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January 21, 2016

Physiology: the study of function at many levelso Subdivisions are based on organ systems (e.g., renal or cardiovascular

physiology) Essential tools for the study of physiology:

o Ability to focus at many level s(From systemic to cellular andmolecular)

o asic physical principles (e.g., electrical currents, pressure, andmovement)

o asic chemical principles !evels of structural organi"ation

o #hemical: atoms and molecules chpt $o #ellular: cells and their organelles chpt%o &issue: groups of similar cells chpt'o rgan: contains t o or more types of tissueso rgan system: organs that or* closely togethero rganismal: multiple organs or*ing together

vervie of organ systemso #irculatory, respiratory, digestive, urinary, musculos*eletal, immune,

nervous, endocrine, reproductive, integumentary+no organs and functions

.E.o ntegumentary system

Forms the e-ternal body covering, and protects deeper tissuesfrom in ury. Synthesi"ed vitamin /, and house cutaneous (pain,pressure, etc.) receptors and s eat and oil glands.

o S*eletal system

Protects and supports body organs, and provides a frame or*o 0uscular system

Allo s manipulation of the environment, locomotion, and faciale-pression

o 1ervous systemAs the fast2acting control system of the body, it responds tointernal and e-ternal changes by activating appropriate musclesand glands

o Endocrine system3lands secrete hormones that regulate processes such asgro th, reproduction, and nutrient use (metabolism) by body

cells.o #ardiovascular systemlood vessels transport blood, hich carries o-ygen, carbondio-ide, nutrients, astes, etc. the heart pumps blood.

o !ymphatic system4immunityPic*s up 5uid lea*ed from blood vessels and returns it to blood./isposes of debris in the lymphatic stream. 6ouses hite blood

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cells (lymphocytes) involved in immunity. &he immune responsemounts the attac* against foreign substances ithin the body

o 7espiratory System+eeps blood constantly supplied ith o-ygen and removescarbon dio-ide. &he gaseous e-changes occur through the allsof the air sacs of the lungs.Surface area of lungs is about the si"e of a tennis court

o /igestive Systemrea*s do n food into absorbable units that enter the blood fordistribution to body cells. ndigestible

o 8rinary (e-cretory) SystemEliminates nitrogenous astes from the body. 7egulates ater,electrolyte and acid2base balance of the blood

o 7eproductive System rgan Systems nterrelationships E-amples

o /igestive system ta*es in nutrients, brea*s them do n, and eliminatesunabsorbed matter (feces). 7espiratory system ta*es in o-ygen andeliminates carbon dio-ide

6omeostasiso 0aintenance of a relatively stable internal environment despite

continuous outside changeso /ynamic state of e9uilibriumo Al ays thin* of ho homeostasis is being maintained and4or altered

All systems or* in the same basic ayo Stimulus produces change in variableo 7eceptor detects changeo nput information sent along a erent path ay to control centero utput: information sent along e erent path ay to e ectoro 7esponse of e ector feeds bac* to reduce the e ect of stimulus and

returns variable to homeostatic levelo S800A7;

A return from imbalance to balance 7eceptor, a erent path ay, control center, e erent

path ay, e ector 6omeostatic control mechanisms

o nvolve continuous monitoring and regulation of many factors(variables)

o 1ervous and endocrine systems accomplish the communication via

nerve impulses and hormones &hings you should *no or revisit< #hapt $

o 0atter: anything that has mass and occupies spaceo =hat are the % states>

Solid!i9uid3as

o 0a or elements of the human body

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o &ypes of chemical bondsonic

Formed by transfer of valence shell electrons bet eenatoms? attraction of opposite charges results in an ionicbond

#ovalent Formed by sharing of t o or more valence shell electrons6ydrogen

Attractive force bet een electropositive hydrogen of onemolecule and an electronegative atom of anothermolecule

o #hemical reactionso Patterns of chemical reactions

Synthesis reactionso #ell &heory

&he cell is the smallest structural and functional living unitrganismal functions depend on individual and collective cellfunctionsiochemical activities of cells are dictated by their speci@csubcellular structures#ontinuity of life

o #ell diversityver $ di erent types of human cells

o 3enerali"ed #ello 0embrane lipids

BCD phospholipids (lipid bilayer) Phosphate ehads: polar and hydrophilic Fatty acids tails: nonpolar and hydrophobic (revie @g.

$. b)CD glycolipids

!ipids ith polar sugar groups on outer membrane surface$ CD cholesterol

ncreases membrane stability and 5uidityo !ipid 7afts

G$ D of the outer membrane surface#ontain phospholipids, sphingolipids, and cholesterol0ay function as stable platforms for cell2signaling molecules

o 0embrane proteinsntegral proteins

Firmly inserted into the membrane (most aretransmembrane)

Functionso &ransport proteins: move stu from the outside of

the cell to the inside of the cello Functions of membrane proteinso #omponents of a control mechanismo 1egative feedbac*

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&he response reduces or shuts o the original stimulusE-amples

