BIOL370 Lecture Notes - Lecture 15: Endocrine Gland, Thyroid, Luteinizing Hormone
24 Dec 2012
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Document Summary
Animals have a variety of signaling mechanisms that allow for communication between cells. Receptor-ligand interactions are critical for the specificity of target effects of these signals. Hormones control a variety of effects throughout the body, including the released of other hormones. The hypothalamus and the pituitary are key regulating organs. Major signalling mechanisms: paracrine/autocrine signaling: local cell-to-cell communication, involves variety of molecules. Cytokines for signal translocation: nerve impulses: long distance fast conduction, electrical signals can occur on order of ms, endocrine signaling: long distance signal through bloodstream, very slow. Peptide hormones (<50 aa: fast acting hormones, t1/2 from sec to hours, hydrophilic in nature, cannot cross cell membrane & are soluble in aqueous solution blood . Synthesized on the ribosome of the rough er as preprohormone (1+ copies of peptide hormone & a signalling sequence for secretion) Preprohormone enters rough er & the signal sequence is cleaved off prohormone.
