Flashcards in Lecture 6 - Nerves Deck (56)
2 Divisions of the Nervous System
Components of CNS
Brain and Spinal Cord
Components of PNS
Cranial, spinal, peripheral nerves and ganglia
What are the 2 types of cells in the CNS and PNS?
2. Glial Cells
Features of a Multipolar Neuron (x6)
1. Dendrites (2 or more)
2. Cell Body
3. Axon (one) - goes off into periphery
4. Located in spinal cord
5. Motor Neurons and CNS interneurons
6. Most Neurons
Features of Bipolar Neuron (x4)
1. Dendrite (1)
2. Cell Body
3. Axon (1)
4. Sensory neurons of the retina, olfactory mucosa, and inner ear
Features of Unipolar Neurons
2. Axon - Peripheral Process, Central Process
3. Cell Body w/ Single short process
What are the types of neurons based on their functional role?
1. Motor (efferent)
2. Sensory (afferent)
3. Interneuron (more than all other neurons combined)
Are Nissl bodies acidophilic of basophilic?
Basophilic --> lots of ribosomes (acid)
Why does the peikaryon have a euchromatic nucleus, very prominent nucleolus, and Nissl bodies?
Making lots of proteins
What is the Axon Hillock?
The thicker extension of the axon closest to the cell body
What maintains the structure of the neuron?
Neurofilaments (aka intermediate filaments) and neurotubules (aka microtubules)
What are the functions of the cytoskeleton in a neuron? (x2)
1. Mechanical Support
2. Intracellular Trafficking
Where are neurotransmitters made? Where do they go? How do they get there?
1. NT's are made in the cell body
2. They are stored in synaptic vesicles at the terminal end of the axon.
3. They get there by traveling down the axon using the cytoskeleton (neurofilaments and neurotubules)
Is transport in the axon unidirectional or bidirectional?
What are the names for the modes of transportation up and down an axon?
1. Anterograde Transport
2. Retrograde Transport
What is the plasma membrane of the axon called?
What is the cytoplasm of the axon called?
What does the axoplasm contain?
*No protein synth is made here - no ribosomes/rER
What are dendrites?
Elongated processes specialized to receive stimuli from other neurons at contact sites known as synapses
Which is longer, dendrite or axon?
Which process will be more numerous, dendrite or axon?
What is the dendritic spine?
The site of synaptic contact w/ other neurons
What is the purpose of dendrites and the dendritic spines?
Increase surface are to receive as much stim as possible
What happens when a neuron receives an impulse?
1. An electrical impulse travels from the dendrite spine to the dendrite
2. Then to the cell body
3. Down the Axon
4. NT is released
What does the NT do after it is released?
1. Travels across the synaptic cleft
2. Binds to a receptor on the post synaptic membrane
3. Causes an effect
How to best see axons and dendrites on a microscopic image?
*can also use basophilic stains like hematoxylin*
What is in the space between neuronal cell bodies?
1. Glial Cells
2. Glial and Neuronal Process (axons/dendites)