Nutrition — Human Physiology — The male reproductive system → The endocrine system is a control system of ductless glands that secrete hormones within. General Principles of Endocrine. Physiology. By. Dr. Isabel S.S. Hwang. Department of Physiology. Faculty of Medicine. University of Hong Kong. Endocrine Physiology, 5e. Patricia E. Molina. Go to Review Questions. Search Textbook Autosuggest Results. Chapter 1: General Principles of Endocrine.

Endocrine Physiology Pdf

Language:English, German, Arabic
Genre:Science & Research
Published (Last):24.02.2016
ePub File Size:17.63 MB
PDF File Size:15.88 MB
Distribution:Free* [*Register to download]
Uploaded by: MORRIS

Endocrine physiology. BOOK REVIEWS Catecholamines as Hormone Regulators (Serono Symposia Publications, Vol. 18). Edited by N. BEN- JONATHAN. The Endocrine System. • Pituitary gland. • Thyroid gland. • Parathyroid glands. • Endocrine Pancreas. • Adrenal glands. • Pineal gland this lecture's main focus. Hormones are organic compounds secreted by endocrine glands, that have a potent effect .. The only gland that is both exocrine and endocrine in physiology.

Insulin The primary function of insulin is to facilitate the uptake of glucose into body cells.

Red blood cells, as well as cells of the brain, liver, kidneys, and the lining of the small intestine, do not have insulin receptors on their cell membranes and do not require insulin for glucose uptake. Although all other body cells do require insulin if they are to take glucose from the bloodstream, skeletal muscle cells and adipose cells are the primary targets of insulin.

The presence of food in the intestine triggers the release of gastrointestinal tract hormones such as glucose-dependent insulinotropic peptide previously known as gastric inhibitory peptide. This is in turn the initial trigger for insulin production and secretion by the beta cells of the pancreas.

Once nutrient absorption occurs, the resulting surge in blood glucose levels further stimulates insulin secretion. Precisely how insulin facilitates glucose uptake is not entirely clear. However, insulin appears to activate a tyrosine kinase receptor, triggering the phosphorylation of many substrates within the cell.

These multiple biochemical reactions converge to support the movement of intracellular vesicles containing facilitative glucose transporters to the cell membrane. In the absence of insulin, these transport proteins are normally recycled slowly between the cell membrane and cell interior. Insulin triggers the rapid movement of a pool of glucose transporter vesicles to the cell membrane, where they fuse and expose the glucose transporters to the extracellular fluid.

The transporters then move glucose by facilitated diffusion into the cell interior. Visit this link to view an animation describing the location and function of the pancreas.

Hormones and the Endocrine System

What goes wrong in the function of insulin in type 2 diabetes? Insulin also reduces blood glucose levels by stimulating glycolysis, the metabolism of glucose for generation of ATP.

Moreover, it stimulates the liver to convert excess glucose into glycogen for storage, and it inhibits enzymes involved in glycogenolysis and gluconeogenesis. Finally, insulin promotes triglyceride and protein synthesis.

The secretion of insulin is regulated through a negative feedback mechanism. As blood glucose levels decrease, further insulin release is inhibited. The pancreatic hormones are summarized in Table 7.

During the Middle Ages and later, the practice persisting well into the 19th century, prepubertal boys were sometimes castrated to preserve the purity of their treble voices. In the 18th century, London-based Scottish surgeon, anatomist, and physiologist John Hunter successfully transplanted the testis of a rooster into the abdomen of a hen.

The transplanted organ developed a blood supply in the hen, though whether masculinization occurred was unclear.

In German physiologist Arnold Adolph Berthold performed a similar experiment, except, instead of hens, he transplanted rooster testes into capons castrated roosters. The capons subsequently regained secondary sex characteristics, demonstrating that the testes were the source of a masculinizing substance.

His conclusions were based in part on observations obtained after he had injected himself with an extract of the testicle of a dog or of a guinea pig. His conclusions were based in part on observations obtained after he had injected himself with an extract of the testicle of a dog or of a guinea pig.

Diseases of the endocrine system

These experiments resulted in the widespread use of organ extracts to treat endocrine conditions organotherapy. Facts Matter. Later, American physiologist Walter Bradford Cannon — used the term homeostasis to describe this inner constancy.

This control system permits the prime functions of living organisms—growth, development, and reproduction—to proceed in an orderly, stable fashion; it is exquisitely self-regulating, so that any disruption of the normal internal environment by internal or external events is resisted by powerful countermeasures.

Table of contents

When this resistance is overcome, illness ensues.In fact, species are rarely mentioned in the text since it is understood to apply to the rat or man in general. Recall that somatostatin is also released by the hypothalamus as GHIH , and the stomach and intestines also secrete it.

For example, seaweed, which is rich in iodine , was prescribed for the treatment of goitre enlargement of the thyroid gland. The pineal gland contains neurons, glial cells, and special secretory cells called pinealocytes.

In general, a gland selects and removes materials from the blood, processes them and secretes the finished chemical product for use somewhere in the body. Once nutrient absorption occurs, the resulting surge in blood glucose levels further stimulates insulin secretion.

This new creas is treated in depth by Cramb and volume consists of some chapters that up- Langslow. Keywords Endocrine and metabolic regulation Endocrine physiology Endocrine system Hormone regulation and action Molecular endocrinology Editors and affiliations. The chapters on the endocrine systems are generally very good, although the secPhysiology and Biochemistry of the Domestic Fowl.