Understanding Heart Disease

Yellow fever

Yellow fever (also called yellow jack or sometimes black vomit or American Plague) is an acute viral disease.It is an important cause of hemorrhagic illness in many African and South American countries despite existence of an effective vaccine. The yellow refers to the jaundice symptoms that affect some patients.

Yellow fever has been a source of several devastating epidemics.Yellow fever epidemics broke out in the 1700s in Italy, France, Spain, and England.Three hundred thousand people are believed to have died from yellow fever in Spain during the 19th century.French soldiers were attacked by yellow fever during the 1802 Haitian Revolution; more than half of the army perished from the disease.Outbreaks followed by thousands of deaths occurred periodically in other Western Hemisphere locations until research, which included human volunteers (some of whom died), led to an understanding of the method of transmission to humans (primarily[citation needed] by mosquitos) and development of a vaccine and other preventive efforts in the early 20th century.

Chromosome diseases

Chromosome diseases are genetic diseases where a large part of the genetic code has been disrupted. Chromosomes are long sequences of DNA that contain hundreds or thousands of genes. Every person has 2 copies of each of the 23 chromosomes, called chromosomes 1..22 (or "autosomes") and the 23rd is the sex chromosome, which is either X and Y. Men are XY and women are XX in the 23rd chromosome pair.

The most common type of chromosomal condition is a trisomy condition involving a triplet of chromosomes. Trisomy conditions are chromosome conditions where the disease results from an extra chromosome. Normal humans have two copies of the non-sex chromosomes 1..22, and disease arises if a fetus wrongly gets a third copy of any of these chromosomes.

The Outer Ear: Catch the Wave

The outer ear is called the pinna or auricle (say: or-ih-kul). This is the part of the ear that people can see. It's what people pierce to wear earrings and what your friend whispers into when it's time for a secret. The main job of the outer ear is to collect sounds, whether they're your friend's whispers or a barking dog.

The outer ear also includes the ear canal, where wax is produced. Earwax is that gunky stuff that protects the canal. Earwax contains chemicals that fight off infections that could hurt the skin inside the ear canal. It also collects dirt to help keep the ear canal clean. So earwax isn't just gross. It's gross and useful.

Ears-the pinna or auricle

The Ear is called the pinna or auricle. This is the part of the ear that people can see. It's what people pierce to wear earrings and what your friend whispers into when it's time for a secret. The main job of the outer ear is to collect sounds, whether they're your friend's whispers or a barking dog.

The outer ear also includes the ear canal, where wax is produced. Earwax is that gunky stuff that protects the canal. Earwax contains chemicals that fight off infections that could hurt the skin inside the ear canal. It also collects dirt to help keep the ear canal clean. So earwax isn't just gross. It's gross and useful.

After sound waves enter the outer ear, they travel through the ear canal and make their way to the middle ear. The middle ear's main job is to take those sound waves and turn them into vibrations that are delivered to the inner ear. To do this, it needs the eardrum, which is a thin piece of skin stretched tight like a drum.

They include:

* the malleus (say: mah-lee-us), which is attached to the eardrum and means "hammer" in Latin
* the incus (say: in-kus), which is attached to the malleus and means "anvil" in Latin
* the stapes (say: stay-peez), the smallest bone in the body, which is attached to the incus and means "stirrup" in Latin

When sound waves reach the eardrum, they cause the eardrum to vibrate. When the eardrum vibrates, it moves the tiny ossicles — from the hammer to the anvil and then to the stirrup. These bones help sound move along on its journey into the inner ear.

Peripheral Nerve Disorders

Your peripheral nerves are the ones outside your brain and spinal cord. Like static on a telephone line, peripheral nerve disorders distort or interrupt the messages between the brain and the rest of the body.

There are more than 100 kinds of peripheral nerve disorders. They can affect one nerve or many nerves. Some are the result of other diseases, like diabetic nerve problems. Others, like Guillain-Barre syndrome, happen after a virus infection. Still others are from nerve compression, like carpal tunnel syndrome or thoracic outlet syndrome. In some cases, like complex regional pain syndrome, the problem begins after an injury. Some people are born with peripheral nerve disorders.

Symptoms often start gradually, and then get worse. They include

* Numbness
* Pain
* Burning or tingling
* Muscle weakness
* Sensitivity to touch