Parotid glandThe parotid gland is a major salivary gland in many animals. In humans, the two parotid glands are present on either side of the mouth and in front of both ears. They are the largest of the salivary glands. Each parotid is wrapped around the mandibular ramus, and secretes serous saliva through the parotid duct into the mouth, to facilitate mastication and swallowing and to begin the digestion of starches. There are also two other types of salivary glands; they are submandibular and sublingual glands.
Salivary glandThe salivary glands in many vertebrates including mammals are exocrine glands that produce saliva through a system of ducts. Humans have three paired major salivary glands (parotid, submandibular, and sublingual), as well as hundreds of minor salivary glands. Salivary glands can be classified as serous, mucous, or seromucous (mixed). In serous secretions, the main type of protein secreted is alpha-amylase, an enzyme that breaks down starch into maltose and glucose, whereas in mucous secretions, the main protein secreted is mucin, which acts as a lubricant.
Salivary gland diseaseSalivary gland diseases (SGDs) are multiple and varied in cause. There are three paired major salivary glands in humans: the parotid glands, the submandibular glands, and the sublingual glands. There are also about 800–1,000 minor salivary glands in the mucosa of the mouth. The parotid glands are in front of the ears, one on side, and secrete mostly serous saliva, via the parotid ducts (Stenson ducts), into the mouth, usually opening roughly opposite the second upper molars.
Human digestive systemThe human digestive system consists of the gastrointestinal tract plus the accessory organs of digestion (the tongue, salivary glands, pancreas, liver, and gallbladder). Digestion involves the breakdown of food into smaller and smaller components, until they can be absorbed and assimilated into the body. The process of digestion has three stages: the cephalic phase, the gastric phase, and the intestinal phase. The first stage, the cephalic phase of digestion, begins with secretions from gastric glands in response to the sight and smell of food.
Gastrointestinal tractThe gastrointestinal tract (GI tract, digestive tract, alimentary canal) is the tract or passageway of the digestive system that leads from the mouth to the anus. The GI tract contains all the major organs of the digestive system, in humans and other animals, including the esophagus, stomach, and intestines. Food taken in through the mouth is digested to extract nutrients and absorb energy, and the waste expelled at the anus as feaces. Gastrointestinal is an adjective meaning of or pertaining to the stomach and intestines.
DigestionDigestion is the breakdown of large insoluble food molecules into small water-soluble food molecules so that they can be absorbed into the watery blood plasma. In certain organisms, these smaller substances are absorbed through the small intestine into the blood stream. Digestion is a form of catabolism that is often divided into two processes based on how food is broken down: mechanical and chemical digestion. The term mechanical digestion refers to the physical breakdown of large pieces of food into smaller pieces which can subsequently be accessed by digestive enzymes.
SialolithiasisSialolithiasis (also termed salivary calculi, or salivary stones) is a crystallopathy where a calcified mass or sialolith forms within a salivary gland, usually in the duct of the submandibular gland (also termed "Wharton's duct"). Less commonly the parotid gland or rarely the sublingual gland or a minor salivary gland may develop salivary stones. The usual symptoms are pain and swelling of the affected salivary gland, both of which get worse when salivary flow is stimulated, e.g.
Digestive enzymeDigestive enzymes are a group of enzymes that break down polymeric macromolecules into their smaller building blocks, in order to facilitate their absorption into the cells of the body. Digestive enzymes are found in the digestive tracts of animals (including humans) and in the tracts of carnivorous plants, where they aid in the digestion of food, as well as inside cells, especially in their lysosomes, where they function to maintain cellular survival.
Bile ductA bile duct is any of a number of long tube-like structures that carry bile, and is present in most vertebrates. Bile is required for the digestion of food and is secreted by the liver into passages that carry bile toward the hepatic duct. It joins the cystic duct (carrying bile to and from the gallbladder) to form the common bile duct which then opens into the intestine. The top half of the common bile duct is associated with the liver, while the bottom half of the common bile duct is associated with the pancreas, through which it passes on its way to the intestine.
Pancreatic ductThe pancreatic duct, or duct of Wirsung (also, the major pancreatic duct due to the existence of an accessory pancreatic duct), is a duct joining the pancreas to the common bile duct. This supplies it with pancreatic juice from the exocrine pancreas, which aids in digestion. The pancreatic duct joins the common bile duct just prior to the ampulla of Vater, after which both ducts perforate the medial side of the second portion of the duodenum at the major duodenal papilla. There are many anatomical variants reported, but these are quite rare.
