1Chapter 18 Endocrine Regulation

The chemical messengers of the endocrine system are Hormones.

The Endocrine system’s effects are slow to appear, yet long lasting.

The intestines are NOT an endocrine gland.
Pineal gland, Placenta, and Parathyroid are all endocrine glands.

The neuroendocrine system performs the following functions of Communication, Control, and Integration. The neuroendocrine system does NOT perform Conduction.

The many hormones secreted by endocrine tissues can be classified simply as Nonsteroid or Steroid hormones,

Nonsteroid Hormones include Proteins Peptides Glycoproteins

Anabolic hormones are hormones that stimulate anabolism in the target organ or in their target cells.

The second messenger often involved in nonsteroid action is cAMP. Cyclic AMP

The control of hormone secretion is usually part of a negative feedback loop and rarely part of a positive feedback loop.

Permissiveness is when a small amount of a hormone allows a second hormone to have its full effect on a target cell. When a small amount of hormone allows a second hormone to have its full effect on a target cell, the phenomenon is called permissiveness.

The nervous system functions at a much greater speed than the endocrine system.

The most widely used method of hormone classification is by chemical structure.

Production of too much hormone of a diseased gland is termed hypersecretion.
Input from the NS influences secretion of hormones.

Because steroids are lipid soluble, Steroids easily pass through the phospholipid plasma membrane of target cells. Important steroid hormones include cortisol, aldosterone, estrogen, progesterone, and testosterone. Steroid hormones are synthesized from cholesterol. Response time of Steroid hormones is usually 1hr to several days. Receptor of Steroid hormone is mobile in the cytoplasm or nucleus. Steroid hormone is a Lipid. Lipid soluble Steroid hormone regulates gene Activity

Most nonsteroid hormones are synthesized from amino acids. Some Nonsteroid hormones are protein hormones. Nonsteroid hormones bind to specific plasma membrane receptors Nonsteroid hormones are stored in secretory vesicles before release
Nonsteroid hormones are one or more Amino Acids (also called protein hormones
Nonsteroid hormones response time is usually several SECONDs to a few minutes

Prostaglandins are referred to as Tissue hormones. Prostaglandins tend to integrate activities of neighboring cells. The first prostaglandin was discovered in semen. PGFs have been used to induce labor and accelerate delivery of a baby.

PARACRINE hormones are hormones that regulate activity in nearby cells within the same tissue as their source.

AUTOCRINE hormones regulate activity in the secreting cell itself. (P556)

The seminal vesicles of the male reproductive system secretes prostaglandin in the semen.

Leukotrienes are regulators of IMMUNITY.

PGFs are required for normal peristalsis to occur in the digestive tract.

Thymus is the endocrine gland located in the mediastinum

Prostaglandin = Tissue Hormone

Insulin, Parathyroid, ACTH, and glucagon are examples of this classification of nonsteroid hormone ....PROTEIN....nonsteroid hormones are also protein hormones

Cells that secret chemical messengers that diffuse into the bloodstream rather than across a synapse are called neurosecretory cells.

Thromboxanes promote bloodclotting and constriction of blood vessels

A Target Cell is a cell with one or more receptors for a particular hormone.

Hypersecretion is production of too much hormone by a diseased gland.

Permissiveness occurs when a small amount of one hormone allows a second hormone to have its full effect on a target cell.

The Hypothalamus is the regulator that releases or inhibits hormone secretion.
Releasing or inhibiting hormones are secreted by the Hypothalamus.

Hormones synthesized primarily from amino acids are