RT Book, Section
A1 Scriver, Charles R.
A2 Valle, David L.
A2 Antonarakis, Stylianos
A2 Ballabio, Andrea
A2 Beaudet, Arthur L.
A2 Mitchell, Grant A.
SR Print(0)
ID 1181421648
T1 Homeostasis, Complexity, and Monogenic Phenotypes: The View from Phenylketonuria
T2 The Online Metabolic and Molecular Bases of Inherited Disease
YR 2019
FD 2019
PB McGraw-Hill Education
PP New York, NY
SN 9780071459969
LK ommbid.mhmedical.com/content.aspx?aid=1181421648
RD 2024/04/23
AB Homeostasis  is  an  abiding  principle  of  living  systems;  it  is  defined  as  that  "relatively  stable  state  of  equilibrium  or  tendency  toward  such  a  state  between  the  different  but  interdependent  elements  and  subsystems  of  an  organism"  (Webster);  accordingly,  metrical  trait  values  (e.g.,  blood  pressure  and  plasma  glucose  concentration)  are  maintained  within  limits.  Whereas  Claude  Bernard  had  only  observed  constancy  of  the  "milieu  interieur"  (extracellular  fluid),  homeostasis  actually  extends  to  intracellular  and  subcellular  environments  and  components.  Because  of  biological  individuality,  each  individual  will  have  a  particular  location  within  the  larger  distribution  of  quantitative  values  that  describe  the  parameter  in  the  population;  the  private  homeostatic  value  may  then  be  seen  to  be  displaced  because  the  individual’s  system  is  undermined  (by  mutation  perhaps)  or  overwhelmed  by  experience.  A  displaced  value  is  likely  to  be  disadaptive  because  evolution  of  biological  diversity  by  natural  selection  was  the  process  by  which  the  optimal  range  of  homeostatic  values  was  obtained.