A&P 2 Flashcards
movement of charge
current
difference in charge between two locaton
voltage
chemicals produced when cyclooxgenase enzymes are activated
prostaglandins
enzyme liberates arachidonic acid from membrane phospholipid
phospholipase A2
what protein does calcium bind to in order to activate a specific protein kinase
calmodulin
organs of CNS
brain, spinal cord
two organ systems that are involved in coordinating the functions of cells to maintain homeostasis
endocrine and nervous
2 sources for calcium that can enter the cytosol of cells
smooth ER, extracellular fluid
3 components of a synapse
presynaptic terminal, synaptic cleft, postsynaptic density
3 types of synapses based on location of synapse on postsynaptic cell
axosomatic, axodendritic, axo-axonic
how does conc of 1st messenger at a receptor decrease over time
broken down by enzymes in synapse
diffuses away
receptor-mediated endocytosis by postsynaptic cell
how does phosphorylation of receptors reduce the activity of the signal transduction pathway
decrease affinity of receptor for G-protein and 1st messenger
glial cell types
oligodendrocyte, astrocyte, microglia, ependymal cells, Schwann cells
oligodendrocyte
CNS forms myelin
astroocyte
regulate concs of NT, ions, nutrients in extracellular fluid of brain (CSF)
helps form blood-brain barrier
microglia
CNS immune-like cells
ependymal cells
regulate production and flow of CSF
Schwann cells
PNS forms myelinated axons
Gs flow chart
1st messenger binds to GPCR
conf change in GPCR
conf change in alpha-sub of G-protein
alpha-sub loses affinity for GDP
GDP dissociates from alpha-sub
conf change in alpha-sub
alpha-sub loses affinity for beta/gamma sub and GPCR
dissociates
alpha-sub binds to AC
conf change in AC
activates AC
AC converts ATP to cAMP
increase cAMP in cytosol
cAMP binds to PKA
conf change in PKA
activates PKA
PKA phosphorylates proteins
Gi flow chart
1st messenger binds to GPCR
conf change in GPCR
conf change in alpha-sub of G-protein
alpha-sub loses affinity for GDP
GDP dissociates from alpha-sub
conf change in alpha-sub
alpha-sub loses affinity for beta/gamma sub and GPCR
dissociates
alpha-sub binds to AC
conf change in AC
inactivates AC
AC doesn’t convert ATP to cAMP
decrease cAMP in cytosol
cAMP doesn’t binds to PKA
doesn’t activates PKA
PKA doesn’t phosphorylates proteins
Pathway phospholipase A2
membrane phospholipids uses phospholipase A2 to free arachidonic acid
—–>cyclic endoperoxides —–> prostaglandins and thromboxanes
cyclooxygenase pathway
——>leukotrienes
lipoxygenase pathway
peripheral NS
peripheral nerve
cell body
nucleus, ER, organelles
dendrites
receiving chem signals from other cells
axon
collaterals, long process that carries info away from neuron’s cell body
initial segment
cell body->axon section
hellock “trigger zone”- action potentials initiated
dendritic spines
increase surface area for neuron to receive signals from other neurons
myelin
brings to action potential
axon terminals
release NT
kinesins
anterograde transport, same direction as action potential
Cell body->terminal
forward rxn
dynesins
retrograde transport, opp direction as action potential
terminal->cell body
reverse rxn
special transport proteins use ATP to transport protein from cell body->axon terminals
kinesins and dyeins
afferent neuron
PNS to CNS
sensory receptor to cell body
efferent neuron
CNS to PNS
cell body to muscle, gland, neuron
interneurons
many
projections within nucleus, carries out integrative functions
ganglion
group of neuronal cell bodies outside CNS
nucleus
group of neuronal cell bodies inside CNS
nerve
group of axons outside CNS
tract
group of axons inside CNS
axon terminals
form a synapse with another cell
axosomatic synapse
synapse onto cell body
axodendritic synapse
synapse onto dendrite
ax-axonic synapse
synapse onto axon terminal
glial cells
provide physical and metabolic support to neurons
second messengers
IP3, alpha subunits of G proteins, DAG
Gs and Gi protein-coupled receptors would not both be present in the same cell.
False
Neurons usually use _______________ for intracellular communication, and _______________ for intercellular communication.
electrical signals, chemical signals
The excess negative change in cells is
only along the membrane
What proteins are involved in anterograde transport in axons?
kinesins
A solution containing 200 mM of a permeable solute and 300 mM of a non-permeable solute would be
hyperosmotic
A solution containing 200 mM of a permeable solute and 300 mM of a non-permeable solute would be
isotonic
What proteins are involved in retrograde transport in axons?
dyneins
A single neuron can be both pre-synaptic and post-synaptic.
True
A single neuron may be post-synaptic to thousands of pre-synaptic neurons.
True
Potassium’s equilibrium potential is
negative
Sodium’s equilibrium potential is
positive
Only an extremely small percentage of the K+ in the cell has to leak out to cause a 80 mV change in membrane potential
True
Which ion is more permeable at rest?
calcium
potassium
sodium
potassium
_______________ have equilibrium potentials.
ions
Assuming the membrane is only permeable to sodium and potassium, at the resting membrane potential, the flux of sodium into the cell equals the flux of potassium out of the cell.
True
If you have two chambers separated by a semi-permeable membrane that is only permeable to potassium, and you put 10 mM of potassium chloride in one chamber, and 1 mM of potassium chloride and 9 mM of sodium chloride in the other chamber, potassium will flux across the membrane until the concentration of potassium is the same on both sides.
