Transcript Nutrient Absorption

Nutrient Absorption
How many different
systems do you see?
1.Digestive-Breaks
down and absorbs
nutrients
2. Respiratoryabsorbs oxygen
3. Circulatory –
transports nutrients
C6H12O6 + 6O2
glucose + oxygen
6 CO2 + 6H2O + 36 ATP
carbon dioxide + water + energy
1. Where does the glucose come from?
Food
2. Where does the oxygen come from?
Breathing
3. What are the final products of cellular respiration?
CO2, H2O, ATP
4. In which organelle does this take place in our cells?
Mitochondria
Evolutionary Trends of the Digestive System
Types of digestive
Filter feeder
systems:
Digestive cavity:
Digestive tract:
1 opening
2 openings
(Gastrovascular cavity)
Description of system
Aquatic animals that
Digestive chamber with
strain tiny floating
food entering and waste
organisms from water
exiting through one
2 openings: mouth,
anus.
opening.
Picture of system
Jellyfish, Sea Anemone,
Examples
Sponges
Snails, oysters, squid,
Corals, Portuguese Man-of- octopus, starfish, sand dollar,
War, Planaria (flatworm)
crayfish, spiders, crabs,
butterflies, humans
Human Digestive System
Purpose: converts food into simpler molecules that can be
used by the cells of the body; absorbs food and eliminates
waste
Parts of the System:
∙ mouth
∙ pharynx
∙ esophagus
∙ stomach
∙ small intestine
∙ large intestine
∙ rectum/colon
∙ accessory organs include the salivary glands, liver, gall bladder,
pancreas
How the Digestive System Works
∙ Digestion begins in the mouth
o chemical digestion – salivary glands produce
amylase which begins to break down sugars
and starches
o mechanical digestion – teeth grind and break
down food into smaller pieces
∙ Esophagus – moves food from mouth to stomach
using peristalsis.
(smooth muscle contractions)
stomach – food is combined with acids and
enzymes (chemical digestion); the stomach muscles
squeeze and contract (mechanical digestion)
• small intestine – absorption of food molecules takes
place here
o inner surface of small intestine heavily folded and lined with
small finger-like projections called villi
o this creates a large surface area for nutrient absorption
∙ large intestine – absorbs water and compacts
waste
∙ rectum/anus – releases wastes outside the body
∙ Smooth muscle lining the digestive organs moves food
through in a one-way direction (peristalsis)
Click on picture
Accessory organs of the digestive system:
∙ pancreas
o Produces insulin to regulate
blood sugar levels
o Produces enzymes that break
down carbohydrates, proteins,
lipids and nucleic acids
∙ liver
o Produces bile, aids in the
digestion of fats
o Bile is stored in a pouch under
the liver, the gall bladder
Digestive System
Levels of Organization
epithelium, villi, smooth muscle
Mouth, esophagus, stomach, small & large intestines
digestive