Umfang:
1 Online-Ressource (1907 pages)
Ausgabe:
3rd ed
ISBN:
9781455733286
Inhalt:
Front Cover -- Inside Front Cover -- IFC_International edition -- Medical Physiology -- Copyright Page -- Contributors -- Video Table of Contents -- Preface to the Third Edition -- The eBook -- Acknowledgments -- Preface to the First Edition -- Target Audience -- Content of the Textbook -- Emphasis of the Textbook -- Creating the Textbook -- Special Features -- Acknowledgments -- Table Of Contents -- I Introduction -- 1 Foundations of Physiology -- What is physiology? -- Physiological genomics is the link between the organ and the gene -- Cells live in a highly protected milieu intérieur -- Homeostatic mechanisms-operating through sophisticated feedback control mechanisms- are responsible for maintaining the constancy of the milieu intérieur -- Medicine is the study of "physiology gone awry" -- References -- References -- II Physiology of Cells and Molecules -- 2 Functional Organization of the Cell -- Structure of Biological Membranes -- The surface of the cell is defined by a membrane -- The cell membrane is composed primarily of phospholipids -- Phospholipids form complex structures in aqueous solution -- The diffusion of individual lipids within a leaflet of a bilayer is determined by the chemical makeup of its constituents -- Phospholipid bilayer membranes are impermeable to charged molecules -- The plasma membrane is a bilayer -- Membrane proteins can be integrally or peripherally associated with the plasma membrane -- The membrane-spanning portions of transmembrane proteins are usually hydrophobic α helices -- Some membrane proteins are mobile in the plane of the bilayer -- Function of Membrane Proteins -- Integral membrane proteins can serve as receptors -- Integral membrane proteins can serve as adhesion molecules -- Integral membrane proteins can carry out the transmembrane movement of water-soluble substances
Inhalt:
Integral membrane proteins can also be enzymes -- Integral membrane proteins can participate in intracellular signaling -- Peripheral membrane proteins participate in intracellular signaling and can form a submembranous cytoskeleton -- Cellular Organelles and the Cytoskeleton -- The cell is composed of discrete organelles that subserve distinct functions -- The nucleus stores, replicates, and reads the cell's genetic information -- Lysosomes digest material derived from the interior and exterior of the cell -- The mitochondrion is the site of oxidative energy production -- The cytoplasm is not amorphous but is organized by the cytoskeleton -- Intermediate filaments provide cells with structural support -- Microtubules provide structural support and provide the basis for several types of subcellular motility -- Thin filaments (actin) and thick filaments (myosin) are present in almost every cell type -- Synthesis and Recycling of Membrane Proteins -- Secretory and membrane proteins are synthesized in association with the rough ER -- Simultaneous protein synthesis and translocation through the rough ER membrane requires machinery for signal recognition and protein translocation -- Proper insertion of membrane proteins requires start- and stop-transfer sequences -- Newly synthesized secretory and membrane proteins undergo post-translational modification and folding in the lumen of the rough ER -- Secretory and membrane proteins follow the secretory pathway through the cell -- Carrier vesicles control the traffic between the organelles of the secretory pathway -- Specialized protein complexes, such as clathrin and coatamers, mediate the formation and fusion of vesicles in the secretory pathway -- Vesicle Formation in the Secretory Pathway -- Vesicle Fusion in the Secretory Pathway
Inhalt:
Newly synthesized secretory and membrane proteins are processed during their passage through the secretory pathway -- Newly synthesized proteins are sorted in the trans-Golgi network -- A mannose-6-phosphate recognition marker is required to target newly synthesized hydrolytic enzymes to lysosomes -- Cells internalize extracellular material and plasma membrane through the process of endocytosis -- Receptor-mediated endocytosis is responsible for internalizing specific proteins -- Endocytosed proteins can be targeted to lysosomes or recycled to the cell surface -- Certain molecules are internalized through an alternative process that involves caveolae -- Specialized Cell Types -- Epithelial cells form a barrier between the internal and external milieu -- Tight Junctions -- Adhering Junctions -- Gap Junctions -- Desmosomes -- Epithelial cells are polarized -- References -- References -- Books and Reviews -- Journal Articles -- 3 Signal Transduction -- Mechanisms of Cellular Communication -- Cells can communicate with one another via