topic 2

Question 1

Digestion

Answer 1

The process of breaking down foods into nutrients to prepare for absorption.

Question 2

Absorption

Answer 2

The uptake of nutrients by the cells of the small intestine for transport into either the blood or lymph.

Question 3

Digestive System

Answer 3

All the organs and glands associated with the ingestion and digestion of food.

Question 4

Gastrointestinal (GI) Tract

Answer 4

The flexible muscular tube extending from the mouth to the anus.

Question 5

Lumen

Answer 5

The inner space of the GI tract, continuous from one end to another.

Question 6

Mouth function (Digestion)

Answer 6

Chews and mixes food with saliva; Carbohydrate digestion begins (starch-digesting enzymes in saliva).

Question 7

Stomach function (Digestion)

Answer 7

Adds acid, enzymes, and fluid; churns, mixes, and grinds food to a liquid mass; Protein digestion begins.

Question 8

Small Intestine function (Digestion)

Answer 8

Secretes enzymes that digest all energy-yielding nutrients; cells of the wall absorb nutrients into blood and lymph.

Question 9

Large Intestine (Colon) function (Digestion)

Answer 9

Reabsorbs water and minerals; passes waste (fiber, bacteria, and unabsorbed nutrients) along with water to the rectum.

Question 10

Liver function (Digestion)

Answer 10

Manufactures bile salts (detergent-like substances) to help digest fats.

Question 11

Gallbladder function (Digestion)

Answer 11

Stores bile until needed.

Question 12

Pancreas function (Digestion)

Answer 12

Manufactures enzymes (carbohydrase, lipase, protease) to digest all energy-yielding nutrients and releases bicarbonate to neutralize acid chyme.

Question 13

Diaphragm

Answer 13

Muscle that separates the abdomen from the thoracic cavity (upper half of the major body cavity from the lower half).

Question 14

Sphincters (Esophageal and Pyloric) function

Answer 14

Allow passage of food and prevent backflow.

Question 15

Bile function

Answer 15

Produced by the liver and stored in the gallbladder; acts as an emulsifier to suspend fat in watery digestive fluids.

Question 16

Saliva composition/function

Answer 16

Secrete saliva (moistens food) that contains starch-digesting enzymes.

Question 17

Gastric Juice composition/function

Answer 17

From gastric glands; includes hydrochloric acid (low pH, highly acidic).

Question 18

Goblet Cells function

Answer 18

Secrete mucus to protect the walls of the stomach from the high acidity levels of the gastric juice.

Question 19

Pancreatic Juice composition/function

Answer 19

Contains intestinal enzymes (carbohydrase, lipase, protease) and bicarbonate.

Question 20

Nutrients absorbed directly into Hepatic Portal Vein

Answer 20

Sugars (from bananas), small fragments of Starch and Protein.

Question 21

Nutrients absorbed into Lymph (eventually to bloodstream)

Answer 21

Small fragments of Fat.

Question 22

Fate of Undigested Residues

Answer 22

Including some fibers, they continue through the digestive tract and form stool (feces); some are partly digested by bacteria in the large intestine.

Question 23

Factor that facilitates Nutrient Absorption

Answer 23

The enormous surface area of the small intestine.

Question 24

Simple Diffusion mechanism/example

Answer 24

Nutrients (like water and small lipids) cross into intestinal cells freely (no carrier, no energy).

Question 25

Facilitated Diffusion mechanism/example

Answer 25

Nutrients (like **water-soluble vitamins**) need a **specific carrier** to transport them (no energy required).

Question 26

Active Transport mechanism/example

Answer 26

Nutrients (like **glucose and amino acids**) move against a concentration gradient, which **requires energy** and a specific carrier.