nerve questions i got wrong Flashcards
What neurogenetic technique measures ion movements across membranes but with poor spatial and termporal resolution.
radioactive ion flux assay.
Can determine where ions are moving into and a re very slow.
What kind of G-protein is used by olfactory receptor cells?
G(olf) leading to activation of adenylyl cyclase
Function of titin in skeletal muscle
maintain structure and elasticity
What protein is involved in the contraction of skeletal muscle but NOT smooth muscle?
Troponin
In skeletal muscle the calcium required for contraction enters the cytoplasm from/via the:
Terminal cisternae
An example of a calcium (Ca2+) reporter that is bioluminescent as opposed to fluorescent is:
Qequorin
Doesn’t require light to be encoded to excite GFP
Coupling mechanisms are found in all varieties of which channels
Ligand gated and voltage gated ion channels
Which cortical lobe of the human brain contains the primary motor cortex?
Frontal
Myosin is a … protein
Hexameric
This layer of the retina contains the cell bodies of bipolar cells
Inner nuclear layer
What kind of G-protein is used in phototransduction in rod/cone photoreceptor cells?
Gt leading to activation of phosphodiesterase
G protein found in melanopsin containing photosensitive retinal ganglion cells
Gq
Leads to Phospho Lipase C activation
In the hair cells of the inner ear, depolarisation occurs predominantly via
Entry of K+ cells
4 mechanisms by which calcium can enter the cytoplasm in smooth muscle.
- L type calcium channels after membrane depolarisation
- Ryanodine receptors on SR
- After GPCR stimulation via Gq, IP3 can open ligand gated Ca channels on SR.
Three principal roles of the neuronal cytoskeleton
- Structural
- Transport
- Tethering of membrane components
True/false do astrocytes produce APs?
FALSE
True/false do pancreatic beta cells produce APs?
TRUE
In skeletal muscle how many L-type calcium channels are associated with each ryanodine receptor?
4
Olfactory neurons synapse onto second order olfactory neurons in the:
Olfactory bulb
The pawn mutant of the protist Paramecium cannot generate action potentials because:
It lacks voltage gated Ca2+ channels
Stimulus intensity in mammalian pyramidal neurons is encoded by:
AP frequency
An example of a genetically encoded protein calcium (Ca2+) reporter that can fluoresce is…
GCamP
Which proteins are necessary to maintain the resting membrane potential at -70 mV?
Potassium channels
Sodium channels
Sodium-potassium ATPase
If someone suffers a head injury that leads to swelling of the brain, an effect known as coning may occur where the brain is pushed through the opening of the skull. Which area of the brain is most likely to be damaged due to coning?
Medulla
What property of myelinated neurons means that they transmit action potentials more efficiently than unmyelinated neurons?
Lower membrane capacitance
The functions of microglial cells include:
Phagocytosis
What is the main factor that determines the value of the resting membrane potential of the typical cell?
diffusion of K+ ions down their concentration gradient
Where are connexins found?
Gap junctions between neurons
What is the mechanism for synaptic depression that underlies habituation of the gill withdrawal reflex in Aplysia?
Reduced calcium influx in the presynaptic neuron0
How does temporal summation reach threshold value to fire an action potential?
Input from a single synapse fires at a sufficiently high frequency to compound to depolarise the postsynaptic cell above threshold
Where does conotoxin work?
Voltage-dependent calcium channels
Halorhodopsin
Chloride pump found in halobacteria. Powered by yellow/green light.
Pyridostigmine
Reversible inhibitor of AChesterase
Tetrodotoxin targets which type of ion channel?
Voltage gated sodium channels
