ThinkRankNutrition in Animals
Animals cannot manufacture food from simple inorganic materials, so they obtain and digest food. Human nutrition involves ingestion, digestion, absorption, assimilation, and egestion. Different animals have different feeding structures and digestive processes suited to their food.
Learning Objectives
- •Sequence the main steps of human nutrition
- •Explain the roles of the mouth, stomach, small intestine, and large intestine
- •Relate teeth and feeding habits to the food an animal eats
- •Distinguish digestion from absorption and assimilation
Key Concepts
Digestion changes food
Large food molecules are broken into simpler soluble substances that the body can absorb and use.
The small intestine is central
Digested nutrients pass through its lining into the blood, while the liver and other organs help process absorbed nutrients.
Structures reflect diet
Teeth, beaks, tongues, and digestive systems differ because animals obtain and process different kinds of food.
Terminology
Historical Insight
Ruminants
Cows and buffaloes bring partially digested food back to the mouth for chewing again, a process called rumination.
Amoeba
Amoeba surrounds food with temporary extensions and digests it inside a food vacuole.
Quick Check
Why is chewing important?
Where does most absorption of digested food occur?
Why do ruminants chew cud?
How to use this lesson
Read the overview first, then explain the main idea in your own words before checking the key concepts. Use the quick-check questions without looking at the answer. For examination preparation, verify dates, definitions, and syllabus requirements against your official textbook and school or examination-board guidance.