Difference Between Receptor and Effector

The key difference between receptor and effector is that receptor is a cell or a group of cells in a sense organ that receives a particular stimulus while an effector is an organ that produces a response to the stimulus.

Receptor, central nervous system, and effector are three components of reflex actions of the nervous system. Receptors receive stimuli and convert them into nerve impulses. Sensory neurons carry these nerve impulses to the central nervous system. The central nervous system processes the information and sends impulses to effectors through motor neurons. Effectors convert impulses into responses or actions.

CONTENTS

1. Overview and Key Difference
2. What is a Receptor 
3. What is an Effector
4. Similarities Between Receptor and Effector
5. Side by Side Comparison – Receptor vs Effector in Tabular Form
6. Summary

What is a Receptor?

Receptor is a specialized cell or a group of cells of a sensory organ which receives a stimulus. Receptors detect changes in the external or internal environments. For example, eyes are sensitive to light; ears are sensitive to sounds; noses are sensitive to chemicals, and skin is sensitive to pressure and temperature. Likewise, different sensory organs are sensitive to different stimuli.  They are able to convert the received stimulus into an electrical signal or nerve impulse. Sensory neurons carry the impulse generated from the stimulus to the central nervous system in order to process. After processing and interpreting the signal, the central nervous system sends information to effector organs to produce the response. Effectors are mainly muscles or glands.

Plants do not have sensory organs, yet they receive stimuli. They receive stimuli via the shoot tips or root tips. Shoots respond to light while roots respond to gravity, moisture and nutrients in the soil.

What is an Effector?

Effector is a muscle or a gland that produces a response to a stimulus. Effectors receive commands from the central nervous system in order to produce a response. Effectors are present in any part of the body. Motor neurons carry impulses to effectors. Once effectors receive impulses, they convert impulses into actions. For example, a muscle contracting to move an arm. A muscle squeezing saliva from the salivary gland is another example. The action of a gland releasing a hormone is also a result of an effector.

What are the Similarities Between Receptor and Effector?

• Both receptor and effector respond to stimuli.
• Information flows from receptors to effectors.
• They generate or convert nerve impulses.
• They are connected to neurons.
• Moreover, they work with the central nervous system.

What is the Difference Between Receptor and Effector?

Receptor detects a stimulus while the effector produces an action to a stimulus. So, this is the key difference between receptor and effector. Furthermore, the receptors are specialized cells of sensory organs, while effectors are mainly muscles and glands. Thus, this is another important difference between receptor and effector. Besides, receptors are connected to sensory neurons, while effectors are connected motor neurons.

Below infographic shows more differences between receptor and effector in tabular form.

Summary – Receptor vs Effector

Sensory receptors are sensitive to changes occurring in external or internal environments. Receptors are found in sensory organs such as ears, eyes, nose, mouth and internal organs. They receive stimuli and convert into nerve impulse and send to the central nervous system for interpretation and processing. Effectors are the muscles and glands that produce an action in response to the stimulus. Effectors convert nerve impulses to responses or actions. Thus, this is the summary of the difference between receptor and effector.

Reference:

1. Marzvanyan, Anna. “Physiology, Sensory Receptors.” StatPearls [Internet]., U.S. National Library of Medicine, 27 Oct. 2020, Available here.
2. “The Structure and Function of the Nervous System – Coordination and Control – The Nervous System – AQA – GCSE Biology (Single Science) Revision – AQA – BBC Bitesize.” BBC News, BBC, Available here.

Image Courtesy:

1. “Img arc reflex muda” By MartaAguayo – Own work (CC BY-SA 3.0) via Commons Wikimedia