circulation patterns, Biology

Assignment Help:

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


Related Discussions:- circulation patterns

Floral apex, Floral Apex Each plant must pass through a minimal 'ripe...

Floral Apex Each plant must pass through a minimal 'ripeness to flower' stage. That is, even to perceive and respond to a specific photoperiodic regime, a plant must be ready

Express the term ctene, Express the term ctene. This unique locomotory ...

Express the term ctene. This unique locomotory structure is found in Ctenophora and is made up of fused cilia arranged into flattened plates. Ctenes are then organized into eig

Which are the brain regions associated with memory, Which are the brain reg...

Which are the brain regions associated with memory? According to researchers some of the main regions of the nervous system associated with the memory phenomenon are the hippoc

What is p-k reaction, The response produced when an allergen is injected in...

The response produced when an allergen is injected into an individual, who is sensitive is known as P-K reaction.

How does sexual reproduction take place in bacteria, Q. How does sexual rep...

Q. How does sexual reproduction take place in bacteria? How dissimilar are the modalities of bacterial sexual reproduction? Sexual reproduction occurs when bacteria incorporate

Can you explaon about aortography, Q. Can you explaon about Aortography? ...

Q. Can you explaon about Aortography? Visualization of the aorta and its branches is possible by several modalities today. Apart from angiography, aorta can also be visualized

Nucellus - ovule, Nucellus - Ovule Enclosed within the integuments li...

Nucellus - Ovule Enclosed within the integuments lies a homogenous mass of tissue which is termed as the nucellus. This is the tissue in which the female gametophyte differen

Explain global burden in the history of mart disease, Explain Global burden...

Explain Global burden in the history of mart disease? In 2001, 17 million people died of CVD of all types. The most important causes were ischemic heart disease (IHD), Hyperten

Describe splitting sequence of s2, Describe Splitting sequence of S 2 ? ...

Describe Splitting sequence of S 2 ? Even though the pulmonary valve closes at about 20 mm Hg and aortic valve at 100 mm Hg, the aortic closure occurs first as the impendence

Sour taste, Sour taste is usually due to the presence of acids such as acet...

Sour taste is usually due to the presence of acids such as acetic acid, citric acid, benzoic acid. Upon dissociation, the acids give H ions which impart acidity. More the H ion con

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

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!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd