Neurophysiology Flashcards
PNS - Peripheral nervous system
Nervous system outside the brain and spinal cord.
In the pns, Schwann cells produce this insulating coating.
CNS - Central nervous system
Complex of nerve tissue that controls activities of the body. Vertebrates comprises the brain and spinal cord.
Nervous system function
@ cellular network, single cells or even subcellular compartments.
Generation and propagation of electrical impulses within and between neurons.
Process
Involves for those that have disorders affecting the NS including Parkinson’s, MS multiple sclerosis, motor neurone disease, viral encephalitis meningitis, stroke or are suffering w/ dementia.
Dentrite
Direct impulse to cell body.
Carry info into cell body which contains the nucleus and other associated organelles of cells.
Axon
Single extension from cell body.
Conducts impulses away from cell body or soma
Synaptic knob
Swollen end of axon.
When electrical impulse arrives @ synaptic knob, neurotransmitters is released into the synaptic cleft.
Axon hillock
Connects soma to axon.
Extends or drawn out to from the axon.
Cell body narrows @ part called Axon hillock
sensory receptor
Detects changes in environment
CNS - central nervous system
Brain and spinal cord
Nissl bodies
Free and fixed ribosomes.
Myelinated internode
Axon region w/ Schwann cell
Neurolemma
outer Schwann cell membrane
Synaptic vesicles
Vacuole of neurotransmitters
Perikaryon
Surrounds the nucleus and contains groups of free and fixed ribosomes called nissl bodies
Telodendria
Axon divide into collateral branches. If the collateral breaches subdivide even more these are known as telodendria.
Each telodendrum ens in synaptic knob.
Neurotransmitters
found in the neuron stored in the synaptic vesicles. When an electrical impulse arrives @ synaptic knob, neurotransmitter is released int the synaptic cleft.
Axon of neuron
Usually covered by a myelin sheath
Gaps in sheath
Gaps in sheath are called nodes of ranvier
Axon membrane
Axon membrane aka axolemma
Neurilemma
Outerlay of Swann cells covering axolemma @ myelinated internodes
Astrocytes
Found @ CNS
Hold neurons in position and forms which aka blood brain barrier.
Depolarisation
When the membrane potential becomes less negative - more positive
- change in the cell during which cell undergoes a shift in electric charge distribution, resulting in less negative charge inside cell.
- opening of channels that let positive ions to flow into the cell causing depolarisation
- AP has changed the membrane potential to +ve value.
- cell reaches its highest voltage from depolarisation.
Latent period
Time interval - resting period of neuron
Stimulus
Event that evokes specific functional reaction in organ or tissu
Repolarisation
Change in the membrane potential that returns to a negative value just after depolarisation
Glial cells
Physical support for neurons
- provide nutrients and regulate extracellulur fluid of brain especially surounding neurons and their synapses
Influx
Flow inward or into something
Hyperpolarisation
Change in cells membrane potential that make it more negative - inhibits AP by increasing stimulus required to move membrane potential to AP threshold.
Action potential
Impulse occurs when you’re on a stimulated above its resting potential
