Pancreas Endocrine Flashcards
Endocrine portion of pancreas
islets of Langerhans
Hormones secreted from:
- Beta cells
- alpha cells
- Delta cells
- F(PP) cells
Beta cells
- Insulin
- IAPP (islet amyloid polypeptide)
Alpha cells
-glucagon
Delta cells
- somatostatin
F (PP) cells
- pancreatic polypetide
Insulin (when secreted & role)
Secreted: in response to elevated blood glucose Role: 1. Transfer glucose into the cells (Hepatocytes, adipocytes, myocytes) 2. Enhances: - Glucose oxidation - Glycogenesis - lipogenesis - ATP &nucleic acid formation 3. Decrease Blood glucose
Glucagon (when secreted & role)
Secreted: In response to decreased blood glucose Role: - increase release of energy from target cell - Promotes: 1. Glycogenolysis 2. Gluconeogenesis 3. Lipolysis - increase blood glucose
T/F Diabetes mellitus always has pancreatic lesions
False
- If there is a lesion:
- -selective degeneration/necrosis of islets
- -digestive enzymes from surrounding tissue destroy islet cells also.
Lesions of Diabetes mellitus
- Increase susceptibility to infection (cystitis)
- Hepatomegaly - lipidosis and glycogen deposition
- Cataracts
- Microangiopathy
More striking in extra-pancreatic organs
(attributed to lack of insulin stimulation)
increases in glucagon exacerbate the lesions
Inflammation associated with Pancreas
- Immune-mediated lymphoplasmacytic inflammation – selective destruction
- Chronic Relapsing Pancreatitis –destroys everything
Growth disturbances of pancreatic islets
- Aplasia
- Hypoplasia
- Atrophy
- Proliferative lesions –usually Beta cells
Term for tumor of Chemoreceptor organ (carotid body/Aortic body)
Chemodectoma
-Aortic body tumors ( heart base tumor )
Hormones secretes from Adipose tissue
- Leptin
2. Adiponectin
Roles of Leptin
- Appetite suppression
- Heat generation
- Pro-inflammatory
Roles of Adiponectin
- Glucose uptake
- Glucose Metabolism
- Anti-inflammatory
Failure of target cell response
- Down regulation of receptors
- decreased adenyl cyclase
Causes of HYPOfunction of pancreatic islets
- hypoplasia
- idiopathic atrophy
- Insular amyloidosis
- General inflammation –> destruction
- Immune- mediated destruction
Equine metabolic syndrome
“Horse diabetes”
- Insulin resistant
- Easy keepers are susceptible
- High levels of glucose –> increase in insulin secretion –> down regulation receptors –> Compensatory increase insulin secretion
What type of diabetes do cats get?
Type 2 - insulin resistance
Causes of insulin resistance
- Equine metabolic syndrome
- Type 2 Diabetes in cats
- Competing hormons –Progesterone, GH
Islet cell adenomas
Most commonly Beta cell tumors
What hormone does the Pineal gland regulate?
Melatonin
- Rare tumors
- Most important in seasonal breeders
Tumors of neuroendocrine cells
Carcinoids
-these are scattered everywhere throughout body
