the invisible army

What Protects our bodies from harmful substances, germs, and cell changes that could make you ill ?? AA Our bodies have several ways to defend themselves against microbes, including: AA Skin : a waterproof barrier that secretes oil wi…

What Protects our bodies from harmful substances, germs, and cell changes that could make you ill ??AA

Our bodies have several ways to defend themselves against microbes, including:AA

Skin : a waterproof barrier that secretes oil with bacteria-killing properties.AA

Lungs :mucous in the lungs (phlegm) traps foreign particles, and small hairs (cilia) wave the mucous upwards so it can be coughed out .AA

Digestive tract :the mucous lining contains antibodies, and the acid in the stomach can kill most microbes.AA

Other defenses : body fluids like skin oil, saliva, and tears contain anti-bacterial enzymes that help reduce the risk of infection. The constant flushing of the urinary tract and the bowel also helps.A

Immune system :The immune system is made up of special organs, cells, and chemicals that fight infection (microbes). The main parts of the immune system are white blood cells, antibodies, the complement system, the lymphatic system, the spleen, the thymus, and the bone marrow. These are the parts of your immune system that actively fight infection.AA

White blood cells

White blood cells are the key players in your immune system. They are made in your bone marrow and are part of the lymphatic system. AA

White blood cells move through blood and tissue throughout your body, looking for foreign invaders (microbes) such as bacteria, viruses, parasites, and fungi. When they find them, they launch an immune attack. AA

White blood cells include lymphocytes (such as B-cells, T-cells, and natural killer cells), and many other types of immune cells. AA

Antibodies

Antibodies help the body to fight microbes or the toxins (poisons) they produce. They do this by recognizing substances called antigens on the surface of the microbe, or in the chemicals they produce, which mark the microbe or toxin as being foreign. The antibodies then mark these antigens for destruction. There are many cells, proteins, and chemicals involved in this attack. AA

Complement system

The complement system is made up of proteins whose actions complement the work done by antibodies.AA

Lymphatic system

The lymphatic system is a network of delicate tubes throughout the body. The main roles of the lymphatic system are to:AA

A) manage the fluid levels in the body

B) react to bacteria

C) deal with cancer cells

D) deal with cell products that otherwise would result in disease or disorders

E) absorb some of the fats in our diet from the intestine.

The lymphatic system is made up of:

lymph nodes (also called lymph glands) -- which trap microbes

lymph vessels -- tubes that carry lymph, the colorless fluid that bathes your body's tissues and contains infection-fighting white blood cells

white blood cells (lymphocytes).AA

Spleen

The spleen is a blood-filtering organ that removes microbes and destroys old or damaged red blood cells. It also makes disease-fighting components of the immune system (including antibodies and lymphocytes).AA

Bone marrow

Bone marrow is the spongy tissue found inside your bones. It produces the red blood cells our bodies need to carry oxygen, the white blood cells we use to fight infection, and the platelets we need to help our blood clot.AA

Thymus

The thymus filters and monitors your blood content. It produces the white blood cells called T-lymphocytes.AA

Without an immune system, we would have no way to fight harmful things that enter our body from the outside or harmful changes that occur inside our bodies.AA

Written by / Manar Ahmed