Ch 12 Nervous Tissue Flashcards
What are the 3 primary functions of the nervous system?
- Sensory
- Interpretation
- Motor function
what composes the CNS?
- Brain
- Spinal Cord
What composes the PNS?
- Any nerve outside the CNS
- ANS (autonomic nervous system)
what does the ANS compose of?
- Sympathetic Nervous System
- Parasympathethic Nervous System
what are the cells of the nervous system?
- Neurons
- Neuroglia
what type of neuron is sensory
They are afferent - because they are affected from stimulation
what type of neuron are interneurons?
Connecting neurons- they cause the signals between afferent and efferent nerves to communicate
what type of neurons are motor neurons?
they are efferent - because they cause an effect to set in motion
This part of the axon is where storage for the chemical Ach is found
Axon Terminal
This part of the axon is the covering or layer of white fatty material that protects and insulates the nerve fiber and increases speed of transmission
Myelin Sheath
This part of the axon is the gaps inbetween the myelin sheath and allow for impulses to travel quicker
Nodes of Ranvier
what are the neuroglia cells of the CNS?
- Astrocytes
- Oligodendrocytes
- Microglia
- Ependymal Cells
what are the neuroglia of the PNS
- Schwann Cells
- Satelite Cells
what is the purpose of the neuroglia?
Support, Protect and nourish the neurons
does not conduct nerve impusle
This neuroglia prevents blood toxins from entering the nervous system; BBB
Astrocytes
This neuroglia is small than astrocytes
Microglia
This neuroglia helps hold nerve fibers together & creates myelin sheath
Oligodendrocytes
This neuroglia lines the indisde of the ventricles of the brain and spinal canal and produces CSF
Ependymal Cells
This type of neurogila is surrounded by fat cells around the cell body and provides structural support
Satellite cells
This type of neurogila forms the myelin sheath that is wrapped around the axon
Schwann Cells
where is it hard for the neurons to regenerate?
Central Nervous System
which type of neuron allows for the nerve to somewhat regenerate?
Schwann Cells
what is neurolemma?
the myelin sheath that is wrapped around the axon
What matter has myelinated fibers and is found in both the CNS and PNS
White matter
what matter consist of cell bodies, interneurons, and unmyelinated fibers?
Gray Matter
Where is gray matter found in the PNS?
Ganglia
Where is gray matter found in the CNS?
Nuclei
what happens to the charge inside of the cell when depolarization ?
the cells becomes positive from Na++ enters
what happens to the charge inside of the cell from repolarization
the cell becomes negative again from K++ reentering
what is refractory period?
short period of time when neuron is unresponsive to any stimuli and cannot depolarize
what is the charge inside the cell during resting membrane potential
negative from K++
What is saltatory conduction?
allows fast movement along the myelinated axons as it allows leaps from one Node of Ranvier to the next.
what is the synaptic cleft?
where the presynaptic cleft and postsynaptic cleft meet but don’t touch
what is the presynaptic cleft
anything before the axon terminal and up the neuron
This type of neural circuit is when presynaptic neuron influences several postsynaptic neurons
Diverging Circuits
This type of neural circuit is when several presynaptic neurons synapse with one specific postsynaptic neuron
Converging Circuit
This type of neural circuit is when a presynaptic neuron causes the postsynaptic neuron to send a series of nerve impulses
Reverberating Circuit
This type of neural circuit is when a single presynaptic neuron stimulates a group of neurons, each of which
synapses with a common postsynaptic cell
Parallel After-Discharge Circuits
What is an example of Diverging circuits
several muscle fibers
what is an example of converging circuits
Receptor neuron receiving information from several muscle fibers
what is an example of reverberating circuits
Breathing
what is an example of parallel after-discharge circuits
quick succession of activities (critical thinking such as
mathematical calculations)
what causes the central nervous system to repair itself slow or if it happens at all?
Lack of neurolemma
what helps the PNS to regenerate and repair itself?
schwann cells and the neurolemma
what type of neural circuit could be the cause of epilepsy
Abnormal reverberating circuits
what are the 4 possible causes of epilepsy?
- Brain Damage
- Toxins
- Metabolic Disturbance (glucose levels)
- Infections
