“…The channel system decreases in diameter after each branch -from the trachea and the large bronchi to the bronchiole with a diameter of less than one millimeter (Aversa et al, 2018a(Aversa et al, b, 2017a(Aversa et al, -b, 2016aAljohani & Desai, 2018;Alexander & Wang, 2018;Apicella et al, 2018 a-c;Marquetti & Desai, 2018;Armah, 2018;Wilk et al, 2017;Babaev et al, 2010;Petrescu et al, 2015;Petrescu, 2008Petrescu, -2009Abdul-Razzak et al, 2012;Ajith et al, 2009;Atasayar et al, 2009;Ahmed et al, 2011;Covic et al, 2007;Willis, 1953Willis, -1954Willis, , 1957Ha, 2010;El-Gendy, 2009;Enstrom, 2014;Hansen, 2014;Rath, 1990Rath, , 2003Yilmaz, 2006;Ravnskov, 2009;Kunutsor, 2016;Hickey, 2007;Choudhury & Greene, 2018;Choudhury, 2018).…”