2. • The pancreas is both an endocrine gland and exocrine gland.
• A flattened organ that measures about 12.5- 15cm in length, the pancreas is
located in the curve of the duodenum, and consists of
• Head
• Body
• Tail
• Roughly 99% of the exocrine cells of the pancreas are arranged in clusters called
acini.
• The acini produce digestive enzymes, which flow into the GI tract through a
network of ducts.
• Scattered among the exocrine acini are 1-2 million tiny clusters of endocrine
tissue called pancreatic islets or islets of Langerhans.
• Abundant capillaries serve both the exocrine and endocrine portions of the
pancreas
3. Cell Types in the pancreas;
4 types of hormone secreting cells
Alpha or A cells – constitute about 17% of pancreatic islet cells and secrete glucagon.
Beta or B cells – constitute about 70% of pancreatic islet cells and secrete insulin
Delta or D cells – constitute about 7% of pancreatic islet cells and secrete somatostatin
F cells constitute the remainder of pancreatic islet cells and secrete pancreatic polypeptide
Glucagon raises blood glucose level and insulin lowers it.
Somatostatin acts in a paracrine manner to inhibit both insulin and glucagon release from neighboring
beta and alpha cells.
It may also act as circulating hormone to slow absorption of nutrients from the GI tract
It inhibits the secretion of growth hormone
Pancreatic polypeptide inhibits somatostatin secretion, gallbladder contraction and secretion of
digestive enzymes by the pancreas
6. Regulation of Glucagon and Insulin secretion
Hypoglycemia stimulates secretion of glucagon from alpha cells of the
pancreatic islets.
Glucagon acts on hepatocytes to accelerate the conversion of glycogen into
glucose and to promote formation of glucose from lactic acid and certain
amino acids
Hepatocytes release glucose into the blood more rapidly , and blood glucose
level rises
If blood glucose continues to rise, hyperglycemia inhibits release of glucagon
7. • Insulin acts on various cells in the body to accelerate facilitated diffusion of glucose
into cells
• To speed conversion of glucose into glycogen
• To increase uptake of aminoacids by cells and to increase protein synthesis
• To speed synthesis of aminoacids
• To slow the conversion of glycogen to glucose from lactic acid and aminoacids.
Blood glucose level falls
If the blood glucose level drops below normal , low blood glucose inhibits release of
insulin and stimulates release of glucagon
8. Several hormones and neurotransmitters also regulate the release of these 2 hormones
• Indirectly human growth hormone ( hGH) and adrenocorticotropic hormone (ACTH) stimulate
secretion of insulin because they act to elevate blood glucose.
Insulin secretion is also stimulated by;
• acetylcholine the neurotransmitter liberated from axon terminals of
parasympathetic vagus nerve fibers that innervate the pancreatic islets
• The amino acid arginine and leucine, which would be present in the blood at
higher levels after a protein – containing meal
• Glucose –dependent insulinotropic peptide , - hormone released by
enteroendocrine cells of the small intestine
• Glucagon secretion is stimulated by;
• Increased activity of the sympathetic division of the ANS, as occurring during
exercise
• a rise in blood aminoacids if blood glucose level is low, which could occur after a
meal that contained mainly protein
9.
10. Diabetes Mellitus
DM is a multisystem disease related to abnormal insulin production, impaired insulin
utilization, or both
Types of DM;
Type 1 DM
Type 2 DM
Type 1 DM:
Formerly known as juvenile onset or insulin dependent diabetes.
Type 1 diabetes occurs because the insulin-producing cells of the pancreas (beta cells) are
damaged. In type 1 diabetes, the pancreas makes little or no insulin, so sugar cannot get into
the body's cells for use as energy. People with type 1 diabetes must use insulin injections to
control their blood glucose. Type 1 is the most common form of diabetes in people who are
under age 30, but it can occur at any age. Ten percent of people with diabetes are diagnosed
with type 1.
11. Type 2 DM;
In type 2 diabetes (adult onset diabetes), the pancreas makes insulin, but it either doesn't
produce enough, or the insulin does not work properly. Nine out of 10 people with diabetes
have type 2. This type occurs most often in people who are over 40 years old but can occur
even in childhood if there are risk factors present. Type 2 diabetes may sometimes be
controlled with a combination of diet, weight management and exercise. However, treatment
also may include oral glucose-lowering medications (taken by mouth) or insulin injections
(shots).
Gestational Diabetes;
Gestational diabetes occurs when there is a high blood glucose level during pregnancy. As
pregnancy progresses, the developing baby has a greater need for glucose. Hormone
changes during pregnancy also affect the action of insulin, which brings about high blood
glucose levels.
12. Causes;
Family history of diabetes
Being overweight
Physical stress (such as surgery or illness)
Use of certain medications, including steroids
Injury to the pancreas (such as infection, tumor, surgery or
accident)
Autoimmune disease
High blood pressure
Abnormal blood cholesterol or triglyceride levels
Age (risk increases with age)
Smoking
History of gestational diabetes
13. Signs and Symptoms;
Increased thirst
Increased hunger (especially after eating)
Dry mouth
Frequent urination
Unexplained weight loss (even though you are eating and feel hungry)
Weak, tired feeling
Blurred vision
Numbness or tingling in the hands or feet
Slow-healing sores or cuts
Dry and itchy skin
Frequent yeast infections or urinary tract infections
