Alterations in Water and Sodium balance

Question 1

Water Balance

Answer 1

• Determined by osmotic gradients established by sodium concentrations
• Antidiuretic hormone (ADH) regulates water balance (kidney gets rid of h20)

Question 2

Sodium balance and functions

Answer 2

-Sodium accounts for 90% of the ECF cations

• Maintains extracellular osmolarity
• maintains resting membrane potential (RMP) and needed for depolarization

Question 3

Aldosterone

Answer 3

Regulates plasma sodium

^ aldosterone = ^ Na+ reabsorption = ^ h20 reabsorp. = ^ BV= ^ BP

Question 4

Isotonic Alterations in Sodium and Water balance

Answer 4

-Changes in total body water (TBW) accompanied by proportional changes in electrolytes

Question 5

isotonic alteration types

Answer 5

FLUID OVERLOAD; administration of intrvenous normal saline solutions/hypersecretion of aldosterone (hyperaldosteronism) (^ aldost. = ^ retention of h20 and Na)

HYPOVOLEMIA; hyposecretion of aldosterone, sweating
( v aldosterone = v retention of h20 and Na)

Question 6

Hypotonic alterations; Hyponatremia (and causes)

Answer 6

LOW SODIUM IN THE BLOOD (lower than 35)
causes;
-Vomitting;gastric suctioning
loss of sodium and acid levels

-inadequate sodium intake

-excessive oral water intake
dilutes plasma sodium to a dangerous level

-Excessive ADH secretion (syndrome of inappropriate elevated ADH -SIADH)
too much ADH = too much water retention

Question 7

Hyponatremia patho

Answer 7

• Shift of h20 from ECF to cyotplasm (ICF)
• too much h20 into icf will cause cell to burst

LOWER RMP
… less Na+ in cell drops memb. potential making it more negative, harder to depolarize & get AP

Question 8

hyponatremia clinical manifestations

Answer 8

NEURONAL SWELLING

• lethargy and confusion,seizures, comas
• gait disturbance, falls

FLUID OVERLOAD

• weight gain
• edema

Question 9

hypertonic alteration; hypernatremia (and causes)

Answer 9

HIGH SODIUM IN THE BLOOD (greater than 145)
causes;
(usually developed w/ kidney malfunction)
-Dietary sodium excess

• administration of hypertonic saline solution
• insufficient intake/ dehydration

-decreased ADH secretion (diabetes insipidus)
( v ADH = v water retention)

Question 10

What is ADH and where is it produced?

Answer 10

antidiueratic hormone… pituitary gland

Question 11

Hypernatremia patho

Answer 11

Shift of water from cytoplasm to ECF

• diluting Na+ in the blood raising blood volume
• cells shrink and become dehydrated

HIGHER RMP
high Na+ in the cell memb making it more positive
-Closer to threshold
-neuromuscular excitability
-more AP fired

Question 12

hypernatremia clinical manifestations

Answer 12

DUE TO SYSTEMIC DEHYDRATION
-thirst

-low bp and increased heart rate (tachycardic)
….high heart rate trying to keep bp up

-dry mucous membranes
…chronic tissue and cell dehydration

-poor skin tugor
..tissue not well hydrated if it doesn’t return quickly

-weight loss

-decreased urine output and concentrated urine
…kidneys working hard to retain water

Question 13

Potassium balance

Answer 13

• major intracellular electrolyte

- plasma concent 3.5-5.5 mEq/L in blood

Question 14

Regulation of plasma potassium by the kidneys

Answer 14

• Potassium normally secreted by renal tubules and excreted in urine
• aldosterone stimulates K+ excretion by kidneys

Question 15

Insulin

Answer 15

-Cells requires insulin to uptake glucose into the cell
-insulin is produced by the pancreas
-
..as insulin binds to insulin receptor, K+ and glucose enter the cell

Question 16

Hypokalemia and causes

Answer 16

TOTAL BODY DEFICIT OF POTASSIUM
causes;
-shifts of K+ from ECF to ICF

-gastrointestinal (diarrhea)
….washing GI tract out, K+ cant get absorbed

-Renal Losses (diuresis)
..washes K+ out by urine

-Shift of K+ form ECF to ICF
..insulin overdose, too much K+ enters cell lowering blood K+ levels

^ insulin + ^ glucose = v K+ plasma levels (in blood bc goes to ICF)

Question 17

Hypokalemia patho

Answer 17

-Lower RMP, harder to reach threshold

Question 18

Sodium imbalances affect;

Answer 18

Effect CNS (neurological)

Question 19

K+ imbalances effect

Answer 19

Effect muscle tissue (ex; heart)

Question 20

Hyperkalemia and causes

Answer 20

TOTAL BODY EXCITATION OF K+
causes;
-Renal failure
..kidnye cant get rid of excess K+

-Increased K+ intake

-Shift of K+ from ICF to ECF
.. ex; crush injuries: cell lyse/die go to ecf and gets in blood stream

-Insulin deficiency
..no insulin= no glucose or K+ intake

Question 21

Hyperkalemia patho

Answer 21

• higher RMP
• mild-moderate; increased muscular excitability
• sever hyperkalemia- cells unable to repolarize
• cells depolarize and can never repolarize, heart pumps and cant relax