4 GI Tract and Bioenergetics - KEVIN E CARPIO MS RND...

Info icon This preview shows pages 1–23. Sign up to view the full content.

D I G E S T I O N , A B S O R P T I O N , A N D M E TA B O L I S M O F N U T R I E N T S - 1 B I O E N E R G E T I C S - 2 KEVIN E. CARPIO, MS, RND
Image of page 1

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

Image of page 2
D I G E S T I O N The process of breaking down ingested food through mechanical and enzymatic activity so that it can be absorbed by the body. The process of breaking down food in preparation for absorption by cells in the GI tract.
Image of page 3

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

T H E D I G E S T I V E S Y S T E M A long, flexible muscular tube that extends from the mouth, to the esophagus, stomach, small intestine, large intestine, and rectum to the anus. Also called the gastrointestinal tract (GI Tract)
Image of page 4
Image of page 5

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

Image of page 6
The process of digestion begins in the mouth (oral cavity) During chewing, large pieces of food are crushed into smaller ones. Fluids also stimulate the tongue to taste the food.
Image of page 7

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

Image of page 8
The bolus of food is then swallowed and passes into the esophagus, a tube leading to the stomach. The bolus slides down and the lower esophageal sphincter (LES) The LES closes so that the bolus and stomach contents do not flow back to the esophagus
Image of page 9

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

Image of page 10
Little by little, the stomach transfer food to its lower portion, adds juices to it, and grinds it into a semi-solid mass called chyme After the bolus slides down the LES, it now enters the stomach
Image of page 11

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

This digestive process continues for roughly an hour before food begins to exit the stomach Bit by bit, the stomach releases chyme through the pyloric sphincter which leads into the small intestine.
Image of page 12
Image of page 13

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

Image of page 14
The chyme first enters the duodenum. Duodenum = where the chyme is mixed with digestive enzymes from the pancreas and gallbladder. Much of the digestion of foodstuffs is completed in the duodenum, making the food ready for ABSORPTION
Image of page 15

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

A B S O R P T I O N Most nutrients are absorbed in the small intestine. Those that cannot be absorbed (undigested) pass into the large intestine. The inner surface of the small intestine looks smooth and slippery , but when viewed through a microscope, it turns out to be wrinkled into hundreds of folds .
Image of page 16
A B S O R P T I O N
Image of page 17

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

W H AT H A P P E N S T O T H E U N D I G E S T E D PA R T O F T H E F O O D ? After travelling down the 3 parts of the small intestine, the remainder of the undigested, unabsorbed food contents arrive at the large intestine , where it is to be excreted Undigested food - foods high in fiber
Image of page 18
Passage of the intestinal contents along the GI tract slows in the large intestine, normally taking 18 to 24 hours to pass through.
Image of page 19

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

Fiber is a type of carbohydrate that the body can't digest
Image of page 20
This is the end of the preview. Sign up to access the rest of the document.
  • Fall '15
  • energy systems

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern