Term
| How many organ systems does the body have? |
|
Definition
|
|
Term
| In order to maintain homeostasis, control systems must be able to :1,2,3 |
|
Definition
1-Detect deviations from normal
2-integrate this infomration
3-Restore the deviation via adjustments |
|
|
Term
| 3 points of Negative feed back system |
|
Definition
Primary type of homeostatic control
Maintains stability by defending set points
Opposes initial change |
|
|
Term
| What is the most important feedback mechanism in homeostasis? |
|
Definition
|
|
Term
| What are the three components of Negative feedback systems? and what nerve pathway does the signal travel? |
|
Definition
Sensor (Afferent)
Integrator
Effector (Efferent) |
|
|
Term
| Describe how positive feedback mechanisms work, give an example |
|
Definition
| Positive feedback amplifies an initial change by driving the physiological values even further from a set point. Example Uterine contractions or the Opening of NA channels during membrane depolarization. |
|
|
Term
| What are the two components of ECF? |
|
Definition
| Plasma, Interstitial Fluid |
|
|
Term
| What are the two properties of particles that influence whether they can permeate the cell membrane without assistance? |
|
Definition
|
|
Term
| What two forces are involved in accomplishing transport a cross a cell membrane? |
|
Definition
|
|
Term
| Compare osmosis and diffusion |
|
Definition
Osmosis-Water
Diffusion-Solutes
Both- down concentration gradient, unassisted membrane transport |
|
|
Term
| What are the two types of assisted membrane transport? |
|
Definition
carrier-mediated
vesicular |
|
|
Term
| membrane channels for the passage of water |
|
Definition
|
|
Term
|
Definition
| diffustion will occur in proportion to the difference in concentration gradients (both sides will equilibriate if both can permeate) |
|
|
Term
| How long will Osmosis occur from a side of low solute conc. to a side of high conc? |
|
Definition
| to the point that hydrostatic pressure pushes back |
|
|
Term
| What does VantHoff's equation estimate? What is the equation? |
|
Definition
Osmotic pressure of a solution.
pi=gCdeltaRT |
|
|
Term
| What effect does hydrostatic pressure have on transport in/bt cells? |
|
Definition
| plasma membranes deform easily so usually ther is no pressure diff. Hydrostatic doesn't have much of a driving force |
|
|
Term
| What changes water concentration? What's the relationship? |
|
Definition
| the concentration of solutes in solution. Inverse |
|
|
Term
| What occurs with semi permeable vs permeable membrane? |
|
Definition
| Osmosis in semipermeable, fick's law in permeable |
|
|
Term
| What is osmolarity? What is the osmolarity of bodily fluids? What is an osmole? |
|
Definition
#mol/L soln (#particles/mol*concentration of particles)
290miliOsmoles/L
Osmole is the # of particles a solute dissociates into when in solution |
|
|
Term
| What is the relationship with Water and osmolarity? |
|
Definition
| It is inverse, if you have more water there will be a lower ratio of particles/liter |
|
|
Term
| Calculate the osmolarity for a 5M solution of CaCl2 |
|
Definition
(#particles*concentration(Molar))
Ca Cl Cl=3
5M= 5
3*5=15 osmolar |
|
|
Term
| Why does effective osmolarity only pertain to impermeable particles? |
|
Definition
| Permeable molecules will diffuse and the osmotic gradient will dissipate |
|
|
Term
| Tonicity refers to what two main points? |
|
Definition
The ultimate effect the SOLUTION has on the CELL,
the osmolarity of non-permeable particles in SOLUTION (and how that works on the cell, EASY!!) |
|
|
Term
| Cell is introduced to isotonic solution with permeable solutes |
|
Definition
| Cell fills with solutes as well as water and lyses |
|
|
Term
| Cell is introduced to isotonic solution with different impermeable solutes |
|
Definition
|
|
Term
| Cell is introduced to isotonic solution,slow addition of permeable substances added to solution |
|
Definition
| water moves out of the cell momentarily to dissolve the solutes that were added, but the solutes will eventually disolve in as well (permeable) so the water comes back in and equals out. |
|
|
Term
| extracellular fluid becomes hypoosmolar and fluid enters the cell (so the interior ratio matches) and it swells. What is the mechanism to help bring the cell back to normal? |
|
Definition
Swelling activates solute efflux (kick solutes out, water will follow).
