Digestive System - Intestines

Question 1

Small Intestine

Answer 1

Coiled tubular organ 6-7 m long
Peristalsis mixes food for 3-6 hours
Lipids, proteins, and carbohydrates are digested here

Question 2

Duodenum

Answer 2

Receives secretions from the liver, pancreas, and gallbladder that contain enzymes that aid in the breakdown of nutrients

Question 3

Jejunum and Ileum

Answer 3

Where absorption takes place (mainly ileum)
Filled with villi covered in microvilli that increases surface area of absorption by factor of 500

Question 4

Nutrients After Absorption (in Jejunum and Ileum)

Answer 4

After absorption:
Proteins and carbs enter bloodstream via capillary networks in villi, fats enter lymphatic system through lacteals (eventually end up in bloodstream)

Question 5

Large Intestine

Answer 5

All wastes move into large intestine; most contents are dead cells, mucus, digestive secretions, bacteria, and yeast. No digestion happens here, but the absorption of water and some vitamins does.

Question 6

Bacteria in the Large Intestine

Answer 6

A mutually beneficial relationship where the bacteria make compounds such as Vitamin K and B as well as aid in compacting undigested material into feces. Byproduct of bacterial action is gas.

Question 7

Rectum

Answer 7

Solids (feces) pass into rectum through peristalsis then eliminated from the body. It takes 12-24 hours for food to travel the entire digestive system.