Question

Which sentence is false regarding mechanoreceptors? a. Action potential is produced by deformation of membrane cells. b. They are found in the semicircular canals. c. Pancinian corpuscles respond to deep pressure. d. All receptors have encapsulated dendritic endings.

Short answer

The false statement is d.

Step-by-step solution

Understand the Function of Mechanoreceptors

Mechanoreceptors are sensory receptors that respond to mechanical pressure or distortion. They play a key role in the sensory system by detecting changes in vibration, pressure, and texture.

Review Each Statement

Read each sentence carefully to determine its validity with regards to the functions and characteristics of mechanoreceptors.

Assess Statement A

Statement A: 'Action potential is produced by deformation of membrane cells.' This is true because mechanoreceptors generate action potentials when mechanical stress deforms their membrane.

Assess Statement B

Statement B: 'They are found in the semicircular canals.' This is true because the semicircular canals contain mechanoreceptors that detect head rotation and contribute to the sense of balance.

Assess Statement C

Statement C: 'Pacinian corpuscles respond to deep pressure.' This is true. Pacinian corpuscles are a type of mechanoreceptor that responds specifically to deep pressure and vibration.

Assess Statement D

Statement D: 'All receptors have encapsulated dendritic endings.' This is false because not all mechanoreceptors have encapsulated dendritic endings. Some sensory receptors may have free nerve endings.

Key concepts

Action Potentials

Action potentials are crucial for the functioning of our nervous system. They are electrical impulses that travel along neurons to transmit information.

In mechanoreceptors, action potentials are generated when mechanical pressure deforms the cell membrane. This deformation opens ion channels, allowing ions to flow in and out, creating an electrical change.

This change propagates along the nerve fiber, sending signals to the brain about sensations like touch and pressure. Action potentials are essential for communicating sensory information quickly and efficiently.

Semicircular Canals

The semicircular canals are part of the inner ear and play a crucial role in maintaining balance. They are filled with fluid and lined with mechanoreceptors called hair cells.

When you move your head, the fluid inside the canals shifts, bending the hair cells. This bending creates action potentials that communicate the movement to the brain, helping you keep your balance.

The semicircular canals are part of the vestibular system, which also includes the utricle and saccule. Together, they help detect rotational movements and linear accelerations.

Pacinian Corpuscles

Pacinian corpuscles are specialized mechanoreceptors located deep in the skin and other tissues. They are responsible for detecting deep pressure and vibration.

Each Pacinian corpuscle consists of a nerve ending surrounded by concentric layers of connective tissue. When pressure is applied, these layers are compressed, deforming the nerve ending and generating an action potential.

These receptors adapt quickly, meaning they stop responding to constant pressure, making them excellent at detecting changes in pressure and vibrations. This allows them to signal sudden physical changes in the environment.

Sensory Receptors

Sensory receptors are specialized cells or nerve endings that respond to various stimuli, such as touch, temperature, and pain.

They convert physical energy into electrical signals that can be interpreted by the brain. Types of sensory receptors include mechanoreceptors, thermoreceptors, and nociceptors.

Mechanoreceptors detect mechanical changes like pressure and vibration. Some have encapsulated dendritic endings, like Pacinian corpuscles, while others have free nerve endings. Sensory receptors are crucial for perceiving the world around us and reacting to environmental changes.