Reproductive System

The human reproductive system is a complex process, both male and female, that must work together flawlessly to produce a new living baby. This is a process where the generation of a living organism brings into being the next generation. It is full of details, facts and complexities that make it one of the most difficult processes to reproduce outside the natural production.

Interesting fact about the reproductive system in the human body is that it isn't essential to the preservation of any individual and yet it is essential to the preservation of the species. Most men would disagree that the act of sexual intercourse is essential to the individual; and at some point in their lives many women feel that reproduction is essential to the individual; but science underscores the point that the preservation of the species doesn't hinge on one reproductive couple.

There are some Interesting Facts about the Reproductive System:

• Male sperm is significantly smaller than the female egg. While the sperm measures 2.5 to 3.5 microns across the head, the fully mature egg is 100-125 microns in diameter.

• The largest cell in the female body is the egg.

• A woman never runs out of eggs. At birth she has between 1 and 2 million potential eggs (follicles) and by puberty has 300,000 to 400,000 viable eggs (follicles) that can be fertilized.

• About 500 million sperm mature every day in a healthy male.

• The male scrotum hangs outside the body since the internal body temperature is too high and will kill the sperm.

• The average lifespan of an egg once it is released from the ovary is 12-24 hours, after which it either disintegrates or is flushed out of the body with the menstrual flow. The average life span of the sperm is 2-3 days.

• The male reproductive system consists of penis, testicles, scrotum, ducts and accessory glands. The system produces millions of sperm to transmit them to the female body to fertilize one egg.

• Once the sperm has penetrated the egg, the outer shell becomes impenetrable to other sperm.

• In the uterus, prior to birth, the baby's body is covered by a thin layer of hair. As soon as the baby is born, that hair soon disappears. The hair is called lanugo.

• When a baby is bom, both male and female, the mammary glands are sometimes so stimulated by the mothers' hormones that they give tiny drops of milk for about a week.

• Female babies can actually bleed vaginally for several days after birth in response to the removal of the mothers' hormones during pregnancy.

• The female human body is capable of giving birth to 35 children in one lifetime.

Supplementary texts for student’s independent work Bronchitis

Bronchitis is an inflammation of the lining of the bronchial tubes, the airways that connect the trachea to the lungs. This delicate, mucus-producing lining covers and protects the respiratory system, the organs and tissues involved in breathing. When a person has bronchitis, it may be harder for air to pass in and out of the lungs than it normally would, the tissues become irritated and more mucus is produced. The most common symptom of bronchitis is a cough.

Bronchitis can be acute or chronic. An acute medical condition comes on quickly and can cause severe symptoms, but it lasts only a short time (no longer than a few weeks). Acute bronchitis is most often caused by one of a number of viruses that can infect the respiratory tract and attack the bronchial tubes. Chronic bronchitis, on the other hand, can be mild to severe and is longer lasting - from several months to years. People who have chronic bronchitis are more susceptible to bacterial infections of the airway and lungs, like pneumonia.

Acute bronchitis often starts with a dry, annoying cough that is triggered by the inflammation of the lining of the bronchial tubes. Other syrnptoms may include: cough that may bring up thick white, yellow, or greenish mucus, headache, generally feeling ill, chills, fever and shortness of breath, soreness or a feeling of tightness in the chest, wheezing (a whistling or hissing sound with breathing)

Smoking and being around tobacco smoke, chemical fumes, and other air pollutants for long periods of time puts a person at risk for developing chronic bronchitis.

Some people who seem to have repeated bouts of bronchitis - with coughing, wheezing, and shortness of breath - may actually have asthma.

If a doctor thinks you may have bronchitis, he or she will examine you and listen to your chest with a stethoscope for signs of wheezing and congestion.

In addition to this physical examination, the doctor will ask you about any concerns and symptoms you have, your past health, your family's health,, any medications you're taking, any allergies you may have, and other issues (including whether you smoke). This is called the medical history. Your doctor may order a chest X-ray to rule out a condition like pneumonia, and may sometimes order a breathing test to rule out asthma.

Because acute bronchitis is most often caused by a virus, the doctor may not prescribe an antibiotic (antibiotics only work against bacteria, not viruses).

The doctor will recommend that you drink lots of fluids, get plenty of rest, and may suggest using an over-the-counter or prescription cough medicine to relieve your symptoms as you recover.

If you have chronic bronchitis, the goal is to reduce your exposure to whatever is irritating your bronchial tubes. For people who smoke, that means quitting!

If you have bronchitis and don't smoke, try to avoid exposure to second-hand smoke.

Tuberculosis or ТВ

Tuberculosis or ТВ (short for tubercles bacillus) is a common and often deadly infectious disease caused by various strains of mycobacteria, usually Mycobacterium tuberculosis in humans. Tuberculosis usually attacks the lungs but can also affect other parts of the body. It is spread through the air; when people who have the disease cough, sneeze, or spit. Most infections in humans result in an asymptomatic, latent infection, and about one in ten latent infections eventually progresses to active disease, which, if left untreated, kills more than 50% of its victims.

The classic symptoms are a chronic cough with blood-tinged sputum, fever, night sweats, and weight loss. Infection of other organs causes a wide range of symptoms. Diagnosis relies on radiology (commonly chest X-rays), a tuberculin skin test, blood tests, as well as microscopic examination and microbiological culture of bodily fluids. Treatment is difficult and requires long courses of multiple antibiotics. Contacts are also screened and treated if necessary. Antibiotic resistance is a growing problem in (extensively) multi-drug-resistant tuberculosis. Prevention relies on screening programs and vaccination, usually with Bacillus Calmette-Guerin vaccine. When the disease becomes active, 75% of the cases are pulmonary ТВ, that is, ТВ in the lungs. Symptoms include chest pain, coughing up blood, and a productive, prolonged cough for more than three weeks. Systemic symptoms include fever, chills, night sweats, appetite loss, weight loss, pallor, and often a tendency to fatigue very easily.

In the other 25% of active cases, the infection moves from the lungs, causing other kinds of ТВ, collectively denoted extrapulmonary tuberculosis. This occurs more commonly in immunosuppressed persons and young children. Extrapulmonary infection sites include the pleura in tuberculosis pleurisy, the central nervous system in meningitis, the lymphatic system in scrofula of the neck, the genitourinary system in urogenital tuberculosis, and bones and joints in Pott's disease of the spine.

A third of the world's population is thought to be infected with M. tuberculosis, and new infections occur at a rate of about one per second. The proportion of people who become sick with tuberculosis each year is stable or falling worldwide but, because of population growth, the absolute number of new cases is still increasing. In addition, more people in the developed world are contracting tuberculosis because their immune systems are compromised by immunosuppressive drugs, substance abuse, or AIDS.