Exam 1 Homeostasis 1 Homeostasis a Regulation of the body b Balance equilibrium dynamic process c Found in all living systems d Although conditions within the body are stable this is a result of many dynamic processes that constantly adjust internal activities to match changing needs e Endocrine and nervous system works together f Constantly adjusting to maintain a relatively constant condition i Large changes to the exterior small changes to the interior of the body ii EX blood pressure glucose levels and body temperature 2 Homeostatic Control Mechanism Imbalance to Balance a Stimulus reacts to change b Change is detected by a receptor c Receptor inputs the information along afferent pathway to the control center d Output information to effector e Response of effector back to homeostasis Signal effector organ back to normal f 3 Body Fluids 4 Negative Feedback System a The volume and composition of the various fluids within our bodies are carefully regulated Intracellular Fluid the fluid inside the cells b c Extracellular Fluid all body fluids outside of the cell Interstitial fluid fluid between cells in tissues i ii Plasma the fluid component of blood iii Lymph the fluid in our lymphatic vessels iv Cerebrospinal Fluid CSF the fluid within the CNS v Synovial Fluid the fluid within most joints a Act to stabilize the body in the face of changing external and internal conditions These systems cause an opposite response to the initial change and so are self limiting Negative because it gives an opposite response b i EX if blood pressure is too high it must be lowered one way is by vasodilation or the expansion of blood vessels which lowers pressure c 3 Essential Components i Receptor detects changes in controlled conditions sending an afferent signal to the control center ii Control Center decides the type and amount of the response the body needs effector 1 Sends output nerve impulse efferent signals to the Exam 1 iii Effector reacts to signals from the control center and produces the required response efferent signal d EXAMPLE i Body Temperature 1 If the body temperature is too high or too low it can cause different system disorders 2 Normal body temperature is 98 6 3 Thermoreceptors detect both increasing and decreasing body temps a They then send impulses to the brain 4 Neurons in the hypothalamus control heat balance 5 Too Hot sweat glands are stimulated ii Too Cold body shivers shakes 5 Blood Pressure Regualtion 3 Components a Baroreceptors detects increase of blood pressure to communicate with the brain b Brain interprets info to send to heart and blood c Heart Blood vessels Take information from the brain and alters the pressure d Beta Cells in hyperglycemia i Blood glucose levels increase ii Pancreas releases insulin iii iv Glucose levels go back to normal v Stimulation of insulin no longer secreted Increase in uptake of glucose by the liver e Alpha cells in hypoglycemia i Blood glucose levels decreased ii Pancreas releases glucagon iii Liver releases glucose to the blood by breaking down glycogen iv Glucose levels go back to normal Exam 1 v Stimulation of insulin is no longer secreted Membrane Transport 1 Basic Structure of the Cell a Cells are made up of 3 parts i Plasma Membrane Flexible outer surface of the cell ii Cytoplasm Numerous organelles surrounded by the cytosol iii Nucleus large organelles with DNA and the cells chromosomes 2 The Plasma Membrane a The separation of intracellular vs extracellular material b Production of charge difference membrane potential across the membrane by regulation of intracellular and extracellular ion concentrations i Outside of membrane is positively charged compared to inside because of gathering ions along outside and inside a Membrane permeability depends on the concentration gradient of the 3 The Fluid Mosaic Model ion molecule b Membrane Lipids i Lipid bilayer forms the fabric of the membrane ii Composed of phospholipid molecules 1 Head Polar and hydrophilic Loving water water soluble likes water 2 Tail Uncharged nonpolar Hydrophobic insoluble in water doesn t like water It is made up of two fatter acid chains c Membrane Proteins Exam 1 i Integral Intrinsic Proteins firmly inserted into the lipid bilayer extend deeply into membrane often extending from one surface to the other 1 Some only protrude from only one membrane surface 2 Most are trans membrane span the entire width of the membrane and stick out both sides 3 Most are involved in transport a Some clump together to form channels or pores through which water soluble molecules or ions can move through b Others are carriers that bind to a substance and then move it through the membrane c Receptors ii Peripheral Proteins are not embedded in the lipid bilayer 1 They attach loosely to integral proteins at either the inner or outer surfaces of the lipid bilayer 2 Functions a Transport from one side to the other b Enzymatic activity i Substrate to produce products c Receptors for signal transduction i Neurotransmitters ii Hormones a Gated ion channels can be opened or closed by certain stimuli 4 Channel Proteins 5 Carrier Proteins a Also called transporters b 3 Forms the same time the same time 6 Receptor Proteins i Symporters moves two particles in the same direction at ii Antiporters moves two particles in opposite directions at a Receptor molecules are linked to channel proteins b Attachment of receptor specific chemical signals or receptors c Channel opens or closes d Changes permeability to some substances i EXAMPLE Sodium 7 Movement Through the Plasma Membrane a Diffusion b Osmosis c Mediated Transport Exam 1 i Facilitated diffusion ii Primary Active transport iii Secondary Active Transport 8 Processes a Passive Process i Spontaneous ii Movement from higher to lower concentration downhill iii This uses no energy due to it moving downhill iv EXAMPLE 1 Simple diffusion facilitate diffusion osmosis b Active Process i Uses stored energy ii Movement is from lower to higher concentration uphill iii EXAMPLE 1 Primary and secondary active transports 9 Diffusion a Movement of solutes from an area of higher concentration to lower i Concentration of density gradient difference between two concentration in solution points b Passive Movement of Solutes i Simple Diffusion and CO2 ii Facilitated Diffusion 1 Movements of solutes directly through the lipid bilayer 2 Along down nonpolar and lipid soluble substances O2 1 Movements of solutes with the help of membrane proteins 2 Carrier or
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