The pancreas is a gland organ in the digestive and endocrine system of vertebrates. The head of pancreas is a portion of the Pancreas that is lodged within the curve of the Duodenum, and is flattened anteriorly (from before In the head of the Pancreas, the angle of junction of the lower and left lateral borders forms a prolongation termed the uncinate process. The pancreatic notch is a separation between the Neck of pancreas and the Uncinate process of pancreas. The body of the pancreas is a subsection of the pancreas organ in the human body Anterior Surface—The greater part of the right half of this surface is in contact with the Transverse colon, only Areolar tissue intervening The inferior surface of pancreas is narrow on the right but broader on the left and is covered by Peritoneum; it lies upon the Duodenojejunal flexure and on some The superior margin of pancreas is blunt and flat to the right narrow and sharp to the left near the Tail. The anterior margin of pancreas separates the anterior from the inferior surface and along this border the two layers of the Transverse mesocolon diverge from one another one The Inferior margin of pancreas separates the posterior from the inferior surface the Superior mesenteric vessels emerge under its right extremity Where the anterior surface of the Pancreas joins the neck there is a well-marked prominence the tuber omentale, which abuts against the posterior surface of the Lesser The tail of the Pancreas, located anatomically left near the Hilum of the Spleen, is not simply an anatomical distinction In Anatomy of the Digestive system, the duodenum is a hollow jointed tube about 25-30 cm (10-12 in long connecting the Stomach to the Jejunum Gray's Anatomy the Respiratory apparatus ( Apparatus Respiratorius Respiratory system Respiratory apparatus Arteries are Blood vessels that carry blood away from the Heart. The inferior pancreaticoduodenal artery is given off from the Superior mesenteric or from its first intestinal branch opposite the upper border of the inferior part of the The superior pancreaticoduodenal artery is an Artery that supplies Blood to the Duodenum and Pancreas. In Anatomy, the splenic artery (in the past called the lienal artery) is the Blood vessel that supplies oxygenated Blood to the Spleen In the Circulatory system, a vein is a Blood vessel that carries Blood back toward the Heart (as opposed to Artery, a blood vessel The pancreaticoduodenal veins accompany their corresponding Arteries: the Superior pancreaticoduodenal artery and the Inferior pancreaticoduodenal artery The pancreatic veins consist of several small vessels which drain the body and tail of the Pancreas, and open into the trunk of the great pancreatic vein A nerve is an enclosed cable-like bundle of peripheral Axons (the long slender projections of Neurons. The pancreatic plexus is a division of the Celiac plexus (coeliac plexus The celiac ganglia are two large irregularly shaped masses of Nerve tissue in the upper Abdomen. The vagus nerve (ˈveɪˌgəs (VĀ-gəs (also called pneumogastric nerve or cranial nerve X) is the tenth of twelve paired Cranial nerves, and is the Embryology (from Greek grc ἔμβρυον embryon, "unborn embryo" and grc -λογία -logia) is the study of the development The ventral and dorsal pancreatic buds (or pancreatic diverticula) are outgrowths of the Duodenum during human Embryogenesis. Medical Subject Headings ( MeSH) is a huge Controlled vocabulary (or metadata system for the purpose of indexing journal articles and books Elsevier, the world's largest Publisher of Medical and Scientific literature, forms part of the Reed Elsevier group A gland is an organ in an animal's body that synthesizes a substance for release such as Hormones or Breast milk, often into the Bloodstream In Biology, an organ ( Latin: organum, "instrument tool" from Greek όργανον - organon "organ instrument Digestion is the breaking down of chemicals in the body into a form that can be absorbed The endocrine system is an integrated system of small organs that involve the release of extracellular signaling molecules known as Hormones The endocrine system is instrumental It is both exocrine (secreting pancreatic juice containing digestive enzymes) and endocrine (producing several important hormones, including insulin, glucagon, and somatostatin). Exocrine glands are Glands that secrete their products ( Enzymes into ducts (duct glands Pancreatic juice is a juice produced by the Pancreas. It contains a variety of Enzymes, including Trypsinogen, Chymotrypsinogen, Elastase Digestion is the breaking down of chemicals in the body into a form that can be absorbed Enzymes are Biomolecules that catalyze ( ie increase the rates of Chemical reactions Almost all enzymes are Proteins The endocrine system is an integrated system of small organs that involve the release of extracellular signaling molecules known as Hormones The endocrine system is instrumental Hormones (from Greek ὁρμή - "impetus" are chemicals released by cells that affect cells in other parts of the body Insulin is a Hormone with intensive effects on both metabolism and several other body systems (eg vascular compliance Glucagon is an important Hormone involved in Carbohydrate metabolism. Somatostatin (also known as growth hormone inhibiting hormone ( GHIH) or somatotropin release-inhibiting factor ( SRIF) is a Peptide hormone It also produces digestive enzymes that pass into the small intestine. These enzymes help in the further breakdown of the daquon mayes,.
