5.3.1: Roles of Sensory Receptors Flashcards
Define pacinian corpuscle
A pressure sensor found in the skin.
What are sensory receptors
specialised cells that detect changes in our surroundings. Most are energy transducers that convert one form of energy to another.
When there is a stimulus, how does the sensory receptor respond?
By creating a signal in the form of electrical energy, this is called a nerve impulse.
Stimulus: change in light intensity.
What are the sensory receptors and what is the energy change involved?
- Light sensitive cells (rods and cones) in the retina.
- Light to electrical.
Stimulus: change in temperature
What are the sensory receptors and what is the energy change involved?
- Temperature receptors in skin and hypothalamus.
- Heat to electrical.
Stimulus: change in pressure on the skin.
What are the sensory receptors and what is the energy change involved?
- Pacinian corpuscles in the skin.
- Movement to electrical .
Stimulus: change in sound.
What are the sensory receptors and what is the energy change involved?
- Vibration receptors in the cochlea of the ear.
- Movement to electrical.
Stimulus: movement
What are the sensory receptors and what is the energy change involved?
- Hair cells in inner ear.
- Movement to electrical.
Stimulus: change in length of muscle
What are the sensory receptors and what is the energy change involved?
- Muscle spindles in skeletal muscles.
- Movement to electrical.
Stimulus: chemicals in the air.
What are the sensory receptors and what is the energy change involved?
- Olfactory cells in the epithelium lining of the nose.
- These receptors detect an presence of a chemical and create an electrical nerve impulse.
Stimulus: chemicals in food
What are the sensory receptors and what is the energy change involved?
- Chemical receptors in taste buds on tongue.
- These receptors detect an presence of a chemical and create an electrical nerve impulse.
What is a Pacinian corpuscle?
A pressure sensor that detects a change in pressure in the skin.
What does a Pacinian corpuscle look like?
Oval shaped structure consisting of a series on concentric rings of connected tissue wrapped around the end of a nerve cell.
What happens to the Pacinian corpuscle when pressure on the skin changes?
Pressure deforms the rings of connective tissue and pushes against the nerve ending.
Why do the corpuscles stop responding when pressure is constant?
The corpuscle is sensitive to only changes in pressure that deform the rings of consecutive tissue.
What are sodium channels sensitive to and how does this allow them to create a generator potential?
- Small movements of the membrane, so when the membrane is deformed by the changing pressure, sodium channels open.
- This allows sodium ions to diffuse into the cell, producing a generator potential.
How do sodium potassium pumps work?
They pump three sodium ions out for every two potassium ions they pump in.
When the channel proteins are all closed, the sodium/potassium pumps work to create a concentration gradient.
Why can some potassium ions leak out of the cell?
Because the membrane is more permeable to potassium ions.
What is the result of these ionic movements?
A potential gradient across the cell membrane. The cell is negatively charged inside compared with outside.
What is the negative potential enhanced by?
The presence of negatively charged anions inside the cell.
What is a generator potential?
The change in potential across a receptor membrane
When is an action potential generated?
- Large enough stimulus is detected
- Opens enough sodium channels allowing enough sodium ions to enter the cell.
- Potential difference across the cell membrane changes significantly.
- Action potential created
