Animal Physiology Chapter1 Introduction Teachering Hours 2 hours Intensive Teaching:Subjects studied in animal physiology:Regulation of functions;Internal environment and hemeostasis Nodi for student Regulation model and its mechanism of animal body functions. Seactionl Subjects,Methods and Tasks Studied of Animal Physiology 1 The content of animal physiology Physiology is the science of studying the functional activities and its mechanisms in biological body.to explain how they are regulated and integrated. Animal physiology is to study the living phenomena and the function activities of normal animal. Animal physiology is composed of studying on three levels of function: 1.1 cellular and molecule levels The basic living unit of the body is the cell,and each organ is an aggregation of many different cells held together by intercellular supporting structures.Cell level research to understand the function of the organ Molecular level research to study the functions of cells. 1.2 organ and system levels The goals are to explore the effects of organs and systems for animal body and how to performe their activities,and the affecting factors. 1.3 integral levels The aims are to study interactions among organs and systems,and interaction between animal body and environment 2 Purpose of Resreach To garsp the rule of vital activities in animal body,to prevent and treat disease in livestock and poultry effectively,and promote the development of stockbreeding. 3 Resreach Methods 3.1 acute experiments Experiment performed on animals under anesthesia or with transection of the brain is called acute experiment: (1)in vitro:Experiments performed on an isolated tissue or organ (2)in vivo:Experiments performed on the whole body. 3.2 chronic experiments Chronic experiments shoud be performed on a conscious subject for a long period of time. -1- This document is produced by trial version of Print2Flash.Visit www.print2flash.com for more information
Seaction2 Regulation of body functions Regulation:the ability of an organism to maintain a stable internal condition in a constantly changing environment Three types: 1)Chemical (hormonal)Regulation:a regulatory process performed by hormone or active chemical substance in blood or tissue. It response slowly,acts extensively and lasts for a long time 2)Nervous Regulation:a process in which body functions are controlled by nerve system Pathway:nerve reflex Reflex:the basic active manner of nervous regulation Reflex arc:including 5 parts:Receptor-->afferent->reaction center->efferent->Effector Types:unconditioned reflex and conditioned reflex Example:baroreceptor reflex of arterial blood pressure Characteristics:response fast;acts exactly or locally,last for a short time 3)Autoregulation:a tissue or an organ can directly respond to environmental changes that are independent of nervous and hormonal control. Seaction3 Internal Environment and Hemeostasis 1.Body fluid:include intracellular fluid and extracellular fluid. 2.Internal environment and Hemeostasis Internal environment:All cells of the body live in the extracellular fluid;extracellular fluid is called the internal environment of the body Homeostasis:Homeostasis is the maintenance of a constant state with special reference to the internal,the various physiological arrangements which serve to restore the normal state. Including two meaning: (1)relatively stable (2)the control process maintaining the constant conditions of internal environment Function:All of the organs and tissues perform function to help maintain these constant conditions. 2. This document is produced by trial version of Print2Flash.Visit www.print2flash.com for more information
Chapter 2 Celluar Physiology Teachering Hours 8 hours Intensive Teaching:structure of cell membrane and transmembrane transport:Transmembrane signal transduction:electrical phenomena of the cells;contraction function of the skeleton muscle Nodi for student:The mechanism of resting potential and action potential:The contraction mechanism of skeleton muscle Seactionl Structure of Cell Membrane and Membrane Transport 1.Composition and structure of cell membrane The approximate composition of the cell membrane is proteins,55%;phospholipids,25%;cholesterol,13%. other lipids,4.and carbohydrates,3%.The fluid mosaic model is used to elucidate the structure of membrane,which was first expounded by Singer and Nicholson in 1972. 1.1 fluid mosaic model The cell membraneconsists of a double layer of lipid meolecules in which globular proteins are embedded. 1.1.1 Lipid bilayer The basic lipid bilayer is composed of phospholipids molecules which are amphipathic molecules.One end of each phospholipids has a charged region and is hydrophilic.The other end consists of twolong fatty acid chains and is hydrophobic.The phospholipids in cell membrane are organized into a bi-molecular layer with the hydrophobic fatty acid chains in the middle.The hydrophilic regions of the phospholipids are oriented toward the surfaces of the membrane as a result of their attraction to the polar water molecules in the extracellular and cytosol. 1.1.2 Membrane proteins:(1)integral proteins (2)peripheral proteins 1.1.3 carbohydrates:Play important roles in enabling cells to identify and interact with each other. 2.Transmembrane transport 2.1 passive transport The movement of substances across the membrane by down their concentration or electrochemical gradient without consumption of metabolic energy. (1)simple diffusion: The movement of small lipid soluble substances directly through the cell membrane down the concentration gradient. (2)Facilitated diffusion The diffusion of small water-soluble substances through the cell membrane with the aid of particular membrane transport proteins.These transport proteins are classified as channel proteins or carrier proteins. Dcharacteristics of carrier-mediated facilitated diffusion: a. specificity b.saturation c.competition -3- This document is produced by trial version of Print2Flash.Visit www.print2flash.com for more information
