Shared Flashcard Set

Details

EXAM 2
N/A
80
Physiology
Undergraduate 3
10/08/2014

Additional Physiology Flashcards

 


 

Cards

Term
Where do action potentials propagate?
Definition
along the membrane of the conductile region of a neuron
Term
What is the conductile region?
Definition
it carries electrical information long distances. It also contains voltage-gated Na+ and K+ channels which are responsible for an action potential
Term
What is the Neuron Doctrine?
Definition
says that a neuron is a functional unit of the nervous system
Term
What is sensory transduction, and what are the 3 forms?
Definition
It is changing the form of energy (conversion to movement of ions across a membrane). Three forms: Electromagnetic, chemical, mechanical.
Term
What is kinesin?
Definition
Kinesin is a motor protein that transports vesicles along microtubles. + end directed, cleaves ATD to ADP
Term
What kind of glial cells are in the central nervous system?
Definition
Astrocytes, oligodendrocytes, microglia
Term
What type of glial cell is in the Peripheral nervous system?
Definition
schwann cells
Term
Myelinating glial cells provide:
Definition
provide insulation and physically surround neurons
Term
Afferent nerves carry information
Definition
toward the brain
Term
Efferent nerves carry information
Definition
away from the brain
Term
Afferent nerves carry information
Definition
toward the brain
Term
Efferent nerves carry information
Definition
away from the brain
Term
Potentials propagating away from the central nervous system carry
Definition
motor information
Term
Mechanisms for removing neurotransmitter from synaptic cleft include
Definition
absorbed by astrocyte, diffuse away, degraded by enzymes
Term
What depolarizes a membrane?
Definition
voltage-gated sodium channels
Term
what is the equilibrium potential of sodium?
Definition
+40 mV
Term
What is threshold?
Definition
the membrane potential where rate of sodium influx through v-gated channels equals the rate of K+ efflux through leak channels
Term
What is the equilibrium potential of potassium?
Definition
-80 mV
Term
What is the concept of ball and chain?
Definition
as soon as the voltage-gated sodium channels open, they also start to inactivate. this limits membrane Na+ permeability
Term
What happens at the top of the action potential?
Definition
Na+ channels inactivate, K+ leak channels are still open, voltage-gated K+ channels are ALL open by the time Na+ channels inactivate
Term
What happens when voltage-gated potassium channels open during an action potential?
Definition
It starts to repolarize the membrane bringing the membrane potential close to the equilibrium potential of potassium. with the help of flickering Na+ channels, and K+ leak channels it will restore to resting membrane potential
Term
Where are voltage-gated Na+ and voltage-gated K+ channels located?
Definition
between the nodes on the axon
Term
What is the voltage at the resting membrane potential?
Definition
about -70mV
Term
What are nerves?
Definition
bundles of nerve cells in PNS
Term
What are tracts?
Definition
bundles of axons in CNS
Term
What is a somatic afferent?
Definition
neuron that brings info about skin, skeletal muscles, and joints to the CNS
Term
What is a visceral afferent?
Definition
a neuron that brings in information to CNS about organs
Term
What are the two motor divisions of PNS?
Definition
Somatic Nervous system, and autonomic nervous system
Term
What nervous system does the parasympathetic and sympathetic branches belong to?
Definition
part of the autonomic nervous system which is a portion of the PNS
Term
What is gray matter?
Definition
collection of cell bodies and unmyelinated proceses (divided into the dorsal and ventral horns)
Term
What is white matter?
Definition
myelinated axons (white because of large amounts of lipids)
Term
Dorsal horn contains...
Definition
cell bodies and dendrites of interneurons that are important for afferent info from PNS to CNS
Term
Ventral horn contains...
Definition
cell bodies and dendrites of lower motor neurons
Term
Where do lower motor neurons exit the CNS?
Definition
through the ventral roots
Term
Afferent neurons enter on the ( ) side, and makes its way to the ( ) side.
Definition
right, left
Term
Efferent neurons enter the ( ) side, and move to the ( ) side.
Definition
left, right
Term
Dendrites are the ( ) region of the cell.
Definition
input region, NEVER myelinated, conduct graded potentials
Term
What is the trigger zone?
Definition
site of action potential initiation
Term
Interneurons are confined to...
Definition
the central nervous system
Term
what is the function of an astrocyte?
Definition
it helps regulate ion concentration in the extracellular environment (mostly K+), also regulates neurotransmitter concentration at synapse, positioned around capillaries.