chemical signals -- Soluble chemical signals interact with target cells via binding to surface or intracellular receptors -- Cells can also communicate by direct interactions-juxtacrine signaling -- Gap Junctions -- Adhering and Tight Junctions -- Membrane-Associated Ligands -- Ligands in the Extracellular Matrix -- Second-messenger systems amplify signals and integrate responses among cell types -- Receptors That are Ion Channels -- Ligand-gated ion channels transduce a chemical signal into an electrical signal -- Receptors Coupled to G Proteins -- General Properties of G Proteins -- G proteins are heterotrimers that exist in many combinations of different α, β, and γ subunits -- G-protein activation follows a cycle -- Activated α subunits couple to a variety of downstream effectors, including enzymes and ion channels
Inhalt:
βγ subunits can activate downstream effectors -- Small GTP-binding proteins are involved in a vast number of cellular processes -- G-Protein Second Messengers: Cyclic Nucleotides -- cAMP usually exerts its effect by increasing the activity of protein kinase A -- Protein phosphatases reverse the action of kinases -- cGMP exerts its effect by stimulating a nonselective cation channel in the retina -- G-Protein Second Messengers: Products of Phosphoinositide Breakdown -- Many messengers bind to receptors that activate phosphoinositide breakdown -- IP3 liberates Ca2+ from intracellular stores -- Calcium activates calmodulin-dependent protein kinases -- DAGs and Ca2+ activate protein kinase C -- G-Protein Second Messengers: Arachidonic Acid Metabolites -- Phospholipase A2 is the primary enzyme responsible for releasing AA -- Cyclooxygenases, lipoxygenases, and epoxygenases mediate the formation of biologically active eicosanoids -- Prostaglandins, prostacyclins, and thromboxanes (cyclooxygenase products) are vasoactive, regulate platelet action, and modulate ion transport N3-16 -- The leukotrienes (5-lipoxygenase products) play a major role in inflammatory responses -- The HETEs and EETs (epoxygenase products) tend to enhance Ca2+ release from intracellular stores and to enhance cell proliferation -- Degradation of the eicosanoids terminates their activity -- Receptors That are Catalytic -- The receptor guanylyl cyclase transduces the activity of atrial natriuretic peptide, whereas a soluble guanylyl cyclase transduces the activity of nitric oxide -- Receptor (Membrane-Bound) Guanylyl Cyclase -- Soluble Guanylyl Cyclase -- Some catalytic receptors are serine/threonine kinases -- RTKs produce phosphotyrosine motifs recognized by SH2 and phosphotyrosine-binding domains of downstream effectors -- Creation of Phosphotyrosine Motifs
Inhalt:
Recognition of pY Motifs by SH2 and Phosphotyrosine-Binding Domains -- The MAPK Pathway -- The Phosphatidylinositol-3-Kinase Pathway -- Tyrosine kinase-associated receptors activate cytosolic tyrosine kinases such as Src and JAK -- Receptor tyrosine phosphatases are required for lymphocyte activation -- Nuclear Receptors -- Steroid and thyroid hormones enter the cell and bind to members of the nuclear receptor superfamily in the cytoplasm or nucleus -- Activated nuclear receptors bind to sequence elements in the regulatory region of responsive genes and either activate or repress DNA transcription -- References -- References -- Books and Reviews -- Journal Articles -- 4 Regulation of Gene Expression -- From Genes to Proteins -- Gene expression differs among tissues and-in any tissue-may vary in response to external stimuli -- Genetic information flows from DNA to proteins -- The gene consists of a transcription unit -- DNA is packaged into chromatin -- Gene expression may be regulated at multiple steps -- Transcription factors are proteins that regulate gene transcription -- The Promoter and Regulatory Elements -- The basal transcriptional machinery mediates gene transcription -- The promoter determines the initiation site and direction of transcription -- Positive and negative regulatory elements modulate gene transcription -- Locus control regions and insulator elements influence transcription within multigene chromosomal domains -- Transcription Factors -- DNA-binding transcription factors recognize specific DNA sequences -- Transcription factors that bind to DNA can be grouped into families based on tertiary structure -- Zinc Finger -- Basic Zipper -- Basic Helix-Loop-Helix -- Helix-Turn-Helix -- Coactivators and corepressors are transcription factors that do not bind to DNA
Inhalt:
Transcriptional activators stimulate transcription by three mechanisms
Weitere Ausg.:
9781455743773
Weitere Ausg.:
Print version Boron, Walter F Medical Physiology E-Book Saintt Louis : Elsevier,c2016 9781455743773
Sprache:
Englisch
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