Mass Transport In Mammals Flashcards
The circulatory system in mammals?
Large organisms need a transport system due to its increasing size which causes a decrease in the SA:V ratio and are metabolically active. This means we can no longer rely on simple diffusion and need a specialist exchange surface. These transport systems take materials from the exchange surface and to different parts of the organism.
Features of a mammalian transport system?
- Blood a suitable medium in which to carry materials.
- circulation is a form of mass transport in which blood is moved around in bulk over large distances.
- blood vessels, arteries, veins and capillaries contain blood within them.
- muscular contractions of the heart moves the blood within the vessels.
- valves maintains the mass flow in one direction.
- heart rate, vasodilation and vasoconstriction control the flow of blood.
The circulatory system?
Mammals have a closed double circulatory system, this means that the blood passes through the heart twice per complete circuit via confined vessels.
Where does diffusion occur?
Rapidly at the tissues even though pressure has fallen due to a large SA, a good concentration gradient and a short diffusion pathway.
What happens at the pulmonary lungs?
The pulmonary lungs oxygenates the blood and removes carbon dioxide. The systemic body has oxygenated blood from the lungs pumped around the body rapidly at an increased pressure.
What do arteries carry?
Arteries carry oxygenated blood away from the heart.
What do veins carry?
Veins carry deoxygenated blood towards the heart.
How blood travels around the circulatory system?
The heart is composed of two separate pumps, the right side pumps blood to the lungs to pick up oxygen, the blood is returned to the left side of the heart. The left side pumps oxygenated blood rapidly and at high pressure to the body, the blood is returned to the right side. The blood must be highly pressured to ensure circulation is rapid enough to support the high level of energy and need to maintain the core body temperature through respiration. A huge number of capillaries in alveoli reduce pressure but need to cover the entire body hence back to the heart and to the body again.
Heart structures?
It has 4 chambers, 2 atria which collect blood and 2 ventricles which are muscular and pump blood. It has 4 valves, the tricuspid and bicuspid (mitral) and 2 semilunar valves, the aortic and pulmonary. It has 4 main vessels, the vena cava in the right atrium carries deoxygenated blood in, the pulmonary vein in the left atrium carries oxygenated blood in, the pulmonary artery in the right ventricle carries deoxygenated blood out and the aorta in the left ventricle carries oxygenated blood out.
Which side of the heart is more muscular?
The left side is more muscular in order to pump the blood around the whole body at a high pressure. There is a septum to separates the deoxygenated and oxygenated blood.
Supplying the heart with oxygen?
Although oxygenated blood is pump through the left side of the heart the heart muscle is supplied with oxygen via the coronary arteries which branch off the aorta. If these are blocked by a blood clot a myocardial infarction (heart attack) can occur, the heart muscles is denied oxygen therefore can’t respire and can’t produce ATP so the tissue will die.
Blood flow through the heart?
Blood comes into the heart from the body. It then has to pass the lungs to collect oxygen, this is called a double circulatory system, after it returns to the heart, it leaves again to be transported to the body.
The flow of blood through the heart order?
Body ⬇️ Vena cava ⬇️ Right atrium ⬇️ Tricuspid valve ⬇️ Right ventricle ⬇️ Pulmonary valve ⬇️ Pulmonary artery ⬇️ Lungs ⬇️ Pulmonary vein ⬇️ Left atrium ⬇️ Bicuspid valve ⬇️ Left ventricle ⬇️ Aortic valve ⬇️ aorta ⬇️ Body
