Midterm 2 Lecture 8 Flashcards
what are Sensory Receptors Cells (also known just as Sensory Receptors)
specialized neurons that detect a specific category of physical events
how do what are Sensory Receptors Cells accomplish their task
accomplish this task with receptor proteins that are sensitive to specific sensory stimuli, specific features of the extracellular environment
what are the receptor proteins that Sensory Receptors have
the presence of specific molecules (via chemical interactions) – physical pressure – temperature – pH (acidity, basicity) – electromagnetic radiation (photons)
what does the protein that senses the presence of specific molecules (via chemical interactions) do
• smell, taste (except for sour), hunger, thirst, nausea, pain
what does the protein that senses physical pressure sense
• touch, stretch, vibration, acceleration, gravity, balance, hearing, thirst, pain
what does the protein that senses temperature proteins sense
• heat, cold, pain
what does the protein that senses pH (acidity, basicity) sense
• sour taste, suffocation, pain
what does the protein that senses electromagnetic radiation (photons) sense
• vision, sunburn
do all organisms sense the same things
Some non-human animals have other senses, such as the ability to detect electrical and magnetic fields, humidity, and water pressure.
what is Sensory transduction
Process by which sensory stimuli are transduced (converted) into receptor potentials
(how the organism senses stuff)
what are Receptor potential
Graded change in the membrane potential of a sensory neuron (sensory receptor cell) produced in response to sensory stimuli
what are Sensory Receptor (Cell)
Specialized neuron that detects a particular category of physical events (sensory stimuli).
E.g., photoreceptor (cells) transduce light into receptor potentials
what is the order of sensory transduction
Sensory transduction
Receptor potential
Sensory Receptor (Cell)
do all sensory receptor cells have action potentials
Not all sensory receptor cells have action potentials, but they all release neurotransmitter.
The sensory receptor cells that do not have action potentials tend to release neurotransmitter in what fashion
a graded fashion, dependent on their membrane potential. The more depolarized they are, the more neurotransmitter-filled vesicles they release
what are Photoreceptor (cell)
The sensory receptor (cell) responsible for vision. Located in the retina, photoreceptor cells transduce the electromagnetic energy of photons into receptor potentials.
Each photoreceptor cell contains how many types of opsin protein.
one
Since humans have 4 different types of opsin proteins, we have how many types of photoreceptor cells
we have 4 different types of photoreceptor cells
what is Opsin
A type of protein that, in conjunction with retinal, is responsible for the transduction of visual information (i.e., light). The opsins found in humans are all inhibitory metabotropic receptors. Rod photoreceptor cells express the rod opsin (rhodopsin). Cone photoreceptor cells express one of the cone opsins (red, blue or green).
what is Retinal
Small molecule (synthesized from vitamin A) that binds to opsin proteins. In mammals, retinal is the actual molecule that absorbs the energy of photons. The type of light that retinal can interact with is dependent on the opsin protein that retinal is bound to.
Visible light refers to electromagnetic energy that has a wavelength between 380 and 760 nm. We detect this light using four kinds of photoreceptor cells , what are they
1 rod cell & 3 cone cells
what is the fovea
the area that cones detect light/color in the centrea
The three cone opsins are sensitive to different wavelengths of light: explain the blue cone
blue cone opsins are most sensitive to short wavelengths
The three cone opsins are sensitive to different wavelengths of light: explain the green cone
green cone opsins are most sensitive to medium wavelengths