B2.021 Altered Mental Status in an Elderly Patient Flashcards
(42 cards)
what characterizes the darker areas of brain matter?
cell bodies in high density
what characterizes the light areas in brain matter?
signaling pathways, axons of neurons present (no cell bodies)
what is a resting membrane potential?
the typically negative electrical charge of the cytoplasm of the cell
what is a synapse?
the interaction between neurons
how is information from sensory systems transmitted?
all information is encoded into action potentials, frequency changes in potentials represent different sets of information
what are motor neurons?
neurons that act on muscle cells
what are interneurons?
local circuitry between neurons
what are sensory neurons?
receive information from periphery
why might some neurons not have dendrites?
simplistic structure = simplistic function, transfer information quickly along axon from point A to point B
what might some neurons not have an axon?
interact exclusively with other neurons through dendrites
why do cerebellar Purkinje cells have a large network of dendrites?
receive 200000 synapses from other neurons
what are glial cells?
cells that fill space between neurons in CNS, 10x more glial cells than neurons
what are 5 functions of glial cells?
- maintain ionic balance
- modulate the rate of nerve signal propagation
- uptake of neurotransmitters
- regulate recovery of neurons from injury
- form the epithelium in the ventricles
what are 4 types of glial cells?
- astrocyte/satellite cell
- oligodendrocyte/schwann cell
- microglial cell
- ependymal cell
what is the function of myelin?
accelerates transmission of action potentials
what are neurotransmitters?
molecules used by neurons to communicate with one another
what are the two types of synapses?
chemical and electrical
what is the distance between the pre-and post-synaptic membrane in a chemical synapse?
50 nm, relatively large and causes a diffusion delay of 1-2 ms
what ion channel activates vesicle functions?
Ca2+
what enzyme is responsible for the degradation of ACh?
ACh esterase
what are two mechanisms for removal of neurotransmitters?
degradation and removal/re-uptake
what types of receptors bind ACh?
nicotinic
what are the types of postsynaptic potentials?
excitatory (EPSP) and inhibitory (IPSP)
what characterizes an EPSP?
depolarization of the membrane due to the transient increase in Na+ or Ca2+ conductance