Transcript How Nutrients Become You!

How Nutrients Become
You!
TEKS 1A, 1B, 2A, 2B, 2C
You are what you eat!
Food is your body’s fuel.
When you eat, your body breaks down
food and the nutrients it contains into
simpler elements.
Energy is released and nutrients are used
to help build, repair, and maintain body
cells.
6 Nutrient Groups
Carbohydrates
Fats
Proteins
Vitamins
Minerals
Water
Each one has a specific job to perform in
your body.
Nutrient Functions
Build and repair body tissues
Regulate all body processes
Provide energy
Build & Repair Body Tissues
Your body is made up of billions of cells
and these cells continually grow and
change to help repair damaged body
tissues and to replace old cells.
You need nutrients to do this job.
Regulate Body Process
The circulation of body fluids requires a
balance of essential nutrients.
Maintaining the correct acid-base level in
the blood is a function of nutrients.
Digestion, absorption, and metabolism rely
on proper nutrients.
Provide Energy
Food is to your body what gasoline is to a
car.
It is the source of energy for performance.
Energy is necessary for all life processes
to occur – to breathe, pump blood, move
muscles, and provide heat.
Kilocalories
A kilocalorie is the amount of heat needed
to raise one kilogram of water one degree
Celsius.
We often refer to them as just calories.
The Process of Digestion
Digestion is the process by which your
body breaks down food, and the nutrients
in food, into simpler substances.
The blood can then carry these simple
substances to cells for use in
growth, repair, and maintenance.
Digestion
It occurs through mechanical and chemical
means throughout the digestive system.
Mechanical digestion happens as food is
crushed and churned.
Chewing food is an observable form of
mechanical digestion.
Digestion
In chemical digestion, food is mixed with
powerful acids and enzymes.
Enzymes are a type of protein produced
by cells that cause specific chemical
reactions.
Digestive enzymes cause food particles to
break apart into simpler substances.
Gastrointestinal (GI) Tract
As food is digested, it passes through a
muscular tube leading from the mouth to the
anus.
This tube is called the GI tract.
The GI tract is 25 to 30 feet in length.
Each section performs important functions.
The Mouth
Food enters the GI tract through the
mouth.
Mastication
Mastication, or chewing, is the first step in
the digestive process.
The teeth and tongue work together to
move food and crush it into smaller pieces.
The process prepares food for swallowing.
The Tongue
You have about 9000 taste buds that cover
the surface of the tongue.
They sense the flavor in food.
This triggers salivary glands in your
mouth.
Saliva
Saliva is a mixture of about 99% water
plus a few chemicals.
One of these chemicals is an enzyme
called salivary amylase.
This enzyme is only found in the mouth
and helps chemically break down (digest)
the starches in foods.
Saliva
It plays other important roles in the
digestive process besides the breakdown
of starches.
Without saliva, your mouth is dry and food
seems to have little taste.
Saliva moistens, softens, and dissolves
food.
It also helps clean the teeth and neutralize
mouth acids.
The Esophagus
As you chew, the muscles of your mouth
and tongue form the food into a small ball.
The tongue moves the food particles to the
back of your mouth and you swallow.
As you swallow, food passes from the
mouth to the stomach through the
esophagus.
The Esophagus
The Esophagus
The esophagus is a tube about 10 inches
long.
It connects the mouth to the stomach
The Esophagus
The esophagus is one of two tubes in the
throat, the other is the trachea (windpipe).
When you swallow food, a flap of skin
called the epiglottis closes to keep food
from entering the trachea.
Breathing automatically stops when you
swallow food to help prevent choking.
Peristalsis
A series of squeezing actions by the
muscles in the esophagus, known as
peristalsis helps move food through the
tube.
Peristalsis is involuntary – you have no
control.
It occurs throughout the esophagus and
intestine to help mechanically move and
churn food.
In the Stomach
When you eat, the stomach produces
gastric juices to prepare for digesting the
food.
Gastric juices contain hydrochloric acid,
digestive enzymes, & mucus.
Gastric Juices
The mixture of gastric juices with chewed
and swallowed food combine in the
stomach.
This mixture is called chyme.
Mucosa
The stomach has a thick wall lining called
the mucosa.
The mucosa secretes mucus.
This is a thick fluid that helps soften and
lubricate food and it helps protect the
stomach from its strong acidic juices.
Protein Digestion
Protein digestion begins in the stomach.
The major gastric enzyme that begins to
chemically break down protein is pepsin.
