Class Notes (809,049)
Canada (493,506)
BIOA01H3 (687)


4 Pages
Unlock Document

University of Toronto Scarborough
Biological Sciences
Mark Fitzpatrick

Digestion System For breaking down food into smaller molecules so they can be diffused and absorbed into the body in a 24-33 hour process through Mechanical and chemical digestion. Structure Mouth- grinds food Tongue- keeps food in place, taste, move food to rear of mouth and creates ball of food Uvula- ball like structure, prevent entrance to pharynx when we swallow Saliva Glands (Parotid, Sublingual, Submandibular): excretes saliva -neutralizes PH to 7 with buffers -Antibacterial agent -salivary amalyse to break carbs -lubrication -Mucin protects mouth lining Esophagus: tub lubricated with mucin -muscle and mucin help push food down through peristalsis -Peristalsis involves circular and longitudinal smooth muscles that surround the digestive tract and to move food the circular muscles over a food mass relaxes while the longitudinal muscles immediately in front of it contracts and the circular muscles immediately behind the food mass then contracts while the longitudinal relax as muscular regions relax and contract food is pushed along. Stomach: Inner folds called Ruggae increase surface area -Gastric Glands release Gastric Juice (acid of ph 2) -Kills bacteria -Breaks cell matrix that glues cells together -Pyloric Sphincter opens way out the stomach -Churns food into Chyme fluid to be taken out -Elasticity helps it expand -Cardiac Orfice opens to the stomach Small Intestine: Duodenum: Opening of small intestine (first 30cm) -Most folds, villi, and microvilli to absorb nutrients -Intestinal juices chemically continue to break down food Jejenum: meters long. -Breaks own protein and carbs Illeum: contains fewer and smaller villi, absorbs rest of nutrients Large Intestine: absorbs water and minerals -Caecum: closed end of large intestine -Appendix: hangs separately to kill off disease -Colon: main part of intestine (transverse, Ascending, descending) Rectum: canal leading to anus (opening for feces to be excreted) Macronutrients: large quantities, large molecules into sub unit
More Less

Related notes for BIOA01H3

Log In


Don't have an account?

Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.