What products would the organism be able to take up for other activities?

What are the products which would cause harm to the body, if they are not removed?

What happens if harmful products are not removed from our body every day?

We have already learnt that different kinds of materials are produced out of various metabolic activities.

Some of these may be harmful for the organism are removed from their body or packed and stored in some other forms. These are all the wastes produced in the body of an organism.

We have already discussed how organisms get rid of gaseous wastes generated during photosynthesis or respiration. Other metabolic activities generate nitrogenous wastes have to be removed along with salts, excess water and several other materials.

Excretion is the term coined for all the biological process involved in separation and removal of wastes or non useful products from the body. (In latin ex means out, crenere means shift.) Now let us study how excretion takes place in human being.

Excretion in Human Beings

A number of reactions take place during various metabolic activities.

Many useful substances and energy are produced. At the same time many other things happen such as, toxic wastes may be produced, water content may increase, ionic balance (homeostasis) in the body may be disturbed.

The waste products include carbon dioxide, water, nitrogenous compounds like ammonia, urea, uric acid, bile pigments, excess salts etc. The most poisonous of all waste products of metabolism is Ammonia.

Where are these waste materials produced? How does the body manage them. Is there a way to detect their presence in our body?

Now let us observe the test reports of Blood and Urine of a person given in table-2, 3 and find out the components present in both Blood and Urine.

(For 24 hours urine test urine is collected for 24 hours From that, 100-150 ml sample will be tested.) observe the reports in the next page and answer the following questions.

What are the substances present in blood?

What are the substances present in urine?

What are the substances present both in blood and urine?

Which substances are present above the normal limits both in the blood and urine?

What do you think a reading above normal limits indicates?