1. Allison Wetshtein Jessica Wetshtein
Ch 41 Animal Nutrition

2. Overview Herbivores- eat mainly autotrophs (plants and algae)
Nutrition- food being taken in, taken apart, and taken up
Herbivores- eat mainly autotrophs (plants and algae)
Carnivores- eat other animals
Omnivores- eat other animals
Animals must eat- balance, consumption, use, and storage

3. 41.1 An Animal’s diet must supply chemical energy, organic molecules, and essential nutrients
Energy from food powers cellular function
Food supplies organic carbon and nitrogen for the construction of organic molecules
Essential nutrients are the materials that an animal’s cells need but can’t synthesize
Three nutritional needs: chemical energy for cell processes, organic building blocks for carbohydrates and macromolecules, and essential nutrients

4. 41.1 cont.
Essential amino acids- amino acids must be obtained from food in prefabricated form
A diet low in amino acids causes and malnutrition called protein deficiency

5. Essential amino acids for humans
Methionine
Valine
Threonine
Phenylalanine
Leucine
Isoleucine
Tryptophan
Lysine
legumes
corn

6. 41.1 cont. Animals synthesize most fatty acids they need
Essential fatty acids- are certain unsaturated fatty acids that must be obtained from the diet

7. 41.1 cont.
Vitamins are organic molecules required in the diet in small amounts
Vitamins are grouped into two categories: fat-soluble and water-soluble
Minerals are simple inorganic nutrients, usually required in small amounts

8. 41.1 cont.
Undernourishment is the result of a diet that consistently supplies less chemical energy than the body requires
Malnourishment is the long-term absence from the diet of one or more essential nutrients

9. Ingestion is the act of eating
41.2 The Main Stages of food processing are ingestion, digestion, absorption, and elimination
Ingestion is the act of eating
Digestion is the process of breaking food down into molecules small enough to absorb
Absorption is uptake of nutrients by body cells
Elimination is the passage of undigested material out of the digestive compartment

10. small molecules
pieces of
food
chemical nutrient
mechanical digestion molecules
digestion enter body
cells
undigested material
1. Ingestion 2. digestion 3. absorption 4. elimination

11. 41.2 cont. Suspension Feeders
Many aquatic animals are suspension feeders, which sift small food particles from the water
Humpback whale

12. 41.2 cont. Substrate Feeders
Substrate feeders are animals that live in or on their food source
larva of a moth

13. 41.2 cont.
Fluid Feeders
Fluid feeders suck nutrient-rich fluid from a living host
mosquito

14. 41.2 cont.
Bulk Feeders
Bulk feeders eat relatively large pieces of food
python

15. 41.2 cont.
Food is processed in specialized compartments that reduce the risk of an animal digesting its own cells and tissue
This is either intracellular or extracellular

16. 41.2 cont.
In intracellular digestion, food particles are engulfed by phagocytosis and pinocytosis and digested within food vacuoles

17. 41.2 cont.
Extracellular digestion is the breakdown of food in compartments that are continuous with the outside of an animal’s body
It occurs in compartments that are continuous with the outside of the animal’s body
Animals with simple body plans have a gastrovascular cavity that functions in digestion and distribution of nutrients

18. Concept 41.3: Organs specialized for sequential stages of food processing form the mammalian digestive system
The mammalian digestive system consists of an alimentary canal and accessory glands that secrete digestive juices through ducts
Food is pushed along the alimentary canal by peristalsis, alternating waves of contraction and relaxation in the smooth muscles lining the canal
Sphincters, ringlike valves, regulate passage of material between compartments

19. 41.3 cont.
The oral cavity is the mouth and begins mechanical digestion
Salivary glands initiate chemical digestion
Amylase is the enzyme in saliva that hydrolyzes starch and glycogen
The tongue forms the food into a ball shape called a bolus and pushes it into the back of the mouth

20. 41.3 cont. The pharynx opens into the esophagus and stomach
The esophagus is attached to the stomach

21. 41.3 cont.
The stomach stores food and secretes gastric juice, which converts a meal to acid chyme
Gastric juice is made up of HCl and the enzyme pepsin
Chief cells release pepsinogen, which is inactive until activated by HCl to form pepsin
Mucus protects the stomach against self digestion

22. 41.3 cont. Hydrolysis of macromolecules occurs in the small intestine
The first 25 cm of 6 m is the duodenum where chyme mixes with stomach juices
The pancreas aid digestion by producing proteases trypsin and chymotrypsin, which neutralizes acidic chyme

23. 41.3 cont.
The liver produces bile which helps digestion and absorption of lipids
Bile is contained in the gallbladder
The liver breaks down toxins and red blood cells that no longer function

24. 41.3 cont.
The epithelial lining of the duodenum produces several digestive enzymes
The jejunum and ileum, the remaining regions of the small intestine, absorb nutrients and water

25. 41.3 cont.
The small intestine has a huge surface area, due to villi and microvilli
Villi are finger like projections and microvilli are on the villi
villus contains lacteal, a network of blood vessels and a small lymphatic vessel
Capillaries and veins from the villi all meet in the hepatic portal vein and carry blood to the liver and heart

26. The structure of the small intestine
Fig
The structure of the small intestine
Vein carrying blood to hepatic portal vein
Microvilli (brush border) at apical (lumenal) surface
Lumen
Blood capillaries
Epithelial cells
Basal surface
Muscle layers
Large circular folds
Epithelial cells
Villi
Lacteal
Key
Lymph vessel
Nutrient absorption
Villi
Intestinal wall

27. 41.3 cont.
The alimentary canal ends with the large intestine, including the colon, cecum, and rectum.
The cecum ferments ingested material
The colon leads the rectum and anus and recovers water
The rectum is the terminal portion of the large intestine, where feces are stored until eliminated

28. Mammals have adaptations associated with the animal’s diet
Concept 41.4: Evolutionary adaptations of vertebrate digestive systems correlate with diet
Mammals have adaptations associated with the animal’s diet
Evolution of animals’ teeth
is the reason they are
successful carnivore
herbivore
omnivore

29. 41.4 cont.
Length of the vertebrate digestive system correlates with diet
Herbivores and omnivores generally have longer alimentary canals than carnivores, because of the longer time needed to digest vegetation
Carnivore herbivore

30. 41.4 cont.
Digestive adaptations involve mutualistic symbiosis, benefitting both species involved
Ex. Koala have an enlarged cecum, where mutualistic bacteria ferment eucalyptus leaves

31. Concept 41.5: Homeostatic mechanisms contribute to an animal’s energy balance
Overnourishment, eating more calories than necessary, leads to obesity and diabetes, colon and breast cancer, and cardiovascular disease
Humans have homeostatic mechanisms that help regulate body weight
In our evolutionary past, having fat meant surviving