Week 2 Flashcards
(22 cards)
What is the difference between neurons and glial cells?
Neurons transmit info. Glial cells support neurons; e.g. removal of debris, keeping chemical environment stable, insulating them.
What are astrocytes responsible for?
Filtering the chemicals in the blood stream as to make sure the brain is not receiving toxins.
What is the difference in function of oligodendrocyte and schwann cells?
CNS myelin; PNS myelin
What is the function of microglia cells?
Removal of debris.
What is the common link between astrocyte, microglia cells, oligodendrocyte and schwann cells?
They are all different type of Glia cells.
What is the difference between an afferent neuron and efferent neuron?
Afferent neuron is a sensory neuron. Efferent neuron is a motor neuron.
___ are collector fibres receiving information from other neurons. The ___ contains the nucleus of the cell and other biological machinery to keep the cell alive. The ___ transmits messages from the soma to where the next neuron is. The _______ are at the end of the axon and send messages to a different neuron.
Dendrites; cell body; soma; axon terminals
What is a synapse and what is a synaptic cleft?
Where on neuron connects to another; space between one neuron and another.
Outline the general principles of a resting potential.
Pumps almost all NA out; high in K. Lots of K inside; wants to balance numbers = crowd control. Very negative, wants to balance charge = power balance. Same with NA outside the cell.
Leak of NA inside; pumps out 3 NA and brings 2 K in.
Resting potential = very negative; full of K.
Outline the general principles of a graded potential.
For every NA ion that comes in, the voltage goes up slightly, NA is positive.
Depolarisation = less negative, NA in the neuron.
For every K that goes out, voltage goes down, K is positive.
Hyper-Polarisation = more negative, less K in the neuron.
Outline the general principles of a action potential.
If voltage depolarises from -70mv to -50mv, threshold = all sodium rushes in. Split second where neuron is full of NA and K.
Voltage is then +40mv. Location 1 has rush of NA; causes change; location 2 has rush of NA, etc.
All NA channels close at +40mv.
K rushes out because cell is too positive with all the NA.
Cell voltage now quickly drops to -90mv; equal K in and out.
Pump works to get back to resting potential.
Describe what happens to the myelin sheath in an individual that has multiple scleroses.
Myelin sheath is destroyed. Myelin hardens to a tissue call scleroses.
What are acetylcholine (Ach), dopamine, serotonin and norepinephrine, GABA, glutamate and endorphins?
Neurotransmitters.
What is the role of acetylcholine?
Learning, memory and especially muscle movement.
What is the role of dopamine?
Arousal and mood states, though processes, and physical movement.
What is the role of serotonin and norepinephrine?
Arousal and mood.
What is the role of GABA?
Main inhibitory neurotransmitter.
What is the role of glutamate?
Main excitatory neurotransmitter.
What is the role of endorphins?
Groups of neurotransmitters involved in pain perception and relief.
What is the difference between white and grey matter?
White - myelin; whitish appearance forms white matter, most important for fast transmission.
Grey - neurons; high density of cell bodies produce grey matter, information is processed and not just transmitted.
What is an agonist molecule?
It excites; similar enough in structure to the neurotransmitter. Mimics the action.
What is an antagonist molecule?
Occupies the receptor site and blocks the action.
