Response to Stimuli

Types of Receptors

• Photoreceptor - located in eyes
• Mechanoreceptor - located in skin, skeletal muscles and inner ear
• Chemoreceptor - located in mouth (tastebuds) and nose
• Thermoreceptor - located in skin, body core and part of brain called hypothalamus
• Pain Receptor - enables you to respond to chemicals released by damaged cells, located throughout body except brain

Stimuli-Response System

The stimuli-response system is when a change (stimulus) is detected by receptors, leading to a response which acts to alter and return the variance to normal. 

Stimuli Response Model

Stimulus --> Receptor --> Control Centre --> Effector --> Response

Vocab

Homeostasis - Constant internal environment.

Control Centre - The central nervous system (brain and spinal cord) where a message in the form of a nerve impulse gets sent and processed to determine which response will be appropriate. A message is then sent to the appropriate effector.

Effector -  Organs that respond to stimuli to initiate a response.

Receptors - Receptors identify changes inside and outside of your body. There are different receptors for different parts of the body.

Responses

Voluntary responses - A response using conscious thoughts 

Involuntary responses - A response that does not use the brain and therefore does not use conscious thought. The impulse goes through the reflex arc.

Reflex Arc

The reflex arc is the pathway that an involuntary action/reflex action goes through. The path does not involve the brain and instead only goes through the spinal cord, which makes the action much faster, also taking in the fact that it uses a smaller amount of neurons than a voluntary action.