Transcript
General Science Final
Definition•Digestion is a process in which un-soluble large, complex food molecules are broken down into smaller, simple molecules that can be absorbed into the bloodstream.Explanation:•After ingestion, food must be digested before it can be absorbed into the cells of body.
The process of Digestion is completed in following steps:
1.Ingestion:The process in which animal take in food by swallowing or absorption is known as ingestion
2. Digestion:It is a complex process in which a large insoluble food particles are converted into smaller simple soluble molecules capable of passing through the membranes.
3. AbsorptionThe passage of material through the lining of the intestine into the blood or through a cell membrane into a cell.
4.Assimilation:Incorporation of nutrients into the cell or It
can be defined as the process in which the absorbed food material is converted into stored form and stored at various places in body
5.Egestion:It is the process in which the undigested food
is removed from the body as a waste product through anus.
There are basically 2 types of Digestions:
1.Extra Cellular Digestion: Digestion that takes place outside the cell in a special cavity or tube, after which the soluble molecules are absorbed into the cells.2.Intracellular Digestion: Digestion that takes place within the cell.
1. Alimentary Canal1. Alimentary Canal•A large coiled tube extended from mouth to anus.
•External opening guarded by lips
•Digestion of carbohydrate begins here.
•Saliva is secreted by salivary glands.
•Saliva contains enzymes (Ptyalin & lysozymes) , water & mucus.
•Common passage for both air and food
•Responsible for swallowing of food and forming of bolus.
•It is a passage of food from pharynx to stomach.
•Stores food for 2-4 hours.
•Secrete gastric juices that contain enzymes, HCL & mucus.
•Enzymes are pepsinogen and renin.
•By the result of Digestion food become paste like called as CHYME.
•The average length of the small intestine in an adult human male is 6.9 m (22 feet 6 inches).
•Adult female 7.1 m (23 feet 4 inches).
Consisting of :1.Duodenum
2.Jejunum
3.Ileum
•Chyme enters duodenum where it mixes with digestive juices
•Digestive juices are produced by Liver, Pancreas & Intestinal glands.
•Digestion of food is completed here.
•A site of final absorption of nutrients like glucose & amino acids.
•Finger like projections called villi absorb food material.
•Blood capillaries absorb glucose & amino acids.
•Lymph capillaries called lacteals absorb fatty acids.
•A site of final absorption of water & minerals.
•Consist of Caecum, Ascending Colon, Transverse Colon, Descending Colon, Sigmoid Colon & Rectum.
•Rectum stores the faeces that is later on egested by Anus.
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