1. Nervous system and Circulatory system


The major organ of the nervous system is the brain.  The brain sends and receives messages.  The major organ of the circulatory system is the heart.  Part of the brain called your brain stem sends messages to your heart telling it to pump.  In return your heart pumps blood to your brain.  The brain gets oxygen and nutrients from the blood.  The blood takes away waste produced in the brain.




  1. Circulatory and Respiratory

The main function of the respiratory system is to provide oxygen for the body which all cells need to provide energy. The circulatory system then transfers the oxygen to all the cells in the body via red blood cells. It also gets nutrients from the blood and brings it to the lungs.



  1. Digestive and Circulatory

The main function of the digestive system is to take away nutrients from the food you eat. The digestive and circulatory systems work together for the digestive system to get nutrients from the food we eat, It will also go to the cells to provide them with nutrients to make energy. The digestive system also gets oxygen from the circulatory system.



  1. Circulatory and excretory

The main function of the excretory system is used to get rid of nitrogenous waste, which is a toxic to our body. Kidneys filter blood brought to them by the circulatory system. The circulatory system gives oxygen and nutrients to the excretory system. Humans get rid of nitrogenous waste by sweating and urine. What this helps us with is homeostasis.




  1. Nervous and Skeletal

The main function of the nervous system is so that you can move and feel stuff. The skeletal system is your bones and without your bones you would not be able to walk or stand up. Also your cranium protects and supports your brain and if that wasn’t protected we would die.



  1. Nutrients+Oxygen=Energy+CO2+ Nitrogenous Waste (explain it how do systems work together)

The digestive system takes the nutrients from the food and the respiratory system to get oxygen from the air. Both of which the mitochondria turns it into energy but also makes it into co2 gas and nitrogenous waste. Our respiratory system gets rid of co2 gas by our breathing. The excretory system gets rid of the nitrogenous waste by us going to the bathroom. The circulatory system helps in this process by moving everything around, such as the blood, oxygen and nutrients.