Untitled Quiz

Study Notes

Oral flora is diverse and includes numerous types of bacteria, including aerobic and anaerobic species.
The composition of oral flora is influenced by factors such as age, diet, and oral hygiene practices.
Some bacteria in oral flora contribute to dental plaque formation, which can lead to tooth decay and gum disease.
Key fact: Oral flora plays a crucial role in maintaining oral health, and imbalances in its composition can compromise oral health.

Key fact: The large intestine harbors a high concentration of bacteria, estimated to be around 10^11 to 10^12 bacteria per gram of feces.

Compromised host defenses: Weakened immune systems can allow opportunistic pathogens to proliferate.
Introduction of new strains: Changes in the normal flora, such as antibiotic use, can create opportunities for new, potentially pathogenic strains to establish themselves.
Changes in the host environment: Factors like pH imbalances or changes in the composition of the gut microbiota can favor the growth of pathogenic bacteria.

Competition with pathogens: Normal flora occupies niches and competes with pathogens for resources, inhibiting their growth.
Production of antimicrobial substances: Certain bacteria in normal flora produce substances that inhibit the growth of other bacteria, including pathogens.
Stimulation of the immune system: The presence of diverse bacteria in normal flora helps to train and strengthen the immune system.

Infections: Viral, bacterial, and parasitic infections can lead to diarrhea by causing intestinal inflammation, damage, or fluid imbalance.
Food poisoning: Ingestion of contaminated food containing toxins or bacteria can trigger diarrheal symptoms.
Malabsorption: Disorders that impair nutrient absorption in the intestines can lead to diarrhea, often accompanied by other symptoms.
Certain medications: Some medications, such as antibiotics, can disrupt the balance of gut bacteria and contribute to diarrhea.

Key fact: The term enteritis refers to the inflammation of the intestines, characterized by severe abdominal cramps and frequent low-volume stools.

Key fact: An enterotoxin is a type of toxin produced by certain bacteria that specifically affects the intestines, causing gastrointestinal distress.

Key fact: The presence of gut flora plays a significant role in the development and function of the immune system, and its absence can lead to a weakened immune response.

Key fact: Bacillary dysentery is characterized by intestinal inflammation and bloody diarrhea caused by bacteria such as Shigella.

Key fact: The lining of the gastrointestinal tract, including the mucous membrane and tight junctions between cells, acts as a physical barrier, preventing the entry of pathogens into the bloodstream.