3.6.1.2 Receptors - Pacinian Corpuscles

Front

What is the primary function of a Pacinian corpuscle?

Back

To detect mechanical pressure and vibrations

Answer explanation

Pacinian corpuscles are specialized mechanoreceptors that primarily detect mechanical pressure and vibrations, making them crucial for sensing changes in touch and texture.

Front

Which type of ion channel is involved in the function of a Pacinian corpuscle?

Back

Stretch-mediated sodium ion channels

Answer explanation

Pacinian corpuscles are mechanoreceptors that respond to pressure and vibration. They utilize stretch-mediated sodium ion channels to detect mechanical deformation, making this the correct choice.

Front

What happens when a Pacinian corpuscle is stimulated?

Back

It establishes a generator potential

Answer explanation

When a Pacinian corpuscle is stimulated, it establishes a generator potential, which is a change in membrane potential that can lead to the generation of an action potential, signaling sensory information.

Front

Role of a generator potential in a Pacinian corpuscle?

Back

To initiate an action potential

Answer explanation

The generator potential in a Pacinian corpuscle is crucial for converting mechanical stimuli into electrical signals, which then initiate an action potential, allowing the nervous system to respond to pressure and vibration.

Front

Structure of a Pacinian corpuscle?

Back

A layered onion-like structure

Answer explanation

A Pacinian corpuscle is best described as a layered onion-like structure, consisting of concentric layers that respond to pressure and vibration, making it distinct from other shapes like a flat disc, hollow tube, or spherical ball.

Front

What specific type of stimulus does a Pacinian corpuscle respond to?

Back

Mechanical stimuli

Answer explanation

Pacinian corpuscles are specialized mechanoreceptors that respond specifically to mechanical stimuli, such as pressure and vibration, making 'Mechanical stimuli' the correct choice.

Front

How does the deformation of the Pacinian corpuscle lead to the opening of ion channels?

Back

By stretching the membrane

Answer explanation

The deformation of the Pacinian corpuscle occurs when pressure is applied, which stretches the membrane. This mechanical stretching leads to the opening of ion channels, allowing ions to flow and generate a nerve signal.

Front

What is the result of sodium ions entering the Pacinian corpuscle?

Back

Depolarisation

Answer explanation

When sodium ions enter the Pacinian corpuscle, they cause depolarisation. This influx of positive ions reduces the membrane potential, making it more positive and leading to the generation of an action potential.

Front

Which of the following is NOT a characteristic of a receptor like the Pacinian corpuscle?

• Specificity to a type of stimulus
• Ability to generate a potential
• Ability to contract
• Sensitivity to mechanical changes

Back

Ability to contract

Answer explanation

The Pacinian corpuscle is a mechanoreceptor that detects mechanical changes and generates potentials, but it does not have the ability to contract, which is a characteristic of muscle tissue, not sensory receptors.

Front

What is the primary location of Pacinian corpuscles in the human body?

Back

In the skin and deep tissues

Answer explanation

Pacinian corpuscles are primarily located in the skin and deep tissues, where they function as mechanoreceptors that detect pressure and vibration. This makes 'In the skin and deep tissues' the correct answer.