7egulation of body temperature (a nervous mechanism) 7egulation of blood volume by A/6 (an endocrine

mechanism)o

Positive Feedbac* &he response enhances or e-aggerates the original stimulus0ay e-hibit a cascade or amplifying e ect8sually controls infre9uent events e.g.:

Enhancement of labor contractions by o-ytocin (chapter$H)

Platelet plug formation and blood clottingo 1egative Feedbac*: 7egulation of blood volume by A/6

7eceptor sense decreased blood volumeo 6omeostatic imbalance

/isturbance of homeostasis

ncreases ris* of disease #ontributes to changes associated ith agingo 1ecessary life functionso Survival 1eeds

January 28, 2016

#ell to cell communicationo Physiological signals

Electrical signals (not direct I no electrical signal goes from onenerve cell to another. Electrical signal causes chemicals to bereleased in synaptic space)

#hanges in the membrane potential of a cell#hemical signals Secreted by cells into E#F

o 0ethods/irect contact and local cell2to2cell communication

3ap unctionso &ransfer both chemical and electrical signalso Form direct cytoplasmic connections bet een

ad acent cells #ontact dependent signals re9uire interaction bet een

membrane molecules on t o cellso

#A0s, cell adhesion molecules, transfer signals inboth directions (turning the signal o , becomeunstuc*, brea*s signaling)

/irect contact and local cell2to2cell communicationo Autocrine signals act on the same cell that secreted

them. Paracrine signals are secreted by one celland di use to ad acent cells

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#ells routinely manufacture molecules thatill bind to a receptor on its o n border

o Paracrine and autocrine are chemical signalso 6ormones are secreted by endocrine glands or cells

into the blood. nly target cells ith receptors for

the hormone ill respond to the signal !ong distance cell2to2cell communicationo 1eurotransmitters are chemicals secreted by

neurons that di use across a small gap to thetarget cell. 1euron use electrical signals as ell.

o 1eurotransmitters have a rapid e ect Signal path ays

o 1eurohormones are chemicals released by neurons into the bloodo Almost all cells can secrete cyto*ines (not 7 #). #yto*ines may act as

both local and long2distance signalso All nucleated cells synthesi"e and secrete cyto*ines in response to

stimulio n development and di erentiation, cyto*ines usually function as

autocrine or paracrine signalso n stress and in5ammation, some cyto*ines may act on relatively

distantJo &arget cell receptorso Fat soluble molecules (and amphipathic) can move into and outside of

the cell through concentration gradient.o Four categories of membrane receptors that are for lipophobic signal

moleculesSignal molecule, receptor, intracellular signal molecules7eceptor2channel7eceptor2en"yme3 protein2coupled receptorntegrin receptor

o Signal Ampli@cation &ransducers convert e-tracellular signals into intracellularmessages hich create a response

o iological signal transductionSteps of signal transduction path ay form a cascade

o 3P#7Adenylyl #yclase2cA0P#alcium activates everything I inside of a cell contains almost

no free 5oating calcium. t is tightly controlled so it is activelypumping calcium out of the cell or into storage units (E7)

1ovel signal molecules 0odulation of signal path ays #ontrol path ays

o 7esponse loopso Feedbac* loops

1itric o-ide causes vasodilation increasing blood 5o

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# irreversibly binds to hemoglobin pain*illers are 1SA /S that stop pressure on nerves that signal for pain 0odulation I to *eep you alive. Alpha receptor response constricts vessels.

eta receptor response dilates vessels. /o n2regulation causes an increase need for drugs (increase tolerance and

cause medical problems) I reason is that something that is al ays boundcauses the cell to remove receptors. =e do not *no if it is possible to regainreceptors.

February 4, 2016 - oyden 6all !ecture 7oom I loo* up mammalianphysiology practice e-am on google

Fundamentals of the 1ervous System and 1ervous &issue: Part o 1euronal Function and Signaling I 6o do e get a nerve to send an

impulse from one area of the body to another &he body is overall electrically neutral so it doesnKt have a

potential but most of the body is ater. =hen you dissolve

something in ater you get ions. 1et a ect is still no electricalpotential. 1eurons can overcome this through an orderedsystem. 1eurons are irritable, meaning they can react to sensory(light, vibration, mechanical, etc.)

&he uni9ue thing about an action potential, every neuron @resthe same action potential se9uentially. &he body can distinguishthis byJ

Principles of Electrcity &he old adage that opposites attract each other is true.

Pos I 1eg attract. n order to generate opposing charges,energy is re9uired. ;our body does the same thing I

spends energy to create an electrical separation ofcharges. =hen charges move, energy is liberated. fopposite charges are separate e say that the system haspotential energy. So you have more of charge on one sidevs charge on the other. &he side that has more hasgreater potential.

/e@nitions that e use to describe hats going onLoltage is a measure of the amount of energy, thepotential generated by separating t o charges. 1otmovement, but the potential movement

Potential di erence is measured voltage bet een t o

points #urrent is the 5o of ions from one spot to another. 7esistance is a hindrance to the 5o of current. &hings ith high electrical resistance are insulators. &hey

stop electrical charge from moving in one direction or theother

A conductor is a substance ith lo electrical resistance

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o A super conductor (ideally) is something thatdoesnKt hinder the 5o of electrical charge at roomtemperature.

