Pancreas gland

Definition The pancreas is a

glandular organ that secretes digestive enzymes and hormones. In humans, the pancreas is a yellowish organ and

about the size of a hand

Location The pancreas is a gland located deep in the abdomen between the stomach and the spine (backbone). The liver, intestine, and other organs surround the pancreas.

Hormones of pancreasHormones of pancreas

pancreas has two types of secretion :pancreas has two types of secretion :

1 – endocrine hormone .1 – endocrine hormone .

2 – exocrine enzyme2 – exocrine enzyme ..

The Endocrine Pancreas.  Approximately 5 percent of the total

pancreatic mass is comprised of endocrine cells.  These endocrine cells are clustered in groups within the pancreas which look like little islands of cells when examined under a microscope.  This appearance led to these groups of pancreatic endocrine cells being called "Pancreatic Islets“ or “islets of langerhans”.  Within pancreatic islets are cells which make specific pancreatic endocrine hormones, of which there are only a few (the most famous of course being insulin).  These cells within the islets are called "Pancreatic Islet Cells".

Pancreatic Islet Cells Pancreatic Islet Cells secretionsecretion

The islets are The islets are endocrineendocrine tissue containing tissue containing four types of cells. In order of abundance, four types of cells. In order of abundance, they are the: they are the:

betabeta cells cells, which secrete , which secrete insulininsulin and and amylin; amylin;

alphaalpha cells cells, which secrete , which secrete glucagonglucagon; ; deltadelta cells cells, which secrete , which secrete somatostatinsomatostatin, ,

and and gammagamma cells cells, which secrete , which secrete a a

polypeptidepolypeptide of unknown function of unknown function

Pancreatic Endocrine Hormones and Their Purpose

A - Insulin Purpose: Regulate blood glucose (sugar) in the

normal range Action: Forces many cells of the body to absorb and use glucose thereby decreasing blood sugar levelsSecreted in response to: High blood glucoseSecretion inhibited by: Low blood glucoseDisease due to deficient action: Diabetes (large section of Endocrine Web is devoted to Diabetes).Disease due to excess action: Hypoglycemia 

Pancreatic Endocrine Hormones and Their Purpose

B - Glucagon Purpose: Assist insulin in regulating blood glucose

(sugar) in the normal range (actions are opposite of insulin)Action: Forces many cells of the body to release (or produce) glucose (increasing blood sugar)Secreted in response to: Low blood glucoseSecretion inhibited by: High blood glucoseDisease due to deficient action: Some times nothing, sometimes hypoglycemiaDisease due to excess action: Hyperglycemia

Pancreatic Endocrine Hormones and Their Purpose

C – Somatostatin ( secreted from hypothalamus ) Purpose: Regulate the production and excretion of

other endocrine tumorsAction: Slows down production of insulin, glucagon, gastrin, and other endocrine tumorsSecreted in response to: High levels of other endocrine hormonesSecretion inhibited by: Low levels of other endocrine hormonesDisease due to deficient action: Poorly definedDisease due to excess action: Diabetes (inhibits insulin production), gallstones, and dietary fat intolerance.

Pancreatic Endocrine Hormones and Their Purpose

D - Gastrin Purpose:    Assist in digestion within the stomach

Action:    Induce acid producing cells of the stomach to produce acidSecreted in response to:     Food in the stomach and intestinesSecretion inhibited by:     Absence of food in stomach and intestinesDisease due to deficient action:     Poorly defined, some times no symptoms at allDisease due to excess action:     Stomach ulcers due to excess stomach acid

Pancreatic Endocrine Hormones and Their Purpose

E - Vasoactive Intestinal Peptide (VIP) Purpose:    Help control water secretion

and absorption from the intestinesAction:    Causes intestinal sells to secrete water and salts into the intestines (inhibit absorption)Disease due to excess action:     Severe watery diarrhea and salt (potassium) imbalances 

Delta cellAlpha cellBeta cell

types of cells

??Inhibits secret

glucagon

------Insulin

ينشط من افرازهاستوماتوستات

ين

ينشط --------افرازها

من االنسولين

Glucagon

افراز --------- يثبطالجلوكاجون

افراز يثبطاالنسولين

Stomatostatin

Diabetes MellitusDiabetes Mellitus

Diabetes mellitus is an endocrine disorder Diabetes mellitus is an endocrine disorder characterized by many signs and characterized by many signs and symptoms. symptoms.

Diabetes mellitus is a disorder quite distinct from the similarly-named diabetes insipidus. They both result in the production of large amounts of urine (diabetes), but in one the urine is sweet while in the other (caused by ADH deficiency) it is not. Before the days of laboratory tests, a simple taste test ("mellitus" or "insipidus") enabled the

doctor to make the correct diagnosis

There are three categories of diabetes mellitus: 1 - Insulin-Dependent Diabetes Mellitus (IDDM) [also called "Type 1" diabetes] and 2 - Non Insulin-Dependent Diabetes Mellitus (NIDDM)["Type 2"]

3 - Inherited Forms of Diabetes Mellitus

Insulin-Dependent Diabetes Mellitus (IDDM) IDDM (also called Type 1 diabetes) is characterized by little (hypo) or no

circulating insulin; most commonly appears in childhood. It results from destruction of the beta cells of

the islets.

