MSK 13 - Nerve-I Flashcards
What are the two main cell types found in nerve tissue? What cells are found in each type?
What is a golgi type-I and golgi type-II fiber? Where are they typically found and what are some of their distinguishing characteristics?
Golgi type-I is another name for a motor neuron. Their axons are more than a meter long.
Golgi type-II is another name for an interneuron. They are found within the vertebral column and cerebellum. They typically have short axons.
What type of neuron accounts for 99.9% of all neurons?
Interneurons
What are some other names for the neural cell body? What are some distinguishing characteristics fot the neural cell body on a light micrograph?
- aka Soma or Perikaryon
- Has a euchromatic nucleus
- Nissl bodies (stacks of rER)
- Numerous mitochondria, lysozomes, microtubules, neurofilaments, transport vesicles, and inclusions
- Large perinuclear Golgi apparatuses
How can an axon be desringuished from a dendrite on a light micrograph?
The Nissl bodies, Golgi, and free ribosomes will extend into the the dendrites but not into the axon
Facts to know about dendrites
Facts to know about axons.
What are the three main types of neurons? Why are they named the way they are?
Multipolar, bipolar, and pseudouniploar neurons. They are named based on the their number of processes.
Multipolar - one axon and 2 or more dendrites
Bipolar - one axon and one dendrite
Pseudounipolar - on axon that divides close to cell body into two processes
Discuss the general location and function of multipolar, bipolar, and pseudounipolar neurons.
Multipolar neurons serve as motor neurons and interneurons. Axon serves to conduct impulses and neurotransmitters are released at the synaptic ending
Bipolar neurons are located in special sense organs
Pseudounipolar neurons have their cell bodies in the dorsal root ganglia
Facts to know about axon anterograde transport.
Facts to know about axon retrograde transport.
What is another name for the bulb shaped end of an axon?
Bouton
Differentiate a chemical from an electrical synapse.
What are the peripheral and central neuroglia cells?
Facts to know about schwann cells
What are the unmyelinated portions of a peripheral neuron
The axon hillock and terminal arborizations
Discuss the structure of a myelin sheath.
T/F - schwann cells do not envelope unmyelinated nerves. Explain
What is slatatory conduction?
Impulse conduction that jumps like with a myelinated axon
What controls the speed of signal conduction in myelinated neurons?
The thickness of the myelin (thicker=faster) and the axon diameter (larger diameter=faster).
What are the demyelinating diseases we need to know?
Guillain-Barre
Multiple Sclerosis
Facts to know about Guillain-Barre Syndrome.
Facts to know about Multiple Sclerosis
Facts to know about neuronal satellite cells
Satellite cells
What are the primary functions of each of the central neuroglial cells?
Facts to know about oligodendrocytes.
What is the largest glial cell and what is this cell types embryological origin?
Astrocytes
Derived from the neural tube
How many kinds of astrocytes are there and why are each most prevalent?
What is the most recognizable morphological charcteristic of astrocytes?
They have elaborate processes extending between vessels and neurons
What are the primary functions of astrocytes?
What is an easy way to identify astrocytes using immunohistochemistry? Explain why this is.
Label diagram and say what kind of cell this is.
Astrocyte
Facts to know about microglia.