2characteristics of channel-mediated facilitated diffusion: 1)Voltate-gated channel: 2)Chemically-gated channel: 2.2 active transport The movement of substances across the membrane occurs against the concentration gradient or electrochemical gradient with the necessity of consumption of metabolic energy. characteristics:(1)movement against the concentration gradient or electrochemical gradient (2)consumption of energy 2.2.1 Primary active transport Making direct use of enery derived from ATP to transport the ions across to the cell membrane. 2.2.2:Secondary active transport The ion gradients established by primary active transport permits the transport of other substances against their concentration gradients. 2.2.3 Sodium--potassium pump (1)Making the Na'and K gradients across the cell membrane (2)Providing energy for secondary active transport 2.3 exocytosis and endocytosis (1)Endocytosis:Very large particles enter the cell by a specialized function of the cell membrane called endocytosis.The principle forms of endocytosis are pinocytosis and phagocytosis. (2)Exocytosis:A stimulus to secrete causes the intracellular vesicles to fuse with the plasma membrane and to release the vesicles contents is called exocytosis. 3 Signal transduction Signal transduction refers to the processes by which intercellular messengers (such as neurotransmitters, hormones and cytokines)which bind to specific receptors on or in the target cell,are converted into biochemical and/or electrical signals within that cell.In turn,such signals can modify cellular function in different ways. Three general patterns of signal transduction occur in almost all mammalian cells.One is signal transduction mediated by G-protein coupled receptor.G-protein serve as intermediaries between receptor and the enzymes or ion channels that activated by agonist binding.The second is signal transduction mediated by ion channel-coupled receptors which help regulate the intracellular concentration of specific ions.The third pattern. some membrane receptors are protein kinases called tyrosine protein kinase that are activated directly by agonist binding. Several basic concepts for the signal transduction first messenger:including the lipid-insoluble messenger and lipid-soluble messenger. Second messenger:it is the signal molecule that produced in interior of cell and can transfer the informations carried by first messenger to regulate the protein kinases and ion channels,and to initiate the physiological and -4- This document is produced by trial version of Print2Flash.Visit www.print2flash.com for more information
biochemical reactions.For example:cAMP,cGMP,IP3.DG,Ca2+etc. protein kinase:It can phosphorylate specific proteins,triggering biochemical reaction that lead to the cell's response to the hormone Signal transduction mediated by G-protein-linked receptor pathway Activation of the receptor by the binding of the first messenter allows the receptor to activate its associated G protein.The activeated G protein activate their effector protein,the adenylate cyclase(AC).The activated adenylyl cyclase the catalyzes the conversion of some intracellular ATP molecules to cAMP.The cAMP then acts as a second messenger to activate the protein kinase and,thereby,lead the phosphorylation of key proteins inside the cell. Seaction2 Excitation and Excitability of Cell 1 excitability and excitation excitability:Ability of living tissues or cells to response to external stimuli. New concept:ability to produce AP excitation:Old concept:from rest to activate or weaker activity to stronger activity New concept:can produce Action potential 1.1 Stimulus and excitation stimulus:The changes in internal or external environment that cause the body to response. Factors of eliciting excitation by stimulus (1)intensity: Threshold intensity(threshold):the minimum intensity to cause the tissues to be excited. Threshold stimulus:intensity-threshold subthreshold stimulus:intensity<threshold (2)duration:If the duration of stimulus is too short,very high intensity of stimulus fails to cause action potential Threshold time:the shortest time needed for eliciting excitation by certain intensity.the stronger the stimulus,the shorter the stimulating time,the opposite is true. (3)changes frequency of stimulus-time Rheobase:The minimum potential for producing stimulating effect by electrical current. 1.2Changes in excitability of the cell during the excitation and recovery states Dabsolute refractory period:Na+channel inactivation,excitability equal to zero 2relative refractory period:inactivated Na+channels begin to recover.It is possible to elicit a second action potential,but the threshold stimulus intensity is higher than usual. ③supranormal period: ④subnormal period: 2 Bioelectrical Phenomenon of cell -5- This document is produced by trial version of Print2Flash.Visit www.print2flash.com for more information