NEUROSCIENCE IN HEALTH/DISEASE
EXAM 1 TERMS QUESTIONS AND
ANSWERS
Nernst Equation- - Answer-Calculates the Equilibrium potential for a given ion-
Reversal potential. Multiplies some constants with the natural log of the
concentration of an ion outside of the cell over the concentration of that same ion
inside of the cell
Goldman Equation- - Answer-Calculates the membrane potential of the cell by
mutliplying some constants with the natural log of all of the ion concentrations
multiplied by their permeability and then added together. outisde over inside except
for chlorine which is reversed due to it's negative charge
4 General Properties (or accepted truths) of the Membrane at Rest- - Answer-1.
RMP= -65mV
2. Voltage gated ion channels are closed
3. The Na/K potassium pump is moving ions as needed
4. membrane is a little leaky (more K+ but still some Na+)
Threshold of excitation= - Answer-~ -70mV; when reached an AP is triggered;
voltage gated Na+ channels open
Depolarization= - Answer-the MP of the cell becomes rapidly more positive as a
result of the voltage gated Na+ channels opening (~ +40mV)
Reversal= - Answer-the MP peaks and voltage gated Na+ channels start to close
while voltage gated K+ channels open and start to drive MP back down
Repolarization= - Answer-Voltage gated Na+ channels close more rapidly than
voltage gated K+ channels so the MP is still being driven down back to RMP (-65mV)
Hyperpolarization= - Answer-when the MP slides past RMP (-65mV) due to the
voltage gated K+ channels closing slower (so a more negative MP)
Myelination's effect on AP Propagation- - Answer-no leaks and the charge can move
passively down the axon more quickly from node to node (Saltatory Conduction)
Where are all of the voltage gated ion channels on a myelinated axon- - Answer-the
Nodes of Ranvier
What kind of axon would you want to be myelinated? - Answer-An axon that has to
carry messages/information long distances
All-or-none law= - Answer-an action potential either occurs or doesn't; once it is
triggered it keeps going until it reaches the end of the fiber; it remains the same
magnitude without growing or diminishing
, the Rate Law= - Answer-the strength of stimuli affects the rate of firing; a strong
stimulus produces more action potentials than a weak stimulus but each AP
amplitude is the same
Axodentritic - Answer-synapse of an axon to a dendrite; the increased SA allows for
more connections
Axospinous - Answer-synapse of an axon to a dendrite spine
Axosomatic - Answer-synapse of the axon connected directly to the soma
Axoaxonic - Answer-synapse of an axon on to another axon; so the second neuron
could be pre- or post-synaptic
Oligodendrocytes - Answer-A type of glial cell located in the CNS with multiple
myelinated axons which each wrap around axons and a central nucleus within the
soma; forms myelin sheaths
Schwann cells - Answer-A type of glial cell located in the PNS with one axon that
wraps around another single myelinated axon (provides one segment of it's myelin
sheath), the nucleus is included in the wrapped around formation.
Number of Neurons in Avg. human brain-
Number of connections- - Answer--100 Billion
-up to 1,000 per neuron
The Father of Neuroscience; what did he do? - Answer-Santiago Ramon y Cajal;
Proposed the idea that the nervous system is made up of individual cells; the Neuron
Doctrine; noted the many varieties
sensory neuron- - Answer-neuron that detects changes in the external or internal
environment and sends information about these changes to the CNS
Motor neuron- - Answer-neuron in CNS that controls contraction of a muscle of
secretion of a gland
Interneuron- - Answer-neuron located entirely within the CNS
Astrocytes- - Answer-the most abundant glial cell in the human brain
Blood Brain barrier form and function- - Answer-semi-permeable barrier between
blood and the brain produced by cells in the walls of the brain's capillaries; protects
brain and regulates substances than can pass from the blood to the brain
can pass into the brain freely- - Answer-glucose, fat-soluble molecules, oxygen,
CO2, anesthetics, alcohol, viruses, hormones
Can't pass into brain freely- - Answer-proteins, ions, bacteria, antibiotics
EXAM 1 TERMS QUESTIONS AND
ANSWERS
Nernst Equation- - Answer-Calculates the Equilibrium potential for a given ion-
Reversal potential. Multiplies some constants with the natural log of the
concentration of an ion outside of the cell over the concentration of that same ion
inside of the cell
Goldman Equation- - Answer-Calculates the membrane potential of the cell by
mutliplying some constants with the natural log of all of the ion concentrations
multiplied by their permeability and then added together. outisde over inside except
