Digestive System PDF

Digestive System RAKCOP Dr Abdalla A E Elamin Dr Abdalla Ahmed Elamin  Digestive System Consist of 1- The alimentary canal(tract), also called the gastrointestinal tract (GIT) which begin from the oral cavity and end at the anus. The organs of the alimentary c...

Digestive System RAKCOP Dr Abdalla A E Elamin Dr Abdalla Ahmed Elamin  Digestive System Consist of 1- The alimentary canal(tract), also called the gastrointestinal tract (GIT) which begin from the oral cavity and end at the anus. The organs of the alimentary canal are the mouth, pharynx, esophagus, stomach, small intestine, and large intestine. alimentary canal is approximately 9 m long. 2-The accessory digestive organs are the teeth, tongue, gallbladder, salivary glands, liver, and pancreas. anus  The Oral Cavity Functions: Digestion, Speech, Emergency air way Major structures: tongue, teeth, lips The tongue -Is the muscular organ -formed of skeletal muscle -mixes food with saliva -Push the Bolus to the pharynx. The food is masticated by the teeth, and tongue  Oral Cavity Teeth: there are two sets of the teeth upper (maxillary) and lower (mandibular) 1-Deciduous or milk teeth 20 2- permanent teeth 32 Gums (gingivae) is soft tissue support (fix) the teeth to the bone Function of the Teeth : is breakdown of food into small pieces and participate in speech  Pharynx It is divided into three regions Nasopharynx: behind the nasal cavity contains the pharyngeal tonsils and opening of eustachian tube Oropharynx: Behind the oral cavity contains Palatine tonsil and Lingual tonsil Laryngopharynx : Behind the larynx  Esophagus Muscular tube About 25 cm long covey food to the stomach connects the pharynx with the stomach. it is three parts 1-Cervical part 2-Thoracic part 3-Abdominal part (smallest part)  Stomach Dilated part of the GIT lies in the abdominal cavity Store and digest the food, Secrete HCL acid The stomach is divided into 4 regions: 1- cardia 2- fundus 3- body 4- pylorus  Small intestine is approximately 6 m long consists of: the duodenum, the jejunum, and the ileum. duodenum site of last stage of digestion jejunum and Ileum site of absorption.  Small intestine duodenum The duodenum is about 25cm long is the shortest part of small intestine pancreatic It is C shape- curves around the head duct of the pancreas Bile duct -is has 4 parts 1. First part 2. Second part 3. Third part 4. Fourth part The bile duct and the pancreatic duct units to from hepatopancreatic duct opens into the second part of the duodenum.  Small intestine Jejunum: It is mostly in the left upper part of the abdomen Has large diameter and thick wall than the ileum jejunum is about 240 cm long Ileum: Is the longest part of small intestine about 360 cm long It is rich in aggregated lymphoid follicles (Peyer‘s patches). End in the cecum at ileocecal junction.  Duodenojejunal Junction Duodenum 1st 2nd 3rd Jejunum 4th Cecum Ileum Ileocecal Junction  Large intestine The large intestine extends from the ileocecal valve to the anus. It consist of Cecum with appendix Ascending colon Transverse colon Descending colon Sigmoid colon Rectum Anal canal Function: Reabsorption of water , electrolytes and excretion of feces  The accessory glands of the digestive system liver and the Gall bladder Salivary glands Pancreas  liver It lies in the abdominal cavity below the diaphragm The liver has four lobes Right lobe, Left lobe, quadrate lobe, caudate lobe The functions of the liver Produce the bile Detoxification metabolism Storage of vitamin A  left right Gall bladder  caudate left right quadrate Gall bladder  Biliary system Parts of the biliary system are Right and left hepatic ducts Common hepatic duct Bile duct (Common bile duct) cystic duct Gall bladder: Lies below the liver, it store and concentrate the bile Has fundus, body and neck  Salivary glands Salivary glands produce saliva which participate in digestion and protect the teeth against bacteria. There are three pairs of salivary glands Parotid gland. Serous Submandibular gland mixed(serous & mucous) Sublingual gland. Mucous salivary glands open by ducts to the oral cavity.  Pancreas has four parts: Head, Neck , body and Tail It is mixed gland endocrine and exocrine The endocrine part secrete hormones they are insulin , glucagon and somatostatin the exocrine part secrete enzymes (pancreatic juice)  Tail body Neck Head THANKS