To Learn Human Organism Flashcards
optimal functioning
variables are kept in homeostatic range
cell excitability
ability of cell to generate electrical signals in response to stimulus
soma
body of neuron
axon
cable that conducts electricity away from dendrites
dendrites
receive information
myelin sheath
lipid that surrounds axon, insulator to make quicker E impulse
afferent neurons
sensory neurons, pass info from tissue + organs to CNS
efferent neurons
motor neurons, pass info from CNS to effector cells
interneurons
connect neurons
resting membrane potential
voltage in non-signaling cells,
- 60 to -90 mv
depolarisation
quick shift of membrane potential from negative to positive
absolute refractory period
between depolarisation + repolarisation
- neuron can’t react to new stimulus until it returns to resting membrane potential
repolarisation
- after depolarisation
- potassium moves out of cell + voltage gates sodium ion channel closes
- cell approaches resting membrane potential
hyperpolarisation
cell becomes more negative than resting membrane potential
relative refractory period
stronger stimulus needed to activate neuron
electrical synapse
passes E signals through gap junctions
- fast
- bidirectional
- less complex
chemical synapse
E activity converted to release neurotransmitters
synaptic weight
strength of firing from neuron
neurotransmitters
signaling molecule secreted by neurons to affect another neuron across synapse
mechanisms of removing neurotransmitters
- diffusion
- reuptake
- degradation
- uptake by astrocytes
biogenic amine neurotransmitters
histamine, serotonin, dopamine, epinephrine, acetylcholine
enzymes that inactivate neurotransmitters
MAO + COMT
MAO
inactivates serotonin, dopamine, epinephrine + norepinephrine
COMT
inactivates dopamine, epinephrine, norepinephrine
glia cells
non neuron cells in CNS
glial cells functions
nutrients
myelin sheaths
neurogeneration
destroy pathogens
remove dead cells
