How our body allows us to go through cellular respiration

 We have evolved complex organ systems, many of which function to help our body go through cellular respiration

 Atom  Molecule  Organelle  Cell  Tissue  Organ  Organ System  Organism

 Glucose or other fuel

 The digestive system allows us to absorb nutrients such as glucose, amino acids and fats  The main organs:  Stomach  Small Intestine  Large Intestine

 Breaks down food with muscles and acid  Sends it on to the small intestine  (no absorption)

 Finishes digestion  Absorbs nutrients like  Glucose  Amino acids  Fats  Minerals  Vitamins  These are absorbed into the bloodstream

 Mostly absorbs water  Also some bacteria break down food that we couldn’t  The undigested material is expelled

 Pancreas  Secretes enzymes  Secretes hormones (insulin)  Liver  Makes bile Digests fat  Gall Bladder  Stores/secretes bile

 The liver stores glucose in the carbohydrate glycogen  Breaks down glycogen when we need to make ATP via respiration  Along with many other vital roles

 Oxygen  Carbon dioxide

 The respiratory system facilitates gas exchange  Examples of respiratory systems:  Lungs  Gills  Skin breathing

 Create an oxygen rich/CO2 poor environment  Oxygen diffuses into blood  CO2 diffuses out of it

 The circulatory system transports glucose, oxygen, carbon dioxide etc. throughout the body  Also things like lactic acid

 The heart is a muscle which moves the substances  Arteries carry blood Away from the heart  Veins return blood to the heart  Capillaries are where gas exchange happens