Learning Objectives:
Animal Nutrition 2/18/08
• Describe the categories of dietary requirements for
adequate nutrition in animals.
• Recognize and explain evolutionary adaptations in
a variety of animals for specific food types and
feeding mechanisms.
• Discuss the advantage(s) of a 1-way digestive tract
(alimentary canal) as compared to a gastrovascular
cavity.
• Describe the levels of structure and function in the
vertebrate digestive system, using examples.
Animal adaptations related to diet
Why do most animals process food
in specialized compartments? Can
you explain why the herbivore has
a longer digestive tract?
Adaptations related to
feeding method:
• Suspension feeders
– Where do these animals live?
– How do these animals increase their chance of
capturing food?
• Substrate/deposit/ detritus feeders
– Is there a high degree of
cephalization in these animals?
• Fluid feeders (blood, nectar, tissue
fluid)
– Compare the adaptations of internal
vs. ecto-parasites
• Bulk feeders (most animals)
– How is external digestion
accomplished?
Adequate Nutrition
• Energy needs
– Name the energy nutrients.
– What is the “best” source of energy for animal cells?
– How is excess energy stored in animal tissues?
• Organic raw material
– What elements are provided in these molecules?
• Water
– Describe the functions of water in biological systems.
• Essential nutrients
– Define, and provide some examples.
Define “essential” nutrient, and provide a variety of examples.
Minerals
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•
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•
•
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Iron
Calcium
Magnesium
Iodine
Sodium
Potassium
– Describe how these
minerals are used.
See Table 43.2, p. 959
Energy Nutrients
• Protein
• Carbohydrate
• Lipid
– In addition to
providing cellular
energy through
oxidation, how else are
these nutrients used by
cells/tissues?
Homeostasis in Nutrition:
Blood Calcium Level
Homeostasis in Nutrition:
Blood Glucose Level See Fig. 43.16
GLUT 4 transporter
(translocation in adipocytes and skeletal muscle cells in
response to the presence of insulin)
compare to GLUT-2 transporter on p. 973
Digestive Functions
•
•
•
•
•
•
Ingestion
Motility
Simultaneous coordination of these
Secretion
functions often occurs in several
regions of a digestive system.
Digestion
Absorption
What is the term used to describe
propelling movements in the
Excretion
digestive tube?
What are the products of hydrolysis
of the energy nutrients?
Describe ways in which different
digestive functions are dependent
on each other.
Secretion &
Absorption
a closer look at two
mechanisms…
p. 967
Gastric glands acidify
stomach contents. Why?
p. 973
The intestinal epithelium
can transport glucose up the
concentration gradient w/o
directly using ATP. How?
Intracellular Digestion:
Does the Paramecium sp. expend energy
to obtain food?
Paramecium sp. produce lysozyme to
digest their food within food vacuoles.
This enzyme is also found in mammalian
sweat, tears and saliva. Why?
Sponges also obtain
nutrition by
intracellular digestion.
In what other ways do
these two organisms
function similarly?
Extracellular Digestion:
2-way digestive system (gastrovascular cavity)
Gastrodermal cells
secrete digestive
enzymes and
phagocytize
macromolecules.
Intracellular digestion
completes the
hydrolysis of nutrients.
What is the other
function of the
gastrovascular cavity?
Alimentary Canals (1-way)
What is this?
Identify areas specialized for transport,
storage, mechanical digestion, chemical
digestion, absorption, and/or excretion.
Structure of the Wall of the
Mammalian Alimentary Canal
What makes
peristalsis
possible?
What features serve to increase surface area? p. 969
Human Digestive System
p. 963
Identify the accessory organs (glands) of the mammalian
digestive system.