Cl and K channels activated, decreasing osmolarity- water follows, cell volume returns to normal. |
|
|
Term
| extracellular fluid becomes hyperosmolar and fluid leaves the cell (so the interior ratio matches) and it shrinks. What is the mechanism to help bring the cell back to normal? |
|
Definition
Shrinking activates solute uptake
Na/H exchanger is activated
decrease in H activates the Cl/HCO3 exchanger.
over-all increase of Na,Cl in the cell draws in water |
|
|
Term
| Increasing what three factors of diffusion increases Net diffusion? What two Decreases Net? |
|
Definition
Conc, SA, Solubility +
MW, Distance (membrane thickness)- |
|
|
Term
| What three characteristics determine thekind and Q of material that can be transferred across a membrane via carrier mediated transport? |
|
Definition
Stereospecificity (the right molecule)
saturation (proteins free)
Competition (similar Molecules,etc) |
|
|
Term
|
Definition
| Tm, when transporters are saturated. |
|
|
Term
| Rate of molecule carrier mediated transport is directly related to |
|
Definition
| the exctracellular concentration of the molecule being transported |
|
|
Term
| Na/K ATPase, function,method,E source, inhibitors. |
|
Definition
Electrogenic
3Na out 2K in
Uses ATP
Inhibited by cardiac glycosides, oubain |
|
|
Term
| How do cardiac glycosides inhibit Na/K ATPase? Cellular effects |
|
Definition
| bind to the E2P site near the K binding site on extracellular side, prevents conversion of E2 back to E1. Causes cell to swell |
|
|
Term
| Describe the two types of secondary active tranpsort |
|
Definition
Cotransport-when the solute moves in the same direction of NA
Countertransport- when the uphill solute moves in the opposite direction of Na |
|
|
Term
|
Definition
| nonselective uptake of ECF particles and retrieves extra plasma membrane added during exocytosis |
|
|
Term
|
Definition
| Nonselective uptake of large particles for attack by lysosomal enzymes. |
|
|
Term
| Receptor mediated endocytosis |
|
Definition
| selective uptake of molecules that are needed. |
|
|
Term
|
Definition
transport jointly
one in/ one out |
|
|
Term
ICF/ECF ratio
ICF compartment ratio
TBW ratio |
|
Definition
2/3, 1/3
3/4, 1/4
60%(total), 40%(ICF), 20%(ECF) |
|
|
Term
| What is the equation for TBW |
|
Definition
|
|
Term
| What is the equation for TBW if LBM is not known? In what case does this not work |
|
Definition
TBW=0.6*weight
Adipose obviously above 20% |
|
|
Term
| H2O intake occurs by 2 sources, what sources, what volume? |
|
Definition
Ingested- 2L
Oxidation of Carbs- 200mL |
|
|
Term
| What are the major Ions in the Plasma and Interstitial fluid? Intracellular fluid? |
|
Definition
|
|
Term
| What is the formula for estimating plasma osmolarity? given GLU and BUN |
|
Definition
|
|
Term
| What is BUN? It also indicates proper function of what organ? |
|
Definition
| Blood urea nigrogen, removed by kidney, so indicative of kidney fx. |
|
|
Term
| Changes in ____ result in changes in ____> ECF?ICF? |
|
Definition
|
|
Term
| Isoosmotic (hypotonic) gain example and changes. |
|
Definition
IV,
+ECF vol
-Hematocrit/plasmaprotein conc. |
|
|
Term
| Isoosmotic loss (hypotonic) example and changes. |
|
Definition
Diarrhea, Burn
-ECF vol
+Hematocrit/plasmaprotein conc. |
|
|
Term
| Hyperosmotic (hypotonic) gain example and changes |
|
Definition
High NaCl intake
+ECF vol, Osmolarity
-ICF vol, Hematocrit, plasma protein conc. |
|
|
Term
| Hyperosmotic (hypotonic) loss example and change |
|
Definition
Sweating, fever, diabetes
+ osmolarity, plasma protein conc.
- ECF/ICF vol |
|
|
Term
| Hypoosmotic (hypotonic) gain example and change |
|
Definition
high H20 intake
+ECF, ICF vol
-Osmolarity, plasma protein |
|
|
Term
| Hypoosmotic (hypotonic) loss example and change |
|
Definition
Aldosterone insufficiency
+ICF, Hematocrit, Plasma protein conc.
