Editing Grasshopper (section)

===Circulation and respiration===
{{further|Insect morphology#Circulatory system|Respiratory system of insects}}
Like other insects, grasshoppers have an [[open circulatory system]] and their body cavities are filled with [[haemolymph]]. A heart-like structure in the upper part of the abdomen pumps the fluid to the head from where it percolates past the tissues and organs on its way back to the abdomen. This system circulates nutrients throughout the body and carries [[metabolic waste]]s to be excreted into the gut. Other functions of the haemolymph include wound healing, heat transfer and the provision of hydrostatic pressure, but the circulatory system is not involved in gaseous exchange.<ref>{{cite web |url=https://projects.ncsu.edu/cals/course/ent425/library/tutorials/internal_anatomy/circulatory.html |title=Circulatory system |author=Meyer, John R. |date=8 April 2009 |work=General Entomology |publisher=NC State University |access-date=12 April 2015 |url-status=live |archive-url=https://web.archive.org/web/20170103003933/https://projects.ncsu.edu/cals/course/ent425/library/tutorials/internal_anatomy/circulatory.html |archive-date=3 January 2017 }}</ref> Respiration is performed using [[Trachea#Invertebrates|trachea]]e, air-filled tubes, which open at the surfaces of the thorax and abdomen through pairs of valved [[Spiracle (arthropods)|spiracle]]s. Larger insects may need to actively ventilate their bodies by opening some spiracles while others remain closed, using abdominal muscles to expand and contract the body and pump air through the system.<ref>{{cite web |url=https://projects.ncsu.edu/cals/course/ent425/library/tutorials/internal_anatomy/respiratory.html |title=Insect physiology: Respiratory system |author=Meyer, John R. |date=1 November 2006 |work=General Entomology |publisher=NC State University |access-date=12 April 2015 |url-status=live |archive-url=https://web.archive.org/web/20170103003044/https://projects.ncsu.edu/cals/course/ent425/library/tutorials/internal_anatomy/respiratory.html |archive-date=3 January 2017 }}</ref>