Download Chapter 30 – Digestive and Excretory Systems

Chapter 30 – Digestive and
Excretory Systems
Let’s hear from Tim and Moby
• http://www.brainpop.com/health/digestives
ystem/digestivesystem/
Foods – these are necessary
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Carbohydrates
Fats
Proteins
Vitamins
Minerals
water
Human Digestive System
Break it on down.
• The breaking down of food
occurs two ways in the
digestive system. Physicalyour teeth chew food so you are
able to swallow it. Chemicalchanges actually change food in
to different substances.
Digestion starts in the mouth
• Saliva starts mixing food
with saliva
- saliva comes from salivary
glands in the cheeks and
under the tongue.
- saliva moistens food,
mixes food with mucus, and
adds enzymes that break down
starch into sugars.
•Saliva -Made by the
salivary glands in the
mouth; it is an enzyme
that begins the
chemical digestion of
carbohydrates.
•Amylase- an enzyme
in saliva and
pancreatic juice that
breaks down starch
into simple sugars.
Teeth carry out mechanical
digestion
• Take care of your teeth
Swallowed food passes into the
esophagus then the stomach
•Peristalsis- the rhythmic
muscles contraction that
forces the food into the
digestive system.
–This occurs in the espophagus,
stomach, small intestine, large
•Chyme- the soupy
mixture of food and
digestive enzymes in
the stomach.
•Pepsin-stomach
enzyme that
digests protein.
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ystem/digestion/
•Duodenum- the first
short section of the
small intestine
immediately beyond the
stomach.
• Villi-Fingerlike projection
located in the lining of the
small intestine. They are
covered with nutrient
absorbing cells that passes
nutrients to the blood
stream.
•Bile- made by the liver
and stored in the
gallbladder; it helps to
break down large fat
droplets into smaller
ones.
•Colon-the section of
the large intestine that
runs from the cecum
to the rectum.
•Rectum- it store the
feces and the lower part
of the large intestine,
between the colon and
the anal canal.
Digestive system problems:
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Food poisoning
Parasites such as worms
Viral infections (hepatitis)
Eating disorders (anorexia and bulimia)
Diarrhea and constipation
Flatulence! (excuse me!)
The End