Phys 1 Exam
there is a high number of ______ ion leak channels
K+
IPSP involve _____ gated ligand channels which _____ the membrane
K+ and Cl-; hyperpolarize
the ICF is composed of what ions?
K+ and Phosphates (-)
why does hyperpolarization occur?
K+ channels stay open longer
______ active transport requires the use of ATP to move molecules while ______ active transport is dependent of ATPase pumps to create a _______ ______
primary; secondary, electrochemical gradient
when cells bring various compounds like hormones and metabolites via a receptor this is called _____ _____ ______
receptor mediated endocytosis
active transport _______ energy and molecules move _____ their concentration gradient from ____ to _____
requires; against; low to high
T or F: part of the function of the cytoskeleton is to assist with intracellular transport.
TRUE
filtration is movement of fluid through a selectively permeable membrane that is generated by ______ ______. ______ in the body is a great example of this
physical pressure; capillaries
mechanically gated channels respond to _______ _____ (pressure/stretch) on the cell membrane
physical stress
in order for an action potential to occur the membrane potential must reach what mV?
-55 mV
what is the RMP of a non-excited neuron
-70 mV
what is the RMP of a non-excited neuron?
-70 mV
RMP is created by what 3 factors?
1. diffusion of ions down concentration gradient 2. electrical attraction of cations and anions 3. selective permeability of the membrane
what are the 6 steps of an action potential
1. graded potential(s) 2. potential threshold met 3. depolarization 4. peak depolarization 5. repolarization 6. hyperpolarization
the extracellular fluid (ECF) makes up ____% of the fluid compartment volume
33
the intracellular fluid (ICF) makes up _____% of the fluid compartment volume
67%
when ECF is brought into the cell through membrane invagination this is called _______
pinocytosis
T or F: Homeostasis is the internal balance of various factors to maintain life, function, repair, and health and common has a positive feedback loop to maintain this balance.
FALSE
T or F: as an action potential reaches the axon terminal, it causes the opening of chloride (Cl-) voltage gated channels to open
FALSE
T or F: facilitated diffusion allows for the movement of a molecule from a higher to lower concentration, but needs a protein carrier and ATP
FALSE
T or F: it is common for potassium (K+) and calcium (Ca2+) ions to have a higher concentration in the ICF compared to the ISF.
FALSE
T or F: sodium (Na+) voltage-gated channels must open for a depolarizing graded potential to occur?
FALSE
T or F: when a neuron receives stimuli at the same time from multiple neurons, it is referred to as temporal summation.
FALSE
what is a cancellation summation?
IPSP and EPSP cancel one another out and RMP stays balaced
what is a spatial summation?
IPSP and EPSP combine from MULTIPLE neurons simultaneously onto one neuron
what is a temporal summation?
IPSP and EPSP from ONE neuron to another
T or F: The equilibrium potential for an ion occurs when the ion reaches electrochemical equilibrium.
TRUE
when repolarization occurs _____ voltage gated channels open and _____ goes out of the cell
K+;K+
passive transport requires _____ energy and molecules move ____ their concentration gradient from _____ to _____
NO; down; high to low
when depolarization occurs ____ voltage gated channels open and _____ goes into the cell
Na+; Na+
EPSP involve _____ gated ligand channels which ______ the membrane.
