Related Concept Videos

Development of Immunocompetence01:22

Development of Immunocompetence

The initiation of cell-mediated immunity can be observed as early as the third month of fetal growth, with active antibody-mediated immunity following approximately one month later.
The initial cells that migrate from the fetal thymus settle within the skin and epithelial tissues lining the mouth, digestive tract, and in females, the uterus and vagina. These cells, including skin-based dendritic cells, serve as antigen-presenting cells, playing a key role in T cell activation.
Subsequent T...
Bacterial Gastroenteritis01:18

Bacterial Gastroenteritis

Bacterial gastroenteritis, characterized by diarrhea, abdominal cramps, and vomiting, is often caused by ingestion of contaminated food or water and is frequently associated with pathogenic Escherichia coli strains. These microbes exploit two principal mechanisms to inflict disease.Shiga toxin–producing E. coli, also referred to as STEC—notably O157:H7—release Shiga toxins that target ribosomes, blocking protein synthesis. The B subunit of the toxin binds the host glycolipid receptor...
Drugs Affecting GI Tract Motility: Antimicrobials as Antidiarrheal Agents01:18

Drugs Affecting GI Tract Motility: Antimicrobials as Antidiarrheal Agents

Acute diarrhea, a common gastrointestinal disturbance, is characterized by the rapid evacuation of fluid stools, leading to an excessive weight in fluid. This condition typically arises from disorders affecting intestinal water and electrolyte transport. It can be triggered by an increased osmotic load within the intestine, excessive secretion of electrolytes and water, mucosal exudation of protein and fluid, or altered intestinal motility. The primary risks of acute diarrhea are dehydration...
Immunodeficiency Diseases01:25

Immunodeficiency Diseases

Immunodeficiency disorders are conditions in which the immune system's ability to fight infectious disease and cancer is compromised or entirely absent. The immune system comprises a complex network of cells, tissues, and organs that work together to protect the body from potentially harmful invaders. When this system is deficient or not functioning properly, it leaves the body susceptible to infections, diseases, or other complications.
There are three main causes of immunodeficiency disorders...
Atypical Pneumonia01:14

Atypical Pneumonia

Atypical pneumonia, often caused by Mycoplasma pneumoniae, is a form of pulmonary infection that differs from the classical presentation of bacterial pneumonia in both its cause and clinical symptoms. Mycoplasma pneumoniae is a pleomorphic bacterium notable for its lack of a rigid cell wall. This structural characteristic imparts resistance to beta-lactam antibiotics and significantly influences the bacterium’s behavior within the human host.Other pathogens responsible for the disease include...
Drugs for Treatment of Diarrhea-Predominant IBS01:17

Drugs for Treatment of Diarrhea-Predominant IBS

Diarrhea-predominant irritable bowel syndrome (IBS-D) is a subtype of IBS characterized primarily by frequent, loose, or watery stools, abdominal pain, and abdominal discomfort. Therapeutic approaches to managing IBS-D include dietary changes, stress management techniques, and pharmaceutical interventions.
Two specific drugs used in the treatment are alosetron (Lotronex) and eluxadoline (Viberzi). Alosetron, a 5-HT3 antagonist, works by slowing the movement of stools in the gut, reducing bowel...