Dehydration Flashcards
What is dehydration
Experiencing a net loss of fluid in the body, either due to inadequate fluid intake or excessive fluid loss
What is isotonic dehydration
No shift as water and solutes are both lost resulting in a decreasing blood volume
What is hypertonic dehdyration
More water is lost than solutes as water moves from intracellular fluid into extracellular fluid
What is hypotonic dehydration
More solutes is lost than water as water moves from extracellular fluid into intracellular fluid
What are Osmoreceptors
Specialized sensory cells that detect changes in osmotic pressure of blood
What do osmoreceptors do
They regulate fluid balance in the body and trigger the release of ADH to maintain water levels
Where are osmoreceptors located
Hypothalamus
What is blood osmolality
The conc. of dissolved particles in the blood
What is antidiuretic hormone (ADH)
Also known as vasopressin, it is a hormone that promotes water absorbption in the kidneys. It is released from the posterior pituitary gland
What does RAAS stand for
Renin-Angiotensin-Aldosterone-System
What is the role of RAAS
RAAS is a complex hormone system that works to restore blood pressure and fluid imbalance when they become low
Why would RAAS decrease urine output
RAAS works to conserve fluids and maintain homeostasis in cases of low blood pressure, sodium deficiency and dehydration.
What is the order of RAAS
Renin is released from the kidneys.
The renin the converts angiotensin from the liver into angiotensin I
Angiotensin I is converted to Angiotensin II by ACE
Angiotensin II stimulates the release of Aldosterone from the adrenal cortex
What are the 2 the roles of Angiotensin II
Angiotensin II causes vasoconstriction in the blood vessels, in an attempt to raise blood pressure.
It also activates the thirst center of the brain
What is the role of Aldosterone
Promotes H2O, Na and K reabsorbption in the kidneys
How is fluid imbalance detected
Osmoreceptors detect an increase in osmotic pressure triggering the thirst center of the brain
How does the brain response to increased osmotic pressure
The brain will release ADH from the posterior pituitary glands to increase water absorbption in the kidneys
Why is water so important
Water is cruical to every bodily process, which is why the body must maintain a specific balance for the body to function properly
Why are dehydrated patient HR so high
Dehydration results in decreased blood volume. The heart is trying to make up for the decrease by pumping more blood
Why are dehydrated patient BP so low
Decreased blood volume decreases overall pressure of blood
Why are dehydrated patient RR so high
Low blood pressure means not enough O2 and nutrients are reaching tisses. The body makes up for this by increasing O2 intake
Why do dehydrated patients have high temp
With less fluid in the body, the body cannot sweat which is essential to the regulation of body temp
Why are fluids so essential
1) Cellular function
2) Maintains Circulation
3) Transports waste
4) Fluid Balance
5) Temperature regulation
What is the role of an electrolyte
Maintaining fluid balance, transmitting nerve signals and supporting muscle function
Role of potassium
Regulates how much water moves in and out of cells
How do oral fluids help replenish the fluids lost
Oral fluids contains the necessary water and electrolytes to make up for the loss