Na+; depolarize
excitable cell
a cell that has the ability to elicit a action potential
polarized
a difference in electrical charge between the inside and outside of the cell membrane
electrical potential
a difference in the concentration of electrical charge from one point to another
What is NOT a mechanism for neurotransmitters to become "deactivated" or non-functional within the synaptic cleft a. phagocytized by immune cells b. pumped up into neuroglial cells near the synaptic cleft c. be enzymatically broken down in the synaptic cleft d. diffuse away from the postsynaptic neuron
a. phagocytized by immune cells
Loss of function of this organelle could lead to inability to synthesis protein. a. ribosome b. proteasome c. lysosome d. endoplasmic reticulum
a. ribosome
leak channels are ___ open and allow ____ molecules to pass through
always, specific
______ protein channels only allow H2O to pass through
aquaporin
Which is NOT TRUE regarding synapses? a. electrical synapses are found in the cardiac muscle tissue b. electrical synapses utilize neurotransmitters to initiate action potentials c. chemical synapses are dependent upon a neurotransmitter d. chemical synapses need ligand gated ion receptors on the post synaptic neuron
b. electrical synapses utilize neurotransmitters to initiate action potentials
what option is TRUE regarding the release of glutamate from a presynaptic neuron to a postsynaptic neuron in the CNS? a. it will cause the opening of a potassium (K+) ion gated channel b. it will cause the opening of a sodium (Na+) ion ligand channel c. it will cause the opening of voltage gated channels in the dendrites of postsynaptic neuron d. it will cause a cancellation summation
b. it will cause the opening of a sodium (Na+) ion ligand channel
what statement is FALSE? a. glutamate is the most common excitatory neurotransmitter in the CNS b. only excitatory post synaptic potentials will cause sodium (Na+) ion channels to open in the axon terminal c. all of the options are false d. electrical synapses are dependent upon gap junctions
b. only excitatory post synaptic potentials will cause sodium (Na+) ion channels to open in the axon terminal
what statement is FALSE regarding plasma membrane transport? a. osmosis only involves the movement of water across a selectively permeable membrane b. secondary transport directly utilizes ATP to move substances in and out of the cell c. active transport will move items against their concentration gradient (low to high concentration) d. exocytosis is the process of moving substances out of the cell through the use of vesicles
b. secondary transport directly utilizes ATP to move substances in and out of the cell
If a cells ICF is hypotonic compared to the ISF surrounding it, what statement would be TRUE? a. the cell would undergo swelling and could lyse open b. the osmolarity of the ICF would be lower than the ISF c. the RMP would be disrupted d. the ICF would have a high concentration of solutes compared to the ISF
b. the osmolarity of the ICF would be lower than the ISF
protein carriers _____ to various molecules and transfer them to the other side of the membrane
bind
the ISF is also known as _____ _____ and is made up of what ions?
blood plasma; NA+, Cl-, Ca+2
action potential
brief change in electrical potential on a specific region of a neuron or muscle cell's plasma membrane
What is NOT a function of the glycocalyx? a. allow binding of hormones b. assist in cellular adhesion with other cells c. all of the above are function of the glycocalyx d. assist in giving the cell an overall negative charge
c. all of the above are function of the glycocalyx
Which of the following is NOT a function of protein? a. enzyme function within a cell b. cellular receptor c. form the glycocalyx d. part of the cytoskeleton
c. form the glycocalyx
what option is TRUE regarding the release of gamma-aminobutyric acid (GABA) from a presynaptic neuron to a postsynaptic neuron in the CNS? a. it will cause the opening of voltage gated channels in the dendrites of postsynaptic neuron b. it will cause the opening of a sodium (Na+) ion ligand channel c. it will cause the opening of a potassium (K+) ion ligand channel d. it will cause an EPSP
c. it will cause the opening of a potassium (K+) ion ligand channel
What is NOT a factor/variable that influences the formation fo the resting membrane potential? a. leak channels b. attraction of cation and anions c. the number of ligand gated channels d. diffusion of ions down their concentration gradient
c. the number of ligand gated channels
what statement is FALSE regarding graded potentials in neurons? a. they only occur at the dendrites and soma b. a hyperpolarization graded potential would cause the membrane potential to become more negative c. they involve both voltage gated and ligand gated ion channels d. a IPSP and EPSP could cancel each toher
c. they involve both voltage gated and ligand gated ion channels
which organelle assists with packaging and modifying proteins? a. endoplasmic reticulum b. lysosomes c. two of the options are correct d. golgi apparatus
c. two of the options are correct
as an action potential reaches the axon terminal, it stimulates the opening of what protein channel? a. ligand gated potassium (K+) ion channels b. voltage gated sodium (Na+) ion channels c. voltage gated calcium (Ca2+) ion channels d. ligand gated calcium (Ca2+) ion channels
c. voltage gated calcium (Ca2+) ion channels
hyperpolarization
change in cell's membrane potential is a more negative value
depoarization
change is cell's membrane potential to a more positive number
what two forces drive electrochemical equilibrium?
chemical and electrical
ligand gated channels respond to ________ ______ or ________
chemical messengers or neurotransmitters
what is the purpose of sodium-potassium ATPase pump?
