Human Nutrition and Digestion Overview

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Questions and Answers

What is a primary function of the colon?

Reabsorb water (correct)

Store bile

Produce insulin

Absorb nutrients from food

Which of the following statements about the caecum and appendix is true?

They aid in the digestion of proteins.

They have essential digestive functions in humans.

They are considered vestigial organs. (correct)

They are primarily responsible for vitamin absorption.

What role do symbiotic bacteria in the colon play?

They synthesize amino acids from glucose.

They produce digestive enzymes.

They compete with pathogenic bacteria. (correct)

They facilitate protein metabolism.

Which of the following enzymes is not produced in the pancreas?

Pepsin Signup and view all the answers

Which of the following best describes a heterotroph?

An organism that cannot create its own food. Signup and view all the answers

What is the primary function of amylase in the mouth?

Digestion of carbohydrates Signup and view all the answers

Which type of tooth is responsible for gripping and tearing food?

Canine Signup and view all the answers

What is the main role of hydrochloric acid in the stomach?

Activating pepsinogen Signup and view all the answers

What does peristalsis refer to?

Contraction and relaxation of muscles Signup and view all the answers

Which component prevents the stomach from digesting itself?

Mucous Signup and view all the answers

What is formed when pepsinogen is activated?

Pepsin Signup and view all the answers

What is the role of fiber in digestion?

Stimulates peristalsis Signup and view all the answers

The final mixture of food and gastric juices in the stomach is known as?

Chyme Signup and view all the answers

What is the primary function of the duodenum?

Digestion and neutralization Signup and view all the answers

Which substance is secreted by the pancreas into the duodenum?

Pancreatic juice Signup and view all the answers

What role does bile play in the small intestine?

Emulsifies lipids and neutralizes chyme Signup and view all the answers

What is the primary adaptation of the ileum for nutrient absorption?

Presence of vili and microvilli Signup and view all the answers

What type of system is the hepatic portal system?

A blood pathway that starts and ends in capillaries Signup and view all the answers

How do villi in the ileum facilitate the absorption of nutrients?

By increasing surface area Signup and view all the answers

What is produced by the liver and stored in the gall bladder?

Bile Signup and view all the answers

Which type of nutrient is absorbed by the lacteal in the villus?

Fatty acids and glycerol Signup and view all the answers

Study Notes

Human Nutrition

Nutrition is the process by which an organism obtains and uses food.
Digestion breaks down food for solubility and transport.

Digestion in the Mouth

Physical digestion occurs through teeth and tongue.
Chemical digestion uses amylase in saliva.
Humans have four types of teeth with specific functions: incisors, canines, premolars, molars.
Human dental formula for an adult is 2,1,2,3/2,1,2,3

Oesophagus

A muscular tube that carries food to the stomach via peristalsis.
Peristalsis involves rhythmic muscle contractions.
The epiglottis prevents food from entering the trachea.

Stomach

A muscular bag that stores and digests food.
Physical digestion: Churning.
Chemical digestion: Hydrochloric acid, pepsinogen, and mucous.
Hydrochloric acid kills microorganisms, loosens fibrous foods, and activates pepsinogen to pepsin.
Pepsin is an enzyme that breaks down proteins.
Chyme is the mixed liquid product of stomach churning.
Chyme passes into the duodenum, a part of the small intestine.

Small Intestine

Composed of duodenum and ileum.
Duodenum: Location of chemical digestion from liver and pancreas.
Ileum: Nutrient absorption.
Liver: produces bile; is under the diaphragm; stores glycogen.
Bile: Emulsifies fats (increases their surface area), neutralizes chyme.
Gall bladder: Stores bile.
Pancreas: Produces pancreatic juice, containing sodium bicarbonate (neutralizes chyme) and enzymes (lipase and amylase).
Pancreatic juice: Breaks down lipids and starches.

Ileum (Small Intestine)

Absorbs nutrients into bloodstream.
Villi and microvilli increase surface area for absorption; rich blood supply.
Lacteals absorbs fatty acids and glycerol.
Nutrients are carried to the liver by the hepatic portal vein.

Large Intestine

Consists of caecum, appendix, colon, and rectum.
Colon: Reabsorbs water, produces vitamins B & K (due to symbiotic bacteria), and eliminates undigested waste.
Symbiotic bacteria benefit from undigested waste.
Heterotrophs: Can't make their own food (herbivores, carnivores, omnivores).

Enzymes

Amylase: Breaks down starch to maltose (in mouth and duodenum).
Lipase: Breaks down lipids (fats) to glycerol and fatty acids (in duodenum).
Pepsin: Breaks down proteins to peptides (in stomach).

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Description

Explore the fascinating process of human nutrition and the stages of digestion. From the mechanics of the mouth to the chemical breakdown in the stomach, this quiz covers the essential aspects of how our bodies process food. Test your knowledge on teeth types, digestion methods, and the function of the oesophagus.