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Histology
Under a microscope, stained sections of the pancreas reveal two different types of parenchymal tissue. Parenchyma is a term used to describe a bulk of a substance It is used in different ways in Animals and in Plants. [2] Lightly staining clusters of cells are called islets of Langerhans, which produce hormones that underlie the endocrine functions of the pancreas. Islets of Langerhans is the area in which the Endocrine (ie hormone-producing cells of the Pancreas are grouped Hormones (from Greek ὁρμή - "impetus" are chemicals released by cells that affect cells in other parts of the body Endocrine glands are Glands that secrete their product ( Hormones, directly into the blood rather than through a duct Darker staining cells form acini connected to ducts. In Anatomy and Physiology, a duct is a circumscribed channel leading from an Exocrine gland or organ. Acinar cells belong to the exocrine pancreas and secrete digestive enzymes into the gut via a system of ducts. The Exocrine Pancreas has ducts that are arranged in clusters called Acini (singular acinus) Digestion enzymes are Enzymes that break down Polymeric Macromolecules into their smaller building blocks
| Structure | Appearance | Function |
| Islets of Langerhans | Lightly staining, large, spherical clusters | Hormone production and secretion (endocrine pancreas) |
| Pancreatic acini | Darker staining, smalll, berry-like clusters | Digestive enzyme production and secretion (exocrine pancreas) |
Function
The pancreas is a dual-function gland, having features of both endocrine and exocrine glands. Islets of Langerhans is the area in which the Endocrine (ie hormone-producing cells of the Pancreas are grouped Hormones (from Greek ὁρμή - "impetus" are chemicals released by cells that affect cells in other parts of the body Islets of Langerhans is the area in which the Endocrine (ie hormone-producing cells of the Pancreas are grouped The Exocrine Pancreas has ducts that are arranged in clusters called Acini (singular acinus) Digestion enzymes are Enzymes that break down Polymeric Macromolecules into their smaller building blocks The Exocrine Pancreas has ducts that are arranged in clusters called Acini (singular acinus) Endocrine glands are Glands that secrete their product ( Hormones, directly into the blood rather than through a duct Exocrine glands are Glands that secrete their products ( Enzymes into ducts (duct glands
Endocrine
The part of the pancreas with endocrine function is made up of a million[3] cell clusters called islets of Langerhans. Islets of Langerhans is the area in which the Endocrine (ie hormone-producing cells of the Pancreas are grouped Islets of Langerhans is the area in which the Endocrine (ie hormone-producing cells of the Pancreas are grouped There are four main cell types in the islets. They are relatively difficult to distinguish using standard staining techniques, but they can be classified by their secretion: α cells secrete glucagon, β cells secrete insulin, δ cells secrete somatostatin, and PP cells secrete pancreatic polypeptide. Glucagon is an important Hormone involved in Carbohydrate metabolism. Insulin is a Hormone with intensive effects on both metabolism and several other body systems (eg vascular compliance Somatostatin (also known as growth hormone inhibiting hormone ( GHIH) or somatotropin release-inhibiting factor ( SRIF) is a Peptide hormone Pancreatic polypeptide is a Polypeptide secreted by PP cells in the Endocrine pancreas predominantly in the Head of the pancreas. [4]
The islets are a compact collection of endocrine cells arranged in clusters and cords and are crisscrossed by a dense network of capillaries. The capillaries of the islets are lined by layers of endocrine cells in direct contact with vessels, and most endocrine cells are in direct contact with blood vessels, by either cytoplasmic processes or by direct apposition. The endocrine system is an integrated system of small organs that involve the release of extracellular signaling molecules known as Hormones The endocrine system is instrumental The cytoplasm is the contents of a cell that is enclosed within the Plasma membrane. According to the volume The Body, by Alan E. Nourse,[5] the islets are "busily manufacturing their hormone and generally disregarding the pancreatic cells all around them, as though they were located in some completely different part of the body. Alan Edward Nourse ( August 11, 1928 – July 19, 1992) was an American Science fiction (SF author and Physician "
Exocrine
