Cytology Flashcards
Which system is associated with decreases in reflexes?
PNS (hyporeflexia)
What system is associated with increases in reflexes?
CNS (hyperreflexia)
which nerve cell is excitable?
neurons
which nerve cells are non-excitable?
glial cells
function of an axon?
Action potential is propagated down it
function of the axon hilock?
contains a high density of gated sodium channels, where AP is generated
what is average range of axon diameter?
.2 micons to 20 micros
Describe the neural doctrine
each neuron is a distinct cell whose processes begin at cell body. no continuity
describe the principle of dynamic polarization
information flows in a precise and consistent direction
Describe principle of connection specificity?
no cytoplasmic continuity, only connect to specific things, precise and specialized contacts
what are the three different shapes of a neuron?
unipolar: one neurite, bipolar: two neurites, multipolar: more than two
three functional classifications of neurons?
Afferent, efferent, interneurons
7 functions of glial cells?
provides firmness, myelin, remove debree, buffer ions, guide neurons to terminal sites, blood brain barrier, shuttle particles from blood to nerves
function of microglia?
mobilized after injury, infection or disease. small enough to cross the blood brain barrier
what are the three types of macroglia?
oligondendrocytes, schwan cells, astrocytes