Transcript The Digestive and Excretory Systems

The Digestive and
Excretory Systems
Journal 3-9
What do you know
about the digestive
system? List at least
5 items.
Write 2 questions
about digestive system
that you don’t know
the answer to, but like
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 your bloodstream.
 Your 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
 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.
 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 that break down the food into tiny
particles.
 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.
Small Intestine
 Bile:
• 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.
The Helper Organs
of the Digestive
System
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.
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.
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