Term
| What the endocrine system does |
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Definition
Influences metabolic activity by means of hormones
Interacts with the nervous system to coordinate and integrate the activity of body cells |
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Term
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Definition
- To excite
- Chemical messengers released into the blood to be transported throughout the body
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| The major processes controlled and integrated by hormones |
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Definition
- Reproduction
- Growth and Development
- Maintenance of electrolyte, water, and nutrient balance of the blood
- Regulation of cellular metabolism and energy balance
- Mobilization of body defenses
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Term
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Definition
The scientific study of hormones and the endocrine organs |
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Term
Arrangement of endocrine organs |
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Definition
| Endocrine organs are widely scattered about the body, not grouped together. |
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Definition
| Produce nonhormonal substances, such as sweat and saliva, and have ducts that carry these substances to a membrane surface. |
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Definition
- Ductless Glands
- Produce hormones and lack ducts
- Release their hormones into the surrounding tissue fluid
- Typically have a rich vascular and lymphatic drainage that receives their hormones.
- Hormone-producing cells are arranged in cords and branching networks - this maximizes contact between them and the capillaries surrounding them.
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Term
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Definition
- Pituitary
- Thyroid
- Parathyroid
- Adrenal
- Pineal Glands
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Term
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Definition
- along with its neural functions, produces and releases hormones
- Considered a neuroendocrine organ
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Term
| Contains endocrine tissue and also perform other functions |
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Definition
- Hypothalamus
- placenta
- pancreas
- Gonads(ovaries and testes)
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Definition
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Definition
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Term
| Other places that hrmone-producing cells are found |
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Definition
| Walls of the small intestine, stomach, kidneys, and heart |
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Term
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Definition
| Chemicals that exert their effects on the same cells that secrete them |
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Definition
| Also act locally but affect cell types other than those releasing the paracrine chemicals. |
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Term
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Definition
| Chemical substances secreted by cells into the extracellular fluids that regulate the metabolic function of other cells in the body |
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Term
Amino Acid Based Hormones |
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Definition
| Most hormones are amino acid based Molecular size varies widely from simple amino acid derivatives, to peptides, to proteins |
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Term
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Definition
| Are synthesized from cholesterol Only gonadal and adrenocortical hormones are steroids |
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Term
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Definition
| Include leukotrienes and prostaglandins; biologically active lipids made from arachidonic acid are released by nearly all cell membranes; leukotrienes are signaling chemicals that mediate inflammation and some allergic reactions; prostaglandins have multiple targets and effects, ranging from raising blood pressure and increasing the expulsive uterine contractions of birth to enhancing blood clotting, pain, and inflammation.; effects of eicosanoids are typically highly localized, affecting only nearby cells, they generally actas paracrines and autocrines, and do not fit the definition of the true hormones |
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Term
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Definition
| a given hormone influences the activity of only certain tissue cells; hormones bring about their effects on target cells by altering cell activity (increase or decrease the rates of normal cellular processes; percise response depends on the target cell type. |
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Term
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Definition
Typically produces one or more of the following changes:
1. Alters plasma membrane permeability or membrane potential, or both, by opening or closing ion channels.
2. Stimulates synthesis of proteins ro regulatory molecules such as enzymes within the cell
3. Activates or deactivates enzymes
4. Induces secretory activity
5. Stimulates mitosis |
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Term
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Definition
| All amino acid-based hormones except thyroid hormone; act on receptors in the plasma membrane; receptors are coupled via regulatory molecules called G proteins to one or more intracellular second messengers which mediate the target cell's response. |
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Term
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Definition
| Include steroid and thyroid hormones; act on intracellular receptors, which directly activate genes |
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Term
| Why hormones must bind where they do |
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Definition
| Receptors for water-soluble hormones must be in the plasma membrane since these hormones cannot enter the cell; receptors for lipid-solublew steroid and thyroid hormones are inside the cell because these hormones can enter the cell |
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Term
| Amino acid-based Hormones |
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Definition
| Exert their signaling effects through intracellular second messengers generated when a hormone binds to a receptor on the plasma membrane (with the exception of thyroid hormone) |
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Term
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Definition
| Generated when a hormone binds to a receptor on the plasma membrane. |
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Term
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Definition
| used by neurotransmitters and olfactory receptors; is a second messenger. |
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Term
| The Cyclic AMP Signaling Mechanism |
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Definition
| Involves the interaction of three plasma membrane components to determine intracellular levels of cyclic AMP (cAMP) - a hormone receptor, a G protein, and an effector enzyme (adenylate cyclase) |
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Term
| Step 1 of cAMP second messenger mechanism of water-soluble hormones |
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Definition
| 1. Hormone, acting as the first messenger, binds to its receptoron the plasma membrane |
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Term
| Step 2 of cAMP second messenger mechanism of water-soluble hormones |
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Definition
| 2. Hormone binding causes the receptor to change shape, allwing it to bind a nearby inactive G protein. G protein is activated as the guanosine diphosphate(GDP) bound to it is displaced by the high energy compound guanosine triphosphate(GTP); the G protein behaves like a light switch;; It is off when GDP is boudn to it and on when GTP is bound. |
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Term
| Step 3 of cAMP second messenger mechanism of water-soluble hormones |
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Definition
| Activated G protein (moving along the membrane) binds to the effectory enzyme adenylate cyclase;Some G proteins (Gs) stimulate adenylate cyclase, but others (Gi) inhibit adenylate cyclase. GTP bound to the G protein is hydrolyzed to GDP and G protein becomes inactive once again. |
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Term
| Step 4 of cAMP second-messenger mechanism of water-soluble hormones |
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Definition
Adenylate cyclase convertos ATP to cyclic AMP.
Only will do this for as long as activated G(s) is bound to it.
Adenylate cyclase generates the second messenger cAMP from ATP. |
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Term
| Step 5 of Cyclic AMP second-messenger mechanism of water-soluble hormones |
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Definition
cAMP activates protein kinases
(the cAMP is free to diffuse throughout the cell, it triggers a cascade of chmeical reactions by activating protein kinase A.) |
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Term
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Definition
| Enzymes that phosphorylate (add a phosphate group to) various proteins, many of which are other enzymes. |
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Definition
add a phosphate group to
phosphorylation activates some of the protein kinases and inhibits others.
Because of this a variety of processes may be affected in the same target cell at the same time. |
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Term
| Sequence of reactions set into motion by cAMP |
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Definition
| depends on the type of target cell, the specific protein kinases it contains, and the substrates within that cell available for phosphorylation by the protein kinases |
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Term
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Definition
| intracellular enzyme that degrades the molecule rapidly during the action of cAMP. |
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Term
| Hormones known to act on their target cells via the PIP(2) Mechanism |
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Definition
thyrotropin-releasing hormone (TRH)
antidiuretic hormone (ADH)
gonadotropin-releasing hormone (GnRH)
oxytocin
epinephrine |
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Term
| How do lipid soluble, steroid hormones and thyroid hormone get into their target cell |
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Definition
| The diffuse into their target cell where they bind to and activate an intracellular receptor. |
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Term
| What happens after the activated receptor-hormone is activated by a lipid soluble, steroid hormone |
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Definition
| The activated receptor-hormone complex then makes its way to the nuclear chromatin, where the hormone receptor binds to a region of DNA specific for it. |
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Term
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Definition
| A hormone response element |
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Term
| Thyroid Hormone Receptors |
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Definition
| are always bound to DNA even in the absence of thyroid hormone |
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