Transport in Animals
Revision notes for Transport in Animals in OCR Biology A (H020). Read the start of any lesson here, then sign in free for the whole lesson, the R.E.C.I.P.E. recall steps and the quiz.
- Specialised Transport SystemsLarge multicellular organisms need a specialised transport system because simple diffusion is not fast enough to meet their metabolic needs.
- Features of a Transport SystemTransport systems or large animals have the following features: A fluid medium which could be liquid or gas to carry substances around.
- Types of Circulatory SystemBlood must be brought close to the cells since nutrient and metabolic waste exchange takes place by passive diffusion.
- Open Circulatory SystemsIn open circulatory systems the transport medium is pumped from the heart and into an open body cavity called the haemocoel.
- Closed Circulatory SystemsIn a closed circulatory system, blood is the transport medium and is confined in blood vessels and does not come directly in contact with tissues…
- Single Closed Circulatory SystemsSingle closed circulatory Systems are a single loop system, where blood passes through two sets of capillaries before it returns to the heart.
- Double Closed Circulatory SystemsIn a double circulatory system, blood flows through the heart twice for each circulation of the body.
- Blood VesselsBlood vessels are a closed system of tubular vessels that contain blood and forms a branching network to distribute blood to all parts of the…
- ArteriesThe function of arteries is to transport blood rapidly under high pressure from the heart to the tissues.
- ArteriolesOxygenated blood is distributed throughout the body by arteries branching into sequentially smaller arteries, arterioles, and capillaries.
- Veins and VenulesVenules connect capillaries to larger veins.
- CapillariesCapillaries exchange metabolic materials such as oxygen, carbon dioxide and glucose between the blood and cells of the body.
- Tissue FluidTissue fluid is a watery liquid that contains glucose, amino acids, fatty acids, ions in a solution and oxygen.
- Return of Tissue Fluid to BloodThe loss of tissue fluid from the capillaries reduces the hydrostatic pressure inside them.
- Chloride ShiftWhen carbon dioxide diffuses out of respiring tissue, 5% of the CO2 dissolves in the plasma and about 10-20% is binds to the amino group of the…
- Human HeartThe human heart consists of two pumps side by side and joined together by a dividing wall called the septum.
- Structure and Function of the HeartThe human heart is made of left and right pumps.
- Cardiac CycleThe events that take place in the heart during a single heartbeat is called the cardiac cycle.
- Heart SoundsThe sounds of the heartbeat heard through a sthetoscope are made by the valves closing due to blood pressure.
- Basic Rhythm of the HeartCardiac muscle is myogenic - it has its own intrinsic rhythm of around 60 beats per minute.
- ElectrocardiogramsThe spread of electrical excitation across the heart can be measured using an electrocardiogram.
- Aortic AneurysmsAn aneurysm is a bulge or weakness in a blood vessel.