notes5 - Maintenance Introduction In this unit you will...

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1 1 Maintenance 2 Introduction In this unit you will learn how insects digest their food, breathe oxygen, and circulate their body fluid. In unit 4 you were introduced to the insect reproductive system by comparing it with our human system. As you go through this unit, continue this comparison by thinking about how the insect digestive, respiratory, and circulatory systems compare to our own. As you make these comparisons, remember that insects and humans (mammals) are so distantly related that any similarities in these systems must be the product of convergent evolution (the independent evolution of structural or functional similarities). A common example of convergent evolution are the wings of birds and bats, structures that are very similar but evolved independently. Also, don't forget to refer often to the unit objectives and the study guide. 3 Objectives By the end of this unit you should be able to: 1. Describe the embryonic origin of alimentary canal divisions. 2. Draw and label generalized alimentary canal and describe function of each component. 3. Draw and label generalized insect circulatory system and describe circulation pattern. 4. Describe the tracheal system of insects and define trachea, tracheoles, and taenidia. 5. Describe how insects maintain proper body temperature and how they keep from freezing. 4 Alimentary Canal The alimentary canal , or digestive tract is very similar to that found in vertebrates. In fact, by simply looking at the diagram of the insect digestive tract many of you will be able to guess what the different structures are. Yet, there are some structures of the digestive tract that are very unique to insects. To complete this portion of the unit, read text pages 68-81 and fill out the corresponding study guide questions and diagram 1. When you are finished finding all the functions and labeling the diagram, review them for a minute because you will take a self-check quiz on the next slide that is designed to help you remember the functions. Read textbook pages 68-81. 5 Quiz 6 Summary of Functions The table below lists each digestive structure and its function. Make sure you have table 1 and diagram 1 on your study guide properly filled out. Acts as a valve between crop and midgut. It often contains heavy teeth for further grinding of food. proventriculus Stores food while midgut enzymes (in some insects) are allowed to enter through proventriculus to digest the food. crop Secretes fluid to lubricate food as it passes out of pharynx and down the esophagus and into the crop. Secretes some digestive enzymes.
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This note was uploaded on 07/23/2011 for the course ENY 3005 taught by Professor Staff during the Spring '08 term at University of Florida.

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notes5 - Maintenance Introduction In this unit you will...

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