Na+ Function/Homeostasis/Imbalances
Call Kai
Learn
Practice Test
Spaced Repetition
Match
Flashcards
Knowt Play1/39
There's no tags or description
Looks like no tags are added yet.
Name | Mastery | Learn | Test | Matching | Spaced | Call with Kai |
|---|
No analytics yet
Send a link to your students to track their progress
40 Terms
What is the principal cation in extracellular fluid (ECF)?
Na⁺
Na⁺ accounts for approximately what percentage of the osmolarity of ECF?
90–95%
Na⁺ is the most significant solute in determining…
total body water and its distribution of among the fluid compartments
The Na⁺ gradient is a source of….
potential energy
The Na⁺ gradient provides energy for…
cotransport of other solutes (glucose- SGLT, potassium- Na/Cl/K, & calcium- Na+/Ca2+)
The Na⁺/K⁺ pump functions to…
exchanges intracellular Na+ for extracellular K+ (3 Na+ out/2 K+ in)
What is the role of sodium bicarbonate (NaHCO₃)?
Buffers pH in extracellular fluid
What coordinates Na⁺ concentration in the body?
Aldosterone
Which hormone is known as the “salt retaining hormone”?
Aldosterone
What is the primary role of aldosterone in Na⁺ homeostasis?
Adjust Na⁺ excretion
What condition stimulates the secretion of aldosterone?
Hypotension
Through which mechanism is aldosterone released when blood pressure is low?
Renin-angiotensin-aldosterone system
Why does the body secrete aldosterone during hypotension?
To reabsorb more Na⁺
How does aldosterone affect sodium reabsorption?
Increases reabsorption
What is an effect of aldosterone on urine composition?
Less NaCl in urine
How does aldosterone affect potassium levels in urine?
Increases potassium in urine
How does aldosterone influence urine pH?
Lowers pH
What mechanism inhibits elevated blood pressure?
renin-angiotensin-aldosterone (more NaCl and H2O in Urine)
How much sodium do the kidneys normally reabsorb?
Almost none
What is the primary role of ADH in Na⁺ homeostasis?
Modifies water excretion independently of Na⁺
What stimulates the release of ADH?
High Na⁺ concentration in the blood
Which part of the body releases ADH?
posterior lobe of the pituitary
How do the kidneys respond to ADH?
reabsorb more water
What is the effect of ADH on blood Na⁺ concentration?
Slows further increase in Na⁺ concentration
What inhibits ADH from being released?
when Na+ levels drop
What occurs when ADH release is inhibited?
More water is excreted
What is the result of increased water excretion on blood Na⁺ levels?
Raises Na⁺ levels
What is the function of ANP (atrial natriuretic peptide)?
Inhibits Na⁺ and water reabsorption
What does ANP inhibit?
Renin and ADH secretion
What effect does ANP have on the kidneys?
Eliminate more Na⁺ and water
What is the overall effect of ANP on blood pressure?
Lowers blood pressure
What is hypernatremia?
High Na+ concentration in plasma
What plasma Na⁺ level defines hypernatremia?
Greater than 145 mEq/L (Increase Blood volume & pressure)
Which of the following can cause hypernatremia?
Administration of IV saline
Which conditions are associated with hypernatremia?
Water retention, hypertension, and edema
What is hyponatremia?
Low Na+ concentration levels in plasma
What plasma Na⁺ level defines hyponatremia?
Less than 130 mEq/L
What is a common cause of hyponatremia?
Losing large volumes of sweat or urine and replacing it with plain water
Hyponatremia is often the result of…
an increased body water
How is hyponatremia typically corrected?
Excretion of excess water