Closed type of circulatory systems, Biology

Closed Type of Circulatory Systems

Some non-chordates, like cephalopods (octopuses, squids), earthworms, polychactes and all vertebrates have a closed circulation along with blood flowing in a closed circuit of tubes from arteries to veins by capillaries. There is better separation of functions in closed circulatory system as compared to in open system. In a closed circulation the heart is the main propulsive organ, pumping blood into arterial system and keeps a high blood pressure in arteries. The arterial system, in turn, works as a pressure reservoir forcing blood through the capillaries. The capillary walls are thin, so permitting high rates of transfer of material between blood and tissues. A blood returning from the systemic circulation that is directed to the gills.

Much of the returning blood flows through the two lateral vena cava through the kidneys before arriving at the bases of the gills. Near the base of each gill is a bulbous accessory pulsatile organ, the branchial heart that receives the systemic venous blood. This heart pumps the blood into an afferent branchial vessel, through which it passes through capillaries in the gill to the efferent branchial vessel and return to the systemic heart. Physiologically the circulatory systems of cephalopods (squid and Octopus) resemble those of chordates far much more than to those of the other molluscan groups. As for example, both cephalopods and chordates have closed circulatory systems; the blood volume of octopus is comparatively small, about 6% of the body weight, well within the range of that of vertebrates however radically lower than in non-cephalopod molluscs.

Posted Date: 2/4/2013 6:04:56 AM | Location : United States







Related Discussions:- Closed type of circulatory systems, Assignment Help, Ask Question on Closed type of circulatory systems, Get Answer, Expert's Help, Closed type of circulatory systems Discussions

Write discussion on Closed type of circulatory systems
Your posts are moderated
Related Questions
What are some of the things scientists may do to analyze data? They may use statistics to determine relation- ships among variables, compare the data with those obtained in ot

Explain Structural protiens Structural proteins are fibrous proteins. The most familiar of the fibrous proteins are probably the  keratins, which form the protective covering o

COMMON RESPIRATORY DISORDERS: Respiration is one of the most vital functions of the body. The purpose of respiration is to provide oxygen ta  the body  cells and to remove exc

Define Absorption, Storage and Elimination of niacin? Nicotinic acid and nicotinamide are rapidly absorbed from the intestine rather than the stomach. At low concentrations, a

These are solid, liquid or gaseous substance present in the atmosphere in such concentrations, as may be or tend to be injurious to human beings or other living creatures, plants a

PREPARATION OF BENZILIC ACID 1.  What is rearrangement reaction? The reactions in which the carbon of the molecule is rearranged to give a structural isomer of the original

Write down any other possible explanations you think of.could the cooler have had any effect? Could something in the water be reasonable? Could there be an object in the water that

Determine the biologic response The biologic response can include: i) Metabolic disturbance. ii) Inflammatory response iii) Immune response iv) Mutagenesis v) Ca

Explain about the Net Protein Ratio (NPR)? This method was introduced by Bender and Doell (1957) and is a modification of the PER method. In this method, an allowance is made f

S m o k in g of Meat Products The purpose of smoking meat is to develop a distinctive flavour, aroma and appearance. These attributes can also be achieved with liquid smok