In the context of the human body, the terms effector and affector play crucial roles in how we respond to stimuli.
An effector is any part of the body that produces a response after receiving signals from the nervous system. Effectors can include muscles that contract to create movement or glands that secrete hormones. For example, when you touch something hot, your sensory receptors detect the heat, send a signal to your nervous system, and then your muscles act as effectors by withdrawing your hand quickly.
On the other hand, an affector, often referred to as a sensory receptor, detects changes in the environment and sends that information to the nervous system. For instance, the photoreceptors in the eyes are effectors that respond to light, while temperature receptors in the skin act as affectors by sensing temperature changes.
In summary, affectors are responsible for detecting stimuli, while effectors are responsible for enacting a response. Together, these components are essential for maintaining homeostasis and allowing the body to interact appropriately with its environment.