CNS 4b Flashcards
Neurons
communicative cell generates and transmits electrical/ chemical signals
-amitotic (don’t divide). extreme longevity, high metabolic rate (brain needs glucose)
astrocytes
attach to neurons and capillaries, monitor chemical environment of brain
microglia
immune cells of the brain, similar to mo (engulf and destroy pathogens)
oligodendrocytes
produce myelin sheath (called schwann cells in PNS)
Ependymal cells
produce CSF and line cavities (ventricles) of brain
Parts of neuron-dendrite
- receiving part filled with receptors
Cell body
-soma
nucleus: collection of cell bodies CNS
ganglion: collection of cell bodies in PNS
Axon
one long, from soma
Myelin
-insulates/protects axon
-speeds nerve conduction
-white matter____, gray matter____
myelinated, non-myelinated
sensory neurons
transmit impulses from peripheral sensory receptors to the CNS
sensory neurons transmitted
via afferent pathway
interneurons
transmit impulses from neuron to neuron
motor neurons
transmit pulses from CNS to an effector organ
via effernt pathway
sensory neuron types
-nociceptors (pain)
-mechanoreceptors (touch, pressure)
-thermoreceptors (temp)
-proprioceptors (location of bosy parts)
Neuronal communication- electrical
AP traveling down nerve axon
Action Potential generated by depolarization of cell membrane
Neuronal communication- chemical
neaurotransmitter release across synapse
in chemical communication, ___synaptic cell releases and ____synaptic cell receives (contains receptor for NT)
Pre, Post
Neurotransmitters
produced in neuron, held in vesicle until signaled to release
Effect of neurotransmitter determined by ____
action on postsynaptic neuron (excitary or inhibitory)
Excitatory
depolarizes cell; EPSPs (excitatory postsynaptic potentials)
Inhibitory
hyperpolarizes cell; inhibitory postsynaptic potentials (IPSPs)
Common neurotransmitters
NE, ACh, dopamine, histamine, endorphins,
major two:
gamma-aminobutyric acid (GABA): inhibitory
glutamate: excitatory
____can interfere with neurotransmitter production, storage, release, reception or metabolism
drugs