Science Form 2 Chapter 1.1, 1.2 and 1.3

Ok, let me start introducing to you science. First of all I want you to know that science is actually a natural phenomena that happens around us and help the human being to have a easier life. Sensory Organs are use to detect stimuli. We have 5 sensory organs...

• Sense of smell (nose/chemical in air)   
• Sense of taste (tongue/chemical in food)
• Sense of hearing (ear)
• Sense of sight (eye)
• Sense of touch (skin)

This is the path way for the brain=

Stimuli------Receptors in sensory organ--(nerve impluses)--nerve------Brain|
                                                                                                           |
                                                                                                           |
              Response------Effectors(muscles, glands)--(nerve impluse)--nerve


The receptors in sensory organ produces nerve impluse. then it's send to the brain to interprets and that's how u response!Effectors are part of your body like muscles.


Now let's enter chapter 1.2(Touch)
The skin is the largest organ in the body. It detect temperature, pain, touch and pressure.
It has two main layers the outer epidermis and inner dermis.

Fot the last layer subcutaneous layer is actually called fatty layer.There are also blood vessel, nerve, gland and more.

Now this is the receptors, there are 5 type of receptors in it which is preassure, heat, cold, pain and touch.The sensitivity of your skin also depends on the deepness of your receptors from the skin and how close together there are.


Chapter 1.3(Smell)
Our nose not just help us breathing but smelling.

The 2 holes in our nose is Nostril and the hollow space is called the Nasal cavity. The receptors for the nose is located on the celling of the Nasal cavity. There is also mucous lining in the Nasal cavity which function is moistens the air before entering the lung.

As you can see the receptors on the celling.The mucous is actually dissolving the chemical in air to stimulate the receptors.But after smelling something to long, the receptors stop sending nerve impluse (electrical messages) to the brain.