Transcript The Digestive and Excretory Systems

The Digestive and
Excretory Systems
DQ#27
What do you know
about the digestive
system? List at least
5 items.
Write 2 questions
about the digestive
system that you don’t
know the answer to,
but want to learn
about it.
What is Digestion
Digestion is the process which
takes food and breaks it down into
small pieces so it can be absorbed
into bloodstream.
The Digestive System is a group of
organs that work together to
digest foods.
Types of Digestion
There are two types of
Digestion:
• Chemical Digestion-Foods
are broken down with the
help of chemicals.
• Mechanical- Foods are
physically broken down into
smaller pieces.
The Mouth
Digestion begins in the MOUTH
through both chemical and
mechanical digestion.
Mechanical Digestion – Teeth
physically break down food
particles into small pieces.
The Mouth
Chemical Digestion – Salivary
glands secrete Saliva in the
mouth which begins to digest
starches.
Food is swallowed and moves
into the ESOPHAGUS where it
is pushed into the stomach.
Stomach
The stomach also does both
mechanical digestion and chemical
digestion.
Mechanical digestion -The stomach
churns the food, breaking it down
into small particles.
Chemical -many chemicals are
secreted into the stomach to break
down the food into tiny particles.
Small Intestine
 The SMALL INTESTINE is a
LONG, coiled tube (about 20
feet long).
 Small fingerlike projections
called VILLI cover the walls of
the small intestine.
 The villa absorb the nutrients
from the food, and pass them
onto the bloodstream.
The Helper Organs
 Bile:
of the Digestive
System
• The LIVER produces bile
• GALLBLADDER stores bile.
• Bile is secreted into the
small intestine to help
digest fats
 Enzymes:
• The PANCREAS secretes
juices into the small
intestine that help break
down proteins,
carbohydrates, and fats.
Solid Waste
 Some of the foods that are
not completely absorbed by
the body, like fiber,
produce solid waste which
is then stored in the colon.
After most of the water is
absorbed by the body, the
waste is called FECES, and
is excreted through the
anus.
Removing Wastes from the
Body
 Your Excretory System removes all
waste from your body and controls
water balance.
 The three types of waste produced
by the body are solids, liquids and
gases.
 The digestive system is responsible
for producing liquid and solid wastes.
Liquid Waste
 KIDNEYS filter water and waste
from the blood.
 The substance secreted by the
kidneys is called urine, and it is sent
to the bladder.
 Urine is excreted from the body
through the URETHRA