Excretory System Flashcards
What is defecation?
Defecation – The process of getting rid of solid waste (Faeces). Faeces (poop) is undigested material that has passed through your digestive tract and is waste that your body has not been able to use.
What is excretion and what are the organs in the excretory system?
Excretion - Getting rid of the wastes your body has produced is called excretion. It is the function of the excretory system. The lungs, skin, liver, and kidneys are all involved in the excretory system.
What do lungs do in the excretory system?
Lungs in excretory system – Respiration produces carbon dioxide and water as waste products. These are carried back to the lungs to be breathed out. The lungs are a part of the respiratory system and excretory system.
What does the liver do in the excretory system?
Liver – Amino acids are the end products of protein digestion. They are used by your body to make proteins and for growth and repair. Amino acids cannot be stored so if you have to much the liver will break it down and excrete it. The liver breaks down these amino acids into a substance called urea. Poisonous substances may enter the body through the digestive tract. These are carried into the liver where they are broken down into harmless substances. The harmless substances return to the blood and get passed down to the kidneys. The liver also breaks down old red blood cells. Any unwanted haemoglobin is added to the bile and passes with the bile into intestines.
What does the skin do in the excretory system?
Skin – Chemical reactions taking place in your body produce heat as a by-product. Some of this heat is required to maintain your core body temperature at approximately 37 degrees. But if you do not get rid of excess heat, then your temperature would rise. This could be fatal. So the skin gets rid of this excess heat by sweating. Sweat also contains a small amount of urea.
What do kidneys do in the excretory system?
Kidneys – Kidneys are filters that process 50 liters of blood every hour. The kidneys excrete urea which is a waste product when proteins are broken down. The kidneys also control the level of water in your body. Your kidneys also control salt level in your blood.
What is urine?
Urine - is the waste material that has been filtered out of the blood by the kidneys. On average, urine is 95% water. The other 5 percent is urea, with small amounts of salt and pigment. The pigment comes from the breakdown of haemoglobin. Urine passes down narrow tubes called the ureter and gets stored down into the bladder which can hold about 500ml of urine.
What is urethra?
Urethra – is a tube that carries the urine to the outside of the body. At the end of the urethra is a sphincter muscle which controls the emptying of the bladder.
* Together the kidenys, bladder and ureters and urethra are called the urinary tract.
What are kidney diseases, kidney stones, and infections?
Kidney Disease – More than 500 000 people have kidney disease. Causes of this is high blood pressure, kidney stones and infections.
High Blood pressure – Your blood travels a short distance around your kidneys. Very little pressure from the heartbeat is lost so blood entering the kidneys is under pressure. This pressure helps the filtering process carried out by the kidneys. However high blood pressure can easily damage the capillaries where the blood is filtered by the kidneys.
Kidney Stones - Kidney Stones occur when chemicals normally present in the urine combine to create hard crystals. Large crystals can block the fine tubes within the kidney causing pain and preventing flow of urine.
Infections – The structure of the urinary tract prevents any backflow of urine from the bladder, and this reduces the chance of infections of the kidneys. Most infections occur because of bacteria. Bacteria can enter through the urethra.
