Homeostasis: Regulating Thirst

Made by @agreyr

Water Balance

A precise balance of fluids and dissolved salts surround all of the cells of the body to allow proper functioning; approximately like diluted seawater

Important to maintain a decent ratio of water in the intracellular compartment vs the extracellular compartments; happens via diffusion and osmosis

Diffusion

Passive spread of the salt components (ions) to evenly space them in the water

Osmosis

Movement of water molecules to equalize the concentration of two solutions on either side of a semi-permeable membrane

Two types of water imbalance (thirst)

Osmotic thirst and Hypovolemic thirst

Osmotic thirst

Volume of extracellular fluid is slightly decreased due to obligatory losses

Concentration of salt in the extracellular fluid increases

Results in water being drawn out of the cells

Detected by osmosensory neurons

Hypovolemic thirst

Caused by a more significant decrease in the overall volume of extracellular fluid

Due to vomiting, hemorrhage, or sustained diarrhea; detected by baroreceptors

Doesn’t change concentration, just volume