Reference no: EM13880872

Instructions

Type each assignment (double-spaced) in the form of an essay, using complete sentences. Limit the length to approximately three-four pages (five pages is too long, and two pages is too short). Grammar, spelling and scientific accuracy are all taken into account during grading. If you need to "quote" from the book or atlas, then do so in a very limited way and cite the source. However, in general you do not need to copy anyone else's work, and obvious plagiarism or copying other students work will impact your grade. Each assignment will be given a maximum of 10 points. Hand-in the assignments in lab on the due date. Late hand-ins will not be accepted unless for medical reasons. Hand-in one copy on paper and one copy as an attached file in email to Dr. Kavanaugh. You MUST put in your Subject Line of the email: "Anatomy Lab Homework 2".

Sources

Use the atlas and textbook for background reading. The information that will help you is scattered across several chapters - so you need to use the index to track down what you need.

Assignment

Write an essay describing the evolution of the circulatory system, using the model organisms that we have used in the lab (Amphioxus=Protochordate, Lamprey/Shark=Fish and Cat=Mammal) as important milestones in the development of the heart and blood vessels. Use the following questions as a guide:

1. What functions are performed by the circulatory system? Are these functions common to all chordates?

2. What significant changes in the lifestyles of the vertebrates have been a major driving force in the structural changes of the heart

and artery branching patterns?

3. Vertebrate circulatory systems are classified as either "single" or "double". Describe what these two patterns of circulation are.

4. How different or similar is the amphioxus circulatory system to the single or double circulatory patterns of the vertebrates? What

does this comparison tell you about what the earliest chordate circulatory system looked like?

5. What is the exact names and sequence of blood vessels used to carry blood starting in the tail and then going to the pharyngeal

bars to pickup oxygen and then back to the tail of amphioxus?

6. What is the exact names and sequence of blood vessels used to carry blood starting in the tail and then going to the gills to pickup

oxygen and then back to the tail of the shark?

7. What is the exact names and sequence of blood vessels used to carry blood starting in the tail and then going to the lungs to pickup

oxygen and then back to the tail of the cat?

8. What are the aortic arches? What changes have occurred in the numbers and pattern of branching of the aortic arches in the

protochordates, fish and mammals?

9. What changes have occurred in the construction of the heart in these same animals?

10. What aspects of the biology of the mammalian heart indicate its ancestral connection through evolution with earlier more primitive

vertebrates?