Accessory Glands of GI Flashcards
Euchromatic
Lightly stained → active transcription
Pacinian corpuscles
Sensory nerve ending / pressure receptor in the pancreas
Pancreatic exocrine cells contain?
Dense secretory granules containing zymogens
Zymogens aka?
Porenzymes
Function of pacinian corpuscles
Food in stomach in SI → puts pressure on pancreas (sensed by pacinian corpuscles) → knows to release enzymes
Types of zymogens secreted by pancreatic exocrine cells
- Prolipase/lipase
- Chymotrypsinogen and trypsinogen
- Amylase
- Others
Intercalated ducts connect?
Acinus to intralobular ducts
What does interlobular duct look like?
Large duct surrounded by smooth m.
Striated ducts are typically seen in?
Salivary gland → never is pancreas!
Diabettes mellitus is?
Chronic disoder of carbohydrate metabolism
Most common endocrine disotrder in dog
Insulin is produced by?
Beta cells of the Islets of Langerhans
Type II diabetes is most common in what dogs?
> 5 years
Females
Samoyeds
Dachshunds
Clinical presentation of diabetes
- Lots of pee
- Sudden weight loss (with increased appetite)
- Weakness
- Acidosis
- Vomiting
Acute pancreatitis is?
Acute inflammation of pancreatic exocrine system
What happens when pancreatic acinar cells are damaged?
Pancreatic digestive enzymes released into local tissue → local activation of pro-enzymes to active proteases
Acute pancreatitis prognosis
Life-threatening
Rare in human; found in dogs, cats, cattle and horses
Acute pancreatitis presentation
- Severe pain
- Vomiting
- Sudden weight loss
- No appetite
Pancreatic cancer occurrence in vet med
Very rare
Most lethal cancer in humans
3 types of pancreatic cancer
- Insulinoma
- Adenocarcinoma
- Ductal adenocarcinoma
Largest single gland in vertebrates
Liver
Liver is endocrine/exocrine
Both
Endocrine secretions of liver
- Angiotensinogen (angiotensin II precursor)
- Albumin
- Clotting factors
Exocrine secretions of liver
Bile
Bile is acidic/alkaline
Alkaline
Components of bile
- Cholesterol
- Phospholipids
- Bile pigments
- Bile salts
- Bicarbonate ions
Bile salts are composed of?
- Sodium glycocholate
2. Sodium taurocholate
2 major cell types
- Hepatocytes
2. Kupffer cells (Ito cells)
6 liver functions
- Fat metabolism
- Carb metabolism
- Protein metabolism
- Storage
- Intermediary metabolism
- Secretion
Liver stroma called?
Capsule
Interlobular CT of liver
Divides parenchyme into hexagonal lobules → usually only seen in portal areas but very prominent in pig
Intralobular CT of liver
Very sparse (not seen)
Hepatocyte plates are supported by what type of collagen?
Reticular fibers
Reticular fiber is type ___ collagen
Type III
Hepatocyte shape
Polygonal
Hepatocyte histological appearance
- Vesicular nucleus
- Prominent nucleolus
- Eosinophilic (usually vacuolated)
Hepatocytes contain many?
- Mitochondria
2. SER
SER is involved in?
Detoxification
Hepatocytes are?
Highly specialized, complex cells which perform hundreds of metabolic processes
Up to 2/3rds of liver can be removed and still completely regenerate. Why is this?
Hepatocytes are capable of mitotic division
Kupffer cells are what type of cells?
Phagocytic (MPS)
Kupffer cell location
Line sinusoids
Kupffer cell histiologic appearance
Only heterochromatic, elongated nuclei seen
Sinusoids
Blood channels which separate trabeculae
Hepatocyte plates are called?
Trabeculae (or laminae)
Blood flow is ____ bile and lymph flow
Opposite → blood flow always toward central vein
Dual blood supply of lier
- Hepatic a. (nutritional)
2. Portal v. (functional)
Liver parenchyma structure
Hepatocyte plates (trabeculae) separated by sinusoids (blood channels)
Portal v. and hepatic a. distributing branches flow into?
Sinusoids
Blood in sinusoids flows into?
Central v.
Blood in central v. flows into?
Hepatic v.
Hepatic v. drains into?
Caudal vena cava
Fat metabolism functions of liver
- Oxidising TGs to produce energy
- Plasma lipoprotein synthesis
- Cholesterol and phospholipid synthesis
Bile flows through?
Bile canaliculi
Bile canaliculi are formed by?
Adjacent hepatocyte surfaces
Direction of bile flow is toward?
Bile ducts in portal areas (retrograde flow)
Lymph flows in?
Space of Disse
Space of Disse aka?
Perisinusoidal space
Space of Disse is located between?
Wall of sinusoid and hepatocytes
Bile and lymph flow are both?
Retrograde flow
Ito cells aka?
Stellate cells
Ito cells are found in?
Space of Disse
Ito cell functions
- Store fat and vitamin A
2. Produce excess CT in abnormal conditions (cirrhosis)
2 types of liver units
- Classical hepatic lobule
2. Liver acinus of rappaport
Structure-based liver unit
Classical hepatic lobule
Function-based liver unit
Liver acinus of rappaport
Classical hepatic lobule shape
Hexagonal; center at central vein → periphery indicated by portal areas
Portal tract contains?
Portal triad
3 parts of portal triad
- Portal v. branch (biggest)
- Hepatic a. branch
- Bile duct
Liver acinus of rappaport relates to?
Disribution of nutrients and O2 along branches of vessels as they leave portal triad
Predominant site of fetal hematopoeisis during early gestation
Fetal liver
Gall bladder aka?
Cholecyst
Function of gall bladder
Stores and concentrates bile
Gall bladder is absent in what species?
- Horse
- Deer
- Rat
- Some birds
→ continuous secretion
Gall bladder is lined by what type of cells?
Simple columnar epithelium
Mucosa extensively folded in dog and cat
Release of bile and pancreatic juice is controlled by?
Sphincter of Oddi and valve systems
Release of bile and pancreatic juice is stimulated by?
CCK (cholecystokinin)
CCK stands for?
Cholecystokinin
CCK is what type of signaling molecule?
Peptide hormone
CCK is released from?
Duodenum endocrine cells
Why is liver disease difficult to diagnose?
- Signs not evident until most of liver is damaged
2. Functional complexity (easily confused with other organs)
Clinical presentation of liver disease
- Icterus (jaundice)
- Ascites
- Lower serum albumin
- Hemorrhage (due to clotting defects)