Term
|
Definition
| The Endocrine System coordinates all the body systems, along side the nervous system. It uses hormones produced by endocrine structures to produce their given effects. |
|
|
Term
|
Definition
| hormones are simply mediator molecules that have effects on cells in the local environment, or in a distant part of the body |
|
|
Term
|
Definition
| Local hormones that are secreted to, and bind to the same cell |
|
|
Term
|
Definition
| are local hormones that are secreted into interstital fluid and act on nearby cells |
|
|
Term
|
Definition
| are secreted into interstial fluid and then absorbed into the bloodstream to be carried systemically to any cells that displays the appropriate type of receptor |
|
|
Term
|
Definition
| bind to receptors in the cytoplasm or nucleus of the cell. They consist of steroid hormones, thyroid hormones, and the gas nitric oxide. They require a carrier protein for transport in the watery environment of the blood. Once they arrive at their destination, they can freely pass through the plasma membrane to bind to receptors in the cytoplasm. |
|
|
Term
|
Definition
| bind to receptors on the surface of the cell. They include peptide and protein hormones, and a group of local hormones derived from the arachidonic acid on our cell membranes called eicosanoids. They are easy to transport in the watery blood. The plasma membrane of target cells, however, is impermeable to them |
|
|
Term
|
Definition
| lipid-soluble hormones, they are derived from cholesterol |
|
|
Term
|
Definition
| lipid soluble hormone, (T3 + T4) they are synthesized by attaching iodine to the amino acid tyrosine |
|
|
Term
|
Definition
| is both a hormone and a neurotransmitter. Its synthesis is catalyzed by the enzyme nitric oxide synthase |
|
|
Term
|
Definition
| A group of homrones dervied from arachidonic acid on our cell membranes. The two major types of eicosanoids are prostaglandins and leukotrienes-- both play a role in mediating the inflammatory response |
|
|
Term
| Water Soluble hormone binding cascade |
|
Definition
| Water soluble hormones exert their effects by binding to receptors exposed to the interstital fluid on the surface of target cells. The hormone binding to its receptor acts as the first messenger in a cascade of signal transduction. The first messenger then causes production of a second messenger inside the cell, where specific hormone-stimulated responses take place. |
|
|
Term
|
Definition
| One second messenger is cyclic AMP. Neurotransmitters, neuropeptides, and several sensory transduction mechanisms also act via second-messenger systems. |
|
|
Term
|
Definition
| eicosinoids with local control. They are synthesized from membrane lipids and have widespread effects. They mediate pain, platelet aggregation, fever, and inflammation. They regulate smooth muscle contraction, gastric acid secretion, and airway size. |
|
|
Term
|
Definition
| Asprin is a drug that works by inhibiting an enzyme necessary for synthesis of certain PGs |
|
|
Term
| Effects of Endocrine hormones |
|
Definition
1. balance the composition and volume of body fluids
2. Regulate metabolism and energy production
3. Direct the rate and timing of growht and development
4. Exert emergency control during physical and mental stress (trauma, starvation, hemorrage)
5. Oversee reproductive mechanisms |
|
|
Term
| Regulation of Hormone Secretion |
|
Definition
| Hormone secretion is regulated by signals from the nervous system, chemical changes in the blood, and other hormones. Most hormonal regulatory systems work via negative feedback, but a few operate via positive feedback. |
|
|
Term
|
Definition
| The hormone output reverses a particular stimulus. If there is too little of a hormone, the body produces more, if there is too much of a hormone the body ceases production. |
|
|
Term
| Parathyroid hormone feedback loop |
|
Definition
| Blood calcium levels are controlled by the parathyroid hormone. If blood calcium is low, there is a stimulus for the parathyroid glands to release more PTH. PTH then exerts its effects in the body until the Calcium level returns to normal. If the level gets too high the body will cease PTH production and secrete calcitonin which lowers the calcium levels. |
|
|
Term
|
Definition
| The hormone output reinforces and encourages the stimulus. |
|
|
Term
|
Definition
| During labor, oxytocin (Posterior Pitutary) stimulates the contractions of the uterus, and uterine contractions in turn stimulate more oxytocin release, a postive feedback effect |
|
|
Term
|
Definition
It is the major link between the nervous and endocrine systems. It mainly controls the pituitary gland. Specialized neurosecretory cells in the
hypothalamus secrete releasing hormones
into the hypophyseal portal system
that supplies blood to the anterior pituitary gland |
|
|
Term
|
Definition
| is anatomically and functionally connected to the hypothalamus by blood vessels that form a portal system called the hypophyseal portal system. |
|
|
