Download The Digestive System

Warm-Up in spiral
 What is the
difference between
mechanical and
chemical
digestion?
The
Digestive
System
Three
functions &
processes
of the
digestive
system…
Digestion=>
Body
breaks
down
food.
Absorption=>
Food molecules
enter the blood
& are carried to
cells.
Elimination=>
Wastes
pass out
of the
body.
Two kinds of
digestion…
Mechanical
digestion…
food is physically
broken down into
smaller pieces by
chewing & churning.
Chemical
digestion…
food is chemically
broken into
smaller molecules
by enzymes.
Enzymes…
Proteins that speed
up chemical
reactions in the
body. (saliva,
pepsin,
hydrochloric acid)
Organs food pass through…
Mouth=> Esophagus=>
Stomach=>
Small intestine=>
Large intestine=>
Rectum=> Anus
Accessory organs that
aid in digestion…
Liver & gall
bladder
Pancreas
The Path and Processes
Mouth…
mechanical
digestion=> teeth
chemical
digestion=> saliva
Esophagus…
muscular
tube that
connects the
mouth to the
stomach
Peristalsis…
Involuntary smooth
muscle contractions
move food in one
direction through the
digestive system
(unless vomiting due to
homeostasis!).
Stomach…
Muscular pouch in the
abdomen…
mechanical digestion=>
churning
chemical digestion=>
pepsin & hydrochloric
acid
 During digestion, the human
body must use mechanical and
chemical energy to breakdown
compounds.
 The chemical energy in these
compounds can then be used
or transferred into thermal
energy (to increase body
temperature) or mechanical
energy (to grow or to move).
Mucus
protects your
stomach lining
from being
digested.
Small
intestine…
Most chemical
digestion & absorption
of nutrients into the
blood stream occurs
here.
Food mixes with
enzymes &
chemicals secreted
into the small
intestine by the
liver (gall bladder)
& pancreas.
Villi…
millions of tiny finger
shaped structures that
line the walls of the
small intestine to
provide more surface
area for nutrient
absorption into
bloodstream.
Liver…
produces bile to
physically break
down fats (like dish
soap on grease).
Gall bladder…
stores bile
produced by the
liver & passes it
into the small
intestine.
Pancreas…
produces enzymes
that flow into the
small intestine &
help complete
chemical digestion.
Pancreas…
Helps to maintain
homeostasis by
insulin production that
controls blood sugar
levels
Large intestine…
water is absorbed into
the blood stream &
the remaining fiber &
undigested food is
prepared for
elimination.
Rectum…
short section at
the end of the
large intestine
where waste is
compressed into
solid form.
Anus…
muscular opening
at the end of
the rectum
where wastes
exit the body.
Organic Compounds
 Compounds containing
carbon and other elements
such as hydrogen, oxygen,
phosphorus, nitrogen, or
sulfur.
 Come from living material
such as plants and animals.
Carbohydrates
 Starches and sugars are a
source of energy
Examples
 potatoes, fruits, cereal,
flour, pastas
Carbohydrates
Mechanical Digestion
 Chewed and broken into smaller
pieces; moved down the digestive
tract through peristalsis
Chemical Digestion
 Digestive enzymes in the mouth,
stomach, and small intestine break
bonds so that carbohydrate become
simple sugars
Proteins
 Build new cells (muscle, skin,
hair) and repair damaged
cells
Examples
 meats, eggs, peanuts, beans
Proteins
Mechanical Digestion
 Chewed and broken into smaller
pieces; moved down the digestive
tract through peristalsis
Chemical Digestion
 Digestive enzymes in the stomach
and small intestine break peptide
bonds so that proteins become amino
acids
Lipids
 Energy, insulation, and
essential building block for
cells
Examples
 fats, oils
Lipids
Mechanical Digestion
 Chewed and broken into smaller
pieces; moved down the digestive
tract through peristalsis
Chemical Digestion
 Digestive enzymes in the mouth,
stomach, and small intestine break
bonds so that lipids become fatty
acids and glycerol