Common bile ductThe bile duct (formerly known as the common bile duct) is a part of the biliary tract. It is formed by the union of the common hepatic duct and cystic duct. It ends by uniting with the pancreatic duct to form the hepatopancreatic ampulla. It possesses its own sphincter to enable regulation of bile flow. The bile duct is some 6–8 cm long, and normally up to 8 mm in diameter. Its proximal supraduodenal part is situated within the free edge of the lesser omentum.
Common bile duct stoneCommon bile duct stone, also known as choledocholithiasis, is the presence of gallstones in the common bile duct (CBD) (thus choledocho- + lithiasis). This condition can cause jaundice and liver cell damage. Treatments include choledocholithotomy and endoscopic retrograde cholangiopancreatography (ERCP). Murphy's sign is commonly negative on physical examination in choledocholithiasis, helping to distinguish it from cholecystitis. Jaundice of the skin or eyes is an important physical finding in biliary obstruction.
Connective tissueConnective tissue is one of the four primary types of animal tissue, along with epithelial tissue, muscle tissue, and nervous tissue. It develops from the mesenchyme, derived from the mesoderm, the middle embryonic germ layer. Connective tissue is found in between other tissues everywhere in the body, including the nervous system. The three meninges, membranes that envelop the brain and spinal cord, are composed of connective tissue. Most types of connective tissue consists of three main components: elastic and collagen fibers, ground substance, and cells.
GallbladderIn vertebrates, the gallbladder, also known as the cholecyst, is a small hollow organ where bile is stored and concentrated before it is released into the small intestine. In humans, the pear-shaped gallbladder lies beneath the liver, although the structure and position of the gallbladder can vary significantly among animal species. It receives and stores bile, produced by the liver, via the common hepatic duct, and releases it via the common bile duct into the duodenum, where the bile helps in the digestion of fats.
Parotid ductThe parotid duct, or Stensen duct, is a salivary duct. It is the route that saliva takes from the major salivary gland, the parotid gland, into the mouth. It opens into the mouth opposite the second upper molar tooth. The parotid duct is formed when several interlobular ducts, the largest ducts inside the parotid gland, join. It emerges from the parotid gland. It runs forward along the lateral side of the masseter muscle for around 7 cm. In this course, the duct is surrounded by the buccal fat pad.
Gastrointestinal cancerGastrointestinal cancer refers to malignant conditions of the gastrointestinal tract (GI tract) and accessory organs of digestion, including the esophagus, stomach, biliary system, pancreas, small intestine, large intestine, rectum and anus. The symptoms relate to the organ affected and can include obstruction (leading to difficulty swallowing or defecating), abnormal bleeding or other associated problems. The diagnosis often requires endoscopy, followed by biopsy of suspicious tissue.
GlandIn animals, a gland is a group of cells in an animal's body that synthesizes substances (such as hormones) for release into the bloodstream (endocrine gland) or into cavities inside the body or its outer surface (exocrine gland). List of glands of the human body Every gland is formed by an ingrowth from an epithelial surface. This ingrowth may in the beginning possess a tubular structure, but in other instances glands may start as a solid column of cells which subsequently becomes tubulated.
Gastrointestinal perforationGastrointestinal perforation, also known as ruptured bowel, is a hole in the wall of part of the gastrointestinal tract. The gastrointestinal tract includes the esophagus, stomach, small intestine, and large intestine. Symptoms include severe abdominal pain and tenderness. When the hole is in the stomach or early part of the small intestine, the onset of pain is typically sudden while with a hole in the large intestine onset may be more gradual. The pain is usually constant in nature.
BileBile (from Latin bilis), or gall, is a yellow-green fluid produced by the liver of most vertebrates that aids the digestion of lipids in the small intestine. In humans, bile is primarily composed of water, produced continuously by the liver, and stored and concentrated in the gallbladder. After a human eats, this stored bile is discharged into the first section of their small intestine. In the human liver, bile is composed of 97–98% water, 0.7% bile salts, 0.2% bilirubin, 0.
Gallbladder cancerGallbladder cancer is a relatively uncommon cancer, with an incidence of fewer than 2 cases per 100,000 people per year in the United States. It is particularly common in central and South America, central and eastern Europe, Japan and northern India; it is also common in certain ethnic groups e.g. Native American Indians and Hispanics. If it is diagnosed early enough, it can be cured by removing the gallbladder, part of the liver and associated lymph nodes.
