Innate Immunity

The human body has the ability to resist almost all

types of organisms or toxins that tend to damage the

tissues and organs. This capability is called immunity.

Much of immunity is acquired immunity that

does not develop until after the body is first

attacked by a bacterium, virus, or toxin, often

requiring weeks or months to develop the immunity. An additional portion of

immunity results from general processes, rather than from processes directed

at specific disease organisms. This is called innate immunity. It includes the

following:

1. Phagocytosis of bacteria and other invaders by white blood cells and cells

of the tissue macrophage system,

2. Destruction of swallowed organisms by the acid secretions of the stomach

and the digestive enzymes.

3. Resistance of the skin to invasion by organisms.

4. Presence in the blood of certain chemical compounds that attach to

foreign organisms or toxins and destroy them. Some of these compounds

are (1) lysozyme, a mucolytic polysaccharide that attacks bacteria and

causes them to dissolute; (2) basic polypeptides, which react with and

inactivate certain types of gram-positive bacteria; (3) the complement

complex that is described later, a system of about 20 proteins that can be

activated in various ways to destroy bacteria; and (4) natural killer

lymphocytes that can recognize and destroy foreign cells, tumor cells, and

even some infected cells.

This innate immunity makes the human body resistant to such diseases as

some paralytic viral infections of animals, hog cholera, cattle plague, and distemper—

a viral disease that kills a large percentage of dogs that become

afflicted with it. Conversely, many lower animals are resistant or even immune

to many human diseases, such as poliomyelitis, mumps, human cholera, measles,

and syphilis, which are very damaging or even lethal to human beings.

Surgical instrument

A surgical instrument is a specially designed tool or device for performing specific actions of carrying out desired effects during a surgery or operation, such as modifying biological tissue, or to provide access for viewing it. Over time, many different kinds of surgical instruments and tools have been invented. Some surgical instruments are designed for general use in surgery, while others are designed for a specific procedure or surgery. Accordingly, the nomenclature of surgical instruments follows certain patterns, such as a description of the action it performs (for example, scalpel, hemostat), the name of its inventor(s) (for example, the Kocher forceps), or a compound scientific name related to the kind of surgery (for example, a tracheotome is a tool used to perform a tracheotomy).

The expression surgical instrumentation is somewhat interchangeably used with surgical instruments, but its meaning in medical jargon is really the activity of providing assistance to a surgeon with the proper handling of surgical instruments during an operation, by a specialized professional, usually asurgical technologist or sometimes a nurse or radiologic technologist.

Medical Instruments

A medical instrument is any tool, apparatus, appliance, material, used alone or in combination with other such items meant to be used on humans for the purpose of:

• Diagnosis, prevention, monitoring, treatment, or alleviation of disease;

• Diagnosis, monitoring, treatment, alleviation of an injury or handicap;

• Investigation, replacement, or modification of the anatomy or of a physiological process;

Medical instruments may be classified based on their uses such as Anaesthesia instrument (use to induce controlled unconsciousness e.g. Anaesthetic Endotracheal Tube), Cardiovascular Instrument (used for procedures performed on the heart e.g Artery Forceps), Dental Instrument (used in dental surgeries e.g. Bone Chisel, Dental Elevator), etc.

Permanent teeth.

Types of Teeth

The shapes of animals' teeth give clues to the type of diets they eat. Meat eaters have sharp, pointed teeth to pierce and tear. Plant eaters have broad, flat teeth to crush and grind. Humans are no exception. As a species, we eat both meats and plants, so we have different types of teeth to handle both types of food. Incisors — The four front teeth in both your upper and lower jaws (a total of eight) are incisors. The pair of teeth at the center of your mouth, top and bottom, are called the central incisors. And the teeth on each side of the central incisors are the lateral incisors. All the incisors are broad, flat teeth with a narrow edge good for cutting or snipping off pieces of food. They have a single root. Canines — On both sides of your upper and lower incisors are the canines (a total of four). Sometimes called eyeteeth or cuspids, canines are the longest and most stable teeth in the mouth. They are thick and come to a single sharp point. They are ideal for ripping and tearing at foods that might be tough, such as meat, and for piercing and holding. They have a long single root. Premolars — Next to each canine are two premolars (a total of eight). Also called bicuspids, premolars are a cross between canines and molars. They have sharp points for piercing and ripping, but they also have a broader surface for chewing and grinding. On the upper jaw, the first premolars (directly next to the canines) have two roots, and the second premolars have one root. On the lower jaw, all premolars have one root. Molars — The last three upper and lower teeth on both sides of your mouth are the molars (a total of 12). They are numbered first, second or third molars depending on their location. The first molars, also called 6-year molars, are those closest to the front of the mouth, directly next to the second premolars. The third molars are also called the wisdom teeth. They are the last teeth, farthest back in the mouth on all sides. In between are the second molars, also called 12-year molars. Molars are large teeth with broad surfaces designed for crushing, grinding and chewing food. On the upper jaw, the molars have three well-separated roots. On the lower jaw, the molars have two roots.

What is Down Syndrome?

What is Down Syndrome?

Down syndrome (DS), also called Trisomy 21, is a condition in which extra genetic material causes delays in the way a child develops, both mentally and physically. It affects about 1 in every 800 babies.

The physical features and medical problems associated with Down syndrome can vary widely from child to child. While some kids with DS need a lot of medical attention, others lead healthy lives.

Though Down syndrome can't be prevented, it can be detected before a child is born. The health problems that can go along with DS can be treated, and there are many resources within communities to help kids and their families who are living with the condition.

What Causes It?

Normally, at the time of conception a baby inherits genetic information from its parents in the form of 46 chromosomes: 23 from the mother and 23 from the father. In most cases of Down syndrome, a child gets an extra chromosome 21 — for a total of 47 chromosomes instead of 46. It's this extra genetic material that causes the physical features and developmental delays associated with DS.

Although no one knows for sure why DS occurs and there's no way to prevent the chromosomal error that causes it, scientists do know that women age 35 and older have a significantly higher risk of having a child with the condition. At age 30, for example, a woman has about a 1 in 900 chance of conceiving a child with DS. Those odds increase to about 1 in 350 by age 35. By 40 the risk rises to about 1 in 100.