-ECF, Osmolarity |
|
|
Term
| Iso/Hyper/Hypo =? in osmolarity of ECF? |
|
Definition
the same
No change/increase/Decrease |
|
|
Term
| What is the charge difference inside/outside the cell? What Ions make the charge? |
|
Definition
| Inside=neg (K), outside=pos (Na) |
|
|
Term
| Which ion has easier transport into the cell and why? |
|
Definition
| K, there are more channels for passive traffic in than Na. (50x more permeable than to Na) |
|
|
Term
| How can ion channels be selective? |
|
Definition
| Based on channel diameter an ion size, they don't have specific binding sites |
|
|
Term
|
Definition
| a channel whose gate is open in the absence of stimuli |
|
|
Term
|
Definition
| the chemical concentration gradient across the membrane pushes ions through a channel |
|
|
Term
|
Definition
| separation of charges create an electrical gradient across the membrane (opposites attract) |
|
|
Term
| electrochemical driving force |
|
Definition
| combined forces lead to an electrochemical gradient. they don't have to act in the same direction. |
|
|
Term
| how do diffusion potentials cause measurable changes in the concentration ions in bulk solution? |
|
Definition
| you're right, they don't cause measurable changes, the potentials are created by the movement of only a few ions |
|
|
Term
| Electrochemical equilibrium |
|
Definition
| when the charge between a ratio of ions offsets the difference in concentrations of ions, and vice versa. |
|
|
Term
|
Definition
| refers tot he diffusion potential that exactly oposes the tendancy for diffusion down the concentration gradient. |
|
|
Term
|
Definition
|
|
Term
|
Definition
| Inverse of equilibrium, Q of ions that can diffuse before it reaches equilibrium potential |
|
|
Term
|
Definition
|
|
Term
|
Definition
| E=(60/valence)*log([ion]in/[ion]out) |
|
|
Term
| What does the nernst equation measure? |
|
Definition
| calculates Equilibrium Potential, determines electrical force to balance a given diffusion force between ionic concentrations inside/outside the cell |
|
|
Term
| Equilibrium potentials Na, K, Cl, Ca |
|
Definition
|
|
Term
| Valence charges for Na, K, Cl, Ca |
|
Definition
|
|
Term
| equilibrium implies that concentration force= |
|
Definition
|
|
Term
| How do you use Ohm's law to predict changes in resting membrane potentials at disturbance? |
|
Definition
Em=(Gk*Ek+GNa*ENa)/Gk+GNa
Easy, may have to determine the equilibrium potentials, though. Practice one or two |
|
|
Term
Conductance=
what is the eqn? |
|
Definition
permeability (closed channels become open)
G=NPy |
|
|
Term
| What are the two ways membrane permeability is changed? |
|
Definition
Open or close Ion channels
Expression and insertion of channels or removal of channels from the membrane |
|
|
Term
| relate hypertension to membrane permeability |
|
Definition
| increased number and opening probability of Ca channels signals SmM contraction |
|
|
Term
| Hypokalemia does what to RMP? this effects muscles how? |
|
Definition
Hyperpolarized, more - than normal
MM cannot contract appropriately, paralysis, asystole, suffocation |
|
|
Term
| Hyponatriamia does what to RMP? this effects the muscles how? |
|
Definition
| negegably hyperpolarized, more-than normal. |
|
|
Term
| What is Na contribution to overall mV of RMP? |
|
Definition
|
|
Term
| What are the two mechanisms in membrane potential, what % of total RMP do the provide? |
|
Definition
NaK ATPase ~20
Background channel diffusion~ 80 |
|
|
Term
|
Definition
| when the membrane potential is other than 0mv |
|
|
Term
|
Definition
| membrane becomes less polarized than at resting potential (Towards 0) |
|
|
Term
|
Definition
| membranes becomesmore polarized than at resting potential |
|
|
Term
| Mechanosensitive channels |
|
Definition
| stretch-activated, generate graded potentials |
|
|
Term
| What two channels produce graded potentials? |
|
Definition
| Ligand gated, mechanosensitive |
|
|
Term
| Change in this potential is proportional to the stimulus |
|
Definition
| graded potentials, (very diff from action) |
|
|
Term
| What are the molecules and effect on an Excitatory synapse? Inhibatory? |
|
Definition
GLutamate, Espartate (depolarization)
Glycine, GABA (hyperpolarization) |
|
|
Term
| The Q of current that flows between 2 areas depends on 1,2. |
|
Definition
1-difference in potential between the areas
2-resistance |
|
|
Term
| 4 good examples of graded potentials |
|
Definition
Postsynaptic potentials
EndPlate potentials
Pacemaker potentials
Slow-wave potentials |
|
|
Term
| Grand Postsynaptic Potential |
|
Definition
| summation of all EPSPs and IPSPs occuring at approximately the same time |
|
|
Term
|
Definition
| summation of several ESPS occuring very close together in time by successive firing of a single presynaptic neuron |
|
|
Term
|
Definition
| summation of several ESPS occuring simultaneously from different presynaptic outputs |
|
|
Term
| What are the 4 terms for events in an action potential? |
|
Definition
Depolarization
Overshoot
Repolarization
After-hyperpolarization (undershoot) |
|
|
Term
| What are the two gatess on the Na channel? |
|
Definition
| activation gate, inactivation gate |
|
|
Term
| Draw the change from resting to inactivated gates of the sodium channel |
