Cell phys. Vosco lecture 1 Flashcards
The Sodium- Potassium Pump:
• Maintains Na+ K+ concentration gradient
•Requires ATP
•___ Na+ out for __ K+ in
•Makes resting membrane potential more negative
3
2
Ions will flow until:
•______ _______ (equilibrium potential is
reached)
•There is a physical barrier that prevents ionic flow from continuing (______-gated channels)
• Nernst potential of potassium = -90
• Nernst potential of sodium = ____
• Nernst potential of chloride = -70
Nernst potential
voltage
60
____ dictates the resting potential of the cell
potassium
There are two types of postsynaptic responses to neurotransmitters released to the synapse
Graded responses –EPSPs •Mediated by \_\_\_\_ influx –IPSPs •Mediated by \_\_\_\_influx •Action potential – All-or-none –Action potentials are the sum result of graded responses, but only to a certain point
Na+
Cl-
Ionotropic = ______-gated (faster)
ligand
Metabotropic binding = __-____ _____(slower)
- Metabatropic is also known as:
1. _______
2. Muscarinic
G-protein coupled
GPCR
membrane potential = ___Mv
trigger zone = ______
-55
Hillock
voltage gated _____ channels open at -55Mv which work with voltage gated ________ channels causing an increase in sodium and decrease in potassium in the cell
sodium
potassium
the action potential has properties specific to the ion channels that carry it… so in the graph sodium channels open –> more sodium channels open –> sodium channels close and potassium channels open causing repolarization–> potassium channels close at about ___Mv
-70
voltage gated sodium channels = _____ ______ ______
Voltage gated potassium channels = ______ _______ ______
Absolute refractory period
relative refractory period
- _________ is the term used to describe the degree to which ion channels are open for a given area on the cell membrane
- __________ is the inverse of resistance
- Increasing diameter increases the number of ion channels that can fit in an area and thus increase its conductance
Conductance
Conductance
______ conduction is when the current only enters through unmyelinated portions of the axon. i.e. ____ __ _____
Saltatory
Nodes of Ranvier
•Vesicles are tied to the active zones by docking proteins, including ____ and synaptophysin
•When AP is generated toward the terminal
end of the axon, voltage gated ___ channels are opened
•Ca2+ causes actin to contract, brings vesicles forward to the membrane. Also, ca2+ activates ______, which causes expulsion of contents of vesicle into the cleft
actin
ca2+
calmodulin
A fixed amount of neurotransmitter is
released for each Action Potential; this is known as _____
quanta
• Amino acids
–Aspartate
–\_\_\_\_\_\_\_\_—most prevalent excitatory NT •Ionotropic (ie ligand-gated) –AMPA— \_\_\_\_ influx –Kainate – NMDA—Requires depolarization, some Mg2+ and then Na+ and Ca2+ influx in addition to glutamate binding
•Metabotropic—big variation. Over 100 subtypes
–MGLURs
Glutamate
Na+
–GABA—most prevalent inhibitory NT
•Ionotropic
–_____ A—Cl-influx
GABA
faster
IPSPs
Glycine— found all through the body. Synthesized form ______ via _______. Particularly active in spinal cord.
glucose
serine
Glutamate and GABA are both recycled with help from ________
astrocytes
Biogenic amines–Acetyl choline(Ach).
•All motoneurons on _____ muscle use Ach.
•Degraded by acetyl _________.
•______ (ionotropic)— skeletal muscle. Na+
and Ca2+ influx.
–More nicotonic in PNS
•________ (metabotropic).
–More muscarinic in CNS and smooth muscle
skeletal
cholinesterase
Nicotinic
Muscarinic
–Dopamine
»D1 (Excitatory) and D2 (Inhibitory) receptors
** both of the above are ________
»GPCRs
»Two major areas are from SUBSTANTIA NIGRA and VENTRAL TEGMENTAL AREA (VTA)
»Substantia nigra is involved with basal ganglia circuit and loss of dopamine here is cause of ________ Disease
»VTA involved with both addiction and
schizophrenia
metabatrophic
Parkinson’s
Monoamines–catecholamines
–Norepinephrine
»Produced in the _____ ______ in the pons
»All about arousal alertness and attention
»PNS sympathetic neurotransmitter
»2 alpha and 2 beta receptor
subtypes (both are _______)
-beta receptors can bind ______ pretty well
Locus Ceruleus
metabatrophic
epinepthrine
•\_\_\_\_\_\_\_ ( 5-HT) –Related to depression, pain inhibition –Raphe nuclei of the brainstem (midbrain) –At least 7 different receptor subtypes –SSRIs
Serotonin
electrical synapses are also known as ____ _______
-______ links 2 dendrites together
gap junctions
conexins
Glia
• _______: glucose delivery, blood brain
barrier, inflammatory response, ATP release,
glutamate recycling
•___________: myelinate axons in the central nervous system
• Microglia: major immune response,
phagocytosis
** microglia is derived from ______
•Ependymal cells: help produce and move
____ through the brain
Astrocytes
Oligodendrocytes
monocytes
CSF
sensory system –> _______ –>change in energy
effectors= ______ and glands
transduction
muscles
Peripheral fibers named according to myelination and axonal thickness
•“A”:myelinated sensory and motor fibers –Alpha: LMNs – Beta: Sensory receptors for light touch, pressure –Gamma: Axons to intrafusal fibers –\_\_\_\_\_\_: sharp pain, cold
•*In “A” fibers, the “A” is often omitted and only the greek letter is used to describe the subtype
•“B”:________ visceral fibers: preganglionic
autonomic
• “C”:Unmyelinated fibers: post ganglionic
autonomic, slow pain, heat, itch
these are arranged from fastest to slowest
Delta
myelinated
•I –Ia: Muscle Spindles –Ib: \_\_\_\_\_ \_\_\_\_\_ \_\_\_\_\_ •II—Same as A-Beta or A-Gamma Fibers •III— Same as A-Delta or B Fibers •IV— Same as C Fibers
** arranged from fastest to slowest**
Golgi Tendon organs
somatic motor neurons travel from the ventral horn to the motor end plate (neuromuscular junction) and ___acts on the effector which is _______ then theres contraction of skeletal muscle
Ach
nicotinic
autonomic motor neurons travel from the lateral horn to an autonomic gagnglion where theres Ach then this travels to postganglionic neuron and works with ___ (muscarinic) and ___ (alpha or beta) then theres smooth muscle contraction or glandular secretion
Ach
NE
receptor potentials =_____ and _____
Generator potentials = action potential specific to receptor terminals
EPSP
IPSP
- Nicotinic receptors between Pre and post ganglionic
- Muscarinic are on all ______ cells
- Sweat glands are exception to the NE-Ach rule
effector
______ are the individual contractile fibers of the muscle
Sarcomeres
- Part of myofibril, between two Z Discs
- Z DISC or Z lines= filamentous proteins, borders of sarcomere
- I bands= ONLY ____ filaments
- A bands= all of myosin filaments and portion of _____ overlap
- H zone= ONLY ______, no actin overlap (disappears during contraction)
ACTIN
actin
MYOSIN
Binding of _____ to troponin moves tropomyosin, exposes myosin binding site on actin. this is known as _____-_____ coupling.
Ca2+
excitation-contraction
in the ear; the intracellular ions are ______ and the extracellular ions are _______
sodium
potassium
______ tells up and down direction and the ______ relates side to side acceleration
sacule
utricle
