18 Cards in this Set
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Endocrine System
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uses a series of ductless glands to secrete hormones into the blood stream
Broad ranging regulatory system in the body
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What does the Endocrine System do?
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Regulates body functions: from calcium metabolism to energy utilization
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Hormones
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Chemicals secreted in trace amounts by 1 cell and carried in blood to another cell to modulate a biochemical, physiological response
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Two types of Hormones
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Steroid hormones- all begin from the 27 carbon Cholesterol and require intracellular receptors (are lipid soluble or hydrophobic)
Protein/peptide-based hormones- Made from transcription in nucleus, then translation in ER then processing in ER -> Golgi A. then packaging from Golgi A. (are…
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What defines the biological response of a cell?
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1. the Concentration of hormone in blood:
[H]blood -> rate of production , rate of degredation/elimination 2. # of receptors on the cell [R]cell -> sensitivity to hormone
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What is the law of Mass Action in Endocrinology?
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[H] + [R] -> [HR] -> biological response
Remember the number of students in classroom example: students=hormone, chairs =receptors, lecture = biological response Once the minimum number of students is reached, additional students won't change the lecture
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What does it take to achieve a biological response?
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1.) Specificity: receptors are hormone specific
2.) Affinity
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Autocrine
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Self signaling- the releasing cell also contains the receptors of the released hormone
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Paracrine
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When the secreting cell and the target cell are near one another
example is the synapses in the nervous system
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Endocrine
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When the hormone enters the blood stream has travels a significant distance to the target cell
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Transmembrane Receptors
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proteins that span the cell membrane
Bind either water soluble hormones or modified amino acids in the extracellular environment. Results in signaling Cascade
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What is a G-protein Receptor?
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Act via G protein complex to activate enaymes
7 transmembrane domains, and release second messengers for signal amplification
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G-Protein Second Messengers
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IP3
DAG Ca2+ cAMP
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Serine/Threonine and Tyrosine Kinase Receptors
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both have ligand binding on the exterior of the cell and initiate a signaling cascade on the interior of the cell that changes "physiology" in the target cell
proteing transport protein synthesis secretion ion channels gene expression
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Peptide Hormones
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all hypothalamic releasing hormones
all pituitary hormones all GI hormones all pancreatic hormones calcitonin parathyroid hormone (PTH)
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Side Chain Clevage
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The process that takes the 27 carbon Cholesterol in the mitochondria and removes 6 carbons to create pregnenolone, a 21 carbon intermediary complex which is eventually turned into a steroid hormone
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Steroid Hormones
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Cortisol/aldosterone (adrenal cortex)
testerone (testes) Progesterone/ estrogen (ovaries) Vitamin D3 (Skin, liver, kidneys)
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Homeostasis
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Feedback and Regulation
Controlled by the hypothalmus Master gland is the anterior pituitary gland Final Target -> thyroid, gonads, adrenal, breast, liver
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Muscle System