Basic neurophysiology Flashcards
Intracellular resting membrane potential
-70mV
Intracellular threshold potential
-55mV
Channels that open at the intracellular threshold potential of -55mV
Na+ channels
Result of the Na+ influx caused by Na+ channels opening
Reversal of the membrane potential to +40mV
Effect of the membrane potential reaching +40mV
Na+ channels close
Voltage gated K+ channels open
K+ ions move out of the axon
Cell membrane is repolarised
Term for a junction between two nerve cells
Synapse
Three types of synapses in the nervous system
Chemical synapse
Electrical synapse
Conjoint synapse
Features of a chemical synapse
Presynaptic neuron is stimulated and releases a chemical molecule
Molecule acts on the postsynaptic neuron to produce an effect, or to carry the impulse further along to a further neuron
Types of chemical synapse depending on their effect on the postsynaptic neuron
Excitatory
Inhibitory
Effect of excitatory chemical synapses on postsynaptic neurons
Depolarises
Effect of inhibitory chemical synapses on postsynaptic neurons
Hyperpolarises
Process where a postsynaptic depolarisation is not enough by itself to induce an action potential in the cell, but with further stimulation an action potential can be generated
Facilitation
Type of facilitation where input from several different presynaptic cells leads to an action potential
Spatial summation
Type of facilitation where recurrent stimulation from the same presynaptic neuron results in an action potential
Temporal summation
Features of an electrical synapse
Response is generated by electrical communication without the need for chemical molecules to be exchanged
Features of a conjoint synapse
Both electrical and chemical properties
Part of the body which acts as the satiety centre
Ventromedial hypothalamus
Part of the body which acts as the feeding centre
Lateral hypothalamus
Neurochemicals which cause increased appetite
Ghrelin
Neuropeptide Y
Neurochemicals which decrease appetite
Leptin
Cholecystokinin
Serotonin
Part of the body where ghrelin is synthesised
Gastric mucosa
Cells which synthesise ghrelin
Adipose cells
Part of the body where activity is increased by food and food cues
Nucleus accumbens
Type of activity produced in the nucleus accumbens by food and food cues
Dopaminergic activity
Part of the body which acts as the hypothermic centre
Preoptic anterior hypothalamus
Part of the body which acts as the hyperthermic centre
Posterior hypothalamus
Effects of stimulating the preoptic anterior hypothalamus
Sweating
Vasodilation
Hyothermia