digestive system the collect name used to describes the analmutal canal some assocary organs and various digestive process takes place in the knal to prepare food for abjopsion.
The process of breaking down of large molecules into small molecules to enter body cell is called as digestion.
The study of structure, function, dignosis and treatment of disease of stomach and intestine is called gestro enterology and the study with the dignosis and treatment of disorder of rectem anus is called proctology. digestive process accurs in 6 steps
1. Ingestion : If is the process of taking food and liquid material into the mouth.
2. Secretion : Each day cells with in GI tracked secreate about 7 liter of water, acid, buffer and engymes,
3. Mixing : The alternate contraction and releaxation of smooth muscels mix food secration and prople them towards anas. This properties is called motility
4. Digestion : The beaking down of large molecules into smaller molecules is called as digestion its accus by two process.
(a). Machanical breakdown : by rich food are masticated by teeth and tongue.
(b). Chemical breakdown : Its accurs by various engymes and acid,.
5. Absorption : It is the process by which digestive food substance pass from the walls of intestine into blood capilarries and serculation is called as absorption.
6. Excretion/Deflacation : The food which have been it in but cannot be digested or absorbed are excerted by the bowl as faeces.
Fuction of tongue
formation of bolus when food in taken into mouth. It is mesticated by the teeth and moved around the mouth by tongue and muscle of cheeks. It is mixed with saliva and founds a bolus radi for deglutition (Swallowing)
Deglutation : Insarly is in volantury but later it is involuntary the muscle of the phyraings are slimulated by a reflexatation insatitated and the walls of aeroflexain contractation of these muscle propul the bonus down into erofagus.
Stomach : It is a J shaped structure sutatied in the apigestric, amblical and left hypochondriac reason of the abnominal cavity.
In the stomach digetation of starch, proteins, tri glucrides and convergen of semi solid bolus into liquid accurs. Some substances are also absorbed like, water, ions, fatty acids and some drugs like usprine, and Alchoala.
Structure : It is continued with the esotagus and cardial and with the duetanium at the pyloric infection. It has two curvatur the lesser convature is short. lies on the posterior surface of stomach where as the isofagus joint the stomach the enterior part angel upward forming curves adn down word forming the grater curvature.
The part of stomach above the cardial orapic its fundus.
The main part is the body and lower part is pyloric Antrum at the distel part of pyloric Antrum there is pyloric sphincter when the somach is snactive the pyloric infenction is relexed (open) and when it contain the food the infection is closed.
Walls of Stomach : It consists of four layers of tissuses
- Outer Peroterium
- Muscle Layer
- Sub Muepopslar
Function of Stomach
The size of stomach varius with the amount of food when a meal has been it in the food aquamulates in the stomach in layers, mixing with the gestin guse takes place gracuarly.
genstin muscle contraction consists of churning movement that breakdown the bolus and mixing with the gestin guse and parastatic wave propare the stomach contant towards the pylorus and through the pylorue into the deogranum in small spurts.
Small Intestine : It continues with the stomach at the pyloric infestion and leads to the large intestine at the Ileocaecal junction. It is five meter long camical diagestion of food and absorption of nuterient takes place in it.
It is divided into 3 parts.
- Dueodenum : It is 25 cm long at the mid point and opening is there which is common for penteritic duct and bio duct guarded by a infectation called oddi.
- Jejunum : It is 2 meter long.
- Illium : it is 3 meter long it ends at aeulocical Iliocacul bool which control the flow of material from Illium of secum.
Structure : It consists of four layer of tissue
- Muscularas Infosa
- Sub Muscosa
Paratonium : A double layer of paritorinum called mesentary attaches the jujnum and alium to the posterior abdominal wall, and forms a fan shaped structure.
Mucosa : Surface area of small istestine increased by permanant sercular foalds villi & micrivilla
vills are finger like projections of the myposal layer there well consists of coloumner epithins cells there epithlsal cells ancloses a network of blood and limfs capilary called lacteals goblet cells are present mupesb that secreat mupus.
Large Instestine (colon) : It is about 1.5 cm long begine at the secum begans at the serum and at the rectum its lumen is larger than small intestine.
The secum is first part of colon and continuous with ascending colan. The veriniform Appendis. Is a fine tube close at one end which leads from the secum.
It is about 30cm long and contains more lymphotis tissue ascending colan binds to the left to become the tranfact colan and transter coloun bends down words to become descending colan.
It is the largest gland in the body waighing around 1-2.3 kg situated in the right hypoconderia reason and extending into left hypoconderia reasion. it is enclosed in a thin capsules and incomperately convered by a layer of paritornium. It is helt in position partly by ligaments and partly by preasure of other organs of abdominel cavity. It is having 4 logs the larger one is right low and smaller one is left logs.
The other 2 hours condate & quadratic
Structure : The logs of liver is made up of tiny lobules are hexeronal arrange in pairs of coloumns readiation from a central weigning between two pairs of colon sinusoids are present some cells lyning are known as knffer cells.
whoes function is to injest destory worn aut blood cells and any foran particle present in blood flowing through the liver.
Golbladder : It is pear shaped shack attach to the posterior surface of liver by connective tissue it is divided into 3 parts