5 Main Sensory Organs S.O Skin Nose Tongue Ear Eye

The function of the sensory organ Detect stimuli or changes in the environment Pass the impulse to the brain for interpretation then followed by action (respond) if necessary. Provide the ability to protects us from harm or injury What if without sensory organ??

The function of 5 S.O Sensory Organ Stimuli Detected Main Function Skin Touch, pressure, pain, heat, cold Organ for touch Nose Chemicals Organ for smell Tongue Organ for taste Ear Sound Organ for hearing Eye Light Organ for sight

The Human Nervous System Central N.S Brain Spinal Cord Nerves Sensory Nerves Motor Nerves

Function of nervous system Detecting stimuli and changes in environment Send the information (in the form of nervous impulse) to the brain for interpretation, The brain sends out instruction (in the form of nervous impulse) to the relevant parts of the body for action to be taken.

Components of nervous system Brain Spinal cord Nerves

Central Nervous System

Nerves

The Pathway From Stimulus To Respond Sensory organ Sensory nerves Brain Motor Nerves Response

Idea through diagram

The Sense of Touch The skin made up of 2 layers: Epidermis and Dermis Epidermis : very thin layer of dead cells which protects the surface of the body Dermis : Consisting the structure such as living cells, blood capillaries, swear glands, nerves, nerve endings (receptors).

Structure of Human skin and Receptors in Human Skin

Type of receptors and Functions Touch receptors Detects any contact made with the skin Pressure receptor Detects pressure exerted on the skin Pain receptor Detects pain when the skin is injured Heat receptor Detects heat or any rise in temperature Cold receptor Detects a cold substance or any fall in temperature

Sensitivity The receptors are not evenly distributed in the skin. This (uneven distribution of receptors) make some parts of the body more sensitive than other parts. Factors of sensitivity: The thickness of the epidermis The concentration of receptors

Activities What is a sensory organ? Which of our senses are known as chemical senses? Which parts of the body form the central nervous system? Where is the spinal cord situated? Name a receptor which is found in the epidermis. What is the function of the epidermis of the skin? What is the function of the skin as a sensory organ?

Answer A sensory organ is one which detects stimuli and changes in the surrounding Sense of taste and sense of smell The brain and the spinal cord Within the backbone Receptor for pain To protect the skin To detect stimuli from the surrounding