circulation patterns, Biology

Circulation Patterns

All vertebrates have some similarities in their circulatory systems but as vertebrate life changes from aquatic to terrestrial, the pattern of circulation becomes more complex. Fish and mammals represent two extremes in vertebrate circulation and Fig. 3.6 compares the two. The principal difference is in heart structure, from two chambered in fish to four chambered in mammals. The fish heart contains two main chambers in series the atrium or auricle and the ventricle. There are two subsidiary chambers (not shown in Figure) the sinus venosus which proceeds the atrium and conus arteriosis which comes after the heart.

These contain valves that prevent backwards flow of blood. Blood makes a single circuit from the heart to the gills where it is' oxygenated and then to the dorsal aorta to be distributed to the body from where it returns to the heart by the veins. Such a system has the advantage that all of the blood going to the body has already been oxygenated in the gills. However, there is a disadvantage i.e. the narrow gill capillaries slow down the blood flow resulting in a low blood pressure. This slows the rate of oxygen delivery to the cells and limits the metabolic rate that fish can attain.

1674_Circulation Patterns.png

                              Figure:  Circulatory system pattern in (a) fish and (b) mammals. Rust shows oxygenated blood

Posted Date: 1/16/2013 12:50:16 AM | Location : United States







Related Discussions:- circulation patterns, Assignment Help, Ask Question on circulation patterns, Get Answer, Expert's Help, circulation patterns Discussions

Write discussion on circulation patterns
Your posts are moderated
Related Questions
Define Mineral Trioxide Aggregate - Materials for Root End Filling Widely used Favorable biocompatibility Superior sealing qualities when compared to S-EBA and am

Explain the Failure to Management of Ledge Apical transportation or perforation: movement of the physiological foramen to a new iatrogenic location. Three types of apical tr

Q. What is gastrulation? How during gastrulation are the first two germ layers formed? What are these germ layers? Gastrulation is the process through which a portion of the bl

Q. What is the nitrogen waste in amphibian larvae and in the adult animal? The terrestrial adult excretes urea since amphibian larvae are aquatic they excrete ammonia.

Q. How does the intensity of facilitated diffusion differ in relation to the concentration of the moved substance? What is limiting factor? Like simple diffusion facilitated di

Which of the following is a false statement regarding prokaryotic and eukaryotic core promoters? A. The core promoters of eukaryotic genes have more recognition elements for ge

Define Briefly about the Pyridoxine vitamin B 6 ? Pyridoxine or vitamin B 6 is one of the B complex vitamins which prevents and cures dermatitis in rats fed on vitamin B 6 de

what type of gametes would be produced from genotype AA, Bb, AABb and someone who is heterozygous for 3 traits

How does the intensity of simple diffusion differ in relation to the concentration gradient of the moved substance? The higher the concentration gradient of a substance the ext

Define Energy Expenditure in Hot Environments? Energy expenditure in hot environments is increased by a small but significant amount because of additional work of ventilation a