Human Digestive System Defense Mechanisms

Questions and Answers

What is the primary source of exogenous nosocomial infections?

Environmental contaminants in the hospital (correct)

Patients' own flora

Bacterial spread through medical equipment

Airborne pathogens from hospital staff

What percentage of nosocomial infections are urinary tract infections?

15-20%

70-80%

50-60%

30-40% (correct)

What is the main goal of medical asepsis?

To reduce the number of pathogens and prevent their transmission (correct)

To sterilize all instruments used in patient care

To eliminate all forms of microbial life

To control environmental factors in healthcare settings

How long should hands be washed using soap and water when they are not visibly soiled?

10-15 seconds Signup and view all the answers

Which moment for hand hygiene is correct after contact with body fluids?

After handling contaminated equipment Signup and view all the answers

What role does hydrochloric acid in the stomach play in the immune defense system?

It kills pathogens that enter the stomach. Signup and view all the answers

What occurs during the inflammatory process when an injury happens?

Histamine is released, leading to blood vessel dilation. Signup and view all the answers

Which type of white blood cells are involved in the tertiary line of defense against pathogens?

B cells and T cells. Signup and view all the answers

What is the primary role of bile in the digestive system's defense mechanism?

To emulsify fats and kill microbes. Signup and view all the answers

Which of the following best describes a reservoir in the chain of infection transmission?

An environment or host where an organism grows and multiplies. Signup and view all the answers

Study Notes

Pathogen Defense Mechanisms

Strong hydrochloric acid in stomach juices often kills pathogens that reach this organ.
In intestines, bile emulsifies fats and kills microbes, acting as a secondary defense.

Inflammatory Process

Injury prompts W cells to release histamine, causing blood vessel dilation.
Dilation results in redness and warmth around the injury site.
Increased permeability of blood vessels allows more phagocytes to enter and attack pathogens.

Fever Response

Body temperature increases to 101°F or higher, hindering the growth of most invading microorganisms.

Tertiary Defense

Specialized lymphocytes, either B cells or T cells, serve as the third line of defense.
Lymphocytes are located in lymph tissues such as the spleen, thymus, lymph nodes, and tonsils.

Chain of Infection Transmission

Infectious Agents:
- Capable of causing disease includes bacteria, viruses, fungi, and protozoa.
Reservoirs:
- Locations where organisms grow, including humans, animals, insects, and environmental surfaces.
Portal of Exit:
- The route through which an organism leaves its reservoir.

Nosocomial Infections

Sources:
- Exogenous: From the hospital environment or personnel.
- Endogenous: Originates from the patients themselves.
Types:
- Urinary tract infections: 30-40% of cases, often due to urinary catheters.
- Lower respiratory and surgical wound infections: Each around 15%.
- Bacteraemia: 5%, along with various other infections.

Medical Asepsis

Aimed at preventing the spread of infection, often referred to as clean technique.
Reduces pathogen numbers and prevents transmission between individuals.

Standard Precautions Components

Hand Washing:
- Most effective method for preventing infection transmission.
- Wash hands for 10-15 seconds with soap or water or use antibacterial gel.
- Surgical scrub lasts 2-5 minutes using antimicrobial solutions.
Hand Hygiene Moments:
- Before and after invasive procedures, patient contact, and handling body fluids.
Masks and Protective Eyewear:
- Required during procedures with a risk of splashing body fluids.
Gowns/Aprons:
- Worn during procedures where exposure to fluids is possible.
- Gowns should be removed carefully to prevent contamination.
Needles and Sharps:
- Never recap used needles; use safety needles and place in puncture-resistant containers.
Respiratory Hygiene/Cough Etiquette:
- Cover mouth and nose when sneezing or coughing; wash hands afterward.
Environmental Control:
- Facilities must meet infection control standards through cleanliness and disinfection protocols.

Chemical Agents in Infection Control

Mercurochrome:
- Alters microbial cellular proteins.
Glutaraldehyde (Cidex):
- Sterilizes equipment by inactivating proteins of bacteria, viruses, and spores.

Personal Protective Equipment (PPE) Usage

Use gloves and gowns when entering patient rooms or in cases of high drainage or infection risk.
Disinfect surfaces and wash hands post-contact to prevent pathogen spread.

Description

This quiz explores the various defense mechanisms of the human digestive system against pathogens. It discusses how stomach acid and bile work to eliminate harmful microbes that enter the body. Test your knowledge on these vital biological processes and their roles in immunity.