Week 3 Flashcards
(48 cards)
Identify the five main parts of a neuron
- Dendrites
- Soma
- Axon
- Myelin Sheath
- Terminal Buttons
What do dendrites do, and where are they located?
Dendrites received stimulation from sensory receptors. And they protrude from the soma
What does a neural impulse travel along?
the axon
What contains neural transmitters located at the end of an axon?
Terminal buttons
What is the soma?
The neuron body.
Where does the metabolism of a cell take place?
soma
What converts sugar from the bloodstream for energy?
soma
What are the three major classes of neurons?
- sensory neurons
- motor neurons
- Interneurons
What class of neuron terminates on muscles and cause them to contract and relax?
Motor neurons
What class of neuron allows the brain to sense things such as smell, touch and hear?
Sensory neurons
What do interneurons do?
o From sensory neurons to other interneurons or to motor neurons. Most of the brain consists of interneurons
What is the one type of movement that doesn’t involve the central nervous system?
Reflex arc - pain withdrawal reflex
Is the signal within a neuron electrical or chemical?
Electrical
When the axon/neuron isn’t being stimulated is the signal positive or negative?
Negative
What makes the signal within the axon positive?
When it is stimulated
What is the voltage of a resting neuron?
-70 milivolts
What is the stimulated voltage of a neuron?
+30 milivolts
What is the all-or-none rule of an action potential?
the size of the action potential is unaffected by increases in the intensity of the stimulation beyond the threshold levels. It means that the spike is the same size no matter how stimulated the cell it.
What is the period during which further stimulation cannot cause another action potential, meaning that when the cell fires, there’s a rapid change, it cannot fire again until a couple of milliseconds have passes called?
The refractory period
T/F - At rest, a neuron is polarized with a negative charge inside the cell membrane and a positive charge outside (resting potential)
true
What part of a neuron stimulates an action potential?
dendrite
What do sodium irons flowing in to the axon achieve?
a positive charge - action potential
A neuron is polarized in a resting state. If it is depolarized what is it doing?
going from negative (-70) closer to positive. (neuron firing action potential)
What is happening when a neuron is hyperpolarized?
it’s going down or remaining negative (resting state)