Answer:
At the beginning you start out with a lot of energy and stamina but as you progress, maybe five minutes in, you start to get out of breath. While breathing harder, you are trying to intake more oxygen and at the 10 minute mark you can feel your muscles burning a little bit and tire out more. At this point you are gasping for oxygen because your muscles are deprived of oxygen and you body makes lactic acids which you muscles can use instead of oxygen. By the end of it you are very tired.
Explanation:
Hope this helps! I am not sure how scientific of an explanation you wanted.
generate energy by photosynthesis
Answer: The hepatic portal vein is one of the most important vein that receives blood from the body and transports it into the liver for filtration and processing. This vein is part of the hepatic portal system that receives all of the blood draining from the abdominal digestive tract, as well as from the pancreas, gallbladder, and spleen.
‘Hepatic’ means of or relating to the liver, therefore the hepatic portal vein is a blood vessel that sends nutrient-rich blood from the gastrointestinal tract and spleen to the liver, but also delivers toxins to the liver that will be chemically modified in the proces of detoxication