False
What protein uses the most ATP in the brain
sodium potassium pump
Increasing the extracellular concentration of sodium chloride will cause the cell to
depolarize
Increasing the intracellular concentration of potassium chloride would cause the cell to
hyperpolarize
Decreasing the extracellular concentration of potassium chloride would cause the cell to
hyperpolarize
Decreasing the intracellular concentration of sodium chloride would cause the cell to
depolarize
Increasing a cell’s permeability to sodium will cause the cell to
depolarize
Decreasing a cell’s permeability to potassium will cause the cell to
depolarize
If there are no active transport mechanisms for chloride in a cell, the concentration of chloride will be
higher outside the cell
If you increase the sodium permeability, what will happen to the membrane potential?
depolarize
If you increase the extracellular concentration of sodium chloride, what will happen to the membrane potential?
depolarize
If you increase the extracellular concentration of potassium chloride, what will happen to the membrane potential?
depolarize
Depolarization ______________ the driving force for potassium to leave the cell.
increases
Voltage-gated sodium channels are regulated by
positive feedback
Voltage-gated potassium channels are regulated by
negative feedback
Axon potentials are decremental.
False
Graded potentials are all-or-none phenomenon.
False
Graded potentials can trigger action potentials.
True
Increasing the intracellular sodium chloride concentration will cause
hyperpolarization
Increasing sodium permeability will cause
depolarization
The inactivation gate of the sodium channel ________________ in response to depolarization.
closes
Which glial cell is involved in regulating brain extracellular fluid potassium concentration?
astrocytes
During the depolarization phase of the action potential,
the sodium channel is open and the potassium channel is closed
Graded potentials can happen in
cell bodies
dendrites
Protein receptors for intercellular messengers have the same four characteristics of protein binding sites (chemical specificity, saturation, affinity, and competition).
True
The number of protein receptors in the plasma membrane of a cell is very stable over time.
False
Intercellular messengers that bind to intracellular receptors are
lipophilic
The JAK protein often phosphorylates what transcription factor as discussed in lecture?
STAT
What was the general name given in lecture for drugs that can bind to a protein receptor but do not activate signal transduction.
antagonist
what term means within the cell
intracellular
what term means between cells
intercellular
what is the term for what happens in a cell between the binding of a ligand to a receptor and the final response in the cell
signal transduction
what is the term for a drug that can bind to a receptor and trigger signal transduction
agonist
what receptor signaling pathway involves a cascade of phosphorylations
receptor tyrosine kinase
what enzyme converts cAMP into AMP, thus inactivating it
cAMP phosphodiesterase
state two type of receptors that are themselves enzymes
receptor tyrosine kinase
guanylyl cyclase
what are the substrate and products of the reaction catalyzed by guanylyl cyclase
GTP to cGMP and 2Pi
whats the advantage of having so many steps in the signal transduction pathway of many of the receptors
allows for amplification of the response
what 2 factors determine driving force for ions
electrical gradient
concentration gradient
what is the name of the equation that can be used to determine the equilibrium potential for an ion
nernst equation
flux of ion equation
Jion=gion(conductance)(Vm membrane potential - Eqion equil permability)
a trivalent cation has an intracellular conc of 0.1mM and extracellular conc of 10mM
equil potential?
1/+3 (61.54) log [10]/[0.1]
41.02mV
if you decrease the extracellular conc of the above cation, what will happen to equil potential
41.02mV
less positive
what happens to potassium’s equil potential if you increase the amount of potassium in the cell
more negative
what happens to sodium’s equil potential if you increase the amount of sodium outside the cell
more positive
if an anion has a higher conc outside than inside, anion’s equil potential will be
negative
at resting membrane potential, which ion has greater driving force
sodium or potassium
sodium
assuming the only permeable ions across the plasma membrane are sodium and potassium, at resting membrane potential the inward flux of sodium ___ the outward flux of potassium
equals
if more potassium leaves the cell than sodium enters, assuming those two are the only permeable ions, then membrane potential will be
come more negative
if the membrane potential becomes mroe negative, what happens to the driving force for sodium
increase
if the membrane potential becomes mroe negative, what happens to the driving force for potassium
decrease
if a cell doesn’t regulate chloride concs, then equil potential for chloride equals RMP in that cell
true
conc of potassium is the same in the CSF and blood
false
if you increase the potassium permeability, what happens to the membrane potential
hyperpolarize
if you increase the intracellular conc of sodium chloride what happens to the membrane potential
hyperpolarize
if you increase the intracellular conc of potassium chloride what happens to the membrane potential
hyperpolarize
changing the extracellular conc of ____ has a bigger impact on the RMP
potassium
Na [100mM]o [10mM]i
K [10mM]o [100mM]i
permeable ions: Na and K
same permeability
membrane potential?
0mV
movement of charge is ____ than diffusion of ions
faster
when a sodium channel opens in a graded potential, the causes the flux of potassium out of the cell to increase
true
at RMP voltage-gated K channel is
voltage-gated Na channel is
closed
closed
during depolarization phase of action potential voltage-gated K channel is
voltage-gated Na channel is
closed
open
during repolarization phase of action potential voltage-gated K channel is
voltage-gated Na channel is
open
inactivated
during hyperpolarization/undershoot phase of action potential voltage-gated K channel is
voltage-gated Na channel is
open
closed
depolarization causes
sodium channel activation gate
sodium channel inactivation gate
potassium channel
open
close
open
repolarization/hyperpolarization causes
sodium channel activation gate
sodium channel inactivation gate
potassium channel
close
open
close
