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
DEMOGRAPHIC CYCLE - 1 . First stage - B high - D high = 0 2 . Second stage - B high - D lo w = G more eg.
At the end of the ventricular contraction, maximum arterial pressure is attained and blood flow is most rapid. This is correctly termed the: a) Arterial maximum b) Diastolic
all of their function on different system
Autonomic Nervous System (ANS) Autonomic Nervous System functions without conscious control of central nervous system. This system controls the functions of cardio-vascular, ga
Vegetative Development - Morphogenesis This term is coined for the process leading to and determining the form and structure of organs. It is used mainly by experimental morph
organism that have wide tolerance range
How can brain research improve the treatment of pain? Despite recent advances in understanding how brain processes and responds to pain, experts say pain continues to be grossl
The holoenzyme is denatured by heat at very high temperature. It is found that two polypeptides, although denatured, contains chains that remain together as a unit, while two other
WHAT ARE THE TYPES OF EGG ON THE BASIS OF YOLK ?
Classification of Viruses No evolutionary or phylogenetic exist between viruses. A nature system of classification cannot, therefore, be devised for viruses. Holmes (1948)
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