Excretory system

   1. Waste products

   When we eat and breathe, we get beneficial elements, but we also get harmful waste products that we must expel. The wastes products are four:

   - Feces containing the useless remnants of the food that we eat. They are expelled from the large intestine through the anus (see the subject of the digestive tract).

   - Carbon dioxide (CO2) are produced in the cells, when the nutrients burn. We expel it from the lungs through the mouth and nose (see the subject of the respiratory system).

   - Urine containing waste products that goes to the blood. It is eliminated through the urinary system, through the urethra.

   - The sweat produced by the sweat glands and it is expelled through the pores of the skin.

   2. Indicate the appropriate waste product: feces, carbon dioxide, urine or sweat

It is expelled through the urethra

It is produced in the cells

It is produce in the sweat glands

They are useless remnants of food

It is expelled through the pores

It is the product of the urinary tract

It is expelled through the nose and mouth

It is expelled through the anus

    3. Urinary system

   The urinary system is responsible for cleaning the blood of waste products that are produced in cells. It has four parts: Kidney, ureter, urinary bladder, and urethra.

   - The kidneys are two organs located near the vertebral column, just above the waist. They filter blood and extract the excess of water, some mineral salts and certain substances with nitrogen. With that the urine is produced.

   - The ureters transport urine to the urinary bladder.

   - The urinary bladder is a cavity that retains and accumulates the urine up to expel it.

   - The urethra is the tube through the urine comes out. This process is called urination.

   4. Answer with one of these words: kidneys, ureters , urinary bladder or urethra

They filter the blood

The urine comes out

Urine is stored

It is between the kidneys and the urinary bladder

It extracts mineral salts

They are located near the vertebral column

   5. Sweat glands

   They are in the skin and develop a liquid similar to the urine; it is called sweat which is expelled through the pores.

   All our skin is covered with small pores.

   A sweat gland consists of a set of tubes that are in the inner part of the skin and a tube connecting with the outside through a pore.

   Through sweat, we eliminate waste substances and we regulate body temperature.

   6. Answer if these sentences are true or false:

The sweat is similar to the urine

A gland consists of a single tube

The sweat out through the pores

The sweat does not regulate the temperature

   7. Diseases and hygiene of the excretory system

   It is important that the organs of the excretory system work well in order to poisonous waste products do not remain in the body.

   When the kidneys are malfunctioning, the artificial kidney is used from time to time to make the cleaning of the patient's blood. This process is called dialysis.

   The kidneys sometimes accumulate solid substances called stones or kidney stones. Doctors can dissolve them with medication or with surgery.

   We must worry about the hygiene and we should follow these instructions:

   - Keep skin clean by frequent showering.

   - Avoid excessive meat at meals, because it can cause uric acid and when it is accumulated in the muscles or joints, it can cause pain (gout, arthritis).

   - Avoid excessive drinking, especially alcoholic beverages.

   8. Indicate if these advices are correct or incorrect:

Use artificial kidney is needed

Do not give importance to kidney stones

Take a shower few days

Do not eat too much meat

Avoid alcoholic beverages

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®Arturo Ramo García.-Record of intellectual property of Teruel (Spain) No 141, of 29-IX-1999
Plaza Playa de Aro, 3, 1º DO 44002-TERUEL