for chlorine which is reversed due to it's negative charge
4 General Properties (or accepted truths) of the Membrane at Rest- - Answer-1.
RMP= -65mV
2. Voltage gated ion channels are closed
3. The Na/K potassium pump is moving ions as needed
4. membrane is a little leaky (more K+ but still some Na+)
Threshold of excitation= - Answer-~ -70mV; when reached an AP is triggered;
voltage gated Na+ channels open
Depolarization= - Answer-the MP of the cell becomes rapidly more positive as a
result of the voltage gated Na+ channels opening (~ +40mV)
Reversal= - Answer-the MP peaks and voltage gated Na+ channels start to close
while voltage gated K+ channels open and start to drive MP back down
Repolarization= - Answer-Voltage gated Na+ channels close more rapidly than
voltage gated K+ channels so the MP is still being driven down back to RMP (-65mV)
Hyperpolarization= - Answer-when the MP slides past RMP (-65mV) due to the
voltage gated K+ channels closing slower (so a more negative MP)
Myelination's effect on AP Propagation- - Answer-no leaks and the charge can move
passively down the axon more quickly from node to node (Saltatory Conduction)
Where are all of the voltage gated ion channels on a myelinated axon- - Answer-the
Nodes of Ranvier
What kind of axon would you want to be myelinated? - Answer-An axon that has to
carry messages/information long distances
All-or-none law= - Answer-an action potential either occurs or doesn't; once it is
triggered it keeps going until it reaches the end of the fiber; it remains the same
magnitude without growing or diminishing
, the Rate Law= - Answer-the strength of stimuli affects the rate of firing; a strong
stimulus produces more action potentials than a weak stimulus but each AP
amplitude is the same
Axodentritic - Answer-synapse of an axon to a dendrite; the increased SA allows for
more connections
Axospinous - Answer-synapse of an axon to a dendrite spine
Axosomatic - Answer-synapse of the axon connected directly to the soma
Axoaxonic - Answer-synapse of an axon on to another axon; so the second neuron
could be pre- or post-synaptic
Oligodendrocytes - Answer-A type of glial cell located in the CNS with multiple
myelinated axons which each wrap around axons and a central nucleus within the
soma; forms myelin sheaths
Schwann cells - Answer-A type of glial cell located in the PNS with one axon that
wraps around another single myelinated axon (provides one segment of it's myelin
sheath), the nucleus is included in the wrapped around formation.
Number of Neurons in Avg. human brain-
Number of connections- - Answer--100 Billion
-up to 1,000 per neuron
The Father of Neuroscience; what did he do? - Answer-Santiago Ramon y Cajal;
Proposed the idea that the nervous system is made up of individual cells; the Neuron
Doctrine; noted the many varieties
sensory neuron- - Answer-neuron that detects changes in the external or internal
environment and sends information about these changes to the CNS
Motor neuron- - Answer-neuron in CNS that controls contraction of a muscle of
secretion of a gland
Interneuron- - Answer-neuron located entirely within the CNS
Astrocytes- - Answer-the most abundant glial cell in the human brain
Blood Brain barrier form and function- - Answer-semi-permeable barrier between
blood and the brain produced by cells in the walls of the brain's capillaries; protects
brain and regulates substances than can pass from the blood to the brain
can pass into the brain freely- - Answer-glucose, fat-soluble molecules, oxygen,
CO2, anesthetics, alcohol, viruses, hormones
Can't pass into brain freely- - Answer-proteins, ions, bacteria, antibiotics