creates and maintains concentration gradient of K+ across the cell -helps establish RMP
a membrane potential allows for the flow of electrical currents from _____ to _____ across the gated the plasma membrane through _____ _____ _____
positive to negative; gated protein channels
What would you predict would happen if a ligand-gated sodium (Na+) channel opened on the plasma membrane of a neurons dendrite? a. the sodium-potassium ATPase pump would be inactivated b. sodium ions would rush out of the neuron c. an inhibitory post synaptic potential form of a graded potential would occur d. depolarization of the membrane potential would occur
d. depolarization of the membrane potential would occur
what statement is TRUE regarding diffusion? a. will occur without the appropriate concentration gradients b. only is associated with water molecules c. facilitated diffusion will require energy d. none of the options are true
d. none of the options are true
What option is a characteristic that WOULDN'T allow a molecule to directly pass through a plasma membrane? a. smaller molecule b. all option would directly pass through c. lipid soluble molecule d. polar molecule
d. polar molecule
If a drug binds to a postsynaptic dendritic receptor, doesn't illicit any response, and basically blocks the binding of the actual neurotransmitter, this is referred to as: a. inhibitory postsynpatic potential cancellation b. receptor agonist c. receptor blocking d. receptor antagonist
d. receptor antagonist
a molecule or chemical that would inhibit or prevent the activation of a postsynaptic neuron/cell would be classified as: a. receptor agonist b. receptor inhibitor c. neurotransmitter reuptake inhibitor d. receptor antagonist
d. receptor antagonist
where does a graded potential occur?
dendrite and soma region
what is known as the chemical gradient
difference in concentration of ions between ICF and ECF and the drive to move down the concentration gradient
when does the greatest flow of K+ occur?
during repolarization
resting membrane potential
electrical potential difference across the plasma membrane when the cell is in a non-excited state
what is RMP?
electrical potential difference across the plasma membrane when the cell is in a non-excited state
the process of cells expelling materials in which the contents of the vesicle are released
exocytosis
glucose is too large to pass through a cell membrane. In order to enter a cell, it must be carried across by a membrane protein. This process does not require ATP. This is an example of what type of membrane transport?
facilitated diffusion
current
flow of charge particles
facilitated diffusion occurs when a molecule is transported across the plasma membrane from ____ to ____ concentration with the assistance of what?
high to low; transmembrane integral proteins
a solution is hypertonic when it has a ______ solute concentration. this _______ osmolarity which ______ H2O concentration
high; increases; decreases
the extracellular fluid (ECF) is made up of:
interstitial fluid (ISF), plasma/lymph, transcellular (synovial and CSF)
when solutions have the same amount of solutes per unit volume of solution this is known as ______
isotonic
what items require a protein channel or carrier to pass through the membrane?
larger molecules, polar molecules, non-lipid soluble
graded potential
local changes in the membrane potential of an excitable cell due to a stimulus
graded potential occurs when _____ changes in membrane potential of an excitable cell due to a ______ stimulus
local; stimulus
a solution is hypotonic when it has a ____ solute concentration. this ______ osmolarity which _____ H2O concentration
low; decreases; increases
voltage gated channels responds to changes in the ______ _____ or action potentials
membrane potential
what ligand gated ion channel or channels, if open, would cause and inhibitory post synaptic potential?
potassium (K+) and chloride (Cl-) ligand gated ion channels
______ is the measurement of total number os solutes in a liquid expressed in osmoles of solute particles per KILOGRAM of solvent (solution)
osmolality
________ is the measurement of total number of solutes in a liquid expressed in osmoles of solute particles per LITER of solvent (solution)
osmolarity
_______ involved movement of H2O between solutions while separated by a semipermeable membrane while diffusion does not
osmosis
when the cell "eats" a large particle like bacteria or debris this is called ______
phagocytosis
what are the three types of endocytosis we talked about in class?
phagocytosis, pinocytosis, and receptor mediated endocytosis
cell membranes are primarily composed of ______
phospholipids
what items can pass through the membrane?
small molecules, non-polar molecules, lipid soluble molecules (water, oxygen, carbon dioxide)
how does a cell return to RMP after hyperpolarization?
sodium-potassium ATPase pumps
the size of the change of a grade potential is proportional to the strength of the ______
stimulus
potential
stored energy in a cell in which the cell has the possibility of ions moving
the size and change of a graded potential is proportional to the _____ of the stimulus
strength
membrane potential
the difference of electrical charge between the ICF and ISF can lead to a change in voltage
the comparison of two solutions separated by a semipermeable cell membrane or comparing the concentration of two solutions is known as what?
tonicity
action potentials involve _____ gated channels
voltage
if a cell is surrounded by isotonic ISF what will occur?
water moves equally in and out of the cell
if a cell is surrounded by hypotonic ISF what will occur?
water will move into the cell
if a cell is surrounded by hypertonic ISF what will occur?
water will move out of the cell