Lesson 1 - Principles of Circulation Flashcards
(17 cards)
meaning single circulation system
a circulation in which the heart pumps the blood to the organs of gas exchange and the blood then travels on around the body before returning to the heart
meaning double circulation system
a circulation that involves 2 circulatory systems, one of deoxygenated blood flowing from the heart to the gas exchange organs and back oxygenated to the heart. And, one of oxygenated blood leaving teh heart and flowing around the body, returning deoxygenated to the heart
meaning systemic circulation
carries oxygenated blood from the heart to the cells of the body where the oxygen is used, and carries the deoxygenated blood back to the heart
meaning oxygenated blood
blood that is carrying oxygen
meaning deoxygenated blood
blood that has given up its oxygen to the body’s cells
meaning pulmonary circulation
carries deoxygenated blood to the lungs and oxygenated blood back to the heart
what are the differences between single and double circulation system
In single circulation, blood flows to and from the heart through a single pathway, whereas in double circulation there are two separate pathways that are connected to the heart through which oxygenated and deoxygenated blood flows.
what are the differences between the pulmonary circulation and systemic circulation
The pulmonary circulation is a short loop from the heart to the lungs and back again. The systemic circulation carries blood from the heart to all the other parts of the body and back again.
advantages of double circulation over single circulation
- maintains a higher blood pressure, so more blood reaches the tissues
- enables higher metabolic rate
- more efficient gas exchange, as there’s a constant high concentration gradient between the blood and alveoli
meaning mass flow transport system
a transport system which uses a fluid, which is moved by a pressure gradient. The fluid flow from one region of higher pressure to regions of lower pressure. Substances to be transported are suspended or dissolved in the fluid and are all moved in one direction
state the features of the mass transport system
- has a system of blood vessels
- has a way of making sure substances are moved in the right direction
- has a means of moving materials fast enough to supply the needs of the organism
- has a suitable transport medium
what is the difference between open and closed circulatory systems
Open circulation e.g. in insects, involves large open spaces for gas exchange, with lower pressure and slower nutrient transport. Closed circulation e.g. in mammals, features a network of vessels, maintaining higher pressure and efficient, faster transport of blood and nutrients
why do birds and mammals have a double circulatory system, and fish a single circulatory system
birds and mammals need far have a higher oxygen demand than fish. This is because they have to move without the support of water and need to maintain a high constant body temperature. So, their cells need a lot of energy and glucose, and produce a lot of waste which needs to be removed quickly
Describe the features of the single circulation system in fish, and the double circulation system in mammals
- A fish’ heart has 2 chambers, an atrium and a ventricle, thus the blood passes through the heart once. There’s a lower pressure in the gills, so slower blood flow to the body
- A mammal’s heart has 4 chambers, two atria and two ventricles, thus blood passes through the heart twice. The circulation system maintains a high blood pressure, to support the high metabolism
what are the disadvantages of the fish single circulation system
- less pressure
- oxygen is delivered to cells slower
- carbon dioxide is removed from cells slower
why would a fish heart not be divided into two complete halves
as a fish has a single circulation system, and doesn’t have any lungs
suggest why fish survive and flourish, even though they have a less efficient single circulation
- have a higher SA:V ratio, so diffusion is more efficient
- have lower oxygen demands, so less need for an efficient circulation system
- don’t need to maintain their body temperature, as they’re cold blooded, thus lower energy demand
- they move through water, which is easier than moving through air
