Digestive (alimentary) system
Post on 24-Feb-2016
29 Views
Preview:
DESCRIPTION
Transcript
Digestive (alimentary) system
Alimentary canal: tubular passage for digestion and absorption of food and the elimination of food residue; begins at the mouth and ends at the anus
Ingestion
• Taking substances like food or drink into the body through the mouth.
Digestion •the break down of large food pieces into small, water soluble molecules
Mouth: the opening through which an animal or human takes in food
Ingestion,
Digestion
Salivary Glands
• Glands that produce saliva, an important part of chemical digestion in the mouth
enzyme - amylase
Digestion
Esophagus: a muscular passage connecting the mouth with the stomach
Food moves down the esophagus via peristalsis – muscles contract and relax
Liver: large gland responsible for:
1) the uptake, storage, and disposal of nutrients and toxins
2) the production of proteins and metabolism of substances produced by the body
Digestion,
Assimilation
Pancreas:
a gland, near stomach; secretes a digestive fluid into the intestine through one or more ducts and also secretes the hormone insulin
Digestion
• Gall Bladder:– stores Bile; a
yellow-green liquid made in the liver used to break up fats
Digestion
Stomach: a saclike enlargement of the alimentary canal; forming an organ for storing, diluting, and digesting food
Digestion
Small intestine: lies between the stomach and colon, consists of duodenum, jejunum, and ileum, secretes digestive enzymes, and is the chief site of the absorption of digested nutrients Absorption
•Absorption – the movement of digested food molecules through the wall of the intestine into the blood
Duodenum:the first portion of the small intestine, from the stomach
Jejunum: middle portion of the small intestine; between the duodenum and the ileum
Ileum:the third and lowest division of the small intestine
•Assimilation – the movement of digested food molecules into the cell where they are used
Large intestine: terminal division of the vertebrate intestine that is wider and shorter than the small intestine; divided into cecum, colon, and rectum; reabsorption of water and the formation of feces Some Absorption
Colon: the part of the large intestine extending from the cecum to the rectum
Rectum: terminal part of the intestine from the colon to the anus
Anus: the opening at the lower end of the alimentary canal, through which the solid refuse of digestion is excreted
Egestion
• Passing food through the anus that has not been digested;
• Called faeces
top related