Digestive System

The mechanical and chemical breakdown of food and the absorption of the resulting nutrients by the body’s cells

Alimentary canal - muscular tube extending from the mouth and anus Accessory digestive organs - everything else involved in the process of breaking food down in smaller molcules for absorption

5-7 meters

Mouth,Pharynx,Oesophagus,Stomach,Small intestine,Large intestine,Rectum,Anus

Inside - Teeth and Tongue Outside - Salivary glands, Liver,Pancreas and Gall bladder

Ingestion Mechanical digestion Propulsion Chemical digestion Absorption Elimination

ingestion takes place in the mouth where food or liquids enter

involves chewing (mouth),churning (stomach) and segmentation (small intestine).

this is include swallowing voluntary and peristalsis involuntary - esophagus,stomach,small intestine and large intestine process is where food is pushed through the alimentary canal

uses certain enzymes to break down nutrients such as carbohydrates,proteins and fats into smaller molecules. into the lumen of the alimentary canal come from the accessory organs e.g pancreas and gall bladder.

The process of taking nutrients from the digestive system into the blood so they can be used in the body through the small intestine by active or passive transport

The removal of indigestible wastes through the anus, in the form of feces, is defecation or elimination.

Happens in the small intestine it mixes food and digestive juices making absorption more efficiently due to moving food all over the walls of the intestine breaking it down further

is the contraction and relaxation of waves allowing food to go down alimentary canal

The layers of the GI tract are broadly the same alll the away from the oesphagus to the anus but the mouth and pharyx are to function differently

Serosa Muscularis Submucosa Mucosa

Made up of three layers that secret digestive enzymes,hormones,mucus and absorbs nutrients. protects the alimentary canal - small intestine produce serotonin

Stratified sqaumous epithelium - short fat cells which are in the mouth,oesphagus,oropharynx and anal canal Columnar - tall which is everywhere else

it has lots of capillaries and are in the muscosa layer - absorption of nutrients

Reservoirs for the immune system waiting for pathogen for when a pathogen re enters retains the genetic information

two layer longitudinal and circular muslces which are used to push down the food through the process perisalsis and segmentation

is made up of loose areolar connective tissues binds and supports organs and to provide flexibility contains glands and blood vessels has elastic layers to allow stretches

outer layer covers the abdomen and throax produce serous fluid that lubricates all the area allows for movements

within the buccal cavity are teeth that is used i mastication of food chewing use of tongue to probe our food with saliva to swallow into a bolus primary breaks down starch but to also lubricate.Saliva protects the inside of the mouth