HUMAN HEART

INTERIAL AND EXTERNAL STRUCTURE OF HEART

HUMAN BRAIN

HUMAN BRAIN PARTS AND FUNCTION

• PART OF BRAIN
• FUNCTION OF BRAIN
• 

PART OF EYES

The Parts of the Eye

You can check out different parts of the eye by looking at your own eye in the mirror or by looking at (but not touching) a friend's eye. Some of the eye's parts are easy to see, so most friends will say OK. Most friends won't say OK if you ask to see their liver!

Big as a Ping Pong Ball

The eye is about as big as a ping-pong ball and sits in a little hollow area (the eye socket) in the skull. The eyelid protects the front part of the eye. The lid helps keep the eye clean and moist by opening and shutting several times a minute. This is called blinking, and it's both a voluntary and involuntary action, meaning you can blink whenever you want to, but it also happens without you even thinking about it.

HUMAN EYE

EYE

Your eyes are at work from the moment you wake up to the moment you close them to go to sleep. They take in tons of information about the world around you — shapes, colors, movements, and more. Then they send the information to your brain for processing so the brain knows what's going on outside of your body.

You can see that the eye's pretty amazing. So, come on — let's take a tour of its many parts.

system of human body

• SYSTEMS IN HUMAN BODY
•                 SkeletaSystem
• Muscular System
• Cardiovascular System
• Digestive System
• Endocrine System
• Nervous System
• Respiratory System
• ImmuneLymphaticSystems
• Urinary System
• Female Reproductive System
• Male Reproductive System
• Integumentary System

Explore the human body like never before! With hundreds of interactive anatomy 

Third Law of motion

Third Law

The third law says that for every action (force) there is an equal and opposite reaction (force). Forces are found in pairs. Think about the time you sit in a chair. Your body exerts a force downward and that chair needs to exert an equal force upward or the chair will collapse. It's an issue of symmetry. Acting forces encounter other forces in the opposite direction. There's also the example of shooting a cannonball. When the cannonball is fired through the air (by the explosion), the cannon is pushed backward. The force pushing the ball out was equal to the force pushing the cannon back, but the effect on the cannon is less noticeable because it has a much larger mass. That example is similar to the kick when a gun fires a bullet forward. 

2nd law of motion

Sir Isaac Newton 2nd law of motion

• Second Law

The second law says that theacceleration of an object produced by a net (total) applied force is directly related to the magnitude of the force, the same direction as the force, and inversely related to the mass of the object (inverse is a value that is one over another number... the inverse of 2 is 1/2). The second law shows that if you exert the same force on two objects of different mass, you will get different accelerations (changes in motion). The effect (acceleration) on the smaller mass will be greater (more noticeable). The effect of a 10 newton force on a baseball would be much greater than that same force acting on a truck. The difference in effect (acceleration) is entirely due to the difference in their masses.