Bio — Nervous syst Flashcards
2 divisions of the nervous system organs
CNS
Peripheral nervous system
What part of the neuron receives information and transmits it towards the cell body
Dendrites
What part of the neuron is the cytoplasmic extension?
Dedrite
What part of the neuron controls the metabolic activity of the neuron?
Cell body
What transmits impulses away from the cell body
Axon
What is the end of the axon called that transmits signal to other neurons?
Synaptic terminal
In what part of the axon are the incoming signals summed up ?
axon hillock
what is myelin made of
oligodedrocytes
Why are long distance neurons myelinated?
To prevent leakage of signal from the exon and allow for faster conduction of impulses
From which gaps are action potentials spread?
nodes of ranvier
Resting potential
potential difference at rest between the extracellular space and the intracellular space
What is the value of the resting membrane potential? is the inside more negative or positive?
-70mV
Inside is more negative
To have a more negative internal environment, which ions are pumped in and out?
3 Na out of the cell
2 K into cell
K is more permeable so it also leaves the cell leaving the internal environment more negative
The cell membrane is permeable to which ion more?
K ions
What is the threshold potential?
-55mV
How is action potential triggered?
When membrane potential -70mV increases to threshold potential -55mV, voltage gated Na channels open
3 phases of action potential
Depolarization, repolarization, polarization
polarized meaning
To separate charges
is the resting potential polarized or depolarized
It is depolarized
Depolarized meaning
Losing the separation of charges which turns the membrane potential to 0mV
Why is brain having white and gray matter?
White matter is heavily malinated for faster transmission
Gray matter is less myelinated for processing information
At the synapse, when the action potential arrives at the axon terminal, what happens to the synaptic vesicles
Synaptic vesicles fuse with the presynaptic membrane
At the synapse, when the action potential arrives at the axon terminal, what happens to the neurotransmitter?
It is released into the synapse and diffuses across the synapse
Neurotransmitter
Chemical signals that send signals across a synapse
Ex: dopamine serotonine
At the synapse, when the action potential arrives at the axon terminal, where does the neurotransmitter act on?
It acts on the receptor proteins embedded in the post synaptic membrane
What are the 3 neuron types?
Afferent neuron
efferrent neuron
interneuron
What kind of information does the afferent neuron carry?
it carries sensory information to the brain and spinal cord and
helps in transmitting information about the external environment
What kind of information does the efferent neuron carry?
It carries motor commands from brain and spinal cord to the muscles
Responsible for movement
what is the function of interneuron & what does it do ?
connect sensory motor neurons
Participating local circuits to connect the re neurons
Nerves
nerves are a bundle of axons covered by connective tissue
Plexus
It is a network of nerve fibers
What does neuronal clusters include?
Ganglia & nuclei
Who protects the neuronal cells?
Neuroglia
Which cell in the CNS maintains the integrity of the blood brain barrier?
what else does it regulate?
➡️astrocytes
➡️also regulate nutrient and dissolved gas concentrations and absorb/recycle neurotransmitters
Which cell in the CNS removes cellular debris and pathogens
Microglia
Which cell in the CNS lines the brain ventricles?
What else does it aid in?
Ependymal cells
Aid in the production, circulation , and monitoring of cerebral spinal fluid
