Digestive System V Flashcards
Anatomical position of pancreas? (Approx., not exact terms)
adjacent to duodenum
Where are pancreatic juice and bile excreted to?
duodenum
Functions of pancreas
both exocrine and endocrine functions
What cells are responsible for exocrine function?
What do they release?
Acinar cells
- Proteases
- Trypsinogen
- Chymotrypsinogen
- Lipase
- Amylase
Function of Islet of Lungerhans?
Endocrine function
Alpha cells = glucagon
Beta cells = insulin
Delta cells = somatostatin
Two types of parenchyma cells?
- hepatocytes
- phagocytotic Kupffer cells
Functional liver unit?
lobes
Hepatocytes are arranged as plates separated by blood channels. What are the blood channels?
sinusoids
Can the liver regenerate?
Liver is very regenerative
2/3 can be surgically removed
Functions of the liver?
- fat metabolism
- carbohydrate metabolism
- protein metabolism
- storage of glycogen, vitamins, and iron
- detoxification of various drugs and toxins, such as alcohol
- synthesis and secretion of bile
Structure of Pancreas
- capsule
- septa = subdivide parenchyma into lobules
What does glucagon do?
increases blood glucose
What does insulin do?
cellular glucose uptake
What does somatostatin do?
inhibit growth hormone secretion
Pacinian corpuscle
Sensory nerve ending, pressure receptor
Pressure from stomach filled with food may be part of signaling for pancreas to produce its product
Diabetes Mellitus and the Pancreas
- Most common endocrine disorder in the dog
- d/t deficient production of insulin by beta cells of islets (Type I, insulin-dependent)
- or d/t insulin receptor marfunction at target tissues (Type II, insulin-independent)
Onset of diabetes?
- usually at an age greater then 5 years
- 5x more likely in females, Samoyeds, and Dachshunds
Clinical presentation of diabetes?
- large amount of urine
- sudden weight loss with increased appetite
Acute Pancreatitis
- acute inflammation of pancreatic exocrine system
- pancreatic digestive enzymes are released into local tissue d/t damage of pancreatic acinar cells
- life-threatening = rare in humans, occasionally in dogs
- sometimes in cats, cattle, and horses
Clinical Presentation of Acute pancreatitis?
- severe pain
- vomiting
- sudden weight loss
- NO appetite
Largest single gland in vertebrates?
liver
Endocrine function of the liver?
- angiotensinogen (angiotensin II precursor)
- albumin
- clotting factors
Exocrine function of the liver?
- bile
- cholesterol
- phospholipids
- bile pigments
- bile salts
Fat metabolism of the liver?
- oxidising triglycerides
- synthesis of plasma lipoproteins
- synthesis of cholesterol and phospholipid
Carbohydrate metabolism of the liver?
- converting carbohydrates and proteins into fatty acids and triglyceride
- regulation of blood glucose concentration by glycogenesis, glycogenolysis, and gluconeogenesis
Protein metabolism of the liver?
- synthesis of plasma proteins, including albumin and clotting factors
- synthesis of non-essential amino acids
- detoxification of metabolic waste products
What is stored in the liver?
- glycogen
- vitamins
- iron
Intermediary metabolism of the liver?
detoxification of various drugs and toxins, such as alcohol
Secretion of the Liver?
synthesis and secretion of bile
In rats, up to 2/3 of the liver can be removed with complete regeneration. How is this possible/
The hepatocytes of the liver are capable of mitotic division
Hepatocytes
- contain many mitochondria
- a lot of S.E.R.
- have hundreds of metabolic processes that take place in them
Kupffer Cells
- phagocytic cells
- line sinusoids
The hepatic artery brings what to the liver?
nutritional blood supply
The portal vein brings what to the liver?
functional blood supply
In the liver, does blood flow toward the central vein or toward the portal vein?
central vein
Gallbladder
- stores and concentrates bile
- absent in horse, deer, rat, and some birds = continuous secretion of the bile
-lined by simple columnar epithelium
Liver Disease
- difficult to diagnose
- signs not evident until much of the liver is damaged b/c of large reserve
- B/c liver’s functional comples, variety of signs can be present, but may look like malfunctions of other organs
Clinical presentation of liver disease
- icterus (jaundice)
- ascites
- lower serum albumin
- photosensitization
- behavioral changes from lethargy to stupor or coma
- tremors
- agitation
- hemorrhage d/t clotting defects
