Nervous System Flashcards
The nervous system is made of the ____ and ____.
CNS and PNS
The CNS consists of the ____ and ____. It has _______ that conduct signals ____ the CNS to _______.
Spinal Cord and Brain
Motor Elements, from effectors cells in muscles, glands, viscera etc.
The PNS consists of ______ and has _____ that conduct information _____.
all other nerves
sensory elements, to the CNS
Motor output can be through the ___ or _____.
Somatic or Autonomic
The autonomic nervous system can be split into _______ and ________.
Parasympathetic (Rest and digest)
Sympathetic (Fight or Flight)
Neurons are polarized. True or False?
True
Neurons are stained with the _________.
Golgi method
Dendrites may have ________ shaped like ____. Axons do not have this structure.
Dendritic Spines, Mushroom
Flow of signals through a neuron.
Signal is received by dendrites, process through the cell body and passed down through the axon to release NT.
There are three different neuron morphologies. Describe them.
Multipolar: Classic neuron shape. One axon with short fat dendrites.
Bipolar: Cell body in center with one dendrite and one axon protruding from opposite ends
Pseudounipolar: No true dendrites but rather one large axon. Peripheral projection may extend into skin while central projection will extend into CNS to TRANSMIT information
The most common neuron shape is _______.
Multipolar
Bipolar neurons are found in ________.
Visual and olfactory organs
Pseudounipolar cells are found in ______.
Sensory ganglia of cranial and spinal nerves
Communication between neurons occurs at the _____ where the ________ of the ______ sends neurotransmitters to the ________ of the _____.
synaptic cleft
pre-synaptic terminal of the axon
post-synaptic terminal of the dendritic spines.
Axons contain several _______ containing _______ that will show up on an EM. They also contain lots of _____ needed to ________.
vesicles containing neurotransmitters
mitochondria needed to make ATP to facilitate release of neurotransmitters
The postsynaptic contacts of ________ on an EM will appear as a ______ due to _______.
dendritic spines, an electron-dense line, clustered NT receptors and their associated proteins
What is the major excitatory NT in the CNS?
This causes _________.
Glutamate
Depolarization (more positive)
What is the major inhibitory NT in the CNS?
This causes________.
GABA
Repolarization (More negative)
What allows for loading of a neurotransmitter into the vesicle of the pre-synaptic vesicle in the axon?
What is it activated by?
Proton gradient activated by glutamate.
There are 4 steps of vesicle transport. What are they?
1.Budding
2.Movement (diffusion or motor driven)
3.Tethering to cytoskeleton
4.Fusion where a pore is created to allow transmission of NT from axon through synaptic cleft into the dendrite.
What are key steps involved with tethering and fusion?
Fusion involves the recognition of V-SNARE and T-Snare which interlock and force the donor and acceptor membranes together allowing for NT to be released into the synaptic cleft.
What signals the fusion of synaptic vesicles?
Ca2+!
In the pre-synaptic cell there are Ca2+ channels. When the cell receives a signal via its dendrites, there is an influx of calcium into the cell which urges the fusion of the membranes and the release of NT.
_________ from ____ and _______ bacteria can ____________.
Neurotoxins from Clostridium botulinum and Clostridium tetani can cleave Synaptic Vesicle SNAREs
BOTOX
A voltage potential exists across the membrane. The inside is _______ than the outside. The voltage change is _____ meaning that it________ with distance from the sight of input. _______ inputs are needed.
more negative
graded, decreases, multiple.
When depolarization occurs above a certain threshold value due to ________, _______ open. This conveys a need for ________.
What happens after?
influx of a excitatory NT like Glutamate, Na+ , Action Potential.
Na+ rushes into the cell creating an electrical signal. K+ channels are then opened to allow ions to flow out to repolarize the membrane.
What is the first step of the action potential?
Influx fo Na+ ions into cell due to depolarization by excitatory NT.
Ca2+ is only for the release of the NT into the cleft and into the dendrite!
Neurons have a very prominent _______ especially in the ______. _________ and ______ are the most prominent elements.
Cytoskeleton, axon and dendrites
Microtubules and Neurofilaments (Neuronal IF)
Microtubules and neurofilaments are non-myelinated. True or false?
True
What is Nissl material?
What can they highlight?
Nissl material is acidic components that show up blue because they can be bound by basic dyes.
Nucleolus, Ribosomes/Polysomes
mRNA,tRNA and rRNA
Do neurons have a large amount of Nissl material?
Yes
The neuronal cell body contains lots of _________ but the ________ and __________ do not.
RER
Dendrite and Axon
An ___ is a morphological feature that _____ Nissal stain. Another name for it is _______.
It contains high levels of __ and ______ and is more likely where _____ but varies from ___ to _____.
Axon hillcock, does not
Axon initial segment
Na+ and K+ channels, action potential occurs , neuron to neuron
Axonal proteins are synthesized in the _______.
Cell body
Anterograde transport occurs from _______ to ______ and is controlled by ______.
Retrograde transport occurs from _______ to ______ and is controlled by ______.
Both ______ and ____carry _____________
Cell body to axon tip, Kinesin
Axon tip to cell body, dyenin
Both dyenin and kinesin carry cargoes along microtubules