Inhliziyo iyisitho semisipha ezilwaneni eziningi, esimpompa igazi ngemithambo yegazi yohlelo lokujikeleza kwegazi.Igazi elimpontshwayo lithwala umoya-mpilo nezakhi zomzimba emzimbeni, ngenkathi lithwala imfucumfucu ye-metabolic efana ne-carbon dioxide emaphashini. Kubantu, inhliziyo icishe ilingane nenqindi evaliwe futhi itholakala phakathi kwamaphaphu, egumbini eliphakathi kwesifuba. Inhliziyo impompa igazi ngesigqi esinqunywa yiqembu lamaseli okwenza amandla ku-sinoatrial node. Lokhu kukhiqiza umsinga wamanje obangela ukusikwa kwenhliziyo, kudlule endaweni engeyokuqala futhi kuhambisane nohlelo lokuqhuba kwenhliziyo. Inhliziyo ithola igazi elinomoya-mpilo ophansi kusuka ekujikelezeni kwesistimu, okungena ku-atrium elungile kusuka ku-venae cavae ephezulu futhi engaphansi futhi kudlulele ku-ventricle efanele. Kusuka lapha kudonswa ekuhambeni kwegazi, ngamaphaphu lapho ithola khona umoya-mpilo futhi ikhiphe isikhutha. Igazi elinomoya-mpilo bese libuyela e-atrium engakwesobunxele, lidlule ku-ventricle engakwesokunxele bese likhishwa nge-aorta liye ekujikelezeni kwesistimu − lapho i-oxygen isetshenziswa khona futhi ihlanganiswe ne-carbon dioxide. Inhliziyo ishaya ngesilinganiso sokuphumula esiseduze kwezingu-72 ngomzuzu. Ukuvivinya umzimba kukhuphula izinga okwesikhashana, kodwa kwehlisa ukuphumula kwenhliziyo esikhathini eside, futhi kuhle empilweni yenhliziyo. Inhliziyo yomuntu itholakala maphakathi ne-mediastinum, ezingeni le-vertebrae ye-thoracic T5-T8. Isaka elinezimbili elibizwa ngokuthi i-pericardium lizungeze inhliziyo futhi linamathele ku-mediastinum.