Sensory Physiology Flashcards
What are sensory systems?
they have the means to sense a physical or chemical condition and translate that into a signal that is detected prior to response.
Where is the signal for sensory stuff usually sent to?
the CNS
What does the CNS do once it receives a signal?
use the info to mount an appropriate response
What is a neuronal receptor?
the cell sensing the stimulus is also a neuron
What is the alternative when the cell sensing the stimulus is not a neuron?
-most work in this manner
-still communicate with the CNS
-includes the various systems that detect electromagnetic radiation at various wavelengths
-detect chemical or physical changes (ex. touch, chemicals)
What is the receptor that senses chemicals?
chemoreceptors
How does a neuron communicate?
through action potentials
What happens when a cell detects a change?
the channels are opened are closed, and this change alters the membrane potential
What happens when a neuron is responding to a physical change?
physical change pulls on the cell membrane, which opens channels that are otherwise closed. if there is a sufficient signal, this could trigger an action potential
What is “coding”?
expresses how different stimuli are encoded by different neural activity patterns.
How does the CNS interpret the intensity of a stimulus?
the number of action potentials in a given time period
as well will determine how many receptors are sending a similar signal to determine what sort of response is needed
What is a non neuronal receptor?
sensory cell is separate from their neuron
Describe what happens when a cell that is a non neuronal receptor senses the environment.
-senses the environment and responds by triggering the release of signalling factors
-these factors are sensed by the dendrites of neurons through their receptor proteins
-this triggers a change in membrane potential
-the cell body of the neuron interprets the incoming info, and if needed sends the a signal to the CNS
-this is sent in the form of an action potential
what are hair cells?
sensory cell that is found in many sensory systems of animals, including our own ears
Describe how hair cells sense.
-detect the movement of fluids (air and water)
-called a hair cell bc of its hair like extensions on the apical surface
-the hair tips are connected by a fiber
-when the hairs (of diff lengths) bend in the directions the fibre connecting their tips change in length
-toward shortest hair means they get closer together
-longest hair get further apart
-tension airising ffrom this fibre is what cells detect
-when hair cells in regular position: there is a pattern of regular action potentials that are always arising from the neuron
-fluid movement changes the direction the hairs bend, the signal from the tips alter the membrane potential of the receptor, which changes frequency of action potentials
What is the apical surface?
features that are located opposite to the base of the organism or structure
Where are pheromones released from?
exocrine glands
How are pheromones sent?
from one animal to another individual of the same species
What form can pheromones be sent in?
smells, specific chemicals that binds a specific receptor to trigger a specific response
Give some examples of pheromones being sent and their processes.
-antennae of the male silkworm moth. covered with sensory hairs that have chemoreceptors that are very sensitive to the sex pheromone released by the female. can sense this chemical, follow the trail, find the female and mate
How can pest managers manipulate pheromones to their advantage?
-use pheromone traps
-can use it to study the density of insect pests
-could be used for monitoring programs, or attract them to their death for control programs
What are taste and smell an example of?
chemosensing
Describe what happens for taste and smell.
specific type of chemical dissolves in a fluid and binds to a receptor on a sensory cell.
What is the sensory cell for smell?
neuron
What is the sensory cell for taste?
non neuronal receptor
Describe why “taste zones” on the tongue are a myth.
each cell is specialized to product only one type of receptor, and each taste bud has sensory cells for all of the ligands
What do humans produce but can’t sense them?
electrical field
What is bioelectricity a consequence of?
having excitable tissues, such as muscles and nerves
How do electrical fish use their electrical field? What happens when it is disrupted?
-to monitor its regularity
-when disrupted, it can sense how the object affects the field which enables the animals to determine its nature and direction