To understand excretion and the importance of the various organs that comprise this system, there are some important scientific concepts you need to know.
Metabolism
Your metabolism is the sum of all the chemical reactions that take place in your body. Cellular respiration from earlier in the year is a key chemical reaction that creates energy. It also produces metabolic waste products. Can you remember what these waste products are?
Homeostasis
Homeostasis is examined in more depth in Year Nine Science. Basically, homeostasis is involved with maintaining a constant internal environment in the body. This happens without you thinking about it. For example, if your blood sugar level rises, your pancreas releases insulin to lower these blood sugar levels automatically so that they are in a "safe" range. There will be examples of homeostasis in action as you look at the organs of excretion.
Excretion
The removal of metabolic waste from the body is called excretion. As blood flows through the body, the cells empty their waste products into it. This waste must be removed by the body before it builds up into dangerous levels and causes damage. The body's main excretory organs are the lungs, kidneys, skin and the liver (which we have already discussed as part of the digestive system).
Metabolism
Your metabolism is the sum of all the chemical reactions that take place in your body. Cellular respiration from earlier in the year is a key chemical reaction that creates energy. It also produces metabolic waste products. Can you remember what these waste products are?
Homeostasis
Homeostasis is examined in more depth in Year Nine Science. Basically, homeostasis is involved with maintaining a constant internal environment in the body. This happens without you thinking about it. For example, if your blood sugar level rises, your pancreas releases insulin to lower these blood sugar levels automatically so that they are in a "safe" range. There will be examples of homeostasis in action as you look at the organs of excretion.
Excretion
The removal of metabolic waste from the body is called excretion. As blood flows through the body, the cells empty their waste products into it. This waste must be removed by the body before it builds up into dangerous levels and causes damage. The body's main excretory organs are the lungs, kidneys, skin and the liver (which we have already discussed as part of the digestive system).
Task:
- in iThoughts, you are to create a new topic off the centre topic and call it "Excretory System"
- you are to add two "callouts" (looks like speech bubble icon on the top toolbar) from this topic and include a definition for metabolism and homeostasis in each one
- create another topic off the excretory system and call it "excretion". As well as the title, include the definition of excretion in this topic bubble.
- Create four separate topic bubbles off "excretion" and call them each of the four main organs of excretion in the body.