Renal Physl 11 Flashcards
How do the kidneys play an essential role in cardiovascular homeostasis?
By maintaining fluid and electrolyte balance
What is maintaining mass balance?
The intake of water and electrolytes must be matched by equivalent output in order to maintain homeostasis
What are other routes that water and ions are lost to?
Feces, sweat and respiration
Why is water and electrolyte balance critical in homeostasis?
Because water and sodium are involved in determining our extracellular fluid volume and the concentration of salt in our blood
What can the total body water be divided into?
ICF (intracellular fluid) and ECF (extracellular fluid)
What can ECF be further divided into?
Plasma and interstitial fluid
How much of Total body water is intracellular fluid?
2/3
What is plasma?
The non-cellular portion of blood
What is the interstitial fluid?
What bathes our cells
Why is extracellular fluid osmolarity normally maintained within a very tight range?
Because cell membrane are readily permeable to water so water can easily pass in and out of cells
What would happen if osmolarity of extracellular fluid were allowed to fluctuate?
Water will move in or out of the cells which alter intracellular volume
What would happen if the osmolarity of extracellular fluid decreases to much (is hypotonic) because too much water is ingested?
Water will move into cells causing them to swell
What would happen if an individual was dehydrated or consumed too much salt?
The osmolarity of the extracellular fluid is increased and hypertonic so water will move out of cells causing them to shrink
What happens if there is a reduction in blood volume?
There will be reduced BP. Volume receptors in the atria, carotid and aortic baroreceptors will rely information which triggers homeostatic reflexes that trigger modifications at the cardiovascular system such as an increase in cardiac output and an increase in peripheral vasoconstriction which increase BP at the kidneys which will conserve water and further volume loss
What will occur if there is an increase in blood volume?
BP will increase and receptors in the atria and the endocrine cells in the atria and carotid and aortic baroreceptors will trigger homeostatic reflexes that involve modifications in the cardiovascular system and kidneys. There will be a reduction in cardiac output and peripheral vasodilation. Excretion of salt and water will reduce extracellular fluid and intracellular fluid volume
