9: Gut Microbiota and Infections Flashcards
What are some toxins the GI tract and the liver can be exposed to? (6 things)
- Chemical
- Bacteria
- Viruses
- Protozoa
- Nematodes (round worms)
- Cestodes (tape worms)
- Trematodes (flukes)
What are the types of defence mechanism in the GI tract? (2 things)
- Innate (Physical / Cellular)
- Adaptive
What are the Innate Physical defence mechanisms of the GI tract? (8 things)
- Sight / smell
- Memory
- Saliva pH 7
- Stomach Acid
- Small Intestine Secretions
- Colonic Mucus
- Anaerobic Environment
- Peristalsis / Segmentation
How does the Sight / Smell defence mechanism work?
If the food looks / smells bad we don’t eat it
How does the Memory defence mechanism work?
If we remember food tasted bad we don’t eat it again
What does saliva contain that acts as a defence mechanism?
- Polymorphs
- igA
- Complement
- Lactoperoxidase
- Lysozyme
PICLL
How does the Saliva pH 7 defence mechanism work?
Washes toxins down to stomach
What are the Small Intestine secretions?
- Bile
- Proteolytic enzymes
How does the Colonic mucus defence mechanism work?
Protects colonic epithelium
How does the Peristalsis / Segmentation defence mechanism work?
Prevents infections
What are the Innate Cellular defence mechanisms of the GI tract?
- MAC (Kupffer cells in liver)
- Tissue Mast Cells
- Eosinophils (for parasitic infections)
- Neutrophils
- Natural Killer Cells
MTENN (M10 lemme spray mans gone)
What are the Adaptive defence mechanisms of the GI tract?
- B-lymphocyes
- T-lymphocytes
- Lymphatic tissues
How does the B-lymphocytes defence mechanism work?
They produce iGs
What are T-lymphocytes directed to?
Intracellular organisms
How does the lymphatic tissue defence mechanism work?
We have GALT (Gut Associated Lymphoid Tissue) found in:
- Tonsils
- Peyers patches of small intestine
- Appendix
What causes Xerostomia (reduced saliva flow)? (2 things)
- Illness
- Dehydration
What is the result of Xerostomia (reduced saliva flow)?
Microbial overgrowth → Parotitis (salivary gland infection)
What is Achlorhydria?
Reduced / Absent HCl in gastric acid
What does Alchlorhydria make you more susceptible to? (3 things)
- Shigellosis
- Cholera
- Salmonella infections
What do Mast Cell granules contain?
Histamine
How do gut infections cause increased fluid loss?
- Gut infections recruit mast cells → release histamine
- Histamine causes vasodilation + increased capillary permeability → increased fuid loss
What happens as a result of defective GALT? (2 things)
- Tonsillitis
- Appendicitis
What can cause Gut Ischaemia? (3 things)
- Arterial disease
- Systemic hypotension
- Intestinal Venous Thrombosis
What can Gut Ischaemia cause?
Sepsis → death
What does liver failure make you more susceptible to? (4 things)
- Infections
- Toxins
- Drugs
- Hormones
What can liver failure cause?
Hepatic encephalopathy (reduced brain function)
No urea cycle → increased blood ammonia → hepatic encephalopathy
What causes liver failure? (5 things)
- Viral hepatitis
- Alcohol
- Drugs (Paracetamol)
- Industrial Solvents
- Mushroom poisoning
VADIM (like gadeeeem)
What can Cirrhosis cause?
- Caput medusa (swollen epigastric veins)
- Oesophagul varices (enlarged veins in tube)
- Haemorrhoids (swollen veins)
COH
How does cirrhosis cause what it causes?
Portal venous hypertension → Porosystemic shunting →toxic shunting → (COH)
