Term
| What interacts to maintain homeostasis? |
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Definition
| Chemical, thermal and neural factors |
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Term
| Three interdependent components of control mechanisms? |
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Definition
| Receptor (stimuli, responds to changes), Control Center (determines the set point), Effector (provides the means to respond to stimuli) |
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Term
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Definition
| turns off something, makes it less powerful. Example: Regulation of room temperature |
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Term
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Definition
| the body's second great controlling system influences metabolic activities of cells by means of hormones. |
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Term
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Definition
| Pituitary Gland, Thyroid, parathyroid, adrenal, pineal, and thymus |
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Term
| What produces hormones and exocrine products? |
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Definition
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Term
| What is the Hypothalamus? |
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Definition
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Term
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Definition
| a chemical substance produced and secreted in one part of an organism and transported via the ECF (extracellular fluid) to another organ where it has a specific effect. |
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Term
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Definition
| intracellular or on the plasma membrane |
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Term
| Hormones produce one or more of what cellular changes? |
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Definition
Alter plasma membrane permeability
Stimulate protein synthesis
Activate or deactivate enzyme systems
Induce secretory activity
Stimulate mitosis |
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Term
| Target cell activation depends on 3 factors |
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Definition
Blod levels of the hormone
Relative number of receptors on the target cell
The affinity of those receptors for the hormone |
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Term
| Concentrations of circulating hormone reflect: |
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Definition
Rate of release
Speed of inactivation and removal from body |
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Term
| Hormones are removed from the blood by: |
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Definition
Degrading enzymes
The kidneys
Liver enzyme systems |
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Term
| Blood Levels of Hormones: |
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Definition
Vary only within a narrow desirable range
Are typically controlled by negative feedback systems
HUMORAL stimuli (blood)
NEURAL stimuli (nerves)
HORMONAL stimuli (hormones triggering another) |
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Term
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Definition
| secretion of hormones in direct response to changing blood levels of ions and nutrients |
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Term
| Sample of Humoral Stimuli |
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Definition
declining blood Ca2+ concentration stimulates the parathyroid glands to secrete PTH (parathyroid hormone)
PTH causes Ca2+ concentrations to rise and the stimulus is removed |
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Term
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Definition
| nerve fibers stimulate hormone release |
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Term
| Example of Neurol Stimuli |
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Definition
| Preganglionic sympathetic nervous systems (SNS) fibers stimulate the adrenal medulla to secrete catecholarmines |
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Term
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Definition
| release hormones in response to hormones produced by other endocrine organs |
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Term
| Example of Hormonal Stimuli |
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Definition
The hypothalamic hormones stimulate the anterior pituitary
In turn, pituitary hormones stimulate targets to secrete still more hormones |
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Term
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Definition
| Hypothalamus and Pituitary (Hypophysis) |
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Term
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Definition
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Term
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Definition
| two-lobed organ that secretes nine major hormones |
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Term
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Definition
posterior lobe (neural tissue) and the infundibulum. Receives, stores, and releases hormones from the hypothalamus
Branchy |
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Term
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Definition
anterior lobe, made up of glandular tissue. Synthesizes and secretes a number of hormones
Cellular |
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Term
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Definition
There is a hypothalamic-pituitary relationship of the anterior lobe as a vascular connection. The hypophyseal portal system, consists of:
The primary capillary plexus
The hypophyseal portal veins
The secondary capillary plexus |
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