|
Definition
|
|
Term
| Where does the threshold measurement and propogation initiate? Why? |
|
Definition
| Axon hillock, b/c it contrains the highest concentration of voltage gated Na channels, if triggered it is positive feedback |
|
|
Term
| When are sodium channels open? |
|
Definition
| At threshold and during depolarization by positive feedback |
|
|
Term
| What is the change in membrane potential as Na flows into the ICF? |
|
Definition
| reverses from -70 to +30 (overshoot peak) |
|
|
Term
| When do potassium channels open? What is the result? |
|
Definition
| When the sodium channels become inactive,this repolarizes the membrane to resting state |
|
|
Term
| What point on the curve is the switch from Na to K channels open |
|
Definition
|
|
Term
| When do the Na channels open? When does the K channel open? |
|
Definition
| They both are triggered at the same time. Na's gate closes at the peak, the same time that the K channels are fully open |
|
|
Term
| What are the effects of Tetrodotoxin, Saxitoxin and Topical lidocaine on membranes? |
|
Definition
| Both inhibit the voltage gated Na channels prevent the occurenc of action potentials |
|
|
Term
What is Absolute refractive period
What is Relative refracory period? |
|
Definition
-interval when NO stimulus will elicit a response
-interval when a crazy stiumuls will elicit an action potential. Why? elevated Gk combined with the residual inactivation of voltage gated Na channels |
|
|
Term
|
Definition
a change in threshold b/c of prolonged depolarization
-some of the voltage gated na channels become inactivated (slow gates closed), so generally too little gates to initiate action potential |
|
|
Term
| How do elevated K levels cause Primary Hyperkalemic Paralysis? |
|
Definition
| elevated plasma K depolarizes muscles (brings RMP closer to threshold), causing muscle contractions, eventually the voltage gated Na channels inactivate (slow gates closed)=paralysis |
|
|
Term
|
Definition
| the speed at which graded and action potentials are conducted along a nerve or muscle fiber |
|
|
Term
| What is the Time Constant in conduction velocity? What is the formula? |
|
Definition
| how quickly a membrane will depolarize or hyperpolarize in response to a curent. It is a measurement of the time it takes for the change in potential to reach 63% of its final value. The smaller, the quicker. t=membrane resistance*membrane capacitance |
|
|
Term
| What is the Length constant in conduction velocity? What is the formula? |
|
Definition
indicates how far a depolarizing current will spread along the membrane. The longer the lenght constant the further the current will spread along the membrane.
Determined by the square root of the ratio of membrane resistance to internal resistance sqrt(Rm/Ri) |
|
|
Term
| What is internal resistance? |
|
Definition
| Resistance is inversely related to how easily current flows through the cytoplasm of a cell and the cross sectional diameter (bigger=less Ri) |
|
|
Term
| What is the internal resistance and length constant of a large diameter fiber? |
|
Definition
| Lower internal resistance, larger lenght constang |
|
|
Term
| What are examples of large rapid fibers? |
|
Definition
|
|
Term
| What are examples of fine slow fibers? |
|
Definition
| Internal organs, ie gut/glands |
|
|
Term
| How does myelination INC the length constant and RED the time constant of a N? |
|
Definition
| decreaces the capacitance of the axon and restricts the action potential generation to the Nodes of Ranvier |
|
|
Term
| When considering Rm and Ri levels, when does current travel further? |
|
Definition
|
|
Term
| What are the two types of action potential propagation? |
|
Definition
|
|
Term
| What forms myelin in the CNS? in the PNS? |
|
Definition
Oligodendrocytes
Schwann Cells |
|
|
Term
| Myelinated fibers conduct impulses how many times faster than unmyelinated fibers of comparable size? |
|
Definition
|
|
Term
| What is the physiological action Multiple Sclerosis has on nerves? |
|
Definition
| It demyelinates them, which causes a disturbance in the force (action potential that is)because the action potential can now become redundant within a nurve (signal loss) |
|
|
Term
| Gun analogy for action potentials |
|
Definition
| It either fires or it doesn't and each neuron can only use one type of ammo |
|
|
Term
| What is the effect that a strong stimulus has on an action potential? |
|
Definition
| can increase AP frequency, no change to magnitude, the frequency is controlled by CNS and is correlated with Intensity |
|
|
Term
Hyponatremia,
Describe changes on a Action potential |
|
Definition
| Reduces the conc. gradient and driving force for sodium, decreases the magnitude of overshoot and the rate or rise of the upstroke (sluggish) |
|
|
Term
| What is the effect of high ionized (free) calcium on action potentials? |
|
Definition
Ca binds to phospholipids, stabilizing the membranes
large threshold needs bigger stimulus
Can lead to M weakness |
|
|
Term
| What is the effect of low ionized (free) calcium on action potentials? |
|
Definition
Threshold potential becomes more negative (the neruon becomes more excitable)
Causes M twitches |
|
|
Term
What is the plasma [Ca]?
