BIOL 112 1st Edition Lecture22Outline of Last Lecture I. Breathing ControlII. Oxygen SensitivityIII. The KidneysOutline of Current LectureIV. Intro to HormonesV. GlandsVI. Cellular Response to HormonesVII. cAMPCurrent LectureI. Intro to Hormones•It’s essential that cells are able to communicate and coordinate with each other•This is achieved in 3ways:•Local Systems: onecell communicateswith other cells (anditself)•Nervous System: onecell communicates with 1 other cell, individual communication, re-quires cells to be really close togetherThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.•Hormone System: one cell communicates with many cells, mass communication•a chemical is released from the cell, regardless, sending a signal•Hormone: A chemical secreted into body fluids by one cell or a group of cells, which exerts a physiological control effect on other cells in the body, two types:•Peptides (small chains of amino acids)•Steroid lipids (all cholesterol derivatives)II. Glands•clusters of epithelial cells specialized for secretion•Two types:•Exocrine Glands: have ducts, secretions are released to the out-side of the body (i.e. pancreas, salivary, sweat), no hormones re-leased•Endocrine Glands: no ducts, secretions are released into body flu-ids (i.e. pituitary, thyroid), hormones are released•Each cell in the gland is specialized tomake only one hormone type:•Peptide - have well-developed roughER•Steroid - have well-developed smoothERIII. Cellular Response to Hormones•Target cells (or tissues) - effected by cellsover which a particular hormone has itsphysiological control, response differs depending on whether the hor-mone is peptide or steroid•has specific receptorsto hormone•Cellular response tosteroid hormone•is relatively slow, cantake hours•Cellular response to pep-tide hormone•peptide hormone is hydrophilic and therefore cannot easily pass through the plasma membrane•the receptor must be on the outer surface of the cell, and there must be some mechanism to communicate presence of hormone into the cell•cellular response is relatively rapid: can take seconds to a few minutes, rapid response isachieved because the systemactivates proteins that are al-ready present and does not re-quire synthesis of new proteinsIV. cAMP•“Second Messenger”•stimulates/activates various en-zymes (kinases, for example)•alteration in cell permeability tovarious molecules•muscle contraction or relaxation•protein synthesis stimulation•release of secretions from gland cells•Destruction of cAMP•molecule is hydrolyzed by phosphodiesterase•Protein transduction array - responds to cAMP activation by activa-tion of enzymes, frequent mechanism involves kinases working in a phosphorylation chain reaction•Self-Regulation - cell automatically shuts down response unless hormone is constantly present and bound to
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