Excretion

• Excretion is the removal of waste products created in the body through cell reactions
• Composition is the amount of each element in a sample of a substance.
• Some physical properties of urine include: pH, composition, colour
• Urine can be used to test for diabetes because if you have diabetes, your urine will contain high levels of glucose
• Urine can be used to test for kidney failure because if you have kidney failure, it will contain a lot of waste products that are meant to be filtered out by the kidneys
• Renal failure is when the kidneys are damaged and unable to filter waste from the blood
• Some ways of treating renal failure include: dialysis, kidney transplants
• Models such as Visking tubing can be used to demonstrate the effect of surface area on the rate of excretion
• The higher the surface area, the more efficient excretion is
• Some examples of waste products in humans include: Urea, ammonia, carbon dioxide, and water
• The site of excretion for humans are the kidneys, but for animals it is the liver
• The diaphragm is a muscle that separates the thoracic cavity from the abdominal cavity

  
• The trachea is a tube that connects the larynx to the bronchi.

  
• The alveolus is the site of gas exchange in the lungs.

  
• The ribs are in the thoracic cavity and protect the lungs and heart.

  
• The bronchiole is a branch of the bronchi that connects to the alveoli.

  
• The rib muscles are the muscles that attach the ribs to the thoracic wall.
• The bronchus is a large airway that connects the trachea to the lungs.

  
• The heart is a muscular organ that pumps blood around the body.

  
• In this diagram, carbon dioxide is excreted and oxygen is received

  
• Features of the alveoli include: thin walls, large surface area
• Lung diseases that affect the function of the alveoli include: Emphysema, Asthma, Pneumonia, Tuberculosis