WATER AND ELECTROLYTE BALANCE. 1 Flashcards
WATER BALANCE (35 cards)
What is the range of average water content in the human body?
The average water content in the human body varies from 40% to 75% of total body weight.
Where is this water located within the body?
The water is located in intra and extra cellular spaces.
How does age affect the average water content in humans?
Average water content tends to decline with age.
Is there a difference between men’s and women’s average water content? If so, what is it attributed to?
Yes, there is a difference. Women have lower average water content than men, primarily due to their higher fat content.
Why is water known as a solvent for all processes in the human body?
Water acts as a solvent for all processes because it:
1. Transports nutrients to cells
2. Removes waste products through urine
3. Determines cell volume
4. Serves as the body’s coolant through sweating
What percentage of body fluids does intracellular fluid account for
Intracellular fluid accounts for two-thirds of total body fluids.
What are the two subdivisions of extracellular fluid?
Extracellular fluid is subdivided into intravascular ECF (plasma) and interstitial cell fluid.
What is the approximate percentage of water in normal plasma?
Normal plasma contains approximately 93% water.
By what means is the distribution of body fluid controlled?
The distribution of body fluid is controlled by maintaining the concentration of electrolytes and proteins.
What is osmolality?
Osmolality is the physical property of a solution based on the concentration of solutes. It is expressed as millimoles per kilogram of solvent (w/w).
How is osmolality expressed
Osmolality is expressed in terms of millimoles per kilogram of solvent (w/w).
What effect does increased blood osmolality have on hormone release
Increased blood osmolality triggers the secretion of arginine vasopressin hormone (AVP) (also known as antidiuretic hormone (ADH)
Which hormones are involved in fluid reabsorption by the kidneys?
The hormones involved in fluid reabsorption by the kidneys are ADH (AVP), which promotes reabsorption of fluids.
What is the parameter to which the hypothalamus responds?
The hypothalamus responds to osmolarity in plasma.
How does Na+ concentration affect plasma
Na+ concentration and its associated anions account for approximately 90% of the osmotic activity in plasma.
What percentage of the osmotic activity in plasma is accounted for by Na+ and its associated anions?
Approximately 90% of the osmotic activity in plasma is attributed to Na+ and its associated anions.
How do osmoreceptors in the hypothalamus respond?
Osmoreceptors in the hypothalamus respond to the smallest change in osmolarity.
what is the clinical significance of osmolarity
- Osmoreceptors in the hypothalamus respond to smallest change in osmolarity
- It affects the Na+ concentration in plasma, Na+ and its associated anions account for approximately 90% of the osmotic activity in plasma.
- Osmolarity in plasma is the parameter to which the hypothalamus responds
- An increase or decrease of 1 – 2% in osmolarity causes a fourfold in AVP concentration and shuts off AVP production respectively
- Hypoosmolality and hyponatremia usually occur only in patients with impaired renal excretion of water
- Hypo-osmolality may occur in diabetes insipidus patient
When does hypoosmolarity and hyponatremia ussually occur
in patients with renal impaired renal excretion of water
in which patients does hypo-osmolarity occur
in diabetes insipidus patients
What is interconnected in controlling blood volume
The regulation of both sodium (Na+) and water is interconnected in controlling blood volume.
Which system responds primarily to a decreased blood volume?
The renin-angiotensin-aldosterone system responds primarily to a decreased blood volume.
What is secreted by renal glomeruli?
Renal glomeruli secrete renin.
What does renin convert angiotensinogen into
Renin converts angiotensinogen into angiotensin I and then into angiotensin II
