The Slim Book of Health Pearls: Challenging Diagnoses

Sheldon Cohen

• Publisher: eBookIt.com
• ISBN:
  9781456615512
• Topic: Medicine
• Subtopic: Diseases & Allergies

Incorrect, delayed, or missed diagnoses have plagued physicians since the beginning of time. The result may be significant patient harm and medical resources wasted as the majority of all primary care physicians surveyed report that an average of five percent of their patients come under the category of difficult to diagnose, or CHALLENGING DIAGNOSES. It is more important than ever for patients to take the time to understand their own symptoms, assist in the zeroing in process of the diagnostic evaluation and collaborate fully with their physician in the sometime twists and turns leading to a final diagnosis.

APPENDIX

The first line of defense (nonspecific defense mechanisms).

I will go into considerable detail here if for no other reason but to impress with the amazing complexity of the immune system, which medical students of my vintage knew absolutely nothing about.

Non-specific means that these mechanisms do not zero in on specific enemies as the lymphocytƒes do that we discussed earlier. But rather the non-specific defenses form defenses against all invading organisms and foreign substances.

These non-specific defense mechanisms (innate immunity) are present at birth, are not required to have a previous encounter with the invading or offending substance, and do not develop memory (ability to quickly recognize an antigen in the future). This in contrast with the T and B lymphocytes

NON-SPECIFIC DEFENSE MECHANISMS

First is the skin. This organ, our largest, acts like a shield of armor. It stops bacteria from entering our bodies and in so doing prevents bacterial infection from gaining a foothold. This assumes, of course, that the skin has maintained its integrity and there are no cuts, bruises or rashes providing an entry point.

The body sheds the outer layer of skin on a regular basis and discards bacteria along with it.

The outer skin layer is the epidermis consisting of five parts. The layers from superficial to deep are:

1.Stratum corneum: a twenty-five cell layer of dead cells filled with keratin, a protein that intertwines and acts as a barrier to infectious agents and makes the skin waterproof. Not only does this layer form a barrier to infectious agents, but it also prevents light, heat, and some chemicals from entering our body. Cells from the lower layers replace these cells as the upper cell layers shed off.

2.Stratum lucidum: five layers of dead cells that contain eleidin, a precursor of keratin.

3.Stratum granulosum: three to five layers of cells that manufacture keratohyalin a precursor of keratin.

4.Stratum spinosum: eight to ten layers of cells that take in melanin, a brown-black pigment that shields the cells from ultraviolet light from the sun.

5.Stratum basale: a single layer of cells that contain stem cells that are capable of new cell growth. This layer also contains nerve endings sensitive to touch.

Beneath the epidermis is the dermis within which are sensory nerves that send messages to the brain (heat, cold, touch, pain, and pressure). In addition, there are suderiferous (sweat) glands, sebaceous (oil) glands, small arteries and veins, blood capillaries, hair follicles, and tiny longitudinal muscles called Arrector Pili muscles attached to the hair follicle and outer skin layers that can make our hair “stand on end” or give us “goose bumps.”

Finally, beneath these two skin layers is a subcutaneous (under the skin) layer consisting of larger arteries and veins and adipose (fat) tissue.

Again, compromising the integrity of the outer layer of the skin may allow bacteria to enter resulting in infection.

THE DEFENSIVE FUNCTION OF THE SKIN

Sebaceous (oil) glands in the skin secrete an oily material called sebum, a mixture of salts, fats, including unsaturated fatty acids, cholesterol, and protein. The unsaturated fatty acids can inhibit the growth of certain bacteria. In addition, sebum keeps the skin moist by reducing evaporation of water from the skin. This prevents the skin from cracking and opening the door to bacteria.

There is a down side here though. Sometimes sebaceous glands enlarge due to accumulated sebum and form a “black head.” The blackness is due to an accumulation of pigment and oxidized oil. From this, pimples (zits) or boils often result because the sebum turns out to be tasty dish for certain bacteria.

That’s not all. The suderiferous (sweat) glands secrete a substance called lysozyme that has antibacterial properties. That is probably why boxers, sewed up by ringside doctors without gloves or sterile technique, never are infected. In addition, the perspiration that flows during a boxing match has the additional effect of washing away any harmful bacteria residing on the skin.

Lysozyme is also an ingredient found in saliva, tears, nasal mucus, and tissue fluid.

OTHER FIRST LINES OF DEFENSE

The mucus membrane is the “skin” of internal body openings. This layer of cells lines body cavities (mouth, nose, throat, upper respiratory tract), and secretes a viscous, sticky substance (mucus) that entraps bacteria and any other foreign substances such as dust or pollen.

The upper respiratory tract, covered with microscopic hair like projections known as cilia, sweep inhaled substances up and out. Besides bacteria and viruses that can harm the respiratory tract and its cilia, cigarette smoke also destroys these cilia, and the next line of defense the body uses is a cough, the purpose of which is to get these inhaled irritants out of the lungs. A cough becomes a member of the immune surveillance system when the bronchial tree’s cilia and its mucus have failed in their mission.

The salivary glands produce saliva that can expel microbes from the oral cavity. Tears wash bacteria from the eye. Urine flow prevents bacterial colonization of the urinary tract. A bowel irritated and inflamed by bacteria or viruses will contract vigorously, and the resultant diarrhea is effective in expelling the offending irritant. The acidity of gastric juice and vaginal secretions provides a very inhospitable environment for bacteria or bacterial toxins.

The point made in all this is that the non-specificity of these mechanical and chemical barriers provides a rapid defense against a large variety of offending bacteria or viruses. These mechanical and chemical barriers capture and eliminate whatever they can without discriminating against specific invaders.

Constituting a first line of defense, these mechanisms are catego...

Table of contents

• eBook Cover
• Title Page
• PROLOGUE
• IMMUNE SYSTEM
• SPECIFIC IMMUNITY
• OTHER LYMPHOID TISSUE
• MEMORY
• ANTIGENS
• T CELLS
• B CELLS AND ANTIBODIES
• MEMORY CAPACITY
• AUTOIMMUNE DISEASE
• AUTOIMMUNE DISEASE BY SYSTEM (AN INCOMPLETE LIST)
• DIAGNOSIS OF AUTOIMMUNE DISORDERS
• THE GOALS OF TREATMENT FOR AUTOIMMUNE DISEASES
• OTHER CHALLENGING DIAGNOSES
• EPILOGUE
• APPENDIX