Human Body

We all here the names of the various scanning techniques that are available these days, here’s a little insight as to what scan is needed for our various body parts:-

• Angiogram – Firtstly they put a special dye in through your blood vessels and into your heart.  Then this dye shows up in X-rays and  reveals the blood network, the doctor can then check for any blockages and help to prevent heart failure.

• Contrast Radiograph – this scan is used to reveal soft tissue and hollow organs.  Barium sulphate, a substance that can be seen by X-ray, is introduced into the soft tissue making the structure visible.  This includes the last intestine part of our digestive system.

• CT Scan – (computerised Tomography) this scanner sends of X-ray beams to work out tissue density.  Then they use a computer to produce a ‘visual slices’ through the body which are then built into 3-d images.
• Endoscope – A long flexible tube with a camera is inserted into a body’s orifice (opening) to reveal internal structures.

• MRI – Magnetic Resonance Imaging uses magnets and radiowaves to produce a picture of soft tissue structures.  Tunnel like scanners emit powerful magnetic orces and radio weaves which cause the body’s molecules to release energy.  Then a computer analysis the energy to form an image.
• Radionuclide Scan – Bones, organs ad other solid body bits can be imaged using small doses of a radioactive substance.  The body cells take up the substance and emit gamma rays that are detected by a gamma camera.  This camera builds up a colour coded picture to reveal different levels of cell activity.

So a lot easier, cleaner and safer for doctors to check out their patients insides without using ‘the knife’!

In ancient civilisation, units of measurement were based on human body parts.   Here’s a few of them…

Cubit – The pyramid builders of Ancient Egypt measure things in cubits.  It was the length of a man’s forearm from elbow to the tip of his middle finger.  The cubit was one of the first recorded units of measurements and was used until the middle ages.

Span – This unit of measurement was based on the width of a hand, stretched out as far as it could go, from thumb tip to pinky finger.

Hand – The width of the four fingers where they meet at the palm is known as a handbreadth.  Used as a unit of length in the ancient world and still used these days to give the height of horses and ponies.

Foot – Don’t be fooled into thinking this is purely the measurement of a mans foot!  In Ancient Greece 16 fingers made up a foot, rather confusingly.  The Romans devised  the measurement of a foot, by using one foot divided into 12 units and measured 29.6cm (12 inches)

Fathom – In Ancient Greece the fathom was two yards, or the distance between the fingertips of a man’s outstretched arm.  Fathoms measured distance on land, but sometime during the 1600’s fathoms became the unit to measure the depth of water.

Yard – there are a few theories on how this measurement is based, some say it may have developed as a double cubit, or the length of a man’s stride, or the distance around your waist.  Also, it has been said that King Henry I  determined that it was the distance between his fingertips and his nose.

Whatever theories or reason’s for these measurements they are all still used today in some shape or form.

Did you know that human beings have five senses? Well here they are…

• Hearing – Sounds are made up of vibrations, which are funnelled inside the ear by the outer ear.  Soundwaves then travel down the ear canal and reach the cochlea.  From here the messages are passed to the brain which interprets them into the sounds we know.

• Touch – There are about three million pain sensors in our skin.  The fingertips are particularly sensitive, as they have 100 touch receptors.   These touch receptors can detect light touch, pressure, vibrations, heat and cold.  Some of these are contained in capsules while others are free nerve endings.

• Smell – Your nose can recognise up to 10,000 different smells.  There are receptors high up in the nasal cavity that can pick up smell molecules and send signals to your brain, in order for you to remember the smell.  People who can’t smell are called ‘anosmic’.

• Taste – The surface of your tongue is covered with tiny bumps (papillae).  Some of them contain taste buds, and they are made up of cells with tiny hairs.  The hairs detect chemicals in food and then your brain tells you the flavour.  We have five basic tastes, and these are sweet, sour, salty, bitter and umani (a savoury taste.)  Children have around 10,000 taste buds, but these numbers decline with age.

• Sight – The eye is like a camera.  Light from an image passes through the cornea and it is adjusted, causing an upside down image on the retina at the back of the eye.  This information is then translated by the brain and turned the correct way up.

 

The answer is simply no.  Identical twins form when a single fertilized egg splits in two and therefore that means although they share identical DNA, there fingerprints don’t develop until three months into pregnancy.

Although activated by genes, it’s also affected by specific factors in the womb, such as position of the unborn baby, nutrition and growth rate.

Ridge patterns are similar, but there will always be some differences.

There are three types of print pattern, arches, loops and whorls all with variable features.

It all started as an innocent laboratory experiment, but Professor Wilhelm Conrad Roentgen discovered x-rays back in the 19th century.

In 1895 Wilhelm Roentgen was experimenting with a Crookes tube (a glass bulb emptied of air).  He knew that when an electric current passed between two electrodes in the tube, a cathode ray (stream of electrons) was released, making the tube glow.  He wanted to see what would happen if he covered the tube with a thick black card.

There was a screen painted with luminescent paint standing in the corner of the room, and as soon as the current was switched on it began to shimmer with a greenish-yellow glow, even though the black card had made the tube light-tight.

Reontgen realised this distant glow might have been an unknown type of radiation.  As he was uncertain of what he had discovered, he decided to call the new rays – X-rays and the name stuck.   These are known as invisible  high frequency electromagnetic waves.

Roentgen placed various objects between the tube and screen, and found that the X-rays passed straight through soft materials such as paper, but metal objects were blocked (absorbed) by the rays.

Finally Roentgen aimed the X-ray at his wife’s hand as it rested on a photographic plate.  Not only did the ring on her finger show up sharply, but all the bones of her hand were visible as well.  He’d stumbled on an amazing technique for looking inside the living body without cutting it open.   Roentgen’s discovery revolutionised medicine.