neurons Flashcards
what are dendrites?
fibers with synaptic receptors that receive information from other neurons
what is the cell body / soma?
most of the neurons metabolism occurs here; they may also have synapses
what is the axon?
long fiber that conveys an impulse toward other neurons, organs, or muscles
presynaptic terminal
at this point, the axon releases chemicals that cross through the junction from one neuron to the next
where are terminals located?
at the end of the axon
multipolar
many dendrites, one axon
bipolar
one dendrite, one axon
uni- or monopolar
have an axon that branches out in two directions (input zone and output zone)
why is there only one axon?
receive a lot of information, but just send one message; more precise
what are spindle neurons?
they are a bipolar neuron important in socialization and empathy; new research
what is another name for spindle neurons?
von economo neurons
motor neurons
its soma is in the spinal cord; conducts impulses along its axon to a muscle
it is efferent
what does efferent mean?
carries information out
sensory neurons
light, sound, touch; soma is located on the trunk
it is afferent
afferent
brings information in
intrinsic neurons
inside the structure
the neuron as a factor: what is the final product?
proteins
MAO does what?
degrades serotonin; increases violent behavior
what is glia?
glue; supporting cells; provide firmness and structure for the brain
functions of glia
guidance - help with migration of neurons
form myelin - oligodendrocytes in CNS, Schwann in PNS
synapse formation
supply oxygen and nutrients
removes dead neurons
removal of K+ by astrocytes
what are the types of macroglia?
astrocytes, oligodendrocytes
astrocytes
serve different functions: nutritive function, together with microglias, remove dead neurons after brain injury
oligodendrocytes
contribute to myelin sheath to the axon in the CNS (Schwann in PNS)
microglia
mobilized after injury, infection, or disease
glia pathology
tumors - majority of malignant brain tumors are derived from glial cells
MS - oligodendrocyte loss
Type 1 Charcot-Marie-Tooth disease - loss of muscle; motor and sensation issues
what is the special function of astrocytes?
coordinating different networks, which doesn’t work properly in schizophrenic people
ramon y cajal
father of neuroscience; discovered that nerve cells don’t touch/are separated
golgi method
silver staining technique that allowed us to see neurons
