Health Treasure

How Does the Respiratory System Work?

The respiratory, or breathing, system is an oxygen delivery system within the human or mammalian body. Through the activity of breathing, the respiratory system supplies oxygen to the blood, and in turn to every cell in the body.

Diaphragm: The diaphragm is located above the ribs and consists of a thin sheet of muscles. It assists in breathing by pulling and pushing the lungs up and down to expand or contract.
Intercostal muscles: These muscles lie between the ribs and help with the mechanism of breathing, including pushing and pulling the lungs to expand or decrease their capacity.
Abdominal muscles: The abdominal area assists people breathe when under pressure, such as running or stress. They assist the diaphragm and intercostal muscles to move much faster and with greater force.

During breathing, several connected events occur. As air enters through the mouth or nose, the lungs expand with the help of the diaphragm, intercostal and abdominal muscles. The air is cleaned in the nose through tiny hairs, and warmed up in both the nose and the mouth. The air travels down the throat and through the "trachea" The trachea funnels the air into one of the two lungs.

What are lungs?

Humans have two lungs, which are positioned above the heart. They consist of the following:

Lobes: Specific tissue areas; the right lung has three lobes, while the left has two. Each lobe has its own air and blood supply. These are simply separations to keep the lungs working optimally.
Cardial Notch: The left lung must accommodate the heart, and the cardial notch allows for the size of the heart in the chest cavity.
Pleural Membranes: These membranes make up the outer walls of the lungs. They are strong but flexible and allow the lungs to expand and contract when breathing.
In addition, the lungs have many "bronchi" or tiny pipes that carry air throughout the lungs.

The function of the lungs is to transfer oxygen from the air to the bloodstream.

How are lungs used to breathe?

To breathe in, the following process occurs:

1. The diaphragm and intercostal muscles push the lungs, causing the lungs to expand as air is sucked in through the nose or mouth, down the throat and through the trachea.

2. Once air has entered the lungs, the bronchi carry the air deeper into the lungs where an important transfer takes place:

3. The bronchi carry the fresh air to the “alveoli”, which are tiny sacs and are instrumental in supplying oxygen to the blood system. There are over 300 million alveoli between two human lungs.

4. Each alveoli is surrounded by “capillaries”, or tiny blood vessels.

5. Molecules of oxygen, which is a vital gas in the human body, travels across the surface of the alveoli and diffuses into the bloodstream in the capillaries with the help of “hemoglobin”, a protein found in blood.

Once oxygen has entered the blood system, the following takes place:

1. The capillaries funnel the oxygen-rich blood to the “pulmonary vein”, or a large blood vessel that takes the blood to the left side of the heart.

2. The heart pumps the blood to all areas of the body, which receive the oxygen.

3. The oxygen-depleted blood is pumped back to the heart and on to the capillaries.

When the blood is returned from the heart to the small capillaries, the lungs begin the process of removing the carbon dioxide from the body, or breathing out. The process for breathing out consists of the following process:

1. The diaphragm and intercostal muscles pull the lungs down, causing them to contract.

2. At the same time, with the help of hemoglobin, carbon dioxide diffuses out of the blood stream and back into the alveoli.

3. The carbon dioxide is pushed out of the alveoli, through the bronchi, up the throat and out of the mouth or nose.

This process is repeated, on average, 20 times per minute.

Other important functions of the respiratory system include:

Yawning: When a human body is not processing enough oxygen, it compensates by yawning, or taking a deep, long breath. This typically occurs when tired, as the body is not functioning at peak performance.
Sneezing: During breathing in, the upper airway passages may attract an irritant such as dust or pollen. Sneezing pushes the irritant out of the airway.
Hiccuping: Hiccups are involuntary contractions of the diaphragm, which cause the lungs to contract and air to be pushed out. The cause of hiccups is unknown.
Coughing: A reflex, a cough is a forced exhalation to push out irritants or debris. It can also be a sign of infection in the lungs as an effort to clear the lungs of mucus.
Laughing: Laughter causes significant pressure on lung walls, expelling air more quickly than during natural breathing. This may cause a human to breath more quickly or deeply in order to reoxygenate blood.

The respiratory system is an essential, interconnected system within the human body. Through the complex interaction of elements within the respiratory system, the circulatory system and other musculature, essential oxygen is continuously provided to all areas of the body. This oxygen enables cells to release energy, and therefore use that energy to keep the body alive, whether it is keeping the brain thinking or the kidney
functioning.

Respiration-Ventilation 3D Medical Animation

Cancer Deaths - Enormous Drop Over Last 20 Years, USA

Over the last twenty years, more than one million deaths from cancer have been avoided, researchers reported in CA: A Cancer Journal for Clinicians. Death rates for the most common cancers, including colon, breast, prostate and lung cancers have been dropping steadily year after year. However, some rarer cancers, such has kidney, thyroid, liver and pancreas cancers have seen death rates and total incidences rise.

In its annual report, titled "Cancer Statistics 2012", plus an accompanying article "Cancer Facts & Figures 2012", the authors estimate how many new cancer diagnoses and cancer deaths there will be this year in the USA.

