Receptors change sensory signals into electrical signals, these electrical signals induce what?
An Action Potential
What is a sensory receptor?
A biological transducer that changes a stimulus to electrical energy allowing us to understand what is happening either in our bodies or in our environment.
What are Nociceptors?
Receptors that detect pain, a type of naked receptor.
What are encapsulated receptors?
Sensory endings encapsulated with connective or epithelial tissues, where if encapsulation is lost then the receptor loses function.
How do olfactory receptors detect smell?
A modified cell that has cilia, the receptor portion, transduction occurs and carries the signal towards the brain.
How do taste receptors work?
A special columnar shaped cell that has a micro villus border and is synaptically linked to a fiber at the bottom of the cell. Saliva allows molecules to dissolve, are then picked up by the micro villus border (the receptor), then causing the receptor to release dopamine as a neurotransmitter to the post synaptic cell, then carrying the signal to the brain.
What are characteristics of a graded potential?
What is the relationship between stimulus strength, Action Potential and the Generator Potential?
As a stimulus increases the generator potential increases and only the frequency of the action potential changes.
How do beta cells in the pancreas work to release insulin?
K channels are open and Ca channels closed. ATP production is low, but as glucose increases in the cell after a meal there is an increase in ATP production, causing phosphorylation of the K channel from increased cell ATP causing the K channel to close. This causes a depolarization in the cell causing Ca to open under a voltage gaiting effect, Ca acts as a secondary messenger with a protein, and promotes the exocytosis of insulin.
What receptor encourages the release of insulin?
Beta cells in the pancreas.
What kind of receptor is the olfactory receptor?
A chemo receptor.
How do olfactory receptors work?
Cilia receptors, located in roof of the nasal cavity, are moist, because of mucus, allowing odorants to dissolve and make contact with the cilia, binding, transduction, brain interpretation.
What are papillae on the tongue responsible for?
Bumps on the tongue that house the taste receptors “taste buds”.
What type of receptors are taste receptors?
Chemio receptors
What cell carries taste receptor information to the brain?
Goostatory cells related to the cranial nerve IX Glossopharyngeal nerve.
What are the different types of taste receptors?
Salty, sour, bitter, sweet, and umami (protein taste).
What are Rods?
Photoreceptors in the eye that detect shades.
What are cones?
Photoreceptors in the eyes that detect colors.
How do Rod cells work (cones work in a similar way)?
Photoreceptors that respond to light. Light hits Rod Cells, cis-rhodopsin and retinal are bound together but in light a photo isomerization causes the cis for to turn to trans and un-binds rhodopsin and retinal, rhodopsin is bound to transducin (G protein GTP), this activates phosphodiesterase that breaks CGMP and closes Na channels causing a hyperpolarization, this causes cells to become inactivated, allowing transduction to occur in bipolar cell.
What protein keeps Na channels open in the eye during the dark?
CGMP
What is a sensory unit?
A sensory neuron with all of its endings?
What does the brain need to interpret about a typical sensory stimulus?
Strength, location, and frequency. The brain achieves this by interpreting the pathway signals take to reach the brain.
How does the brain interpret the strength of a signal?
By interpreting the frequency of the Action Potential. Low frequency is a weak stimulus, and a high frequency is a strong stimulus.
What are two types of pain detected by nociceptors?
Acute pain (pathological pain) and Chronic pain (Neuropathic pain).