IDDM is controlled by carefully-regulated IDDM is controlled by carefully-regulated injections of insulin. (Insulin cannot be taken injections of insulin. (Insulin cannot be taken by mouth because, being a protein, it would by mouth because, being a protein, it would

be digested. However, the U.S. FDA has be digested. However, the U.S. FDA has approved [in January 2006] an insulin inhaler approved [in January 2006] an insulin inhaler

that delivers insulin through the lungs and that delivers insulin through the lungs and may reduce the number of daily injected may reduce the number of daily injected

doses needed.) doses needed.) For many years, insulin extracted from the For many years, insulin extracted from the

glands of cows and pigs was used. However, glands of cows and pigs was used. However, pig insulin differs from human insulin by one pig insulin differs from human insulin by one amino acid; beef insulin by three. Although amino acid; beef insulin by three. Although both work in humans to lower blood sugar, both work in humans to lower blood sugar,

they are seen by the immune system as they are seen by the immune system as "foreign" and induce an antibody response in "foreign" and induce an antibody response in

the patient that blunts their effect and the patient that blunts their effect and

requires higher dosesrequires higher doses

Two approaches have been taken to solve this Two approaches have been taken to solve this problem: problem:

Convert pig insulin into human insulin by removing Convert pig insulin into human insulin by removing the one amino acid that distinguishes them and the one amino acid that distinguishes them and

replacing it with the human version. This approach replacing it with the human version. This approach is expensive, so now the favored approach is to is expensive, so now the favored approach is to Insert the human gene for insulin into E. coli and Insert the human gene for insulin into E. coli and grow grow recombinant human insulinrecombinant human insulin in culture in culture

tanks. Insulin is not a glycoprotein so E. coli is able tanks. Insulin is not a glycoprotein so E. coli is able to manufacture a fully-functional molecule (trade to manufacture a fully-functional molecule (trade

name = Humulin). Yeast is also used (trade name = name = Humulin). Yeast is also used (trade name = Novolin). Novolin).

Recombinant DNA technology has also made it Recombinant DNA technology has also made it possible to manufacture slightly-modified forms of possible to manufacture slightly-modified forms of

human insulin that work faster or slower than human insulin that work faster or slower than

regular human insulinregular human insulin..

Non Insulin-Dependent Diabetes Mellitus (NIDDM)

Many people develop diabetes mellitus without an accompanying drop in insulin levels (at least at first).

In many cases, the problem appears to be a failure to express a sufficient number of glucose transporters in the plasma membrane of their

skeletal muscles.

Skeletal muscle is the major "sink" for Skeletal muscle is the major "sink" for removing excess glucose from the removing excess glucose from the

blood (and converting it into blood (and converting it into glycogen). In NIDDM, the patient's glycogen). In NIDDM, the patient's ability to remove glucose from the ability to remove glucose from the

blood and convert it into glycogen may blood and convert it into glycogen may be only 20% of normal. This is called be only 20% of normal. This is called

insulin resistanceinsulin resistance . .

NIDDM (also called NIDDM (also called Type 2Type 2 diabetes diabetes mellitus) usually strikes in adults and, mellitus) usually strikes in adults and,

particularly often, in overweight particularly often, in overweight people. However, over the last few people. However, over the last few years in the U. S., the incidence of years in the U. S., the incidence of NIDDM in children has grown to the NIDDM in children has grown to the

point where they now account for 20% point where they now account for 20% of all newly-diagnosed cases (and, like of all newly-diagnosed cases (and, like their adult counterparts, are usually their adult counterparts, are usually

overweight)overweight)..

Inherited Forms of Diabetes Mellitus

• Some cases of diabetes result from mutant genes inherited from one or both parents. Examples:

• mutations in one or both copies of the gene encoding the insulin receptor. These patients usually have extra-high levels of circulating insulin but defective receptors. The mutant receptors

• a mutant version of the gene encoding glucokinase, the enzyme that phosphorylates glucose in the first step of glycolysis

Pancreatitis

An estimated 50,000 to 80,000 cases of acute pancreatitis occur in the United States each year. This disease occurs when the pancreas suddenly becomes inflamed and then gets better. Some patients have more than one attack but recover fully after each one. Most cases of acute pancreatitis are caused either by alcohol abuse or by gallstones.  Other causes may be use of prescribed drugs, trauma or surgery to the abdomen, or abnormalities of the pancreas or intestine.

What Are the Symptoms of AP?

Acute pancreatitis usually begins with pain in the upper abdomen that may last for a few days. The pain is often severe. It may be constant pain, just in the abdomen, or it may reach to the back and other areas. The pain may be sudden and intense, or it may begin as a mild pain that is aggravated by eating and slowly grows worse. The abdomen may be swollen and very tender. Other symptoms may include nausea, vomiting, fever, and an increased pulse rate. The person often feels and looks very sick.

Chronic Pancreatitis

The term "chronic pancreatitis" defines the histologic, functional, and clinical results of long-standing or irreversible pancreatic injury. There are a number of things that increase a persons risk of deveolping chronic pancreatits including alcohol consumption, smoking, genetic factors and other conditions or tramatic events that injure the pancreas. Within the National Institute of Health, the National Institute of Diabetes, Digestive and Kidney Diseases has been give the challange of addressing the problem of pancreatitis.

The human pancreas is an The human pancreas is an amazing organ with two amazing organ with two main functions: [1] to main functions: [1] to

produce pancreatic produce pancreatic endocrine hormones (e.g., endocrine hormones (e.g., insulin & glucagon) which insulin & glucagon) which help regulate many aspects help regulate many aspects of our metabolism and [2], of our metabolism and [2],

to produce pancreatic to produce pancreatic digestive enzymesdigestive enzymes . .