Term
What is the function of an oligodendrocyte?
Definition
myelinating axons, and forming white matter in CNS, they can wrap around multiple axons, inhibit regeneration in CNS
Term
What is the function of a schwann cell?
Definition
to myelinate axons, only one axon at a time, cleans up debris after nerve damage in peripheral, regenerate nerves
Term
Ribosomes are located
Definition
in the cell body, and dendrites only
Term
Microtubules are composed of
Definition
tubulin
Term
When do stretch activated channels open?
Definition
when we tug on the membrane it opens the channel, the change in membrane brings in sodium. # of stretch activated channels is proportion to the amount of stretch.
Term
Voltage-gated Na+ channels are triggered by ( ), unlike Na+ stretch activated channels which are triggered by ( ).
Definition
V-gated activated by charge, stretch activated by stretch in membrane
Term
Cell bodies of preganglionic sympathetic neurons are located in...
Definition
the intermediolateral gray column of spinal cord
Term
Where do preganglionic sympathetic neurons exit?
Definition
exit the spinal cord in the ventral root and synapse on post ganglionic sympathetic neurons
Term
Where do cell bodies of somatic afferents reside?
Definition
in the dorsal root ganglia
Term
Where would protein synthesis take place for a lower motor neuron?
Definition
in the ventral horn of the spinal cord
Term
By severing a nerve, one would cut..
Definition
the conductile processes in the PNS (because nerve is a term used in the peripheral nervous system, not central.)
Term
What does fast axoplasmic transport move?
Definition
vesicles
Term
What does slow axoplasmic transport move?
Definition
moves actin, tubulin, and neurofilaments
Term
What are tracts?
Definition
bundles of conductile regions in the CNS
Term
Where are voltage-gated Ca+ channels for NT release synthesized?
Definition
synthesized in the cell body in the rough ER
Term
Input regions from post synaptic cells at chemical synapses contain what kind of channels?
Definition
ligand gated
Term
An EPSP (excitatory post synaptic potential) results from:
Definition
the opening of ligand-gated channels
Term
What dictates the postsynaptic response at chemical synapses?
Definition
the receptor that binds the NT
Term
the synapse between postganglionic parasympathetic neurons requires what kind of receptors?
Definition
muscarinic and metabrotropic acetycholine receptors
Term
Huntington's Disease which is associated with the uncontrolled generation of movement results from:
Definition
damage to the neurons in the striatum
Term
What does adenylyl cyclase do?
Definition
it converts ATP to cyclic AMP
Term
Cutting the vagus nerve would cut..
Definition
the conductile regions of preganglionic parasympathetic neurons
Term
Visceral efferents innervate
Definition
glands, cardiac muscle, and smooth muscle
Term
somatic efferents innervate
Definition
skeletal muscle
Term
In skeletal muscle contraction Calcium leaves SR through what type of receptors?
Definition
ryanodine receptors
Term
How does calcium reenter the SR?
Definition
by Calcium pumps
Term
What does calcium bind to after leaving the SR?
Definition
troponin to move tropomyosin
Term
When does a power stroke occur in muscle contraction?
Definition
when ADP and P leaves myosin
Term
Myosin releases its hold on actin when...
Definition
ATP binds to myosin
Term
Myosin binds to
Definition
thin filaments
Term
a motor unit is composed of
Definition
a lower motor neuron and all the cells it innervates
Term
what is spatial summation?
Definition
when EPSP's come together from different places
Term
What is temporal summation?
Definition
when EPSP's come together at the same time
Term
Where are the cell bodies located for a neuron whose output region is in the left ventral horn?
Definition
on the right precentral gyrus
Term
Where are EPSPs initiated?
Definition
in the input region of the postsynaptic cell
Term
What causes neurotransmitter to be released from the presynapse?
Definition
the opening of voltage gated calcium channel causes exocytosis of synaptic vesicle to synaptic cleft releasing neurotransmitter.
Term
What happens when action potential arrives to presynaptic element?
Definition
it delivers positive charge, allowing calcium to flow in through voltage-gated calcium channels
Term
What happens when neurotransmitter leaves the presynaptic element?
Definition
it binds to ligand-gated channels opening the gates for sodium to flow into post synaptic element
Term
What happens when sodium flows into the post-synaptic element?
Definition
it depolarizes membrane
Term
What happens after the sodium ions move into post synaptic element?
Definition
it depolarizes membrane and then releases neurotransmitters from the ligand-gated channels
Supporting users have an ad free experience!