HOW TO SEE INSIDE THE BODY?

When x-rays passed into the body, it casts shadow of the bones. A doctor can read x-ray film and diagnose. But the body is also made up of soft tissues, nerves, muscles, fluids. They cannot be detected using x-rays. The 'magnetic resonance imaging (MRI) gives the full picture.

Our body mostly contains water, we know each water molecule has one oxygen atom and two hydrogen atoms. Hydrogen atom is nothing but a single proton. So each water molecule has two single protons. Proton is positively charged and spins like earth and moon. When a charge spins, it acts like piece of magnet. Hence each water molecule is a magnet. (or 2 magnets) . These magnets are oriented in various directions normally.

A patient is put inside the MRI machine and a strong magnetic field is applied to the body. This field is a thousand times powerful than that of a fridge magnet. (Remember, no magnetic substance like keys, coins are allowed inside the MRI room). Now all the proton magnets (n the water component of a particular part of a body) are oriented and aligned in the direction of MRI machine's magnetic field.

Now, the machine sends some electromagnetic energy (high frequency) wave into the particular part of the body.

The spinning protons absorbs it and reverses its direction (flips its magnetic direction). When the external field is switched off, the protons return to its original state by emitting the same absorbed energy.

It is like; water is raised to the overhead tank by the water pump using electrical energy and stored. Once the value is opened it flows down using absorbed energy.

The amount of water content in a particular part of the body (say brain), energy released , value of returning to the normal state(protons). All these factors are interpreted by the computer software(MRI) and give us 2D or 3D image.

In functioned MRI, even blood flow can be detected. The brain is mainly made up of soft tissues containing water. The MRI greatly helped to study the brain. But still, we have not 100% understood about the brain. But we have almost mastered the heart.

Note: Radiation risk is not there in MRI.
Resonance means same frequency energy is absorbed and released by the protons (H2O).
-------------------------------------------------------------------------------------------------------------------------

Comments

LISSAJOUS FIGURES

Definition: "When a particle is subjected to two sine wave motion or two oscillatory motion at right angles, the particle describes lissajous figures". We know sine wave motion and circular motion is basically same. Hence we draw two circles A and B perpendicular to each other. The circle B rotates twice faster than circle A. That is, frequency of circle B is two times than that of A. A particle at the intersection of two circles is subjected to two sine wave motion A and B at 90 degree simultaneously. The particle will describe figures depending on the frequency and phase of A and B . In our case, the ratio of frequency is 1:2 and the two waves are in phase. To draw lissajous figures : A moving point in both the circles are chosen. Here we should remember; during the time taken by the circle A to complete one rotation, circle B completes two. Hence the points are marked on the circles according to their speed. Then straight lines

THE PARABOLA

A jet of water shooting from a hose pipe will follow a parabolic path. What is the so special about parabola. Y= x^2 Draw a graph for the above equation. It will result in a parabola. This parabola is also called unit parabola. Any equation involving square will yield a parabola. Example: Y = 2x^2 +3x+3 (also called quadratic equation) X= 2 and -2, both satisfies the equation 4 = X^2. Parabolic equations always have two solutions. Any motion taking place freely under gravity follows parabolic path. Examples: An object dropped from a moving train, A bomb dropped from flying plane, A ball kicked upwards. If a beam of light rays fall on the parabolic shaped mirror, they will be reflected and brought to focus on a point. This fact is made use of in Dish Antenna, Telescope mirrors, etc. Inverted parabola shape is used in the construction of buildings and bridges. Because the shape is able to bear more weight. A plane

CASINO'S GAME

Let us find out how the casino survives with mathematics. Say, your friend invite you for a game of dice. You must bet (wager) 2 dollars. If you roll 'six' you will get back 8 dollars. The game will go on for 30 rounds. All sounds good. The probability of rolling 'six' is 1/6. Since the game will be played for 30 times, the 'expected win' is 30*1/6 = 5. That is, you are expected to win 5 rounds out of 30. Hence your gain will be 5 * 8 =40 dollars. ok. This also implies that you will loose 25 rounds. Hence your loss will be 25*2 =50 dollars. Your net gain will be gain-less = 40-50 = -10 dollars. For 30 rounds, the loss is -10 dollars, Hence, for one round =-10/30 = -1/3 dollars. There will be a loss of -1/3 or 0.33 dollars per round. It is not a fair game. Let us make a simple formula to calculate 'Pay out per round\. The probability for a win = p The pay-out in case of win = V No. of rounds = n The expect

sciencecapsules

Search This Blog