पाचन तंत्र, DIGESTIVE SYSTEM, ANATOMY & PHYSIOLOGY, FUNCTIONS, GASTROINTESTINAL TRACT, GIT
This Expert Lecture By ??? Fayeja S Zankhwala B.pharm, M.pharm Assistant Professor Department of Pharmaceutics The digestive system is made up of organs that are important for digesting food and liquids. These include the mouth, pharynx (throat), esophagus, stomach, small intestine, large intestine, rectum, and anus. Two groups of organs compose the digestive system The gastrointestinal (GI) tract, alimentary canal. Organs of the gastrointestinal tract include the mouth, most of the pharynx, esophagus, stomach, small intestine, and large intestine. The length of the GI tract is about 5–7 meters (16.5–23 ft) in a living person. It is longer in a cadaver (about 7–9 meters or 23–29.5 ft) because the muscles along the wall of the GI tract The accessory digestive organs include the teeth, tongue, salivary glands, liver, gallbladder, and pancreas. ORAL CAVITY Food enters the oral cavity (or buccal cavity) by way of the mouth. The boundaries of the oral cavity are the hard and soft palates superiorly, the cheeks laterally, and the floor of the mouth inferiorly. Within the oral cavity are the teeth and tongue and the openings of the ducts of the salivary glands Lips (labia) – protect the anterior opening Cheeks – form the lateral walls Hard palate – forms the anterior roof Soft palate – forms the posterior roof Uvula – fleshy projection of the soft palate Tonsils Palatine tonsils Lingual tonsil TEETH The function of the teeth is course chewing. This is the process that mechanically breaks food into smaller pieces and mixes it with saliva TONGUE The tongue is made of skeletal muscle that is innervated by the hypoglossal nerves (12th cranial). On the upper surface of the tongue are small projections called papillae, many of which contain taste buds. The sensory nerves for taste are also cranial nerves: the facial (7th) and glossopharyngeal (9th). SALIVARY GLANDS The digestive secretion in the oral cavity is saliva, produced by three pairs of salivary glands, Parotid glands are just below and in front of the ears. The submandibular glands are at the posterior corners of the mandible. the sublingual glands are below the floor of the mouth. These glands have ducts such as Stenson’s duct, Wharton’s duct and Bartholin’s duct or duct of Rivinis. The salivary juice secreated by the salivary glands reaches the mouth through these ducts. The daily secretion of saliva from salivary glands ranges from 1000 to 1500mL PHARYNX Nasopharynx – not part of the digestive system Oropharynx – posterior to oral cavity Laryngopharynx – below the oropharynx and connected to the esophagus Function: Serves as a passageway for air and food ESOPHAGUS (e-SOF-a-gus - eating gullet) is a collapsible muscular tube, about 25 cm (10 in.) long, that lies posterior to the trachea. The esophagus is a muscular tube that takes food from the pharynx to the stomach. The junction with the stomach, the lumen (cavity) of the esophagus is surrounded by the lower esophageal sphincter (LES or cardiac sphincter), a circular smooth muscle. STOMACH The stomach is located in the upper left quadrant of the abdominal cavity, to the left of the liver and in front of the spleen. Food enters at the cardioesophageal sphincter SMALL INTESTINE Most digestion and absorption of nutrients occur in a long tube called the small intestine. Its length alone provides a large surface area for digestion and absorption, and that area is further increased by circular folds, villi, and microvilli It averages 2.5 cm (1 inch) in diameter its length is about 3 m (10 ft) in a living person and about 6.5 m (21 ft) in a cadaver due to the loss of smooth muscle tone after death. DUODENUM- starts at the pyloric sphincter of the stomach, shortest region, about 25 cm (10 in.) JEJUNUM- about 1 m (3 ft) long, extends to the ileum. ILEUM - about 2 m (6 ft) and joins the large intestine at a smooth muscle sphincter called the ileocecal sphincter. LARGE INTESTINE Larger in diameter, but shorter than the small intestine The large intestine, which is about 1.5 m (5 ft) long and 6.5 cm (2.5 in.) in diameter, extends from the ileum to the anus. Four major regions- cecum, colon, rectum, and anal canal LIVER The liver consists of two large lobes, right and left, and fills the upper right and center of the abdominal cavity, just below the diaphragm. The structural unit of the liver is the liver lobule, a roughly hexagonal column of liver cells (hepatocytes). GALLBLADDER The gallbladder is a sac about 3 to 4 inches (7.5 to 10 cm) long located on the undersurface of the right lobe of the liver. Bile in the hepatic duct of the liver flows through the cystic duct into the gallbladder , which stores bile until it is needed in the small intestine. The gallbladder also concentrates bile by absorbing water PANCREAS The pancreas is located in the upper left abdominal quadrant between the curve of the duodenum and the spleen and is about 6 inches (15 cm) in length.
