ch. 12: swine (omnivore) digestion

what is the pH of swine saliva?

7.4

is a pig a monogastric or ruminant?

monogastric

what type of digestion is the mouth primarily used for?

mechanical (grinding feed)

what 3 glands produce saliva

parotid, submandibular, and sublingual

what is ptyalin?

• a salivary amylase (breaks down starch)

• pigs are the only farm mammal with this enzyme

• not really useful to pigs because feeds doesn’t stay in the mouth very long and the pH of the stomach is too low for it to work

what gastric juices are present in the pig’s stomach and what is their purpose?

• mucin: made from neck cells; provide protective coating

• HCl: made from parietal cells; denatures proteins, activates enzymes, provides acidic environment, kill bacteria

• pepsinogen: made from chief cells; inactive form of pepsin (pepsin is a protease)

where does protein digestion start and finish?

starts in stomach and finishes in the small intestine

what is the function of the small intestine?

continue the process of digestion with:

• pancreatic juice (enzymatic)

• duodenal juice (enzymatic)

• bile (chemical)

• movement of the intestinal wall (mechanical)

what are the three ways that the pancreas contributes to digestion?

1) produces enzymes for protein, fat, and CHO digestion

2) produces sodium carbonate (NaCO3) and bicarbonate (HCO3) to work as buffer to the acidity of the stomach

3) produces insulin for CHO metabolism

what are the 4 proteases used for protein digestion, their inactive forms, and how are they activated?

1) trypsin

• produced by pancreas as trypsinogen

• activated by Ca ions and enterokinase from BB

2) chymotrypsin

• produced by pancreas as chymotrypsinogen

• activated by trypsin

3) carboxypeptidase

• produced by pancreas as procarboxypeptidase

• activated by trypsin

4) aminopeptidases

• produced by brush border of duodenum

• breaks small peptides down into single amino acids

go study the image on slide 7

yes chef o7

what are the 4 functions of bile in fat digestion

1) emulsifies fat (allows fat & water to interact)

2) works to digest and absorb fat

3) absorption of fat soluble vitamins

4) activates lipase

what is the function of pancreatic lipase in fat digestion?

1) breaks fat down into fatty acids and glycerol enzymatically

• this is most effective after emulsification

what 4 enzymes are used in carb digestion?

1) pancreatic amylase (starch → maltose)

2) maltase (maltose → glucose)

3) sucrase (sucrose → glucose and fructose)

4) lactase (lactose → glucose and galactose)

what makes up the large intestine and what is its function?

• made up of the colon and cecum before terminating as the rectum at the anus

• function: absorb water, absorb VFAs, and act as a reservoir for waste materials

• overall though, absorption is limited