Chapter 2 Homeostasis of Body Fluids: Concept of Steady State Balance Flashcards
Concept of Steady State Balance
What is steady state balance?
volume and composition of body fluids remain constant despite the addition and elimination of water and solutes from the body
What is the extracellular fluid [ECF]?
cells, which constitute the interface between the internal environment of the body and the external world, maintain the volume and composition of the fluid bathing all cells
What is intracellular fluid (ICF)?
Fluid inside cell
What is the role of kidneys in steady state balance?
regulating the excretion of water and NaCl, respectively
How does the body maintain a steady state balance?
by ensuring that the amount of water added to the body each day is exactly balanced by the amount lost or excreted from the body
How does the body monitor steady state balance?
monitors the amount of water that it contains through changes in the osmolality of ECF
What happens to ECF when excess water is added?
the osmolality of ECF decreases
What happens to ECF with a negative balance of water?
the osmolality of ECF increases
What part of the brain is responsible for monitoring ECF osmolality?
Cells within the hypothalamus
What does ADH stand for?
antidiuretic hormone
What does ADH do?
secreted from the posterior pituitary and acts on the kidneys to reduce the excretion of water
What happens when the osmolality of ECF is decreased?
thirst is inhibited, as is the secretion of ADH, intake of water is reduced and excretion by the kidneys is increased
