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!
Open Type of Circulatory Systems
Several non-chordates have thus an open type of circulation - a system in which blood pumped by the heart empties through an artery into an open sinus filled with blood which lies between the ectoderm and endoderm. The blood filled space is considered to as haemocoel, particularly in arthropods. The fluid contained within the haemocoel, referred to as haemolymph or blood, is not circulated by capillaries but bathes the tissue directly. Figures show the organisation of the main vessels from two groups of non- chordates having open circulation, a Cray fish and a bivalve mollusc.
Figure: Invertebrate circulations (A) simplified diagram of the circulation in the crayfish, (B) Simplified diagram of the circulation in bivalve mollusc.
In several animals the haemocoel is large and constitutes 20 - 40% of body volume. In contrast, chordates along with a closed circulation contain a blood volume of 5 - 10% of the total body volume. Open circulatory systems have low pressures; seldom exceeding 5 - 10 mm Hg. Animals that have an open circulation generally have only limited capability to alter the velocity and distribution of blood flow. As a result, in bivalve molluscs and other animals that have an open circulation and use blood for gas transport, change in oxygen uptake is slow and rate of oxygen transfer is low per unit weight. In other words, their metabolism is extremely low, Inseots have, however, avoided this problem by evolving a tracheal system where gas transport to tissues occurs direct through air filled tubes or tracheae that bypass the blood. Accordingly, although insects have an open circulation, they have greater metabolic rate.
what is cation and anion? list of cation and anion and its biological function?
How do taenias classify according to the division of sexes? Taenias are monoecious (hermaphrodite), the similar individual has female and male reproductive organs and undergoes
Explain Transfer from Solid Culture to Liquid Media The steps involved in this technique are included herewith: 1. Sterilized inoculating loop or needle is touched carefully
discuss locomotion in annelids
is the leukamia dangerous
Taeniasis Taeniasis is a zoonotic disease caused by specific cestodes. The two parasites of major importance are Taenia saginata and T. solium. Both in their adult forms, are
Explain the Biography of Pedanius Dioscorides? Pedanius Dioscorides, a Cicilian Greek, who lived in the first century A.D. was the most important botanist after Theophrastus. H
Purpose of Supervision: Purpose: To help the personnel to grow, to know themselves and what they need in order to render the most efficient service and to give them assistance
Industrial melanism refers to the dark pigmentation that evolved in some insects giving them protective coloration on vegetation darkened by soot in heavily industrialized areas pr
Why is the uricotelic excretion essential for avian and reptile embryos? In reptiles and birds the excretory system is uricotelic as uric acid is insoluble, less toxic and sui
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