▁Illinois ▁Category : 1 8 3 7 ▁establish ments ▁in ▁Illinois ▁Category : Pres by ter ian ism ▁in ▁Illinois ▁Category : Univers ities ▁and ▁colleg es ▁affili ated ▁with ▁the ▁Pres by ter ian ▁Church ▁( USA ) ▁Category : Work ▁colleg es <0x0A> </s> ▁In ▁phys i ology , ▁the ▁term ▁ser ous ▁fluid ▁or ▁ser os al ▁fluid ▁( origin ating ▁from ▁the ▁Med ieval ▁Latin ▁word ▁ser os us , ▁from ▁Latin ▁ser um ) ▁is ▁any ▁of ▁various ▁body ▁flu ids ▁res emb ling ▁ser um , ▁that ▁are ▁typically ▁pale ▁yellow ▁and ▁transparent ▁and ▁of ▁a ▁ben ign ▁nature . ▁The ▁fluid ▁fills ▁the ▁inside ▁of ▁body ▁cav ities . ▁Ser ous ▁fluid ▁origin ates ▁from ▁ser ous ▁g lands , ▁with ▁secret ions ▁en rich ed ▁with ▁prote ins ▁and ▁water . ▁Ser ous ▁fluid ▁may ▁also ▁origin ate ▁from ▁mixed ▁g lands , ▁which ▁contain ▁both ▁m uc ous ▁and ▁ser ous ▁cells . ▁A ▁common ▁trait ▁of ▁ser ous ▁flu ids ▁is ▁their ▁role ▁in ▁assist ing ▁dig estion , ▁ex cret ion , ▁and ▁resp iration . ▁ ▁In ▁medical ▁fields , ▁especially ▁cy top ath ology , ▁ser ous ▁fluid ▁is ▁a ▁syn onym ▁for ▁eff usion ▁flu ids ▁from ▁various ▁body ▁cav ities . ▁Ex amples ▁of ▁eff usion ▁fluid ▁are ▁ple ural ▁eff usion ▁and ▁per ic ard ial ▁eff usion . ▁There ▁are ▁many ▁causes ▁of ▁eff us ions ▁which ▁include ▁invol vement ▁of ▁the ▁cav ity ▁by ▁cancer