Cell As A Basic Unit Of Life

Do you know teens? This is the best chapter I would like to introduce, to explain, to deliver to you. Why did I say so? Because, this is about you, me and all around you.

As for an introduction, let me explain to you where is the term cell comes from?

The term cell comes from the Latin word Cellula, which means small compartments.

Cell is the basic units of all living things including you(humans), animal, plant and all organisms.

All of organisms are made up of cells.

Look at this organisation of cells!

You are made up of cells. (That is a basic unit of you!)

Made up of cells - then form of various tissue - then form as different organs - then complete  with various system body - Lastly, you're form as complex organisms.

Now, are you clear with the term of CELL?Good!

We move into the next post is about HOW TO USE A MICROSCOPE?

We can observed the cell using a microscope!

Bye! Bye! Teens....

SKIN ( SENSE OF TOUCH )

Hello teens....

Do you know, skin is the largest organ in humans? Skin is the largest and fastest growing organ in your body. Skin is your body's coat and it protects you. Top part your skin is epidermis. Your skin helps you to stay warm when it's cold and stay cool when it's hot.

LAYERS OF YOUR SKIN

There are three main layers of your skin.

• Epidermis is the top layer of the skin, the part of the skin you see.
• Dermis is the second layer of the skin. It is much thicker and does a lot for your body.
• Subcutaneous Fat is the bottom layer.

SENSE OF TOUCH

In medicine, the colloquial term "touch" is usually replaced with "somatic senses" to better reflect the variety of mechanisms involved. Touch receptors in our skin is known as somatosensory system. Within the somatosensory system,there are four main types of receptors ; mechanoreceptors, thermoreceptors, pain receptors and proprioceptors. 

1. Mechanoreceptors : These receptors perceive sensations such as pressure, vibrations, and texture. For you level knowledge, there are two mechanoreceptors that you should know. Meissner's corpuscles ( senses touch ) and Pacinian corpuscles  ( senses pressure ).

2. Thermoreceptors : These receptors perceive sensations related to the temperature of objects the skin feels. They are found in the dermis layer of the skin. There are two basic categories of thermoreceptors: hot and cold receptors.

3. Pain receptors : and also known as nocireceptors. These receptors detect pain or stimuli that can or does cause damage to the skin and other tissues of the body. They can detect pain that is caused by mechanical stimuli (cut or scrape), thermal stimuli (burn), or chemical stimuli (poison from an insect sting).

MECHANISMS SENSE OF TOUCH 

HOW YOU FEEL PAIN ?
This is the diagram to show you the pain pathway.

This is how the way you feel pain. When the stimuli of pain receive on your pain receptors. It will activated. A signal travel up the nerve to your spinal cord and activated the other nerves that pass signals to your brain. Then, your brain will release the signals on to the somatosensory cortex , frontal cortex and limbic system. The end of the results is you feel the pain on your finger and give reaction as "ouch!".

Now, do you understand how your skin works through the senses of touch?
Easy right?

Happy learn and study teens!

Human Sensory Organs

Okay teens, FYI in this chapter will guide you to explore the human sensory organs. What are they?

Human sensory organs are :

EYES, SKIN, TOUNGE, EARS & NOSE

Each of these sensory organs have their own stimuli and their sense of too.

EYES ( SENSE OF SIGHT )

• is stimuli to the light and detected by the sense of sight.
• is the sensory organ of sight.

SKIN ( SENSE OF TOUCH )

• is the sensory organ of touch.
• is responds to heat, cold,pressure, touch and pain stimuli.

TOUNGE ( SENSE OF TASTE )

• is the sensory organ of taste.
• is responds to the taste of sweet, bitter, sour and salty.
• has groups of cells known as taste buds. ( its detected the taste )

EARS ( SENSE OF HEARING )

• is the sensory organ of hearing.

NOSE ( SENSE OF SMELL )

• is sensory organ of smell.
• has smell receptors @ cells sensitive to smell.

Okay teens! All of these five sensory organs have been introduced and will be explain more on the next post.