Question

Which one of the following acts as a physiological barrier to the entry of microorganisms in the human body?

• A. Epithelium of Urogenital tract
• B. Monocytes
• C. Tears
• D. Skin

Answer 1

The correct option is C

Tears

The correct option is C.

Explanation of correct option:

1. Tears in the eyes, saliva in the mouth, and HCl in the stomach are all physiological barriers against microbes entering the human body.
2. The lysozyme enzyme is found in tears and saliva and prevents the creation of peptidoglycan, which can be found in the cell wall of microorganisms, particularly eubacteria.

Explanation of incorrect option:

Option A:

1. The lining of the urinary system is made up of three types of epithelial cells.
2. Transitional cells, renal tubular cells, and squamous cells are the three types of cells that make up the human urinary system.
3. Squamous epithelial cells in your urine could indicate that your sample was tainted.
4. Epithelium of the urogenital tract and skin are physical barriers.

Option B:

1. Monocytes are a type of white blood cell (leukocyte) that lives in your blood and tissues and searches for and destroys germs (viruses, bacteria, fungus, and protozoa) as well as remove infected cells.
2. Monocytes mobilize other white blood cells to aid in the treatment of injuries and infection prevention.
3. The cellular barrier is composed of monocytes.

Option D:

1. Skin is a layer of soft, flexible outer tissue that covers the bodies of vertebrates and provides three functions: protection, regulation, and sensation.
2. A physiological barrier is formed by tears, saliva, skin, an acidic pH in the stomach, and bile in the intestine.

Final answer: Tears act as a physiological barrier to the entry of microorganisms into the human body