What % free/bound? |
|
Definition
10mg/dl or 2.5mmoles
50 free
50 bound (10 to plasma proteins, 40 to small anions:citrate, phosphate, bicarb) |
|
|
Term
| Hypo/Hyperparathyroidism on phosphate levels/results. |
|
Definition
Hypo-increased phosphate (counterintuitive) dec free Ca, increase neuron excitability
Hyper- increase free cacium, dec phosphate levels, reduce neuron exictabilyt |
|
|
Term
| What do H and Ca compete for? |
|
Definition
| negative sites on plasma membranes. |
|
|
Term
| Explain Acidemia's effect on excitability |
|
Definition
| More H attaches to albumin, leaving free ca, which reduces excitability (binds to membrane) |
|
|
Term
| Explain Alkalemias effect on excitability |
|
Definition
| less H means Ca binds to albumin, decreasing free Ca, Increases neuron excitability (not bound to membrane) |
|
|
Term
|
Definition
| junction b/t pre and post synaptic neuron |
|
|
Term
| what are the two types of synapses? What are the two types of transmission? |
|
Definition
Excitatory and Inhibitory synapses
Electrical (gap junctions) and Chemical |
|
|
Term
|
Definition
| when a neuron terminates ina muscle or gland the neuron is said to innervate it |
|
|
Term
| The signal in an electrical synapse between two cells travels through what? |
|
Definition
|
|
Term
|
Definition
| the .5 to 1 msec that signal transmission takes. it is the conversion of the electrical signal, release of signal molecule, response to molecule |
|
|
Term
|
Definition
| space between the pre and post synaptic neurons |
|
|
Term
| Write out the 7 steps on slide 11 of Chemical message transmission b/t synapses |
|
Definition
|
|
Term
| What is EPP? what is the receptor? what type of potential? |
|
Definition
the postsynaptic poteinatil induced and the neuromuscular junction by the opening of nicotinic acetylcholine receptors.
Graded potential that partilly depolarizes the membrane and can initiate AP |
|
|
Term
| Dense cores secretary granules |
|
Definition
| vessicles that are in the nerve terminal, contain neuropeptides (not ach) |
|
|
Term
| Synaptic vesicles neurotransmitter synthesis |
|
Definition
| arrive in the nerve terminal w/o transmitter, they take up the transmitter that was made in the nerve terminal (Ach example) |
|
|
Term
| What are the tyrosine derivatives that are neurotransmitters? |
|
Definition
|
|
Term
| What is the neurotransmitter in the neuromuscular junction? |
|
Definition
|
|
Term
| What is the major excitatory neurotransmitter in the CNS? Inhibitory? |
|
Definition
| Glutamate/ Glycine and NO |
|
|
Term
| Neuropeptide synthesis/release mech/effect |
|
Definition
| Mede in cell body, packaged in dense core vessicles, released via Ca++ exocytosis, exhibit a slow prolonged response,act as neuromodulators |
|
|
Term
|
Definition
| chemical messengers that do not cause the formaiton of EPSPs or IPSPs but bring long term changes that modulate the action of the synapse |
|
|
Term
| What is the process of formin the ternary complex in synaptic vssicle fusion and exocytosis |
|
Definition
| N-Sec-1 dissociates from syntaxin, allows syntaxin free end to coil with Synaptobrevin and SNAP-25. Makes a-helices, as they tighten it pulls the vissicle closer to the membrane |
|
|
Term
| What is the sensor of the Ca message that triggers the final stage and release of the neurotransmitter in the synaptic cleft? |
|
Definition
| synaptic vessicle protein synaptotagmin |
|
|
Term
| What dissociates the tightly coiled SNAREs? |
|
Definition
| SNAP, which actually just sticks on a NSF to the bunch, which will hydrolyze the bonds, they then turn inward |
|
|
Term
| What neuronal receptors are ion channels? what is the response generated? |
|
Definition
| Ionotropic receptors, these control rapid ionic flow to perpetuate or reduce hyperpolarization (nerve signals) |
|
|
Term
| What neuronal receptors are G Protein coupled receptors? what is the response generated? |
|
Definition
| Metabotropic receptors, these mediate slow, biochemically mediated synaptic responses. Activation results in the production of a and b subunits. RXN= few seconds to minutes |
|
|
Term
| What is the most common type of Physiological modulation of synaptic transmission? |
|
Definition
| Presynaoptic modulation, Facilitation or inhibition |
|
|
Term
| What are the three types of Synaptic transmission modulations? |
|
Definition
|
|
Term
|
Definition
| an excitatory synapse impinging on presynaptic terminal or axon cna increase the amout of neurotransmitter released from the presynaptic terminal |
|
|
Term
|
Definition
| an inhibitory neuron impinging on presynaptic terminal or axon can decrease the amount of neruotransmitter released from the presynaptic terminal |
|
|
Term
| What is the effect of Tetanus and Botulinum toxin on nerves/signal transmission/ |
|
Definition
| Bacterial toxins cleave SNAP, syntaxin proteins involved in exocytosis at NM junction and Cholinergic N endings in CNS preventing fusion of synaptic vessicles, prevents the relase of GABA, affecting skeletal muscles |
|
|
Term
| What are effects of cocaine on NS? |
|
Definition
blocks reptake of dopamine at presynaptic terminals
downregulates dopamine receptors
Blocks voltage gated Na channels acting as a local anesthetic
vasoconstriction |
|
|
Term
|
Definition
| Competes with glycine, causes muscular convulsions and eventually death through asphyxia or sheer exhaustion |
|
|
Term
|
Definition
Autoimmuned isorder
antibodies attack the pre-synaptic voltage gated CA channels, seen in Pt with small cell lung carcinoma |
|
|
Term
|
Definition
the sarcolemma directly across fom the synaptic terminal,
Ion channels are chemically gated (bind ACh)
capable of EPP, not AP |
|
|
Term
|
Definition
| Presynaptic storage and release site for vesicles, keeps a constant supply ready for use |
|
|
Term
| Nicotinic ACh receptors: how many molecules have to bind? how often can they open? how long do they stay open? |
|
Definition
2 molecules/receptor
they can open as fast as ACh can find them
they stay open for 1ms |
|
|
Term
| What causes an AP in M at NM junction? |
|
Definition
| MiniEPP sum =EPP, if big enough can create action potential |
|
|
Term
| What is the margin of safety |
