circulatory systems

Why do multicellular organisms need transport systems 

multicellular organisms have a small SA:V (large distance between outside to middle of organism)

-facilitated diffusion alone would be too slow to meet their metabolic needs for oxygen so require specialised transport systems

What does a mass transport system mean 

When substances are transported in a mass of fluid 

What is a circulatory system 

Made up of a transport medium e.g. blood, which carries gases, nutrients, hormones and waste products around an organisms body

What is an open circulatory system and what animals have this

Invertebrates e.g. insects

- their transport medium, haemolymph, flows freely through the body cavity and comes in direct contact with cells 

What is pressure like and what substances are carried in an open circulatory system 

> haemolymph is pumped at low pressure and it transports food and waste products NOT oxygen or carbon dioxide because these gases are transported in tracheal system

What is a closed circulatory system and what animals have this 

Vertebrates e.g. mammals and some invertebrates like annelid worms 

- their transport medium, blood, remains inside blood vessels and does NOT come in direct contact with cells 

What is pressure like and what substances are carried in a closed circulatory system 

> blood is pumped by the heart at high pressure, allowing it to flow quickly around the body to deliver oxygen to tissues and remove carbon dioxide

Closed circulatory systems can be … or …

single or double

What is a single close circulatory system 

Blood passes through the heart once per cycle and it consist of 1 circuit 

Name an animal with a single circulatory system and how blood travels around its body 

Fish 

Blood is pumped by the heart to the gills > to body tissues > returns back to the heart 

What is a double closed circulatory system 

Blood passes through the heart twice per cycle and it consist of 2 circuits 

Name an animal with a double circulatory system and how blood travels around its body 

Humans 

Blood is pumped by the heart-> around the body-> back to heart-> to the lungs-> back to heart 

What are the two circulatory systems in humans 

Systemic 

Pulmonary

What is the systemic circulatory system responsible for 

>oxygenated blood is pumped out the heart via the aorta to deliver oxygen and nutrients and collect waste products from body tissues 

>blood now deoxygenated returns back to the heart via vena cava 

What is the pulmonary circulatory system responsible for

>deoxygenated blood is pumped out the heart via pulmonary artery to the lungs to unload co2 and pick up o2

>blood now oxygenated returns back to the heart via pulmonary vein 

Why is a double closed circulatory system the most efficient for transporting substances in animals 

Since blood is pumped twice per circuit that means blood is repressurised keeping it high pressure which enables rapid transport of oxygen and nutrients and removal of waste products to meet high metabolic demands

what side of the heart contains oxygenated blood and which contains deoxygenated blood

Right side = deoxygenated 

Left side = oxygenated 

When looking at a diagram of the heart, how should you read the image 

> the image is mirrored from your perspective so 

Left side of image = right side of heart (deoxygenated)

Right side of image = left side of heart (oxygenated)