!1!EXAM!1!STUDY!GUIDE!!Explain!the!resting!membrane!potential!and!how!it!maintains!balance!by!using!Potassium!and!Sodium!ions:!• Na+!binds!to!the!pump!protein!stimulating!phosphorylation!by!ATP,!causing!the!pump!protein!to!change!shape!• The!shape!change!expels!Na+!to!the!outside.!Extracellular!K+!binds!causing!release!of!the!phosphate!group!• Loss!of!phosphate!restores!original!conformation!of!the!pump!protein.!K+!is!released!to!cytoplasm!and!Na+!sites!are!ready!to!bind!Na+!again.!Cycle!repeats!!MEMBRANE!POTENTIAL!• !K+!diffuse!down!the!concentration!gradient!out!of!the!cell!via!leakage!channels.!Loss!of!K+!results!in!a!–!charge!on!the!inner!plasma!membrane!face!• K+!move!into!cell!bc!they!are!attracted!to!the!–!charge!on!in!the!inner!plasma!membrane!face!• A!–!membrane!potential!is!established!when!the!movement!of!K+!out!of!the!cell!=!K+!movement!into!the!cell.!The!concentration!gradient!promoting!K+!exit!exactly!opposes!the!electrical!gradient!for!K+!entry!!More!membrane!potential:!• Separation!of!oppositely!charged!particles!(ions)!across!a!membrane!creates!a!membrane!potential!(potential!E!measured!as!voltge)!• Resting!membrane!potential!(RMP):!voltge!measured!in!resting!state!in!all!cells!o Ranges!from!U50!to!U100!mV!in!diff!cells!o Results!from!diffusion!and!active!transport!of!ions!(mainly!K+)!!!(Sodium!pumped!out!of!cell!using!ATP!and!K+!into!cell!and!you!get!a!gradient.!High!Sodium!outside!of!cell!and!K+!inside!cell.!Primary!Active!transport!bc!we!use!ATP!directly.!If!you!use!K+!or!Na+!from!gradient,!its!secondary!active!transport!(using!ATP!indirectly)!create!a!membrane!potential!bc!lots!of!K+!inside.!This!creates!a!neg!charge!inside!cell!bc!youre!pumping!out!more!positive!than!bringing!in!more!positive.!The!cell!is!really!permeable!to!K+.!K+!want!to!leave!cell!bc!there!is!a!concentration!gradient.!So!much!in!the!cell!that!it!wants!to!go!down!the!gradient.!Na+!wants!to!get!into!the!cell.!K+!wil l !freely!leave!but!not!all!leaves!bc!t heres! an!electrical!gradient.!Membrane!becomes!more!negative!as!K+!leaves!cell.!When!the!positive!charge!leaves,!it!leaves!negatively!charged!protein.!)!!!!HOMEOSTASIS!IN!REFERENCE!TO!THERMOREGULATION!AND!NEGATIVE!FEEDBACK!LOOP!(body!does!something!to!cancel!out!a!stimulus):!• HomeostasisU!used!for!maintenance!of!a!stable!internal!environment,!necessary!for!normal!body!fxing!and!to!sustain!life!!2!• Stimulus!produces!change!in!variable!• Change!detected!by!RECEPTOR!• Input:!info!sent!along!afferent!pathway!to!the!control!center!(BRAIN)!• Output:!info!sent!along!efferent!pathway!to!activate!EFFECTOR!• Response!of!effector!feeds!back!to!influence!magnitude!of!stimulus!returns!variable!to!homeostasis!• Negative!feedback:!decreases!the!original!stimulus!or!reduces!intensity!of!original!stimulus!• Positive!feedback:!increases!original!stimulus!to!push!the!variable!farther.!Only!occurs!in!blood!clotting,!milk!let!down,!birth!of!baby!• Body!temperature!goes!up,!you!have!centers!that!tell!the!brain!you!are!hot.!Set!point!is!37!degrees.!Hypothalamus!in!brain!says!the!normal!set!point!should!be!37!degrees!but!its!higher!than!that.!Brain!in!the!output!direction!says!to!sweat,!bring!bloodflow!to!skin.!Increa se! bloodflow!to!skeletal!musclesUdirects!away!from!core!bc!its!too!hot!so!blood!can!cool!down.!Body!temp!goes!down.!Called!negative!feedback!bc!the!response!by!body!cancels!out!the!stimuli.!