Already have an account? Get multiple benefits of using own account!
Login in your account..!
Remember me
Don't have an account? Create your account in less than a minutes,
Forgot password? how can I recover my password now!
Enter right registered email to receive password!
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.
Figure: Circulatory system pattern in (a) fish and (b) mammals. Rust shows oxygenated blood
Is the epithelium vascularized? How do nutrients and oxygen reach the epithelium? Why is this feature a significant evolutionary acquisition? Epithelia are not vascularized (ca
Q. Concerning extracellular digestion what is meant by chemical digestion? Chemical digestion is the series of enzymatic reactions to break macromolecules into smaller ones.
In which meiotic division does the separation of the homologous occur? What are the ploidies of the generated cells after the end of that process? The separation of the homolog
Explain the differences between a thrombus and an embolus. Include predisposing factors, mechanism of occurrence, treatment, and methods of detection with medical imaging, if any.
Explain Dental Care Delivery System In the dental care delivery system: there are: patients, insurance payers and dentists For patients: Success = function + esthetics
Q. Marking regulations of honey? The marking regulations indicate that each container of honey shall be suitably marked so as to give suitable information as follows: a) N
Normal 0 false false false EN-IN X-NONE X-NONE MicrosoftInternetExplorer4
Q. How do taenias obtain food and make gas exchange? The Tapeworms have sucking and hooks structures on their heads (scolex) that fixate the parasite in the gut wall these stru
In humans, the recessive allele that causes a form of red-green colour blindness (c) is found on the X chromosome. a) Determine the genotypes and phenotypes of the F1 generation fr
Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!
whatsapp: +91-977-207-8620
Phone: +91-977-207-8620
Email: [email protected]
All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd