Download BIOLOGY 12

BIOLOGY 12
12: Digestive System
Worksheet
Name:________________________
Block__________
1. Food is received by the ____________________, which possesses ________________ to grind and
break up particles. _______________ glands secrete ________________ that moisten food and binds it
together for swallowing. The taste of food is detected by _________________ located on the
_________________.
2. At the back of the mouth, the muscular ____________________ is involved in swallowing food. The
epiglottis folds over the glottis during the swallowing ________________.
3. The esophagus propels food toward the __________________, using muscular contractions called
_____________________ At the lower end of the esophagus, a muscular ring called a(n)
____________________ regulates the entrance of food to the stomach.
4. The stomach is lined with _______________ that secretes protective ______________. Otherwise, the
lining would be injured by the strong _____________ acid secreted by _______________ glands. Gastric
juice also contains ____________ that breaks down proteins.
5. The first section of the small intestine is the __________________. It receives secretions from the
____________________ and __________________ and also receives food known as
______________________ from the stomach.
6. The mucosa of the small intestine is folded into ___________________, which, in turn, have
projections from individual cells called ____________________________. Proteins in the microvilli
transport nutrients such as ______________________ directly into the bloodstream, and fats must be
reconstructed so they can travel into vessels of the lymphatic system called
_______________________________.
7. A number of hormones control the secretions of digestive juices. _________________ is secreted in
response to protein in foods and enhances gastric gland output, while _____________ inhibits gastric
secretions. _________________ is secreted in response to acidic chyme. When fats are present in
chyme, __________________ triggers the release of bile from the gallbladder.
8. The large intestine functions to store and compact _________________. Unusual outgrowths of the
lining of the colon, called ___________________, can be either benign or cancerous. Colon cancer
incidence increases for people who do not have enough __________________ in their diet.
9. Pancreatic juice contains a mix of __________________ solution to neutralize stomach acid, and
digestive __________________ to further break down food.
10. The liver produces a greenish substance called ______________________, which is stored and
concentrated by the ____________________. The liver has been called the _____________ to the blood
because it detoxifies substances entering the blood from the ___________________.
11. ________________________ is a fat-digesting enzyme produced by the accessory organ, the
________________. Starch digestion begins in the _______________ with salivary _________ and
continues in the __________________ with pancreatic ____________________.
12. Protein digestion begins in the _________________ where the enzyme _________________ is
produced, and continues in the small intestine with the aid of the enzyme _________________ from the
pancreas.