Neuron Physiology Flashcards
Define neuroscience.
study of the nervous system; including cellular and molecular processes, behavioural, affective and cognitive abilities, systems or circuitry, and disease.
What are the components of a neuron?
- Dendrites
- Cell bodies
- Axon.
Define neural unit.
brain is made up of individual neurons that contain specialized features (dendrites, cell body, axon).
Define neuron specialisation.
units may differ size, shape, and structure according to their location or functional specialization.
Define neuronal fibres.
Outgrowths of neurons.
Define neuronal contacts.
Neurons are connected by sites of contact and not cytoplasmic continuity.
Define resting potential.
A product of the electrical difference between extracellular and intracellular solutions.
Define oligodendrocytes,
Cells that that send out projections that wrap around axons.
Name the golgi stains used for identifying neurons and it’s colour.
Silver nitrate and potassium dichromate. Labels neurons dark brown/black.
What is the Nissl stain used for and what colour is it.
Identifies all cells in the brain. Turns the RNA within the endoplasmic reticulum blue.
Define dendrites.
Part of neuron that transmits information from sensory receptors, other neurons.
Define cell bodies.
Part of neuron that integrates information; also has a nucleus).
Define the axon of a neuron.
Signal output, passes information to subsequent neuron.
Define neural unit.
The brain is made up of individual neurons that contain specialized features (dendrites, cell body, axon).
Define neuronal fibres.
Outgrowths of neurons.
Describe neuronal contacts.
Neurons are connected by sites of contact and not cytoplasmic continuity.
Define Dale’s Law.
Each neuron has a specialised chemical. However recent research has found this is NOT TRUE for all neurons.
How does the voltage within a neuron compare to the voltage of the surrounding solution.
Significantly lower.
Define resting potential.
a product of the electrical difference between extracellular and intracellular solutions.
Whereabouts does the resting potential usually sit?
between -60 and -70mV.
What is the minimum voltage required to achieve an action potential?
-40mV.
What causes the initial rising and falling voltage of an action potential?
Rising - inward flux of sodium.
Falling - outward movement of both sodium and potassium.
What is the absolute refractory period?
The period when an action potential cannot be stimulated.
What is the relative refractory period?
The period when a small voltage change can be stimulated.
Define the excitatory presynaptic potential.
Presynaptic neuron stimulates a mild depolarization in neuron; leading to a graded increase in voltage.
Define inhibitory presynaptic potential.
Presynaptic neuron stimulates a mild hyperpolarization in neuron; leading to a graded decrease in voltage.
Define oligodendocytes.
Cells that send out projections that wrap around axons.
What happens when myelin is degraded.
Multiple sclerosis - disrupts transmission of nerve signals.
What is myelin?
Myelin sheaths coat Nodes of Ranvier.
