SPLH 620 STANDARD EXAMS ANSWERS AND
QUESTIONS SET A+
✔✔what is an interneuron? - ✔✔a neuron located entirely within the CNS
✔✔neuron signaling can be either... - ✔✔electrical or chemical
✔✔what are ions? - ✔✔chemicals in the body that contain an electrical charge
✔✔what are the important ions in the nervous system? - ✔✔- sodium (Na+)
- potassium (K+)
- chloride (Cl-)
✔✔what does it mean that nerve cells are semi-permeable? - ✔✔it means that they only
allow some ions to pass in and out of the cell
✔✔what is an action potential (AP)? - ✔✔the fundamental units of neural
communication
✔✔what are some properties of APs? - ✔✔- stereotyped event (all or none)
- actively propagated down the axon
- reflects the property of the membrane
✔✔what is a resting membrane potential? - ✔✔it is the pre action potential conditions in
a cell and it is measured at -70mV
✔✔what is the depolarization of a cell? - ✔✔the movements of ions during the action
potential. NA+ flows in and K+ flows out.
✔✔resting potential - ✔✔-70 mV
✔✔threshold of excitation - ✔✔-55 mV
, ✔✔action potential peak - ✔✔40 mV
✔✔depolarization - ✔✔+ charge
✔✔hyperpolarization - ✔✔below -70 mV
✔✔2 types of membrane refractory periods - ✔✔absolute and relative
✔✔characteristics of absolute refractory period - ✔✔- ~1 msec
- an action potential cannot be generated during this period
✔✔characteristics of relative refractory period - ✔✔- action potential may be generated
during this period
✔✔what the heck is saltatory conduction? - ✔✔when APs are propagated down the
axon, they begin at the axon hillock and jump from node to node only, depolarizing
membrane at each node. Voltage sensitive Na+ channels are concentrated in these
areas.
✔✔do nonmyelinated axons have fast or slow transmission? - ✔✔slow transmission
✔✔what are the 2 factors that determine conduction velocity? - ✔✔myelin and diameter
of axon
✔✔fastest conduction? - ✔✔- 120 m/sec
- large diameter
- myelinated
✔✔slowest conduction? - ✔✔- 1 m/sec
- small diameter
- unmyelinated
✔✔what are the 3 parts to synapse? - ✔✔1. presynaptic neuron (axon terminal)
2. synaptic cleft
3. postsynaptic neuron (dendrite)
✔✔what are synaptic vesicles? - ✔✔discrete "packages" of chemical transmitter that is
released into the synaptic cleft
✔✔synaptic cleft - ✔✔the tiny gap between the membrane of two neurons, 0.02-0.03
micrometers
✔✔2 types of post-synaptic potentials - ✔✔epsp and ipsp
QUESTIONS SET A+
✔✔what is an interneuron? - ✔✔a neuron located entirely within the CNS
✔✔neuron signaling can be either... - ✔✔electrical or chemical
✔✔what are ions? - ✔✔chemicals in the body that contain an electrical charge
✔✔what are the important ions in the nervous system? - ✔✔- sodium (Na+)
- potassium (K+)
- chloride (Cl-)
✔✔what does it mean that nerve cells are semi-permeable? - ✔✔it means that they only
allow some ions to pass in and out of the cell
✔✔what is an action potential (AP)? - ✔✔the fundamental units of neural
communication
✔✔what are some properties of APs? - ✔✔- stereotyped event (all or none)
- actively propagated down the axon
- reflects the property of the membrane
✔✔what is a resting membrane potential? - ✔✔it is the pre action potential conditions in
a cell and it is measured at -70mV
✔✔what is the depolarization of a cell? - ✔✔the movements of ions during the action
potential. NA+ flows in and K+ flows out.
✔✔resting potential - ✔✔-70 mV
✔✔threshold of excitation - ✔✔-55 mV
, ✔✔action potential peak - ✔✔40 mV
✔✔depolarization - ✔✔+ charge
✔✔hyperpolarization - ✔✔below -70 mV
✔✔2 types of membrane refractory periods - ✔✔absolute and relative
✔✔characteristics of absolute refractory period - ✔✔- ~1 msec
- an action potential cannot be generated during this period
✔✔characteristics of relative refractory period - ✔✔- action potential may be generated
during this period
✔✔what the heck is saltatory conduction? - ✔✔when APs are propagated down the
axon, they begin at the axon hillock and jump from node to node only, depolarizing
membrane at each node. Voltage sensitive Na+ channels are concentrated in these
areas.
✔✔do nonmyelinated axons have fast or slow transmission? - ✔✔slow transmission
✔✔what are the 2 factors that determine conduction velocity? - ✔✔myelin and diameter
of axon
✔✔fastest conduction? - ✔✔- 120 m/sec
- large diameter
- myelinated
✔✔slowest conduction? - ✔✔- 1 m/sec
- small diameter
- unmyelinated
✔✔what are the 3 parts to synapse? - ✔✔1. presynaptic neuron (axon terminal)
2. synaptic cleft
3. postsynaptic neuron (dendrite)
✔✔what are synaptic vesicles? - ✔✔discrete "packages" of chemical transmitter that is
released into the synaptic cleft
✔✔synaptic cleft - ✔✔the tiny gap between the membrane of two neurons, 0.02-0.03
micrometers
✔✔2 types of post-synaptic potentials - ✔✔epsp and ipsp
