Block 1 Flashcards
individual, highly specialized cells in the brain
neurons
functional space in which neurons communicate
synapse
cell body
soma
cellular fibers emerging from the soma
neurites
receive messages from other cell; many exist in the cell
dendrites
pass messages away from the cell body to other neurons, muscles, or glands; only one in cell
axons
contain synaptic vesicles
pre-synaptic terminals
contain neurochemical signals essential for neuron function (neurotransmitters)
synaptic vesicles
specialized proteins embedded in the membrane of the next neuron that bind neurotransmitters
neurotransmitter receptors
specialized proteins embedded in the membrane of the presynaptic terminal that bind and transport the neurotransmitter back into the presynaptic terminal for breakdown or reuse
re-uptake pumps
interneuron; single cell body with 2 neurites
bipolar neurons
sensory neuron; single cell body with 1 neurite
unipolar neuron
motoneuron; one single axon up to 3 feet long
multipolar neuron
explains neuronal function; information flows from dendrite to soma to axon via axodendritic connections (synapses); however cells receive information in the soma, axon, and terminals as well so the theory had to be revised
Law of Dynamic Polarization: First Theory
information always flows from presynaptic to postsynaptic cell with regard to a specific synapse
Law of Dynamic Polarization: Revised
bring information into the CNS from the body
sensory neurons
transmit information out of the CNS to muscles
motor neurons
lie between sensory and motor neurons; can be pre or post synaptic dependent on synapse in question
interneurons
molecules that have an electric charge (e-charge)
polar molecules
opposite charges…
attract
like charges…
repel
molecules that have no poles and lack e-charge; CANNOT interact with polar molecules like water (major problem in cell function)
nonpolar molecules
carbon, hydrogen, grease, oil, and fats are… (regarding charge)
nonpolar
when nonpolar molecules acquire a phosplate group; phosphate head attaches to lipid hydrocarbon tail; confest water solubility to normally insoluble fat
phospholipids
polar heads interact with water, so they are…
hydrophilic
nonpolar tails cannot interact with water, so they are…
hydrophobic
have both hydrophobic and hydrophilic regions (major component of nerve cell membranes)
amphipathic (phospholipids)
hydrophobic inside (effective barrier to charged particles trying to enter the cell) and hydrophilic outside
lipid bilayer
communication could not exist if ____ didn’t exist in the membrane
proteins
fluid mosaic
proteins form hydrophilic channels and pumps that float in the membrane
regions of DNA that code for proteins
genes
genetic sequence that exists in the nucleus of a cell; acts as a template for RNA
DNA
single stranded copy of DNA molecule with slightly different sugar; genetic intermediary
RNA
production of an RNA copy of the DNA gene in the nucleus; mRNA codes for specific amino acid sequence and exits to the cytoplasm of cells (allows DNA to go into cell body)
transcription
proteins are sequences of ___
amino acids; 20 essential amino acids
some amino acids function as ___
neurotransmitters
glutamate, aspartate effect
neuronal excitation
glycine effect
neuronal inhibition
assembly of amino acids in a specific sequence encoded for by the mRNA - essentially reads mRNA sequence and inserts amino acids in a particular order
translation
very small proteins released from the nerve cell; act as neurochemical signals between neurons like neurotransmitters (except PHs are proteins, not chemicals like NTs)
peptide hormones
proteins bound to the cell membrane; bind to neurochemical signals released from nerve cells; convey signals between neurons
neurotransmitter transporters and receptors
proteins bound to the cell membrane; bind and transport charged salts (sodium, potassium) across cell membranes; establish and maintain electrical signal potential within cells
neurotransmitter channels and pumps
(actin, tubulin, elastin) determine nerve cell shape and movement; make up cytoskeleton and cellular architecture
structural proteins
protein catalyst that causes chemical reactions to create products from building blocks; can produce new things or break things down
enzyme
transport of new proteins to distant locations in the neurites
axoplasmic transport
brings proteins away from cell body (to neurites)
orthograde/anterograde transport
brings proteins towards the cell body (from neurites)
retrograde transport
structural proteins that move proteins
microtubules and neurofilaments
anterograde transport motor protein (AWAY)
kinesin
retrograde transport motor proteins (TOWARDS)
dynein-dynactin
fusion of the synaptic vesicle with the plasma membrane; the synaptic vesicle dumps hormonal signals or neurotransmitters into the extracellular space; process of secretion
exocytosis
a piece of the membrane pinches back to form a new vesicle
endocytosis
neurons send out neuritic processes; exocytosis > endocytosis; axons from one neuron connect with another neuron to form synapses
neuronal growth
axons withdraw; exocytosis < endocytosis
neuronal pruning
stable associations between neurons; endocytosis = exocytosis
mature synapse
proteins that help nerve cells develop and recognize each other are exchanged between synaptic partners; put out to attract other growing cells; can attract all, but can only connect with a cell that is the same (ex. two 5HT cells)
chemical signals (trophic factors)
tip of a growing neuronal axon
growth cone
“finger feet” sent out by the neuronal axon to contact another cell
filopodia
What does a cell do as it is deciding whether or not to develop signal?
withdrawal and approach cycles of growth
presynaptic cell increases trophic influence (less neurotransmitters); postsynaptic cell decreases receptor number
receptor down-regulation
presynaptic cell decreases trophic influence (more neurotransmitters); postsynaptic cell increases receptor number
receptor up-regulation
reduction in the sensitivity of postsynaptic cell; postsynaptic cell is overwhelmed by amount of neurotransmitters from presynaptic cell; decreases number of receptors and becomes less sensitive to neurotransmitter presence
desensitization
presynaptic cell decreases trophic influence; starves postsynaptic cell; postsynaptic increase receprots becomes supersensitive to any of the remaining neurotransmitter around the cell
denervation supersensitivity
synapse on the soma (cell body)
axosomatic synapse
synapse on an axon
axoaxonic synapse
synapse on a terminal
axosynaptic synapse
associated with a single neuronal axon; when an axon is severed, forms a guidance tube to guide regenerating end of the axon to target end to help it heal and regenerate
Schwann cells
Schwann cells are located in the __
peripheral nervous system (PNS)
oligodendrocytes are located in the __
central nervous system (CNS)
each supports several axons, when axon is damaged, the __ fails to respond so damage is permanent
oligodendrocyte