Test 2 Flashcards
Presynaptic
referring to the component of a synapse specialized for transmitter release. UPSTREAM of a synapse.
Postsynaptic
referring to the component of a synapse specialized for transmitter reception. DOWNSTREAM of a synapse
Neurotransmitter
substance released by synaptic terminals for the purpose of transmitting info from one nerve cell to another
synapse
specialized opposition between a neuron and its target cell for transmission of info by release and reception of a chemical transmitter agent.
axon
the neuronal process that carries the action potential from the nerve cell body to a target
Neurotransmission
process in which a substance is released by synaptic terminals for the purpose of transmitting info from one nerve cell to another
neurons
cells specialized for the conduction and transmission of electrical signals in the nervous system
Inhibitory synapse
synapse that decreases the likelihood of the downstream neuron sending an action potential
excitatory synapse
a synapse that increases the likelihood of the downstream neuron sending a signal (action potential)
(Auditory)
Middle Ear
convey and amplify sound waves
(Auditory)
Inner Ear
translate sound waves into nerve impulses
(auditory)
Amplitude
magnitude of displacement of a sound pressure wave
(auditory)
Outer Ear
- Pinna
- auditory canal
- eardrum (tympanic membrane)
(Auditory)
Middle Ear
Ossicles: 3 tiny bones
- malleus
- incus
- stapes
(Auditory)
Inner Ear
- semicircular canals
- sensory organs involved in balance - cochlea
(Auditory)
Pitch
psychological aspect of sound related to the fundamental frequency
(Auditory)
Loudness
psychological aspect of sound related to magnitude
Outer Ear
Picks up sound waves in the environment
frequency
number of times per second a pattern of pressure change repeats
Probiotic
denoting a substance that stimulates the growth of microorganisms, especially those w/ beneficial properties (such as those of the intestinal flora)
agnosia
inability to name objects
Aphasia
difficulty comprehending language due to damage in Broca’s or Wernicke’s area (or others)
Wernicke’s area
temporal lobe are that mediates language comprehension
Broca’s Area
frontal lobe are specialized in the production of language
Map
the ordered projection of AXONS from one region of the nervous system to another, by which the organization of the body (or some function) is reflected in the organization of the nervous system
tonotopic map
the topographic mapping of frequency across the surface of a structure, which originates in the cochlea and is preserved in ascending auditory structures
somatotopic map
cortical or subcortical arrangements of the sensory pathways that reflect the organization of the body
retinotopic map
the two dimensional representation of the retinal image in the neurons of the primary visual cortex
Hippocampus
part of the temporal lobe involved in the consolidation of short-term memories into long-term memories (cortex)
ion channel
integral membrane proteins possessing pores that allow certain ions to diffuse across cell membranes, thereby conferring selective ionic permeability
action potential
the electrical signal conducted along axons (or muscle fibers) by which info is conveyed from one place to another in the nervous system.
ion
an atom or molecule w/ a net electrical charge
learning
the acquisition of novel behavior through experience
memory
the faculty by which the mind stores and remembers information
molecular basis of memory
strengthening or weakening of synapses
cellular basis of memory
altering the interconnections between neurons
synaptic bouton
a swelling specialized for the release of neurotransmitter that occurs at the end (or along) an axon-pre-synaptic (before synaptic cleft)
Also Known As an axon terminal or terminal boutons
receptor
a molecule specialized to bind any one of a large number of chemical signals, preeminently neurotransmitters.
ionotropic receptor
receptors in which the ion channel is an integral part of the receptor molecule (as of course is the ligand binding site)
Also known as ligand gated ion channel
ligand gated ion channel
a large group of neurotransmitter receptors that combine receptor and ion channels functions into a single molecule
-presence of ligand allows ion flow “gating” (controlling the passage of)
ligand
a molecule that binds to another (usually large) molecule
metabotropic receptors
receptors in which the ligand binding site is an integral part of the receptor molecule but the receptor is only indirectly linked to an ion channel.
-AKA: G-protein-coupled-receptors- the intracellular signaling pathways use G-proteins. Also known as 7 transmembrane receptors
ionotropic
direct effect on ion flow, effects fast and brief
- ions flow through the receptor
- most fast receptors are of this type
metabotropic
indirect effects of ion flow
- conformational change transmits info across the membrane
- often involve biochemical cascades that can affect many processes
- can be longer lasting
voltage sensitive sodium channels
allows ion flow in response to membrane depolarization
Node of Ranvier
periodic gaps in the myelin of axons where action potentials are generated
salutatory conduction
mechanism of action potential propagation in myelinated axons; so named because action potentials “jump” from 1 node of Ranvier to the next due to generation of action potentials only at these sites
voltage gated CA++ channel
Influx of CA++ synapse causes vesicles to fuse w/ the membrane and release neurotransmitter
agonist
substance that binds to a receptor and activates it
antagonist
substance that binds t o receptor and prevents its activation
fast excitatory
neurotransmitter typically binds to an ionotropic receptor on the post-synaptic membrane activating a single neuron
- glutamate is a key ex. in the brain
- glutamate synapses can be readily strengthened or weakened
- acetylcholine is used at the neuromuscular junction
neuromuscular junction
the synapse made by a motor neuron on a muscular fiber
fast inhibitory
rapidly inhibit target neurons via ion channel
- GABA is the main brain inhibitor, glycine in the spinal cord
- sedatives typically enhance GABA signaling
slow neuromodulators
typically small proteins acting via GPCRs that change neural activity for longer periods, often in multiple neurons
-dopamine, serotonin, epinephrine (adrenaline)
resting potential
the electrical differences across the cell membrane of -milli volts that result from the action of the Na+/ K+ pump
polarized
there’s an electrical difference across the cell membrane
depolarization
displacement of cell’s membrane potential to a less negative value
hyperpolarization
displacement of cell’s membrane potential to a more negative value
ligand gated channel
activation by ligand binding such as a neurotransmitter allows ion flow across the membrane
voltage gated channel
activated by changes in the membrane potential allowing ion flow across the membrane
axon hillock
swelling at the body junction of the neural cell body (soma) and the start of the axon. Starting point for action potentials.
action potential characteristics
- self regenerating
- all or no change in voltage
- propagates from axon hillock ( cell body)
- induces synaptic transmission
excitatory neurotransmitter
depolarizes target neuron
-glutamate allows Na+ and Ca++ influx
inhibitory neurotransmitter
hyperpolarizes target neuron
-GABA allows CI ion influx
neurotransmitter recovery or degradation mechanisms
diffusion: away from synapse
reuptake: neurotransmitter reenters presynaptic axon terminal
- enzymatic destruction inside terminal cytosol inside terminal cytosol or synaptic cleft
tetrodotoxin
an alkaloid neurotoxin, produced by certain puffer fish, tropical frogs, and salamanders, that selectively blocks voltage-sensitive Na+ channels
Acetylcholine (ACh)
small molecule excitatory neurotransmitter that acts at motor neuron synapses. Also acts in the autonomic nervous system ( unconscious functions such as breathing, digestion) and modulates synapses in the brain (important in Alzheimer disease)
glutamate
amino acid that is predominant excitatory neurotransmitter in the brain.
GABA
major inhibitory neurotransmitter in the brain (technically an amino acid)
excitotoxicity
cell death resulting from the toxic actions of excitatory amino acids such as glutamate. Progression of hyper excitability, excitotoxicity, cell death. elevated calcium levels trigger cell death enzymes.