A guy called hm came up ith hms la I used todescribe the relationship bet een current, voltage, and

resistance: ML47 or LN 7 =e use the plasma membrane as a baseline to separatecharges

o 6o do e get charges things from one side toanother>

o Plasma membrane has a nonpolar interior. Scharged substances cannot move through ithoutusing a ton of energy. =e achieve the ability tomove through the membrane by using proteins thathave uncharged and charged side chains. &hedi erent types that neurons use are

!ea* channels. &hese channels are ust polesthat are al ays open. Stu ust lea*s outconstantly.

3ated #hannels prevents the movementfrom one direction or the other

#hemically gated 2 nly allo s acertain si"e in, 0oves through itsconcentration gradient

o !igand must bind to open Loltage2gated channels change their

shape based on the di erence of ionso /ependent on the charges that

are present right outside ofthem

o &his is ho neurons propagatean action potential

0echanically gated channels open andclose in response to physicaldeformation to receptors

=hen gated channels open, ions travelfrom areas of high concentration tolo concentration (do n theconcentration gradient) causeselectrical current

Every neuron maintains a resting membrane potential (Lr)o 0ade up in the di erences of the e-tracellular and intracellular and

permeability of the plasma membraneo &his tells us that the inside of a neuron has a lo er concentration of

sodium than the outside and it has a higher concentration ofpotassium, negatively charged ions than the inside.

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o !ea*age channels allo potassium to constantly lea* out. Somesodium is lost, but for the most part is it bloc*ed from leaving the cell.f there is constantly a hole ith these potassium ions lea*ing out, itKllcontinue to lea* out until it reach e9uilibrium at hich point there is noconcentration di erence. f e had holes that only allo potassium,

neurons ould be very negative (2O mL). So e need to e-pendenergy to maintain 2B mL environmento #hanges in membrane potential is used to integrate and receive

information by sending action potentials. &ypes of signals e can send are

3raded potentials I small signal, short distance, localo #ombine is a given spaceo #an have a positive or negative signalo !ittle area in membrane gets stimulated

Action potentials I big signal, long2distance, globalo A brief period here the membrane potential is

changed from 2B mL to % mL.o /oes not decrease in magnitude over distance

(unless it is myelinated.o 7esting state (2B ), depolari"ation state (up to % ),

repolari"ation, hyperpolari"ation (overshoot passed2B )

o 7esting State nly lea*age channels for 1a and + are

open All gated ion channels are closed

/epolari"ation is ma*ing the cell less polar. =e get less negativerelative to the outside of the cell. =e approach and during anaction potential, overshoot.

6yperpolari"ation ma*es the cell more negative. &he morehyperpolari"ed the cell is, the less li*ely itKll @re an actionpotential. f e ma*e this strong enough, e can inhibit a neuronfrom @ring an action potential

Properties of 3ated #hannels Activation 3ates 2 #losed at rest, open ith depolari"ation nactivation 3ates I open at rest, closed ith

depolari"ation 8nli*e sodium, potassium only has one voltage2sensitive gate

pens slo ly, in comparison to sodium &his slo er opening causes the Absolute 7efractory Period

I allo s spatial separate of action potentials. /uring the depolari"ing phase

!ocal currents open voltage2gated 1a channelso !ocal currents are synapses if e are regular

neurono Each synapse causes its o n graded potential

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o f enough synapse activity is done at once, it cancause an action potential

Sodium in5u- causes further depolari"ation. &hresholdlevel is 2CC to 2C mL is enough to send an actionpotential. f the threshold level is not reached, an action

potential is not created 7epolari"ing phase Sodium channel slo inactivation gates close 0embrane permeability to sodium declines to resting

levels Slo voltage sensitive + gates open

6yperpolari"ation 7ole of the Sodium2Potassium Pump

/uring repolari"ation, pumps or* to shuttle 1a out ofthe cell(neuron) and shuttles + into the cell

Sodium in5u- causes membranes to depolari"e

Small changes in local areas ill cause (if enough of them I to2C mL) but if a synapse @res to an area of a neuron, you mightget a small bit of sodium in5u- I the channels get inactivated.

&hreshold 1eurons are getting lots of signals all the time. &hey need

the right number in the right combination to stimulate theneuron

Subthreshold I ea* local depolari"ation that does notreach threshold

&hreshold stimulus I strong enough to put the membranein action potential

n hyperpolari"ation, e have the refractory period here theneuron can no longer be stimulated =e can tell the di erence by loo*ing at the fre9uency of

the neuron =e code for signals by the number of times per second

that a neuron @res.Absolutely 7efractory Period ensures that @ring is an all ornothing event. &hereKs only one direction that an action potentialmoves in. 1o matter hat e do, after hyperpolari"ation ecannot stimulate the neuron to @re again because it is in theprocess of @ring

7elative 7efractory Period #onduction Lelocity

=e have di erences in conducting action potentials.0yelin provides a complete change in the ability to @reaction potentials (speed increases greatly, % - faster)

Sch ann cells insulate and protects a-ons from lea*age.Loltages only change at node of ranvier