|
Definition
| The excess ACh released to make sure that the action potential is created, this helps prevent catastrophic failure. Usually the signal is 1:1 EPP/AP |
|
|
Term
| What degrades ACh in the junctional gap and post-synaptic folds? How long does it take/How many? |
|
Definition
Acetylcholinesterase
degrades within 1msec of release
10k/second (1 quantum or 1 vessicle) |
|
|
Term
| Explain acetylcholine recycling and enzymes |
|
Definition
| ACh exocytosed and degraded (by acetylcholinesterase) into Choline and Acetate, it is then re-uptaken into the N terminal and converted (via choline acetyltransferase) into Acetylcholine agian |
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Term
| What do non-depolarizing drugs do/ what are they used for? |
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Definition
competitively bloc the binding of ACh to receptors causing reversible paralysis
Tubocurarine
Used in adjucnt to anesthesia |
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Term
| What do depolarizing drugs do/what are they used for? |
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Definition
depolarize the sarcollemma and desensitize the receptors via an influx of ACh
Succinylcholine helps w/ intubation |
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Term
| What is the mechanism for anticholinesterase poisoning? |
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Definition
Inhibits Acholinesterase (pesticides or N gases)
ACh accumulates in the synaptic cleft, depolorizes M, shakes, weakness, death |
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Term
| What is Myasthenia Gravis? |
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Definition
Antibodies block ACH receptors,
EPP down
Margin of safety down, not enough signal to propagate AP
Treated with Nestigmine |
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Term
| What are the two myofilaments? What are they composed of? |
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Definition
Myosin-two proteins twisted together makes tail and two heads
Actin- G-actin molecules form F actin 2 stranded helical structure |
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Term
| What does tropomyosin do? |
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Definition
| Inhibits the binding of myosin and actin |
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Term
| What are the three complees of Troponin? |
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Definition
TNC-calcium sensor, binding promotes movement of TM
TnT: links Tn to TM
Tll: binds to actin and inhibits myosin ATPase |
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Term
| What two other protiens were discussed in class that stabilize myofilaments. what do they do? |
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Definition
Titan- stabilizes on longitudinal axis
Nebulin- "ruler" that regulates the lenght of the actin filaments |
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Term
| be able to draw slide 41 from memory (in Muscle lecture) with the IZMbands, etc |
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Definition
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Term
| What are the 6 steps in Excitation-Contraction coupling? |
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Definition
1 AP at NM junction
2 Ca release
3 Myosin and Actin interxn
4 M contraction
5 Ca removal
6 Relaxation |
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Term
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Definition
| A protien that binds calcium in the SR, allows to stare a large Q of calcium, keeps free Ca concentration low, prevents leakage |
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Term
| What is malignant hyperthermia? |
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Definition
Anesthetics exacerbate a defect in calsequestrin or DHPR
Ca channel is abnormally sensitive to anesthetic, muscles contract forcefully b/c calcium is released freely, generates tremendous heat,
Dantrolene Sodium (abolishes E-C coupling) |
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Term
| What does the Sliding Filament Theory predict? |
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Definition
| The contractile force produced by the M figber is proportional to the N of myosin cross bridge- interactions |
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Term
| What happens to the Sarcomere during contraction? A band? I band? H zone? |
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Definition
Sarcomere shortens
A band doesn't change
I band shortens
H band shortens |
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Term
| What are the 4 characteristics of the Energized state during Cross bridge cycling? |
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Definition
Ca++ low
Myosin and Actin are dissociated
ADP, P on Myosin head
Trm/trp complex blocs actin |
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Term
| What are the five steps in myosin binding to actin? |
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Definition
Ca binds trp C
Conformation shift in Trm/trp complex
exposure of myosin binding site on actin
myosin binds
Pi releases and initiates the powerstroke |
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Term
| What are the details fo the powerstroke to release? |
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Definition
Myosin head shifts causing filament to slide
ADP released
Myosin remainds bound to actin until a new ATP binds (rigor mo0rtis)
ATP hydrolyzed to ADP-P
Head released and returns to origianl pos. |
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Term
| What causes Ca++ to be pumped from M cytoplasm? |
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Definition
| high Ca++ trigers Ca-ATPase pump (SeRCA) in sarcoplasm that pumps Ca back in. |
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Term
| Compare Passive and Active Tension |
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Definition
Passive: due to stretching muscle
Active: force due to M working (cross bridge cycling) |
