Chapter 41
Animal Nutrition
Teaching Objectives
Nutritional Requirements of Animals
1.Compare the bioenergetics of animals when energy balance is positive and when it is negative.
2.Name the three nutrition needs that must be met by a nutritionally adequate diet.
3.Distinguish among undernourishment, overnourishment, and malnourishment.
4.Explain why fat hoarding may have provided a fitness advantage to our hunter-gatherer ancestors.
5.Explain the role of leptin in the regulation of fat storage and use.
6.Define essential nutrients and describe the four classes of essential nutrients.
7.Distinguish between water-soluble and fat-soluble vitamins.
Overview of Food Processing
8.Define and compare the four main stages of food processing.
9.Compare intracellular and extracellular digestion.
The Mammalian Digestive System
10.Describe the common processes and structural components of the mammalian digestive system.
11.Name three functions of saliva.
12.Compare where and how the major types of macromolecules are digested and absorbed within the mammalian digestive system.
13.Explain why pepsin does not digest the stomach lining.
14.Explain how the small intestine is specialized for digestion and absorption.
15.Describe the major functions of the large intestine.
Evolutionary Adaptations of Vertebrate Digestive Systems
16.Relate variations in dentition and length of the digestive system to the feeding strategies and diets of herbivores, carnivores, and omnivores.
17.Describe the roles of symbiotic microorganisms in vertebrate digestion.
Student Misconceptions
1.Students may have difficulty understanding that many features of human anatomy and physiology can be understood as adaptations to the selective pressures faced by our hunter-gatherer ancestors. Human fat hoarding and preference for high-salt foods are deadly today, but likely gave our ancestors a fitness advantage.
2.Students may not realize that essential nutrients vary from organism to organism, depending on their individual biosynthetic capabilities.
3.Point out to your students the enormous numbers—and important roles—of symbiotic bacteria in the human colon.
Chapter Guide to Teaching Resources
Overview: The need to feed
Instructor and Student Media Resources
Activity: Feeding mechanisms of animals
Video: Whale eating a seal
Video: Lobster mouth parts
Video: Paramecium vacuole
Video: Paramecium cilia-V
Concept 41.1Homeostatic mechanisms manage an animal’s energy budget
Transparencies
Figure 41.3Homeostatic regulation of cellular fuel
Figure 41.5A few of the appetite-regulating hormones
Concept 41.2An animal’s diet must supply carbon skeletons and essential nutrients
Transparencies
Figure 41.10Essential amino acids from a vegetarian diet
Table 41.1Vitamin requirements of humans
Table 41.2Mineral requirements of humans
Student Media Resource
Activity: Analyzing food labels
Concept 41.3The main stages of food processing are ingestion, digestion, absorption, and elimination
Transparencies
Figure 41.12The four stages of food processing
Figure 41.13Digestion in a hydra
Figure 41.14Variation in alimentary canals
Instructor and Student Media Resource
Video: Hydra eating Daphnia
Concept 41.4Each organ of the mammalian digestive system has specialized food-processing functions
Transparencies
Figure 41.15The human digestive system
Figure 41.16From mouth to stomach: The swallowing reflex and esophageal peristalsis (layer 1)
Figure 41.16From mouth to stomach: The swallowing reflex and esophageal peristalsis (layer 2)
Figure 41.16From mouth to stomach: The swallowing reflex and esophageal peristalsis (layer 3)
Figure 41.17The stomach and gastric juice
Figure 41.19The duodenum
Figure 41.20Protease activation
Figure 41.21Flowchart of enzymatic digestion in the human digestive system
Figure 41.22Hormonal control of digestion
Figure 41.23The structure of the small intestine
Figure 41.24Digestion and absorption of fats
Student Media Resources
Activity: Digestive system function
Investigation: What role does amylase play in digestion?
Activity: Hormonal control of digestion
Concept 41.5Evolutionary adaptations of vertebrate digestive systems are often associated with diet
Transparencies
Figure 41.26Dentition and diet
Figure 41.27The digestive tracts of a carnivore (coyote) and herbivore (koala) compared
Figure 41.28Ruminant digestion
For additional resources such as digital images and lecture outlines, go to the Campbell Media Manager or the Instructor Resources section of
Key Terms
absorption
acid chyme
alimentary canal
appendix
bile
bolus
bulk feeder
carnivore
cecum
chylomicron
colon
complete digestive tract
digestion
duodenum
elimination
enzymatic hydrolysis
epiglottis
esophagus
essential amino acid
essential fatty acids
essential nutrient
extracellular digestion
feces
fluid feeder
gallbladder
gastric juice
gastrovascular cavity
hepatic portal vein
herbivore
ingestion
intracellular digestion
lacteal
large intestine
liver
malnourished
microvillus
mineral
omnivore
oral cavity
overnourishment
pancreas
pepsin
pepsinogen
peristalsis
pharynx
pyloric sphincter
rectum
ruminant
salivary amylase
salivary glands
small intestine
sphincter
stomach
substrate feeder
suspension feeder
undernourishment
villus
vitamin
Word Roots
chylo- 5 juice; -micro 5 small (chylomicron: small globules composed of fats that are mixed with cholesterol and coated with special proteins)
chymo- 5 juice; -trypsi 5 wearing out (chymotrypsin: an enzyme found in the duodenum; it is specific for peptide bonds adjacent to certain amino acids)
di- 5 two (dipeptidase: an enzyme found attached to the intestinal lining; it splits small peptides)
entero- 5 the intestines (enterogastrones: a category of hormones secreted by the wall of the duodenum)
epi- 5 over; -glotti 5 the tongue (epiglottis: a cartilaginous flap that blocks the top of the windpipe, the glottis, during swallowing)
extra- 5 outside (extracellular digestion: the breakdown of food outside cells)
gastro- 5 stomach; -vascula 5 a little vessel (gastrovascular cavities: an extensive pouch that serves as the site of extracellular digestion and a passageway to disperse materials throughout most of an animal’s body)
herb- 5 grass; -vora 5 eat (herbivore: a heterotrophic animal that eats plants)
hydro- 5 water; -lysis 5 to loosen (hydrolysis: a chemical process that lyses or splits molecules by the addition of water)
intra- 5 inside (intracellular digestion: the joining of food vacuoles and lysosomes to allow chemical digestion to occur within the cytoplasm of a cell)
micro- 5 small; -villi 5 shaggy hair (microvilli: many fine, fingerlike projections of the epithelial cells in the lumen of the small intestine that increase its surface area)
omni- 5 all (omnivore: a heterotrophic animal that consumes both meat and plant material)
peri- 5 around; -stalsis 5 a constriction (peristalsis: rhythmic waves of contraction of smooth muscle that push food along the digestive tract)Instructor’s Guide for Campbell/Reece Biology, Seventh EditionChapter 41Animal NutritionInstructor’s Guide for Campbell/Reece Biology, Seventh EditionChapter 41Animal Nutrition