5 Written questions
5 Matching questions
- Axons are classified into 3 groups according to the relationship between diameter, myelination and propagation speed: define Type A, B and C fibers.
- What parts of neurons are found in gray matter? White matter? Why is it white?
- What are the two major divisions of the nervous system? Name the three subdivisions of the PNS, and tell how they differ in functions. What are the two subdivisions of the Motor pathway system?
- What is salutatory conduction of an action potential? Does it occur in all nerve fibers? How does diameter of a nerve fiber affect speed of conduction?
- What is an electrochemical gradient?
- a spatial variation of both electrical potential and chemical concentration across a membrane.
- b Salutatory conduction of an action potential is when you jump from node to node.
- c Central Nervous System (CNS) and Peripheral Nervous System (PNS)
Autonomic (involuntary). Within this, there are Sympathetic (Fight or Flight) and Parasympathetic (Rest and digest).
- d Type A - large-diameter, myelinated. Conduct at 15-120 m/s. Motor neurons supplying skeletal and most sensory neurons
Type B - medium-diameter, lightly myelinated. Conduct at 3-15 m/s. Part of ANS
Type C - small-diameter, unmyelinated. Conduct at 2 m/s or less. Part of ANS
- e Cell bodies found in gray matter
Because the tissue is composed of fatty tissue.
5 Multiple choice questions
- In order to get back to polarization, they have to pump in 3 Na out, 2 K in
- A change in the membrane potential that is localized to one area of the plasma membrane. Also known as local potentials.
Cannot travel long distances because they spread in a decremental fashion. They rapidly decrease in magnitude as they spread over the surface of the plasma membrane (teacher's voice in a large lecture hall)
- Presynaptic - The neuron that sends the action potential to the next dendrite
Postsynaptic - Receives the message
Convergence of Neurons - First one neuron is influenced by many others, resulting in a convergence of input.
Divergence of Neurons - When the neuron fires, the signal is sent to many other neurons, resulting in a divergence of output.
- In CNS, it doesn't heal.
In PNS, if mylineation cells are still in tact, they will reform a path for the neuron to grow.
Schwann Cells or Oligodendricites
5 True/False questions
What is a monosynaptic reflex? Name the elements necessary in a polysynaptic reflex arc. → 3 Na out, 2 K in
If a neuron synapses on a second neuron and drives the resting membrane potential further from threshold, what is this called? Where does it occur? → The fact that the cell membrane is relatively negative and they are charged ions inside and outside the cell.
Concentration gradients involved because K+ ions are inside, Na+ ions are outside. Keep polarity of cell in check.
Describe the importance of the Schwann cells in regeneration of the nerve fiber following injury. → Schwann cells can point the neuron in the right direction so it can regrow to the proper receptor sites.
You may recall that a muscle fiber is an entire muscle cell; is a nerve fiber an entire neuron? (explain) → No because the neuron consists of many other things that make up the neuron (dendrites, axons, cell bodies, axon terminals)
Exactly what is a nerve? → A bundle of neurons that travel to and from the same place.