complex can be thought of as the “command center” of the endocrine system. This complex secretes several hormones that directly produce responses in target tissues, as well as hormones that regulate the synthesis and secretion of hormones of other glands. In addition, the hypothalamus–pituitary complex coordinates the messages of the endocrine and nervous systems. In many cases, a stimulus received by the nervous system must pass through the hypothalamus–pituitary complex to be translated into hormones that can initiate a response. The hypothalamus is a structure of the diencephalon of the brain located anterior and inferior to the thalamus ( pituitary gland (or hypophysis), a bean-sized organ suspended from it by a stem called the infundibulum (or pituitary stalk). The pituitary gland is cradled within the sellaturcica of the sphenoid bone of the skull. It consists of two lobes that arise from distinct parts of embryonic tissue: the posterior pituitary (neurohy...

The name “pituitary” for the hormone-secreting gland beneath the brain originates from ideas of Aristotle that the brain secretes phlegm or pituita which cools the body. This fluid was thought to pass from the brain via the pituitary body and into the nasal passages. In the nineteenth century ideas about the function of the pituitary began to change when it was realized that certain pathological conditions were associated with tumors of the pituitary: for example, acromegaly, which is excessive growth of parts of the skeleton in adults. From a mixture of clinical observations and experiments on laboratory mammals, the relationships between the pituitary and other endocrine organs were established. Comparative studies have also made significant contributions to our understanding of pituitary hormone physiology. Early studies on tadpoles established the pituitary as an important controlling organ in development and function of the adrenals, gonads, and thyroid, and, moreover, that the pituitary was important for skin color changes in amphibia. The proliferative response of pigeon crop sac mucosa to prolactins from all tetrapods became a standard bioassay and hastened the isolation and characterization of this pituitary hormone. Because of the position of the pituitary beneath the brain, and its connections with it, it was realized that the pituitary must be a coordinating center for stimuli from the brain and, moreover, is probably dependent on signals from the brain for its...

[ "article:topic", "prolactin", "oxytocin", "vasopressin", "anterior pituitary", "pituitary gland", "posterior pituitary", "authorname:mgrewal", "showtoc:yes", "columns:two", "infundibulum", "cssprint:dense", "program:oeri", "licenseversion:30", "license:ck12", "source@https://www.ck12.org/book/ck-12-human-biology/" ] \( \newcommand\) • • • • • • • • Milk on Demand This adorable nursing infant is part of a positive feedback loop. When he suckles on the nipple, it sends nerve impulses to his mother’s hypothalamus, which “tell” her pituitary gland to release the hormone prolactin into her bloodstream. Prolactin travels to the mammary glands in the breasts and stimulates milk production, which motivates the infant to keep suckling. Figure \(\PageIndex\): Nursing infant What Is the Pituitary Gland? The pituitary gland is the master gland of the endocrine system, the system of glands that secrete hormones into the bloodstream. Endocrine hormones control virtually all physiological processes. For example, they control growth, sexual maturation, reproduction, body temperature, blood pressure, and metabolism. The pituitary gland is considered the master gland of the endocrine system because it controls the rest of the endocrine system. Many pituitary hormones either promote or inhibit hormone secretion by other endocrine glands. Figure \(\PageIndex\): The pituitary gland in the endocrine system is closely connected to the hypothalamus in the brain Structure and Function of the Pit...