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Term
| Explain the force relationship between passive and active tension |
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Definition
The force of the M acting continually decreases as the M is stretched, b/c of the decreasing overlap of actin/myosin
The passive tension force goes up at the same time as the M fascia begin to resist stretching
At maximums tretch there is no work tension, just passive tension |
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Term
| What is the force velocity relationship? |
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Definition
The higher the force needed, the slower the velocity of the lift.
Slower allows more time for M/A crossbridge interaction. Force is proportional to crossbridges bound |
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Term
| A single threshold stimulus causes what? |
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Definition
|
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Term
|
Definition
| one Motor neuron and all the fibers it innervates |
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Term
| What sets M Force generation? Frequency of operation? ATP synthesis rate? |
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Definition
Myofibrillar volume
SRvolume
Mito volume |
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Term
| SNS pre/post ganglionic lenghts and origins |
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Definition
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Term
| PNS pre/post ganglionic lenghts and origins |
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Definition
Long Pre
Short Post
Cranial sacral |
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Term
| What neurons are myelinated? |
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Definition
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Term
| What is teh differing primary neurotransmitter from acetylcholine? Which neurons use it? |
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Definition
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Term
| Which Neurons have nicotinic receptors? |
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Definition
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Term
| What are the primary postsynaptic receptors for Postganglionic in both symp and parasyp? |
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Definition
symp- adrinergic
para-muscarinic |
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Term
| Epinephrine works on which nervous system? |
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Definition
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Term
| Acetylcholinesterase inhibitors are used to treat what 3 things discussed in lecture? |
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Definition
| Glaucoma, Increase GI motility, Treat Myasthenia gravis |
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Term
| the path from tyrosine to NEpi |
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Definition
| tyrosine-DOPA-dopamine-NE |
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Term
| What are the elements of presynaptic and target cell disposition of NE? |
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Definition
Pre- uptake1, then metabolized by MAO
Post- Uptake 2, then metabolized by COMT |
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Term
| What letters do all Cholinergic receptors begin with? |
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Definition
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Term
| What letters are all Adrenergic receptors? |
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Definition
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Term
| What letters do all Dopaminergic receptors begin with? |
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Definition
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Term
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Definition
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Term
| What determines the net effect of neuronal input on an organ? |
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Definition
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Term
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Definition
| response to a change in environment, many basic autonomic reflexes can be modulated by other inputs to CNS or by higher brain centers |
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Term
| What NS predominates when filling the bladder? During Micturition? |
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Definition
Sympathetic
Parasympathetic |
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Term
| Reciprocal vs Cooperative effects |
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Definition
-inhibit or promote= fine control
-both promote the same goal |
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Term
| What are the three exceptions to the general rule of dual reciprocal innervation? |
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Definition
A&V only sympathetic
Sweat Glands ony sympathetic
Salivary Glands Both ANS/but cooperative |
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Term
| Hypothalamus' role in Autonomics? |
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Definition
| integrates autonomic, somatic and endocrine responsis that automatically accompany various emotional and behavioral states |
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Term
| What autonomic reflexes can be integrated at the spinal cord? |
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Definition
| Urination, defication, erection |
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Term
| What region inthebrain is direction responsible for autonomic output |
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Definition
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Term
|
Definition
Both bind receptor
Agonist elicits the same effect
Antagonist blocks any response |
|
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Term
| what is a second messenger, what is an example |
