Plasma
Biology: Edexcel IGCSE, topic 3.3.11
Blood Plasma
Plasma is the liquid that makes up blood and carries the red and white blood cells and platelets around the body. Plasma also transports other substances:
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Carbon dioxide
- Carbon dioxide is a waste product made by cells in respiration.
- It is dissolved in the plasma, and transported to the lungs where it is breathed out.
Heat energy
- Because plasma is a liquid, it can easily carry heat energy around the body.
- When we are too hot or too cold, our blood flow changes to increase or decrease the amount of heat energy we lose from our bodies.
Urea
- Urea is a substance made in the liver from excess protein.
- Urea is dissolved in the blood plasma, and then passes out of the body in urine.
Hormones
- Hormones such as insulin and sex hormones are transported around the body dissolved in the plasma.
Digested food
- Digested food particles are absorbed into the blood from the small intestine.
- They are transported, dissolved in the plasma, to the parts of the body where they are needed.
Test yourself on Plasma
Which of these is not a waste product dissolved in the plasma?