Exam 2: Sensory System Flashcards
What are ionotropic receptors?
ligand gated ion channels that interact with ions
Is mechanoreception performed by ionotropic or metabotropic sensory receptors?
Ionotropic
Is electroreception performed by ionotropic or metabotropic sensory receptors?
Ionotropic
Is thermoreception performed by ionotropic or metabotropic sensory receptors?
Ionotropic
Is photoreception performed by ionotropic or metabotropic sensory receptors?
Metabotropic
Is gustation performed by ionotropic or metabotropic sensory receptors?
Metabotropic
Is olfaction performed by ionotropic or metabotropic sensory receptors?
Metabotropic
What are metabtropic receptors?
receptors that cause a response but not a direct change
What is the principle of labeled lines?
Brains detect what kind of information is coming in based on the receptor that detected it
How do mammal brains deal with redundant or intense signal?
quiets them down
What is a phasic response?
When the brain quickly shuts off integration of stimulus
What is tonic adaptation?
When it takes a longer period of time for the brain shut down a stimulus
What is an example of cells that would be adapted for phasic response?
Cells that detect vibrations
What are A1 cells in insects?
they detected low frequency sounds
What are A2 cells in insects?
They detect sounds coming from a source close by
How do A1 and A2 cell activation interact in insects?
When A1 cells are activated, the inside hides; when both are activated, the insect engages in random movement
What do organisms have in common when it comes to detecting sound?
they have structures to identify the location
What is a requirement of chemoreception?
Must occur in an aqueous medium
What pigment complex is used in both vertebrates and invertebrates?
Rhodopsin
What is rhodopsin made of?
retinal and opsin
What is the pigment molecule in rhodopsin?
retinal
What is the reaction that occurs when light interacts with rhodopsin?
11-cis-retinal becomes all-trans-retinal
What is triggered when 11-cis-retinal is reacted to form all-trans-retinal?
A G-coupled protein
What does the G-coupled protein triggered by retinal activate in invertebrates?
Phospholipase c
What does phospholipase activate in invertebrates?
Production of diacylglycerol (DAG) outside of the photoreceptor cell
What does diacylglycerol cause in an invertebrate photoreceptor cell?
Non-specific ion channels in the photoreceptor cells open and the membrane is depolarized
What does depolarization of an invertebrate photoreceptor cell cause?
Generation of an receptor potential which then transmits via neurotransmitters to a neuron and generates an action potential
What polarization state is a vertebrate photoreceptor cell in when it is dark?
Depolarized
What causes vertebrate photoreceptor cells to remain depolarized in the dark?
Cyclic GMP keeps Na+ channels open which maintain a less negative charge on the cell interior
What keeps a vertebrate photoreceptor cell from becoming too depolarized?
Na+/K+ pump, pumps K+ out while Na+ comes in
What keeps a vertebrate photoreceptor cell from becoming too depolarized?
Na+/K+ pump, pumps K+ out while Na+ comes in
What does the G-coupled protein trigger by retinal activate in vertebrate photoreceptors?
Phosphodiesterase
What does activation of phosphodiesterase trigger in vertebrate photoreceptor cells?
Deactivation of cyclic GMP
What does deactivation of cyclic GMP cause in vertebrate photoreceptor cells?
Closing on Na+ channels that lead into the photoreceptor
What does closing of the Na+ channels in vertebrate photoreceptor cells cause?
The membrane is hyper polarized
What does hyperpolarization of the vertebrate photoreceptor cell cause?
Generation of a receptor potential which is transmitted to a neuron using neurotransmitters and an action potential is generated in the neuron
What are invertebrate photoreceptor cells called?
Rhabdom cells
What are vertebrate photoreceptor cells called?
Rod and cone cells
How do invertebrates regenerate rhodopsin?
Photochemical regeneration
How do invertebrates perform photochemical regeneration?
Absorb a different wavelength of light to reset all-trans-retinal to 11-cis-retinal
How do vertebrates reset rhodopsin?
Perform enzymatic regeneration
What is enzymatic regeneration of rhodopsin beneficial?
It is guaranteed to occur
What is a benefit of photochemical regeneration of rhodopsin?
It is faster than enzymatic regeneration
What is a benefit of photochemical regeneration of rhodopsin?
It is faster than enzymatic regeneration
What is a con of photochemical regeneration of rhodopsin?
Requires changing location or light source to regenerate rhodopsin
What is a con of photochemical regeneration of rhodopsin?
Requires changing location or light source to regenerate rhodopsin
What is a con of photochemical regeneration of rhodopsin?
It is metabolically costly and slow than photochemical regeneration
