Question

INFECTION PREVENTION AND CONTROL

1. THE BODY HAS NORMAL DEFENSES TOWARDS INFECTION. DESCRIBE EACH DEFENSE BELOW.

SKIN

MOUTH

EYE

RESPIRATORY TRACT

URINARY TRACT

GASTROINTESTINAL TRACT

Answer 1

Barrier Defenses (Table 2)

Site Specific defense Protective aspect

Skin Epidermal surface Keratinized cells of surface, Langerhans cells

Skin (sweat/secretions) Sweat glands, sebaceous glands Low pH, washing action

Mouth (oral cavity): Salivary glands Lysozyme

Stomach Gastrointestinal tract Low pH

Mucosal surfaces Mucosal epithelium Nonkeratinized epithelial cells

Normal flora (nonpathogenic bacteria): Mucosal tissues Prevent pathogens from growing on mucosal surfaces.

- Additionally, the mucus layer of the gastrointestinal tract, respiratory tract, reproductive tract, eyes, ears, and nose traps both microbes and debris, and facilitates their removal.

- In the case of the upper respiratory tract, ciliated epithelial cells move potentially contaminated mucus upwards to the mouth, where it is then swallowed into the digestive tract, ending up in the harsh acidic environment of the stomach.

- Considering how often you breathe compared to how often you eat or perform other activities that expose you to pathogens, it is not surprising that multiple barrier mechanisms have evolved to work in concert to protect this vital area.