In contrast to the endocrine pancreas, which secretes hormones into the blood, the exocrine pancreas produces digestive enzymes and an alkaline fluid, and secretes them into the small intestine through a system of exocrine ducts. The Exocrine Pancreas has ducts that are arranged in clusters called Acini (singular acinus) Digestion enzymes are Enzymes that break down Polymeric Macromolecules into their smaller building blocks In Biology the small Intestine is the part of the Gastrointestinal tract (gut between the Stomach and the Large intestine, and comprises In Anatomy and Physiology, a duct is a circumscribed channel leading from an Exocrine gland or organ. Digestive enzymes include trypsin, chymotrypsin, pancreatic lipase, and pancreatic amylase, and are produced and secreted by acinar cells of the exocrine pancreas. Trypsin ( is a Serine protease found in the Digestive system, where it breaks down Proteins Trypsin predominantly cleaves peptide chains at the carboxyl Chymotrypsin (bovine γ chymotrypsin,) is a digestive enzyme that can perform Proteolysis. Pancreatic lipase is an Enzyme (more specifically a Lipase) secreted from the Pancreas that uses Hydrolysis to break apart Fat Amylase is an Enzyme that breaks Starch down into Sugar. Amylase is present in human Saliva, where it begins the chemical process Specific cells that line the pancreatic ducts, called centroacinar cells, secrete a bicarbonate- and salt-rich solution into the small intestine. In some animals spindle-shaped cells occupy the center of the Alveolus of the Pancreas and are known as the centroacinar cells of Langerhans. In Inorganic chemistry, bicarbonate ( IUPAC -recommended nomenclature hydrogencarbonate) is an intermediate form in the Deprotonation Salt is a Dietary mineral composed primarily of Sodium chloride that is essential for Animal life but toxic to most land plants [6]
Regulation
The pancreas receives regulatory innervation via hormones in the blood and through the autonomic nervous system. Hormones (from Greek ὁρμή - "impetus" are chemicals released by cells that affect cells in other parts of the body &trade The autonomic nervous system ( ANS) (or visceral nervous system) is the part of the Peripheral nervous system that acts as a Control These two inputs regulate the secretory activity of the pancreas.
| Sympathetic (adrenergic) | Parasympathetic (muscarinic) |
| α2: decreases secretion from beta cells, increases secretion from alpha cells | M3[7] increases stimulation from alpha cells and beta cell |
Diseases of the pancreas
Because the pancreas is a storage depot for digestive enzymes, injury to the pancreas is potentially very dangerous. The Sympathetic Nervous System ( SNS) is a branch of the Autonomic nervous system along with the Enteric nervous system and Parasympathetic nervous The parasympathetic Nervous system ( PSNS) is a division of the Autonomic nervous system (ANS along with the Sympathetic nervous system Muscarinic receptors, or mAChRs, are Acetylcholine receptors that form Metabotropic Ion channels in the Plasma membranes of certain Beta cells ( beta-cells, β-cells) are a type of cell in the Pancreas in areas called the Islets of Langerhans. Alpha cells are endocrine cells in the Islets of Langerhans of the Pancreas. Alpha cells are endocrine cells in the Islets of Langerhans of the Pancreas. Beta cells ( beta-cells, β-cells) are a type of cell in the Pancreas in areas called the Islets of Langerhans. Pancreatic diseases include Pancreatitis Pancreatitis is Inflammation of the pancreas A puncture of the pancreas generally requires prompt and experienced medical intervention.
History
The pancreas was first identified by Herophilus (335-280 BC), a Greek anatomist and surgeon. Herophilos, sometimes Latinized Herophilus (335-280 BC was a Greek physician The Greeks ( Greek: Έλληνες) are a Nation and Ethnic group native to Greece, Cyprus and neighbouring regions Anatomy (from the Greek anatomia, from ana separate apart from and temnein, to cut up cut open is a branch of Biology that is the consideration Surgery (from the χειρουργική cheirourgikē, via chirurgiae meaning "hand work" is a medical specialty that uses operative manual and instrumental Only a few hundred years later, Ruphos, another Greek anatomist, gave the pancreas its name. The term "pancreas" is derived from the Greek pan, "all", and kreas, "flesh", probably referring to the organ's homogeneous appearance. Greek (el ελληνική γλώσσα or simply el ελληνικά — "Hellenic" is an Indo-European language, spoken today by 15-22 million people mainly [8]
Embryological development
The pancreas forms from the embryonic foregut and is therefore of endodermal origin. The foregut is the anterior part of the Alimentary canal, from the Mouth to the Duodenum at the entrance of the Bile duct. Endoderm, (sometimes called Entoderm) is one of the Germ layers formed during animal Embryogenesis. Pancreatic development begins the formation of a ventral and dorsal anlage (or buds). Each structure communicates with the foregut through a duct.
