Osmoregulation

Intracellular fluid

found within cells

interstitial fluid

surround/bathing cells

extracellular fluid

made of water, electrolytes, and non-electrolytes

what ions does extracellular fluid mostly contian

Na+ and F-

What ion is high in blood plasma/interstitial fluid

Na+

What ion is high in intracellular fluid

K+

What are the functions of ECF

1. ensure basic cell function

2. maintain cell structure

3. vehicle for nutrients/chemicals

how does ECF maintain cell function

maintains electrical gradients across membrane (Na+ out, K+ in)

How does ECF maintain cell structure

water/ions alter cell volume, hydrostatic pressure maintains tissues/organs

Osmoconformer chracteristics

no homeostasis, stable environment, cells are iso-osmotic with environment, raise osmotic blood pressure with environment

Osmoregulator characteristics

homeostasis, tissues have stable internal conditions, unstable environment, maintain osmotic blood pressure

Examples of osmoregulators

shrimp, salmon

examples of osmoconformers

mussels, barnacles

How do osmoregulators work in freshwater

solve salt loss/water gain, excrete water but retain solute

How do osmoregulators work in saltwater

fish faces inward salt diffusion, kidneys excrete high salt concentration but retain water

What is hypertonic thirst triggered by

high electrolyte levels (high plasma osmolarity)

Hypertonic thirst

increase plasma osmolarity, increase solute concentration outside cell, decrease saliva production (dry mouth), osmoreceptors in hypothalamus trigger thirst center, drink water

What triggers hypovolemia

fluid volume decrease

isotonic dehydration

decrease fluid volume, decrease blood pressure, baroreceptors triggered, decease kidney perfusion, trigger extracellular thirst, drink water/eat salt

where are baroreceptors found

aortic artery and carotid arteries

Where are osmoreceptors found

hypothalamus