Ch 39 Flashcards Preview

NSG 250 > Ch 39 > Flashcards

Flashcards in Ch 39 Deck (68)
Loading flashcards...
1

Electrolytes

-Substances that develop an electrical charge when dissolved in water
-Responsible for maintaining the fluid balance between intracellular and extracellular. Important because it helps with hydration, nerve impulses, muscle function, pH level
-Important because cells, tissues, and fluids thrive in a homeostatic environment

2

Cation

Electrolytes that carry a positive charge

3

Anion

Electrolytes that carry a negative charge

4

Interstitial fluid

lies between the spaces in the blood

5

Intravascular fluid

lies in the plasma within the blood

6

Transcellular fluid

includes specialized fluids like cerebrospinal, pleural, peritoneal, and synovial fluid

7

Active transport

-movement of fluid and solutes that requires energy
- Molecules (solute)
- low concentration to high concentration

8

Passive transport

-movement of fluid and solutes that does not require energy.
- 3 types: osmosis, diffusion, filtration

9

Osmosis

Water
low concentration to high concentration

10

Diffusion

Molecules (solute)
high concentration to low concentration

11

Filtration

Water and small particles
high pressure to low pressure

12

Sensible fluid loss

measurable and perceived
(urine, diarrhea, ostomy, gastric drainage)

13

Insensible fluid loss

not perceived and not easily measured
(evaporated from the skin and lungs)

14

Sodium (Na+)

-Major cation in the ECF
-Normal serum level is 135-145 mEq/L

Function:
-Regulates fluid vol.
-Maintains blood vol.
-Interacts with calcium to maintain muscle contraction
-Stimulates conduction of nerve impulses

Regulation:
-Moves by Active transport
-Regulates aldosterone and ADH levels
-Reabsorbed and excreted through kidneys
-Minimal loss through perspiration and feces
-Low sodium may be caused by excess water intake

Sources:
Table salt, soy sauce, cured pork, cheese, milk, processed foods, canned products, foods preserved with salt

15

Potassium (K+)

-Major cation in ICF
-Normal serum level 3.5-5 mEq/L

Function:
-Maintains ICF osmolality
-Regulates conduction of cardiac rhythm
-Transmits electrical impulses in multiple body systems
-Assists with acid-base balance

Regulation:
-Regulated by aldosterone
-Excreted and conserved through the kidneys
-Lost through vomiting and diarrhea
-Lost triggered by many diuretics

Sources:
bananas, oranges, apricots, figs, dates, carrots, potatoes, tomatoes, spinach, dairy products, and meats

16

Calcium (Ca2+)

-Most abundant electrolyte in the body
-Normal serum level 8.5-10.5 mg/dL

Function:
-Promotes transmission of nerve impulses
-Major component of bone and teeth
-Regulates muscle contraction
-Maintains cardiac automaticity
-Essential factor in the formation of blood clots
-Catalyst for many cellular activities

Regulation:
-Combines with phosphorus to form the mineral salts of the teeth and bone
-Calcium and phosphorus levels inversely proportional
-Parathyroid hormone (PTH) stimulates release from bone and reabsorption for kidneys and intestines
-Calcitonin (from the thyroid) blocks bone breakdown and lowers calcium levels
-Absorption stimulated by vitamin D

Sources:
-Milk, milk products, dark green veggies, salmon, breads and cereals

17

Magnesium (Mg2+)

-Presents in skeleton and ICF
-Second most abundant cation in ICF
-Normal serum level is 1.6-2.6 mEq/L

Function:
-Involved in protein and carbohydrate metabolism
-Necessary for protein and DNA synthesis within the cell
-Maintains normal intracellular levels of potassium
-Involved in electrical activity in nerve and muscle membranes, including the heart
-May have a role in regulating BP and may influence the release and activity of insulin

Regulation:
-Ingested in the diet and absorbed through the small intestine
-Excreted by kidneys
-Loss may be triggered by diuretics, poorly controlled DM, and excess alcohol intake

Sources:
-Average daily requirement is 18-30 mEq
-most foods, high levels present in green veggies, cereal, grains, and nuts

18

Chloride (CI-)

-Major anion in the ECF
-Normal serum level is 95-105 mEq

Function:
-Works with Na+ to maintain osmotic pressure between fluid compartments
-Essential for production of HCI for gastric secretions
-Functions as buffer in oxygen-carbon dioxide exchange in RBCs
-Assists with acid-base balance

Regulation:
-Reabsorbed and excreted through the kidneys along with sodium
-Regulated by aldosterone and ADH levels
-Deficits lead to potassium deficits; potassium deficits lead to chloride deficits

Sources:
-foods high in sodium

19

Phosphate (PO4-)

-Major anion in the ICF
-Normal serum level is 1.7-2.6 mEq/L

Function:
-Serves as a catalyst for many intracellular activities
-Promotes muscle and nerve action
-Assists with acid base balance
-Important for cell division and transmission of hereditary traits

Regulation:
-Combines with calcium to form the mineral salts of the teeth and bones
-Calcium and phosphorus levels inversely proportional
-Regulated by PTH; has inverse response to calcium
-Excreted and reabsorbed by the kidneys

Sources:
-meat, fish, poultry, milk products, carbonated beverages, legumes
-Readily available in body as a result of metabolism

20

Bicarbonate (HCO3-)

-Major buffer in the body
-In ECF and ICF
-Normal serum level is 22-26 mEq/L

Function:
-Maintains acid-base balance by functioning as the primary buffer in the body

Regulation:
-Lost through diarrhea, diuretics, renal insufficiency
-Excess possible if person ingests quantities of acid neutralizers

21

Hydrostatic pressure

-The force created by fluid within a closed system
-It is responsible for normal circulation of blood

22

Osmotic pressure

the power of a solution to draw water

23

The IOM recommends a total fluid intake of

women- 2700ml/day
men- 3700 ml/day

24

What is the principal regulator of fluid and electrolyte balance

the kidneys

25

Renin

enzyme responsible for the chain of reactions that converts angiotensinogen to angiotensin II

26

Angiotensin II

Acts on the nephrons to retain sodium and water and directs the adrenal cortex to release aldosterone

27

Thyroid hormone affects fluid volume by?

influencing cardiac output

28

Natriuresis

The discharge of sodium through urine

29

Acid

-Any compound that contains hydrogen ions (H+) that can be released
-Referred to as cation donors

30

Base

-A compound that combines with hydrogen ions in solution
-Referred to as cation acceptors