Neuroscience Flashcards
3 ways Neurons differ from standard cells
- Their metabolism is specialised
- Their cell membranes contain selective ion channels
- They have cell processes which are where metabolic processes occur
what supporting cell are neurons surrounded by
glial cells
what does it mean when a neuron is myelinated by a glial cell, and why does this benefit the neuron?
The glial cell membrane wraps around the axon, surrounding it in myelin (lipid/fat). Good for the neuron because myelin acts as an insulating layer meaning the conduction of the nerve impulse can happen faster
why is the balance of ions unequal in neurons
the sodium-potassium pump removes the sodium ions making the electrical charge of the neuron negative (-80)
What is the number for the threshold
-60mV
What is action potential
When the + sodium ions outnumber the - chloride ions, making the electrical charge positive
What is the all or none rule
A neuron will either fire (action potential) if threshold is exceeded or it wont
What is the refractory period
The time taken for an axon to recover its ionic balance before it can generate another action potential
What is a synpase
A junction between 2 neurons or between a neuron and its target organ
Why do synapses only allow one way communication
- only presynaptic axons contain neurotransmitters
- only post synaptic dendrites contain receptors for neuro transmitters
Name the 5 main neuro transmitters
Acetyl choline
Glycine
Glutamate
Gamma amino butyric acid (GABA)
Noradrenaline
What is acetyl choline
NT at neuro-muscular junctions in the PNS
what is Glycine
Inhibitory NT in the CNS
what is Glutamate
excitory NT in the CNS
What is GABA
inhibitory NT in CNS
What is Noradrenaline
NT in sympathetic system
why are NT rapidly destroyed
to prevent a repeated transmission
what does grey matter comprise of
dendrites, cell bodies, and synapses
what does white matter comprise of
axons
where does ascending sensory pathways transmit information from and to
from the sensory spinal nerves to the brain
where does descending motor pathways transmit information from and to
from the brain to motor spinal nerves
what enters the dorsal horn
sensory axons
what leaves the ventral horn
motor axons
what area of the brain is arranged somatopically
the primary motor cortex
