AMINA RADIYAATHENA

CHARISHMA ZOE DEVANGIKA

FARZANA FIROSHFATHIMA LINSHA

FAUZIA ASHRAF ALI

BIOLOGY PRESENTATION

TOPIC :NUTRITION

MEMBERS

TOPICS AND THEIR PRESENTERS

INTRODUCTION-AMINA RADIYA

AUTOTROPHIC NUTRITION-ATHENA.S AND CHARISHMA ZOE

HETEROTROPHIC NUTRITION-DEVANGIKA. S

AMOEBA NUTRITION-FAUZIA AHRAF

NUTRITION IN HUMAN BEINGS –FARZANA FIROSH AND FATHIMA LINSHA

DEFINITION… • Digestion is the process in which the body breaks down food into molecules that can be used for nourishment.

• The stomach is not the only organ involved in the digestion process.

• A series of organs comprise the human digestive tract, including the mouth, esophagus, stomach, small intestines, liver and large intestine.

• Each organ in the digestive tract plays an integral part in the digestive process.

DID YOU KNOW THAT THE PROCESS OF DIGESTION STARTS EVEN BEFORE YOU TAKE IN THE FOOD TO YOUR MOUTH ?? GUESS HOW ………..??

FROM MOUTH TO THE ESOPHAGUS….• Compounds and enzymes begin to break

down food once it enters your mouth. • Once food is chewed, it is swallowed and it

enters your esophagus.

• The saliva contains an enzyme called the salivary amylase that breaks down starch into sugars .

• The food is mixed thoroughly with the muscular tongue.

• The food is moved through the esophagus in a regulated manner so that it process properly in each part .

• The esophagus is a muscular tube that carries chewed food to the stomach.

• The process of transporting food to the stomach via the esophagus requires a series of muscle contractions known as peristalsis.

DIGESTION….• From the mouth the food is taken to the

stomach through the food pipe .• The stomach is a large organ which

expands when food enters it . The muscular walls of stomach help in mixing the food thoroughly with more juices.

• Gastric glands are responsible for digestive functions

• These release hydrochloric acid , an enzyme pepsin and mucus. The hydrochloric acid creates an acidic medium which facilitates the action of pepsin.

• The mucus protects the inner lining of the stomach from the action of the acid under normal conditions

SMALL INTESTINE• The exit of food from the stomach is

regulated by a sphincter muscle which releases it in small amounts into the small intestine.

• The small intestine is approximately 17 feet long and divided into three sections: the duodenum, the jejunum and the ileum.

• Foods from the stomach enters the duodenum where bile and pancreatic secretions are released to further break down the food.

• When digested food reaches the final part of the small intestine, the nutrients from the food are absorbed into the bloodstream and sent to the liver where they will be stored or sent to other parts of the body.

• The inner lining of the small intestine contains many finger like projections called villi which increase the surface area for absorption.

• The liver, gallbladder and pancreas play vital roles in the digestive process even though they are technically not part of the digestive tract.

• The liver produces bile, which is an essential compound for the body to absorb fats.

• The pancreas secretes pancreatic juice like trypsin for digesting proteins and for breaking down emulsified fats.

• The liver's main job is to filter the blood coming from the digestive tract, before passing it to the rest of the body.

• The liver also detoxifies chemicals and metabolizes drugs. As it does so, the liver secretes bile that ends up back in the intestines.

• The liver also makes proteins important for blood clotting and other functions.

LIVER, GALL BLADDER AND PANCREAS

LARGE INTESTINE• The colon is the last part of

the digestive system in most vertebrates.

• It extracts water and salt from solid wastes before they are eliminated from the body .

• Unlike the small intestine, the colon does not play a major role in absorption of foods and nutrients.

• About 1,500 milliliters or 45 ounces of water arrives in the colon each day.

• The rest of the waste material is remove from the body via anus .

AMAZING FACTS• The average human being has over 400 different species of bacteria in their colon• It takes approximately seven seconds for food to travel through the esophagus and reach

the stomach.• An adult female’s small intestine is longer than the average adult male’s• Paul Hun, who lives in London, holds the world record for the loudest human burp. The

liver has over 500 different functions, one of which is producing bile to break down digestive fats

• The stomach of an adult holds up to 1.5 liters of food and food stays here for 2 to 3 hours• Although the large intestine is up to 4 inches in diameter, the small intestine is only 1 inch

in diameter• The approximate surface area of the small intestine is 2,700 feet; That’s over half the size of

a basketball court!• Hydrochloric acid, produced by the stomach, can dissolve metal but has no effect on plastic• Estimates of how much saliva our bodies produce each day range from 1 to 3 liters• The whole digestive tract is over 29 feet long, starting at the mouth and ending at the anus• The stomach wall has three layers of muscles• Food is cooled or warmed in the mouth until it is a good temperature for the body• The large intestine is approximately 5 feet in length• Muscles contract and relax in the esophagus to push food down to the stomach — it works

even when you’re upside down!