SMALL INTESTINE, PANCREAS, LIVER AND GALL BLADDER

Use the Nelson text, "Biology 11", pp. 216-218 and 222-223 to complete the blanks.


Small Intestine and Pancreas

Most digestion takes place in the ___________ ______________. In humans, the small intestine is about _______ long and _______ in diameter. The ___________ intestine is only __________ long but is _________ in diameter. The ____________ of the small intestine is related to _________. Carnivores have ____________ small intestines whereas herbivores have ____________ small intestines.

The majority of digestion occurs in the first part of the small intestine called the _________________. The second part is called the ______________ and the third part is called the _________________.

When ____________ (from the stomach) enter the small intestine, a chemical called ________________ is converted into ______________ which is absorbed into the bloodstream and carried to the ________________ where it signals the release of a solution containing __________________ ions. The HCO3- ions are carried to the small intestine where they _______________ the _______ in gastric fluid and raise the _______. The now basic pH inactivates ___________ (from the stomach).

The ________________ secretions also contain _____________ that promote the breakdown of the 3 major components of food: _______________, __________________, and _____________. A protein-digesting enzyme called ___________________ is released from the pancreas. Once in the small intestine, an enzyme called ___________________ converts the inactive trypsinogen into _______________ which acts on partially digested proteins breaking them down into ______________. Another group of enzymes called _______________, also from the pancreas, breaks peptides into individual ____________ ____________.

The pancreas also releases ________________ enzymes which continue the breakdown of _________________ begun in the mouth by __________________ amylase, which breaks down starch into disaccharides (___________________). The small intestine releases ________________ enzymes, called _____________________ (ie. maltase), which breaks maltose into _____saccharides (ie. ________________).

________________ are enzymes released from the pancreas that break down __________ into ________________ and fatty ___________.

Liver and Gall Bladder

The liver continually produces a fluid called _____________ which contains bile __________ which speed up ________ digestion. Bile is stored and concentrated in the __________ ______________. When there are ________ in the small intestine, the hormone __________________ (CCK) is released and carried by the blood to the gall bladder which is triggered to release bile. The bile salts ______________ or break down large fat globules into smaller droplets which allow the fat-digesting enzyme, _______________, to work better.

___________________, an insoluble component of bile, can precipitate and form larger crystals called _______________ which can block the bile duct impairing _________ digestion and causing considerable _________. Bile also contains _____________. The liver breaks down __________________ from RBC's and stores the products in the gall bladder for removal. The brown colour of feces results from ___________________ breakdown. Any obstruction of the ___________ duct or accelerated destruction of RBC's can cause _________________, turning skin and other tissues ________________.

The liver also stores __________________ and vitamins ____, ______, and _______. In addition, the liver is able to ______________ many substances in the body. Some substances can then be excreted in the urine but some harmful substances (ie. large amounts of alcohol) destroy liver tissue which is replaced by _______________ tissue and _________. The result is a condition called _________________ of the liver.