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Definition
| after the first messenger's "message" the cell synthesis of a second messenger amplifies the original, and tells the cell to get things going. cAPM, cGMP, DAG IP3 |
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Term
| What are the 3 functions of Sm M? |
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Definition
Produce Motility
Maintain Pressure
Regulate internal flow |
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Term
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Definition
| no striations, No t-tubes, caviolae, spindle shaped, sheets of M, Contain gap junctions, single vs Multi unit |
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Term
| What do gap junctions in smooth M conduct as a signal? |
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Definition
|
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Term
|
Definition
| when cells function via anatomical and electrically connexns thru gap junctions |
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Term
| Sm M actin contains ? but is missing ? |
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Definition
| Contains Tropomyosin but lacks troponin |
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Term
|
Definition
attachment for Actin
Same role as z disks in skeletal M
Some attached to cell membrane |
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Term
| What are the three types of smooth M? |
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Definition
| Multiunit, Single unit, vascular (combination of the two) |
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Term
| Do Smooth M have end plates? |
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Definition
| No they have vericosities |
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Term
| What type of Sm M is neurogenic? |
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Definition
| (innervated) Multiunit, in eye, piloerector M, vas deferens |
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Term
|
Definition
| (Self excitable) visceral sm M, functional syncytium, slow contraction, E efficient, GI, bladder, uterus, ureter |
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Term
| describe pacemaker potential |
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Definition
| membrane potential gradually depolarizes until it reaches threshold for firing a single action potential |
|
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Term
| describe Slow wave potential |
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Definition
| membrane potential alternately depolarizes and hyperpolarizes (oscillates) when the threshold is reache dthe cell fires a burst of action potentials |
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Term
| Sm M action potential uses what anion? |
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Definition
|
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Term
|
Definition
| Typical action potential of unitary sm M cells. Depolarization phase is due to voltage gated Ca channels |
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Term
|
Definition
Spontaneous depolarization of the resting membrane potential in unitary Sm M cells
typically slow wave |
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Term
|
Definition
| Repolarization is delayed allowing for prolonged contraction (ureter, uterus, certain vascular sm M cells) |
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Term
| Describe Cross bridge cycling of Sm M |
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Definition
| rgulation occurs on teht thick filament by light-weight proteins attached to the myosin molecules called Myosin Light Chains |
|
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Term
| describe the process of contraction in sm M |
|
Definition
Ca up
Ca binds to calmodulin
Ca-Calmodulin activates myosin light chain kinase (MLCK)
MLCK phosphorylates the Light chain (MLC)
interacts w/actin and contracts
Ca down
myosin ligh chain phosphatase (MLCP) removes phosphate from MLC |
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Term
| What are latch bridge contractions, how are they achieved? |
|
Definition
Sm M tonic contraction, tension w/less ATP
Dephosphorylation of MLC immediately after myosin/actin interxn result in lower atpase activity |
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Term
|
Definition
| rapid production of force and subsequent relaxation of sm M as ca concentration returns to basal levels |
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Term
|
Definition
| continuous production of force int he face of falling ca, cross bridge cycling continues at low levels (vessels, GI) |
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Term
| What are the three mechanisms for increaseing intracellular Ca in smooth M? |
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Definition
Voltage Gated Ca channels
Ligand gated ca channels
IP3 gated SR ca channels |
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Term
| What two mechanisms decrease intracellular Ca in smooth M? |
|
Definition
Sarcolemmal Na/Ca exchanger
Sarcolemmal CaATPase |
|
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Term
|
Definition
| block voltage gated Ca channels, reduce ca influx, vasodilators |
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Term
| Potassium channel openers Sm M drugs mechanism |
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Definition
| cause hyperpolarization promote relaxation, vasodilators |
|
|
Term
| how doe cAMP decrease sm M tone? |
|
Definition
inhibits MLCK even in the presence of increased intracellular Ca,
Albuterol, stiumlated by B2 adrenergic receptors |
|
|
Term
| how doe cGMP decrease sm M tone? |
|
Definition
| avtivates myosin phosphatase, resulting in myosin dephosphorylation |
|
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Term
| How does nitroglycerin reduce high coronary blood flow? |
|
Definition
| works on endothelial cells to produce nitric oxide with stimulates cGMP production in sm M, |
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