This Expert Lecture By ??? Fayeja S Zankhwala B.pharm, M.pharm Assistant Professor Department of Pharmaceutics The digestive system is made up of organs that are important for digesting food and liquids. These include the mouth, pharynx (throat), esophagus, stomach, small intestine, large intestine, rectum, and anus. Two groups of organs compose the digestive system The gastrointestinal (GI) tract, alimentary canal. Organs of the gastrointestinal tract include the mouth, most of the pharynx, esophagus, stomach, small intestine, and large intestine. The length of the GI tract is about 5–7 meters (16.5–23 ft) in a living person. It is longer in a cadaver (about 7–9 meters or 23–29.5 ft) because the muscles along the wall of the GI tract The accessory digestive organs include the teeth, tongue, salivary glands, liver, gallbladder, and pancreas. ORAL CAVITY Food enters the oral cavity (or buccal cavity) by way of the mouth. The boundaries of the oral cavity are the hard and soft palates superiorly, the cheeks laterally, and the floor of the mouth inferiorly. Within the oral cavity are the teeth and tongue and the openings of the ducts of the salivary glands Lips (labia) – protect the anterior opening Cheeks – form the lateral walls Hard palate – forms the anterior roof Soft palate – forms the posterior roof Uvula – fleshy projection of the soft palate Tonsils Palatine tonsils Lingual tonsil TEETH The function of the teeth is course chewing. This is the process that mechanically breaks food into smaller pieces and mixes it with saliva TONGUE The tongue is made of skeletal muscle that is innervated by the hypoglossal nerves (12th cranial). On the upper surface of the tongue are small projections called papillae, many of which contain taste buds. The sensory nerves for taste are also cranial nerves: the facial (7th) and glossopharyngeal (9th). SALIVARY GLANDS The digestive secretion in the oral cavity is saliva, produced by three pairs of salivary glands, Parotid glands are just below and in front of the ears. The submandibular glands are at the posterior corners of the mandible. the sublingual glands are below the floor of the mouth. These glands have ducts such as Stenson’s duct, Wharton’s duct and Bartholin’s duct or duct of Rivinis. The salivary juice secreated by the salivary glands reaches the mouth through these ducts. The daily secretion of saliva from salivary glands ranges from 1000 to 1500mL PHARYNX Nasopharynx – not part of the digestive system Oropharynx – posterior to oral cavity Laryngopharynx – below the oropharynx and connected to the esophagus Function: Serves as a passageway for air and food ESOPHAGUS (e-SOF-a-gus - eating gullet) is a collapsible muscular tube, about 25 cm (10 in.) long, that lies posterior to the trachea. The esophagus is a muscular tube that takes food from the pharynx to the stomach. The junction with the stomach, the lumen (cavity) of the esophagus is surrounded by the lower esophageal sphincter (LES or cardiac sphincter), a circular smooth muscle. STOMACH The stomach is located in the upper left quadrant of the abdominal cavity, to the left of the liver and in front of the spleen. Food enters at the cardioesophageal sphincter SMALL INTESTINE Most digestion and absorption of nutrients occur in a long tube called the small intestine. Its length alone provides a large surface area for digestion and absorption, and that area is further increased by circular folds, villi, and microvilli It averages 2.5 cm (1 inch) in diameter its length is about 3 m (10 ft) in a living person and about 6.5 m (21 ft) in a cadaver due to the loss of smooth muscle tone after death. DUODENUM- starts at the pyloric sphincter of the stomach, shortest region, about 25 cm (10 in.) JEJUNUM- about 1 m (3 ft) long, extends to the ileum. ILEUM - about 2 m (6 ft) and joins the large intestine at a smooth muscle sphincter called the ileocecal sphincter. LARGE INTESTINE Larger in diameter, but shorter than the small intestine The large intestine, which is about 1.5 m (5 ft) long and 6.5 cm (2.5 in.) in diameter, extends from the ileum to the anus. Four major regions- cecum, colon, rectum, and anal canal LIVER The liver consists of two large lobes, right and left, and fills the upper right and center of the abdominal cavity, just below the diaphragm. The structural unit of the liver is the liver lobule, a roughly hexagonal column of liver cells (hepatocytes). GALLBLADDER The gallbladder is a sac about 3 to 4 inches (7.5 to 10 cm) long located on the undersurface of the right lobe of the liver. Bile in the hepatic duct of the liver flows through the cystic duct into the gallbladder , which stores bile until it is needed in the small intestine. The gallbladder also concentrates bile by absorbing water PANCREAS The pancreas is located in the upper left abdominal quadrant between the curve of the duodenum and the spleen and is about 6 inches (15 cm) in length.