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Phys3 endocrine sys
Phys3 Overview of the Endocrine system
Question | Answer |
---|---|
CLASSIC endocrine... organs | 1.Hypothalamus. 2.Pituitary. 3.Pineal gland. 4.Parathyroid glands. 5.Thyroid gland. 6.Adrenal gland. 7.Pancreas. 8.Testes. 9.Ovaries. 10.Placenta. |
Assays for measuring hormones | 1.Radioimmunoassay (RIA). 2.Enzyme immunoassay (EIA). 3.Enzyme-linked immunosorbant assay (ELISA). 4.Immunoradiometric assay (IRMA). |
4 things Hormones regulate | 1.enzyme reactions. 2.Transport of ions. 3.gene expression. 4.Protein synthesis. |
What two things mediate the effects of hormones? | 1.Receptors. 2.Half-life of hormone. |
Types of hormonal communication: Hemocrine | Hormone is released from cell into a BV. |
Types of hormonal communication: Paracrine | Hormone is released from cell and interacts with nearby cells. |
Types of hormonal communication: Intercrine | Direct transfer of hormone from cell to cell via GAP JUNCTIONS. |
Types of hormonal communication: Juxtacrine | Hormone remains associated with secreting cell's membrane, but interacts with receptors on neighboring cells. |
Types of hormonal communication: Autocrine | Hormone is released from cell and interacts with that SAME cell. |
Types of hormonal communication: Neurocrine | Hormone produced by neuron. 1.Synaptic: hormone traverses synaptic space. 2.Non-synaptic: Hormone is carried to site via ECF/BL. |
Types of hormonal communication: Solinocrine | Hormone released into lumen of ductal system (respiratory, GI, urogenital) |
Types of hormonal communication: Intracrine | Uptake of hormonal precursor, intracellular conversion to active hormone which binds to intracellular receptors. |
4 types of hormones | 1.AA derivatives. 2.Peptide. 3.Steroid. 4.FA derivatives |
Process within the cell for the Creation of AA derivative hormones | 1.mRNA binds and creates preprohoromone, takes it to ER. 2.In ER, enzymes convert to inactive prohormone. 3.Prohormone passes from ER to Golgi. 4.Buds off golgi in a secretory vesicle which converts to active hormone. 5.expelled from cell via exocytos |
What compound are FA derivatives created from? | Arachidonic acid |
4 things that regulate hormone release | 1.Nerve activation (Ferguson reflex). 2.Environmental stress (internal: metabolic/osmotic, external: stress). 3.Hormonal stimulation (hypothalamus-pituitary axis). 4.Feedback to endocrine tissue |
Intracellular Receptors associated with hormonal responses | 1.Cytoplasmic. 2.Nuclear. |
4 types of Plasma Membrane Receptors associated with hormonal responses | 1.G proteins. 2.Tyrosine Kinase. 3.Serine/threonine Kinases. 4.ion Channel. |
What type of hormones bind to plasma membrane receptors? | Peptide hormones. |
What type of hormones bind to intracellular receptors? | Steroid hormones. |
3 different hormone-hormone interactions | 1.Synergistic (ex: glucose & EPI). 2.Antagonistic (ex: insulin & glucagon). 3.Permissive (ex: steroid priming of hypothalamus/pituitary) |
5 Factors effecting hormonal effects | 1.Synthesis of hormone. 2.Receptor mediated signal transduction. 3.Hormone inactivation/clearance. 4.Feedback systems. 5.Rhythm of hormone release |
Modifications to hormones post-synthesis | 1.Post-transcriptional, 2.Post-translational processing of hormone, 3.Post-secretory extracellular transport of hormone. |
Influences on Receptor mediated signal transduction | 1.Affinity, #, occupancy, desensitization. 2.Secondary messanger components. 3.Degradation of secondary messanger signal factors. |
Influences on hormone inactivation/clearance | 1.Processing (carrier) bound Vs Free circulating hormone. 2.Metabolic clearance rate. **the relationship b/w hormone secretion, carrier protein binding, & degradation determines the amt of hormone available to bind to receptors |
Types of feedback loops | 1.Positive. 2.Negative. 3.Complex (stim & Inhib). 4.Long (sec of peripheral gland indirectly affects pituitary sec). 4.Short (Sec of pituitary affect hypothal sec). 5.Ultrashort (Sec from a cell inhibits further sec from that cell). |
Type of feedback loop: Thyroid hormone inhibits the release of TRH from hypothalamus, therefore decreasing the stimulus to the pituitary gland to release TSH | LONG. **Peripheral gland is inhibiting pituitary secretions. |
type of feedback loop: TSH released from pituitary negatively influences the secretion of TRH from the hypothalamus | SHORT. **Pituitary secretions are affecting hypothalmic hormone release. |
Type of feedback loop: TSH inhibits the release of TSH from thyrotrophs | ULTRASHORT. **Hormone feedback to cell of its production or neighboring cell to inhibit secretion of that same hormone. |
3 different rhythms of hormone release | 1.Circadian: pattern of secretion is every 24hrs (melatonin & ACTH). 2.Ultradian: pattern of secretion is frequent (GH). 3.Infradian: pattern of secretion is >24 period (LH & FSH). |