Lesson 5 Flashcards
(143 cards)
Glial Cells
- provide support and nutrients to neurons
1. astrocytes
2. Microglia
3. Oligodendrocytes
4. Schwanns Cells
Astrocytes (glial cells)
- suspends and separates neurons
- connects to blood capillaries & assists in transporting substances from the blood to the nerve cells
microglia (glial cells)
- cleans damaged tissue from a lesion in the nervous system
- surrounds and destroys harmful organisms
schwanns cells (glial cells)
-form myelin in peripheral nervous system
Neuron (nerve cell)
-communication elements of the nervous system
What are the Neuron structures?
- Soma (cell body)
- Dendrite
- Axon
- Axon hillock
- myelin sheath
- Nodes of Ranvier
- Telodendria
- Terminal Buttons
- Synaptic Vesicles
- Neurotransmitters
- Synapse
Dendrite (neuron structure)
short projections that conduct impulses toward the cell body
Axon (neuron structure)
longer projection that conduct impulses away from the cell body
axon hillock (neuron structure)
junction between axon and soma
myelin sheath (neuron structure)
- white fatty covering on axon
- protects and insulates the axon
- increases rate of neural conduction
Nodes of Ranvier (neuron structure)
- area between myelinated segments where the axon is exposed
- permit saltatory conduction
- > process in which info in the axon passes from node to node, thereby greatly increasing conduction in speech
Telodendria (neuron structure)
smaller branches extending from end of axon
Terminal buttons (neuron structure)
- located at tip of telodendria
- transmit information to next neuron
- contain synaptic vesicle
synaptic vesicles (neuron structure)
contain neurotransmitters
neurotransmitters (neuron structure)
chemical substance that transmits nerve impulses across a synapse
synapse (neuron structure)
small gap between connecting neurons
multiple sclerosis
- chronic disease
- myelin in the central nervous system is destroyed
- myelin forms scar tissue (sclerosis)
- nerve impulses are distorted or interrupted
- symptoms vary based on located and severity of myelin damage
Neurotransmission
communication between neurons by the movement of chemicals across a synapse
neurotransmitters are released…
into synaptic cleft to facilitate transmission of info from the presynaptic neuron to postsynaptic neuron
Neurotransmitters
- acetylcholine, serotonin, dopamine
- excitatory ->increase in activity
- inhibitory ->reduction in activity
Functional differences between neurons
- interneurons
- sensory neurons
- motor neurons
interneurons
communicating within the nervous system
sensory neurons (afferent)
communication sent from the body toward the central nervous system
motor neurons (efferent)
communication sent from the central nervous system to the body