• Primary!way!to!maintain!homeostasis:!negative!feedback!!OSMOTIC!PRESSURE!(movement!of!water)!• Isotonic!solution!equal!concentration!of!ions!in!solution!and!cell!(iso=same,!tone=shape)!bodies!have!osmolarity!of!300!• Hypertonic!solution!higher!concentration!of!ions!in!solution!than!in!cell!(cells!shrink,!water!moves!out!of!cell)!• Hypotonic!solutionlower!concentration!of!ions!in!solution!than!in!cell!(water!goes!into!the!cell,!cell!expands)!!NECESSARY!LIFE!FUNCTIONS!• Maintain!boundaries!• Movement:!locomotion!and!movement!of!substances!• Growth:!increases!cell!size!and!#!of!cells!• Responsiveness:!ability!to!sense!changes!and!react!• Digestion:!breakdown!and!absorption!of!n u trients!• Metabolism:!chemical!rxns!within!the!body!• Excretion:!eliminates!waste!from!metabolic!rxns!!LEVELS!OF!ORGANIZATION!• Gross!anatomy:!large!structures,!easily!observable!• Microscopic!anatomy:!very!small!structures,!can!only!be!viewed!with!microscope!• CellsU!smallest!living!unit!• TissuesU!collection!of!cells!of!same!type!• OrgansUcollection!of!2!or!more!types!of!tissue!put!together!into!structures!that!perform!a!specific!fx!• Organ!systemsU!collection!of!organs!that!work!together!to!accomplish!a!particular!task!!3!!BODY!FLUID!COMPARTMENTS!• Total!body!waterUall!water!in!body!• Intracellular!fluidU!inside!cells!• Extracellular!fluidUoutside!cells!(includes!plasma)!• PlasmaU!fluid!blood!is!dissolved!in!matrix!of!connective!tissue!called!blood!• Interstitial!fluidU!cells!surrounded!by!solution!that!bathes!cells!(very!similar!to!extracellular!but!does!not!include!plasma)!!FOUR!TISSUE!CLASSES!• Muscle!• Nervous!• Epithelial!• Connective!!!BODY!PLANES!AND!SECTIONS!• sagittalUdivides!body!or!organ!into!left!and!right!pa rt s!• median!or!midsagittalU!divides!body!or!organ!into!equal!left!and!rights!parts!• frontalU!divides!body!or!organ!into!anterior!(ventral)!and!posterior!(dorsal)!parts!• transverse!or!crossUsectionU!divides!body!or!organ!into!superior!and!inferior!parts!!CHEMISTRY!• matter:!anything!that!takes!up!space!and!has!mass,!composed!of!atoms/molecules!• elements!are!fundamental!units!of!matter!• energyU!capacity!to!do!work,!used!in!cells!to!perform!specific!functions!• 4!main!elements!o carbon!o oxygen!o hydrogen!o nitrogen!• atomic!mass:!protons!+!neutrons!• atomic!number:!protons!!• atoms!of!the!same!element!share!the!same!properties!• isotope:!elements!can!have!atoms!with!diff!masses.!Diff!#!of!neutrons!!CHEMICAL!BONDS!• bond:!interaction!bw!2!atoms,!many!diff!types!of!bonds!• Covalent!bonds!o Octet!rule:!most!atoms!want!8!eUs!in!outer!shell!o Single!bond:!sharing!1!pair!of!eUs!(1!eU!from!each!atom)!o Double!bond:!sharing!2!pairs!of!eUs!o Some!are!nonpolar!(electrically!neutral),!some!polar!have!a!+!and!–!charge!!4!o Polar!covalent!bond:!results!in!regions!of!slight!pos!charge!and!regions!of!slight!neg!charge!o Polar!molecules!can!interact!with!ionic!bonds!!•
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