Differential rotation and fusion of the ventral and dorsal pancreatic buds results in the formation of the definitive pancreas. [9] As the duodenum rotates to the right, it carries with it the ventral pancreatic bud and common bile duct. Upon reaching its final destination, the ventral pancreatic bud fuses with the much larger dorsal pancreatic bud. At this point of fusion, the main ducts of the ventral and dorsal pancreatic buds fuse, forming the duct of Wirsung, the main pancreatic duct. The pancreatic duct, or duct of Wirsung, is a duct joining the Pancreas to the Common bile duct to supply pancreatic juices which aid in Digestion
Differentiation of cells of the pancreas proceeds through two different pathways, corresponding to the dual endocrine and exocrine functions of the pancreas. In progenitor cells of the exocrine pancreas, important molecules that induce differentiation include follistatin, fibroblast growth factors, and activation of the Notch receptor system. Follistatin is a single chain Autocrine glyco Protein found to be ubiquitous within the body of nearly all higher animals that is the product of a single Fibroblast growth factors, or FGFs, are a family of Growth factors involved in Angiogenesis, Wound healing, and embryonic development [9] Development of the exocrine acini progresses through three successive stages. These include the predifferentiated, protodifferentiated, and differentiated stages, which correspond to undetectable, low, and high levels of digestive enzyme activity, respectively.
Progenitor cells of the endocrine pancreas arise from cells of the protodifferentiated stage of the exocrine pancreas. [9] Under the influence of neurogenin-3 and Isl-1, but in the absence of Notch receptor signaling, these cells differentiate to form two lines of committed endocrine precursor cells. The first line, under the direction of Pax-6, forms α- and γ- cells, which produce the peptides glucagon and pancreatic polypeptide, respectively. Glucagon is an important Hormone involved in Carbohydrate metabolism. Pancreatic polypeptide is a Polypeptide secreted by PP cells in the Endocrine pancreas predominantly in the Head of the pancreas. The second line, influenced by Pax-4, produces β- and δ-cells, which secrete insulin and somatostatin, respectively. Insulin is a Hormone with intensive effects on both metabolism and several other body systems (eg vascular compliance Somatostatin (also known as growth hormone inhibiting hormone ( GHIH) or somatotropin release-inhibiting factor ( SRIF) is a Peptide hormone
Insulin and glucagon can be detected in the fetal circulation by the fourth of fifth month of fetal development. [9]
Additional images
 Accessory digestive system. |
 Digestive organs. |
 The celiac artery and its branches; the stomach has been raised and the peritoneum removed. |
 Lymphatics of stomach, etc. The stomach has been turned upward. |
 Transverse section through the middle of the first lumbar vertebra, showing the relations of the pancreas. |
 The duodenum and pancreas. |
 The pancreatic duct. |
 Pancreas of a human embryo of five weeks. |
 Pancreas of a human embryo at end of sixth week. |
 Front of abdomen, showing surface markings for duodenum, pancreas, and kidneys. |
References
- ^ Physiology at MCG 6/6ch2/s6ch2_30
- ^ Histology at BU 10404loa
- ^ Hellman B, Gylfe E, Grapengiesser E, Dansk H, Salehi A (2007). The Medical College of Georgia, also known as MCG, is a public medical Research university located in downtown Augusta Georgia. For similarly-named academic institutions see Education in Boston MA. "[Insulin oscillations--clinically important rhythm. Antidiabetics should increase the pulsative component of the insulin release]" (in Swedish). Lakartidningen 104 (32-33): 2236–9. PMID 17822201.
- ^ BRS physiology 4th edition ,page 255-256, Linda S. Constanzo, Lippincott publishing
- ^ The Body, by Alan E. Nourse, in the Time-Life Science Library Series (op. Alan Edward Nourse ( August 11, 1928 – July 19, 1992) was an American Science fiction (SF author and Physician cit. , p. 171. )
- ^ Maton, Anthea; Jean Hopkins, Charles William McLaughlin, Susan Johnson, Maryanna Quon Warner, David LaHart, Jill D. Wright (1993). Human Biology and Health. Englewood Cliffs, New Jersey, USA: Prentice Hall. ISBN 0-13-981176-1.
- ^ Verspohl EJ, Tacke R, Mutschler E, Lambrecht G (1990). "Muscarinic receptor subtypes in rat pancreatic islets: binding and functional studies". Eur. J. Pharmacol. 178 (3): 303–11. doi:. A digital object identifier ( DOI) is a permanent identifier given to an Electronic document. PMID 2187704.
- ^ Harper, Douglas. Pancreas. Online Etymology Dictionary. Retrieved on 2007-04-04. Year 2007 ( MMVII) was a Common year starting on Monday of the Gregorian calendar in the 21st century. Events 1581 - Francis Drake completes a circumnavigation of the world and is knighted by Elizabeth I.
- ^ a b c d Carlson, Bruce M. (2004). Human embryology and developmental biology. St. Louis: Mosby, pp372-4. ISBN 0-323-01487-9.
Dictionary
pancreas
-noun
- (anatomy) A gland near the stomach which secretes a fluid to help with food digestion and also the hormone insulin which helps the body process glucose (or sugars).
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