2. Integration- Reading the information that was sensed during sensory input and sending it to the Peripheral Nervous System.
3. Motor output- Receiving information from integration and sending instructions to effector cells to perform movements.
Dendrite- A highly branched group of relatively short projections. collects electrical signals.
Axon- A long projection which may or may not branch. Passes electrical signal to dendrites of another cell or to an effector cell.
Interneurons- make a connection between sensory neurons and motor neurons.
resting potential is neuron not transmitting an electrical signal.
4 factors- low concentrations of sodium and chloride ions on the inside of the membrane, large concentrations of potassium and some anions.
Define equilibrium potential, and explain why the K+ equilibrium potential is more negative than the resting potential.
equilibrium potential: equilibrium between the concentration gradient that moves K+ out and the electrical gradient that moves K+ into the cell. More negative because K+ ions are continuously moving into and out of the cell membrane.
Define graded potential, and explain how it is different from a resting potential or action potential.
Changes in the transmembrane potential that cannot spread far from the area surrounding the site of stimulation. Resting potential DOES NOT spread at all. Action potential spreads ALL THE WAY down the axon.
Describe the characteristics of an action potential, and explain the role membrane permeability changes and ion gates play in the generation of an action potential.
K+ leakage, sodium pumps open to allow an intake of Na+ ions for a brief period of time. Sodium pumps close for a "refractory" period. K+/Na+-ATPase bring 2 K+ ions back into the cell and excretes 3 Na+ ions from the cell membrane.
This is all happening in the action potential.
Explain how the action potential is propagated along a neuron.
Sodium channels open to allow an influx of Na+ into the cell membrane when action potential is activated. then there is a "refractory" period. The Na+ ions propagate the action potential down the neuron.
Increase the voltage/amplitude of the neuron's action potential and decrease the resistance the action potential encounters.
Describe synaptic transmission across an electrical synapse and a chemical synapse.
Electrical synapses-travel down the myelin sheath of the neuron's axon.
Chemical synapses- carry neurotransmitters across the synaptic cleft to the post synaptic cleft of another neuron.
Describe the role of cholinesterase, and explain what would happen if acetylcholine was not destroyed.
If acetylcholine was not destroyed then the ligand would perpetually block the activation of some of the parasympathetic neurons.
List some other possible neurotransmitters.
Amino acids: Glutumate, gamma-aminobutyric acid.
Peptides: endorphins, enkephalins and substance P.
Neuromodulator- regulates diverse populations of neurons.
It may affect nerve transmission because it may inhibit or excite a/many different neurons into action potential or resting potential.
Explain how excitatory postsynaptic potentials (EPSP) and inhibitory postsynaptic potentials (IPSP) affect the postsynaptic membrane potential.
EPSP- makes the action potential more likely in the post synaptic cell.
IPSP- makes the action potential less likely in the post synaptic cell.