Sensory organs
external image ei_0325.gif
We have a total of five sensory organs in our body. They are:
1) The nose
2) The ear,
3) The tongue
4) The skin
5) The eyes

They all contribute to us something special. And that is our senses. Changes in the surrounding are called stimuli. Our sensory organs then function as receptors and receive the stimuli. (singular: stimulus) For example, our ears detect stimuli when we hear something. The way the stimulus travels through our body is described below.


Stimulus > Receptors > Nerves > Brain > Nerves > Effectors (such as muscles)> response
( > is used to describe nerve impulses)


As seen above, after our sensory organs receive the stimuli, it sends nerve impulses to the brain which then interprets it, and effectively decides what to do. It then sends nerve impulses to the related effectors (parts of the body which carry out responses according to what the brain 'says') Some examples of effectors are muscles and glands.

Here is a simple chart of which shows our senses, and their corresponding sensory organs and stimuli.

Action
Senses
Sensory Organs
Stimulus
Eating
Sense of Taste
Tongue
Taste
Listening
Sense of Hearing
Ear
Sound
Looking
Sense of Sight
Eyes
Light
Touching
Sense of Touch
Skin
Touch
Smelling
Sense of Smell
Nose
Smell



Below are several pictures relating to the above sensory organs.
tongue.gif
The Ear
the_ear_large.jpg
The Eye

Eye.gif
ei_0390.gif

The Nose
image002.jpg

Initial material by Qi Shaun
Further editing and image changes by Jun Vinh
ear.jpegear.jpeg


Senses
1. Sense of touch: Sensory organs=Skin
2. Sense of smell: Sensory organs=Nose
3. Sense of taste: Sensory organs=Tongue
4. Sense of sight: Sensory organs=Eye
5. Sense of hearing: Sensory organs=Ear

Stimulus - Receptors in sensory organs - Nerves - Brain - Nerves - Effectors - Response

Pathway from stimulus to response


A stimulus will stimulate receptors in sensory organs to produce electrical messages known as nerve impulses. These impulses are sent along the nerves to the brain. The brain receives the message and interprets it. Depending on the message, it decides what to do. The brain sends out nerve impulses to related effectors . effectors are part of the body that carry out responses . Muscles and glands are examples of effectors.


By Zhi Yan