Stomach
Most people can hold about 1 quart of
food in their stomachs.
Food generally remains in the stomach for
2 to 3 hours.
Liquids leave before solids.
Carbohydrates and proteins digest faster
than fats.
Now we travel to the small intestine.
Small Intestine
About 95% of digestion occurs in the small
intestine.
The small intestine is coiled in the
abdomen in circular folds
It has 3 sections
– Duodenum
– Jejunum
– ileum
Duodenum
The first section of the small intestine and
about 12 inches long
Jejunum
The middle section and about 4 feet long.
Ileum
The last section which is about 5 feet in
length
Food Travel
It takes 5 to 14 hours for food to travel
from the mouth through the small intestine.
Peristalsis helps move food through this
process.
The small intestine needs less acid than
the stomach to break down food.
The Pancreas
The pancreas, an elongated gland behind
the stomach, helps create the correct
environment.
It secretes bicarbonate, which neutralizes
hydrochloric acid that has come from the
stomach with the partially digested food.
The Pancreas
It also produces digestive enzymes that
aid in the chemical digestion that takes
place in the small intestine.
These enzymes break down proteins, fats,
and carbohydrates into their most basic
parts so your body can use them.
The Pancreas
Breaks down proteins into amino acids
Breaks down carbohydrates into
monosaccharides
Breaks down fats into fatty acids, glycerol,
and monoglycerides
Proteases
The enzyme that breaks down proteins
into amino acids
Lipases
Fat digesting enzymes which break down
fats into fatty acids, glycerol, and
monoglycerides
Saccharidases
Breaks down carbohydrates into
monosaccharides (also known as simple
sugars)
The Liver
Also involved in chemical digestion
It produces a digestive juice called bile
Bile aids in fat digestion and it helps disperse fat
in the water-based digestive fluids
Bile gives these fluid access to fats so they can
break it down
Bile is stored in the gallbladder and secreted into
the first part of the small intestine
Large Intestine
Sometimes called the colon
Measures about 3 ½ feet in length in your
body but about 5 or 6 feet if stretched out
Its main job is to reabsorb water
Absorption of Nutrients
Absorption is the passage of nutrients
from the digestive tract into the circulatory
or lymphatic system.
We will learn more about nutrients later in
this study.
Metabolism
Once nutrients are digested and absorbed,
the circulatory system takes over.
It carries nutrients and oxygen to individual
cells.
All the chemical changes that occur as
cells produce energy and materials
needed to sustain life are known as
metabolism.
Metabolism
Through metabolism, cells break down
some nutrients to release energy.
The body stores this energy as
ATP(adenosine triphosphate).
ATP is the source of immediate energy
found in muscle tissue
When the body needs energy, chemical
reactions break down ATP to release
energy.
Waste Products
Waste products leave the body through
the kidneys, lungs, and skin
Factors Affecting Digestion and
Absorption
Eating habits
Emotions
Food allergies
Physical activity
Lifestyle choices
Food Allergies
A food allergy is a reaction of the immune
system to certain proteins found in food.
The protein that stimulates the immune
system to produce antibodies is called an
allergen.
Digestive Disorders
Diarrhea
Constipation
Indigestion
Heartburn
Ulcer
Gallstones
diverticulosis
Diarrhea
Diarrhea is frequent expulsion of watery
feces.
Food sensitivity, harmful bacteria, and
stress are just a few of the factors that can
cause diarrhea.
Constipation
Constipation occurs when chyme moves
very slowly through the large intestine.
When this happens, too much water is
reabsorbed from the chyme and this
causes the feces to become hard.
Constipation can result from erratic eating
habits, low fiber intake, lack of physical
activity and drinking too little water.
Indigestion
Indigestion is a difficulty in digesting food.
It may be caused by stress, eating too
much or too fast, or eating particular
foods.
Heartburn
Heartburn is a burning pain in the middle
of the chest but it has nothing to do with
the heart.
It is caused by stomach acid flowing back
into the esophagus, known as reflux.
A more serious condition is called
gastroesophageal reflux.
Ulcer
An ulcer is an open sore in the lining of the
stomach or small intestine.
It is caused by bacterium
Gallstones
Gallstones are small crystals that form
bile in the gallbladder.
The presence of gallstones may slow fat
digestions and cause fluids to pool and
back up in the liver.
Diverticulosis
Diverticulosis is a disorder in which many
abnormal pouches form in the intestinal
wall.
When these pouches become inflamed,
the condition is called diverticulitis.
The best prevention is a high fiber diet