Lab 7: Vertebrate Anatomy: Difference between revisions

Based on your previous knowledge of each of these four animals and observation of the skulls of each of these animals, how would you classify their diets’ (herbivorous, carnivorous, or omnivorous)? Observe the skulls and teeth of the four animals. What role to the teeth play in the digestive system? Do any of the organisms have teeth that you think are used for specific functions (grinding, tearing, etc.)? How does the shape of the animals' teeth vary based on diet? <br>

Note the size of the stomach relative to the total length/size of the digestive tract in each organism. Which diet (herbivore, carnivore, or omnivore) correlates to the largest stomach relative to overall size of the digestive tract? What does this tell you about which type of diet is consumed in larger volumes in one feeding? Do you think each animal can eat more sporadically than others due to the size of the stomach? What does this in turn tell you about the nutrient content of the food consumed by each organism per feeding? <br>

Note the large sac at the beginning of the large intestine of the rabbit. It is called the caecum. Do you see a similar structure in the other vertebrates available for comparison, including your fetal pig? What is the main difference in diet between these animals and the rabbit? What does this tell about the possible function of the caecum and whether the diet of a rabbit is easier to digest than the diet of a Necturus, perch or snake? <br>

Note the clear, membranous balloon-like structure in the body cavity of the perch. It is not pinned since it would break if a sharp structure is stuck into it. This structure is called the swim bladder, and it is formed by an outpocketing of the digestive system. However, it does not serve a role in the digestive tract. What do you think is the function of the swim bladder? (Hint: Think of the environment in which you would find a perch!)

Overall, how do you think length/complexity of the digestive tract is related to diet of these animals? <br>

Using the numbered key below and the flags, compare the following structures in all of the specimens, unless otherwise noted, and answer the questions below. <br>

Based on your previous knowledge and observations of each of these four animals, what respiratory medium (water, air, or both) is used by the organism to obtain oxygen?  

'''Urogenital System - labeled with Yellow pins in each of the specimens'''<br>

Using the numbered key below and the flags, compare the following structures in all of the specimens, unless otherwise noted, and answer the questions below. We have mostly female specimens so we will focus on the female urogenital system.<br>

Based on your previous knowledge and observations of these organisms, determine which animals bear eggs and which bear live young. How might this difference be reflected in the number of eggs that are produced? If animals bear live young, where are they "housed" while they undergo embryological development? What is the source of nutrition during development for each of the organisms? How is mode of fertilization tied to the site of embryological development? <br>

Compare the following structures in all of the specimens, unless otherwise noted, and answer the questions below.<br>

Based on your previous knowledge and observations of these organisms and the fetal pig, how many chambers of the heart (atria and ventricles) does each animal possess? <br>

Observe the diagrams that display the path of blood flow to and from the heart in each of the specimens. In each organism, how does blood pass from the heart to the respiratory structures? Does the oxygenated blood re-enter the heart after entering the blood vessels of the respiratory structures? If so, how is it pumped to the rest of the body? What might this mean in terms of efficiency of the circulatory system? What does this tell you about the functional implications for division of the heart chambers? <br>