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Anatomy and Physiology of the Immune System: Defending Your Body

Anatomy and Physiology of the Immune System: Defending Your Body

Immune System

The immune system is a complex web of cells, major organ systems, and proteins that work together to fight microbes (infections).

Immune System and Microbial Infections

The immunity system stores a record in memory cells of all its defeated microbes. These are white blood cells called B-lymphocytes or T-lymphocytes. The immune functions can recognize the microbe and kill it quickly if it enters your body again. In health care facilities, human anatomy & physiology & night and weekend nursing programs in nursing with pre – requisites courses in community college play a vital role in equipping healthcare professionals with the necessary knowledge to combat infections by expanding their understanding of immune system cells, comprehensive knowledge of evidence-based practice and their major functions in clinical facilities.

It is necessary to fight some sites of infection like influenza or the common flu several times because so many viruses and strains can cause them. The fact that you have a cold, flu, or other virus doesn’t give immunity to the rest. Let’s discuss the parts of the immune system.

Parts of the Immune System

The immune system is composed of:

  • White blood cells
  • Antibodies
  • Complement system
  • Lymphatic System
  • Spleen
  • Bone marrow
  • Thymus

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White Blood Cells

The white blood cells of your immune system are key players. These cells are produced in the bone marrow, and they are part of your lymphatic system. The white blood human cells search through the blood and tissues of your body for microbes such as viruses and bacteria. They launch an attack when they locate them. The white blood cells are made up of lymphocytes such as B-cells (such as T-cells), natural killer cells, and other immune cells.


Antibodies are proteins that help the body fight microbes and the poisons they produce. The antibodies do this by recognizing substances called foreign antigens, either on the surface or in the chemical products of microbes, that mark them as foreign called foreign substances. Antibodies subsequently identify these antigen-presenting cells for degradation. This attack involves many different cells, proteins, and chemical compounds. By enrolling in an A&P class, students can also understand the overall concepts of nursing practice & antibodies in a variety of health care.

Complement System

The complement body system is composed of proteins that complement the work performed by antibodies.

Lymphatic System

The system consists of a delicate network of tubes that run throughout the entire body. The lymphatic system’s primary functions are:

  • Manage fluid levels in your body.
  • React to bacteria.
  • Deal with cancer cells & infected cells.
  • Deal with cell products that would otherwise result in major disease or disorder.
  • The intestine can absorb some of the fats we eat.

The lymphatic system is composed of:

  • The lymph nodes, also known as lymph glands, are microbe-trapping lymph nodes.
  • The lymphatic vessels are tubes that carry the lymph fluid. This colorless fluid bathes tissues in your body and contains white blood cells that fight infection.
  • White blood cells (lymphocytes)


The spleen filters blood and destroys damaged or old red blood cells. The spleen also produces immune system cellular components that fight disease (such as antibodies and lymphocytes).

Bone Marrow

Bone Marrow refers to the soft tissue that is found in your bones. The marrow produces red blood cells that carry oxygen to our body, white blood cells to fight bacterial infections, and platelets to help our blood clot.


It filters your blood and keeps track of its level. It produces white blood cells known as T-lymphocytes.

Other Defenses of the Body Against Microbes

The body can also defend itself from microbes by using:

  • Skin is a waterproof barrier that secretes an oil that has antibacterial properties.
  • Lungs- the mucous in your lungs (phlegm), which traps foreign particles or viral infections and is waved upward by tiny hairs called cilia, allows you to cough it out.
  • Digestive system- the mucous layer contains antibodies, and the acid can kill the majority of microbes
  • Other defenses-Body fluids such as skin oil, saliva, and tears contain anti-bacterial proteins that reduce the risk of infection. Constant flushing helps.

Immune Disorders That Affect the Body

Over or underactive immunity is not uncommon. The immune system can be overactive in many ways.

  • Allergies: When the immune response to allergens. Allergic diseases can be widespread. Allergic diseases include:
    • Allergies to foods, medications, or stinging insect
    • Anaphylaxis (a life-threatening allergy)
    • Allergic rhinitis (hay fever)
    • Sinusitis
    • Asthma
    • Hives (urticaria)
    • Dermatitis
    • Eczema

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  • Autoimmune diseases: When the immune system responds against standard human body components. Autoimmune disorders can be standard or rare. Autoimmune diseases include:
    • Multiple sclerosis
    • Thyroid disease autoimmune
    • type 1 diabetes
    • Systemic lupus erythematosus
    • Rheumatoid arthritis
    • Systemic asculitis