Related Concept Videos

The Oral Microbiota01:27

The Oral Microbiota

The oral microbiome includes a complex ecosystem comprising over 700 microbial species, identified through genomic sequencing and culture-based analyses to date. This community includes a core microbiome, found universally among individuals, and a variable component influenced by environmental factors such as diet, lifestyle, and host genetics. Site-specific conditions, including oxygen gradients, pH levels, and nutrient availability, determine the spatial distribution of these microorganisms...
Gastritis II: Pathophysiology01:26

Gastritis II: Pathophysiology

The pathophysiology of gastritis begins with the colonization of the stomach lining by Helicobacter pylori (H. pylori). This bacterium spreads mainly via the oral-oral route through saliva or shared utensils, and can also be transmitted in overcrowded or unhygienic environments through contaminated water, despite its brief survival outside the body.ColonizationOnce ingested, H. pylori enters the stomach and begins colonization by navigating through the mucus layer lining the stomach wall. It...
Peptic Ulcer Disease II: Pathophysiology01:28

Peptic Ulcer Disease II: Pathophysiology

Peptic Ulcer Disease (PUD) is characterized by the development of ulcers in the stomach or duodenal mucosa. Its pathophysiology is complex, involving a balance between damaging and protective elements.
Damaging agents such as Helicobacter pylori, gastric acid, pepsin, and nonsteroidal anti-inflammatory drugs (NSAIDs) can weaken the mucosal defense, allowing hydrogen ions to infiltrate back and harm epithelial cells.
Peptic Ulcer Disease II: Pathophysiology01:24

Peptic Ulcer Disease II: Pathophysiology

Peptic ulcer disease develops when protective mechanisms of the gastrointestinal mucosa are overwhelmed by harmful factors, leading to localized erosions in the stomach or proximal duodenum. The main causes are Helicobacter pylori infection and chronic use of nonsteroidal anti-inflammatory drugs (NSAIDs).Helicobacter pylori–Induced InjuryBacterial Adaptation and Colonization:H. pylori is a spiral, Gram-negative bacterium adapted to the acidic stomach. and transmitted through oral-oral or...
Gastritis-II: Pathophysiology01:17

Gastritis-II: Pathophysiology

Gastritis is marked by disruption of the mucosal barrier that usually protects the stomach tissue from digestive juices and manifests in acute and chronic forms.
In acute gastritis, the gastric mucosa becomes swollen and red and undergoes superficial erosion. Superficial ulceration may lead to bleeding.
In chronic gastritis, persistent or repeated insults lead to chronic inflammatory changes and, eventually, thinning or atrophy of the gastric tissue.
Gastritis can stem from various causes, each...
Skin Diseases and Disorders01:23

Skin Diseases and Disorders

Skin is the first line of defense and encounters a variety of microbes. Some pathogenic strains are often the cause of a broad range of infections of the skin and other body systems. These conditions can affect people of all ages and may have different causes, including genetic factors, infections, autoimmune reactions, environmental factors, and lifestyle choices.
Gram-positive Staphylococcus spp. and Streptococcus spp. are responsible for many of the most common skin infections. However, many...