The authors predict that:

There will have been 1,638,910 new cancer diagnoses in 2012 in the USA
There will have been 577,190 cancer deaths in 2012 in the USA
From 1990 to 2008, overall death rates dropped by approximately 23% in adult males
From 1990 to 2008, overall death rates dropped by about 15% in adult females
These figures mean that over a million cancer deaths during that period were avoided

Cancer incidence and cancer death rates vary considerably between different ethnic and racial groups. Overall, African-American adult males have a 15% higher incidence of new cancer diagnoses and a 33% higher death rate from cancer compared to Caucasian men.

African-American women, on the other hand, have a 6% lower incidence of new cancer diagnoses, but a 16% greater death rate than Caucasian women.

The steepest fall in death rates from cancer over the past two decades were seen in African-American men.

The authors of both reports say that existing knowledge about combating cancer needs to be applied across all segments of society, especially in lower income households.

Tobacco use and obesity are estimated to be the two main cancer-causing factors for 2012. Tobacco use is estimated to cause one third of cancer deaths over the coming twelve months, and obesity, poor nutrition and physical inactivity another third.

Even though overall cancer rates and cancer death rates have dropped over the last two decades, there has been a corresponding rise in those two rates for some rarer cancers.

The following rarer cancers have seen incidence and total deaths increase over the last two decades:

Kidney cancer. Rates rose in all groups, except for American Indian/Alaska Native men.
Thyroid cancer. Rates rose in all groups, except for American Indian/Alaska Native men.
Liver cancer. Rates rose among Caucasian, African-American and Hispanic males, as well as African-American females.
Esophageal adenocarcinoma. Rates increased among Caucasian and Hispanic adult males.
Melanoma of the skin
Some throat cancers (linked with HPV infection). The increase was only among Caucasians.

Experts are not sure why rates have increased in these cancers. Some are associated with higher current rates of obesity (liver, kidney, pancreas and esophagus cancers). Perhaps these cancer are being detected earlier - this could push figures up.

Written by Christian Nordqvist

What Is Cancer? What Causes Cancer?

Cancer is a class of diseases characterized by out-of-control cell growth. There are over 100 different types of cancer, and each is classified by the type of cell that is initially affected.

Cancer harms the body when damaged cells divide uncontrollably to form lumps or masses of tissue called tumors (except in the case of leukemia where cancer prohibits normal blood function by abnormal cell division in the blood stream). Tumors can grow and interfere with the digestive, nervous, and circulatory systems, and they can release hormones that alter body function. Tumors that stay in one spot and demonstrate limited growth are generally considered to be benign.

More dangerous, or malignant, tumors form when two things occur:

a cancerous cell manages to move throughout the body using the blood or lymph systems, destroying healthy tissue in a process called invasion
that cell manages to divide and grow, making new blood vessels to feed itself in a process called angiogenesis.

When a tumor successfully spreads to other parts of the body and grows, invading and destroying other healthy tissues, it is said to have metastasized. This process itself is called metastasis, and the result is a serious condition that is very difficult to treat.
How cancer spreads
- scientists reported in Nature Communications (October 2012 issue) that they have discovered an important clue as to why cancer cells spread. It has something to do with their adhesion (stickiness) properties. Certain molecular interactions between cells and the scaffolding that holds them in place (extracellular matrix) cause them to become unstuck at the original tumor site, they become dislodged, move on and then reattach themselves at a new site.
The researchers say this discovery is important because cancer mortality is mainly due to metastatic tumors, those that grow from cells that have traveled from their original site to another part of the body. Only 10% of cancer deaths are caused by the primary tumors.
The scientists, from the Massachusetts Institute of Technology, say that finding a way to stop cancer cells from sticking to new sites could interfere with metastatic disease, and halt the growth of secondary tumors.
In 2007, cancer claimed the lives of about 7.6 million people in the world. Physicians and researchers who specialize in the study, diagnosis, treatment, and prevention of cancer are called oncologists.

What causes cancer?

Cancer is ultimately the result of cells that uncontrollably grow and do not die. Normal cells in the body follow an orderly path of growth, division, and death. Programmed cell death is called apoptosis, and when this process breaks down, cancer begins to form. Unlike regular cells, cancer cells do not experience programmatic death and instead continue to grow and divide. This leads to a mass of abnormal cells that grows out of control.

What is cancer?

- Video A short, 3D, animated introduction to cancer. This was originally created by BioDigital Systems and used in the Stand Up 2 Cancer telethon.

Mental Health Statistics: Men & Women

Women are more likely to have been treated for a mental health problem than men (29% compared to 17%).This could be because, when asked, women are more likely to report symptoms of common mental health problems. (Better Or Worse: A Longitudinal Study Of The Mental Health Of Adults In Great Britain, National Statistics, 2003)
Depression is more common in women than men. 1 in 4 women will require treatment for depression at some time, compared to 1 in 10 men. The reasons for this are unclear, but are thought to be due to both social and biological factors. It has also been suggested that depression in men may have been under diagnosed because they present to their GP with different symptoms. (National Institute For Clinical Excellence, 2003)
Women are twice as likely to experience anxiety as men. Of people with phobias or OCD, about 60% are female. (The Office for National Statistics Psychiatric Morbidity report, 2001)
Men are more likely than women to have an alcohol or drug problem. 67% of British people who consume alcohol at ‘hazardous’ levels, and 80% of those dependent on alcohol are male. Almost three quarters of people dependent on cannabis and 69% of those dependent on other illegal drugs are male. (The Office for National Statistics Psychiatric Morbidity report, 2001)

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