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 tofeeding 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

• Iron• Calcium• Magnesium• Iodine• Sodium• Potassium

– Describe how these minerals are used.

• Protein• Carbohydrate• Lipid

– In addition to providing cellular energy through oxidation, how else are these nutrients used by cells/tissues?

Energy Nutrients

See Table 43.2, p. 959

Homeostasis in Nutrition: Blood Calcium Level

Homeostasis in Nutrition: Blood Glucose LevelSee 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• Secretion• Digestion• Absorption• Excretion

Simultaneous coordination of these functions often occurs in several regions of a digestive system.

What is the term used to describe propelling movements in the 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 & Absorptiona closer look at two

mechanisms…

p. 973

p. 967Gastric glands acidify stomach contents. Why?

The intestinal epithelium can transport glucose up the concentration gradient w/o directly using ATP. How?

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?

Intracellular Digestion:

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)

Identify areas specialized for transport, storage, mechanical digestion, chemical digestion, absorption, and/or excretion.

What is this?

Structure of the Wall of the Mammalian Alimentary Canal

p. 969

What makes peristalsis possible?

What features serve to increase surface area?

Human Digestive System

Identify the accessory organs (glands) of the mammalian digestive system.

p. 963