Histology
What do you call excitable cells that transmit electrical signals?
Neurons
Neurons are long lived and amitotic. What does Amitotic mean?
Loses the ability to divide
What is the measure of potential energy?
Voltage
What are the three types of gated channels we discuss?
Chemically gated
Voltage gated
Mechanically gated
Bonus Q: what is a non-gated channel we also discuss?
What is the "middle man" between sensory input and motor output?
Integration or interneurons
This neuroglia cell lives cavities separating fluid from the spinal cord and acts as a permeable barrier, What cell is this?
Ependymal cells
All neurons must have what three things?
Dendrites, Axon, Cell body
Describe the effects of an insulator versus a conductor on the current.
Insulator adds resistance slowing the current
Conductor minimizes resistance speeding up the current
What kind of gated channel opens in response to acetylcholine binding to it in the intermuscular junction?
Chemical or Ligand gated channel
What would happen to someone cognitively if they lost or degraded their myelin sheath on their neurons?
Severe cognitive decline
- slowed reaction time
- slowed processing time
-degraded memory, problem-solving, organization, and multitasking skills
Neuroglia are supporting cells in the CNS and PNS. Name every glial cell and a quick description of their function.
Astrocytes (CNS) – capillaries and neurons
• Microglia (CNS) – neuron health
• Ependymal cells (CNS) – barrier
• Oligodendrocytes (CNS) – myelin sheath
• Satellite cells (PNS) – similar to astrocytes
• Schwann cells (PNS) – myelin sheath
When a signal comes through a neuron to be passed to the next neuron, the signal enters through one side and comes out the next. Which part of the neuron does the signal enter and exit?
Dendrites receive the signal, it runs down the axon and out through the axon terminal to the next neuron
What leakage ion channels most contribute to the ability for an action potential to be generated?
Potassium Ion channels
What two factors contribute the resting membrane potential?
Differences in ionic compounds - extracellular and intracellular fluids
Differences in plasma membrane permeability
What is the absolute refractory period? What is the Relative refractory period?
Absolute = Depolarizing and partial repolarizing wave
Relative = Partial repolarizing and hyperpolarizing dip
If a neuroglia cell covers axons in myelin sheaths in the central nervous system, which cell is it?
Oligodendrocytes
Draw the different structural classifications of neurons on a piece of paper or white board.
Did you do it and label them correctly?
Bonus Q: Which classification is only found in special sense organs?
Which is the most common type in humans and mostly in the CNS?
What is Ohm's law? Which components are directly related? Inversely related?
Current = Voltage/Resistance
Bonus Q: if voltage and resistance are equal to each other what is the current?
Walk us through the steps of generating an action potential and include the channels opening and closing.
1.Resting state
• All gated Na+ and K+ channels are closed
2. Depolarization
• Voltage-gated Na+ channels open
3. Repolarization
• Na+ channels are inactivating and voltage-gated K+ channels open
4. Hyperpolarization
• Some K+ channels remain open and Na+ channels reset
What is the difference b/w Graded potentials and Action potentials?
Graded: Usually incoming signals operating over short distances that have variable (graded) strength
Action: Long-distance signals of axons that always have the same strength