Animals including Humans Year 6 Lesson 4 LI: To describe the function of blood and blood vessels

Input What is blood? Ask the children what they already know about blood.

How much blood do we have? How much blood does an adult have? Does this vary from how much you have? Using bottles of liquid, get the children to guess how much blood an adult and a 10 year old child has in their body. Share the facts with the children. Adults have around 5 litres of blood. A 10 year old has around 4 litres of blood.

The different blood vessels There are three main types of blood vessel: Arteries- These carry blood away from the heart. Usually they contain oxygenated blood (the only exception is the pulmonary artery- can you remember where this is found?) Veins- These carry blood to the heart from the body and usually carries deoxygenated blood (except the pulmonary vein). Capillaries - These are small blood vessels that link the arteries and veins. They supply the organs and tissues

Functions of blood There are five main functions of the blood: The blood carries oxygen to the body in red blood cells. The blood carries nutrients. The blood carries waste away from the body to specific organs that will remove it from the body. The blood contains certain cells (white blood cells) that help fight infection. The blood helps regulate body temperature.

Blood groups There are 4 different types of blood group: A B AB O The antigen on the surface of the red blood cell determines what blood type you are. The blood group you are is determined by the blood group of your parents. Giving the wrong type of blood can be fatal as your body attacks itself which is why it is important to only be given your type of blood during a blood transfusion (or O as it doesn’t contain antigens). In the UK blood group A and O are the most common. Antigens act as signals for your body to make antibodies- which is why it is important to only be given your type of blood during a blood transfusion (or O as it doesn’t contain antigens). UK figures: A- 40% B- 11% AB- 4% O- 46%

Activity Children to complete the worksheet.

How much blood do we have to lose for it to be life threatening? Plenary How much blood do we have to lose for it to be life threatening? Around 30% blood loss will be fatal. If any children enquire about girls losing blood during their period, the blood loss is only between 10-80ml for the whole period.