Anatomy/physiology Hole 8Th Edition; Ch. 18, Water, Electrolyte, Acid-Base

Front 1

water1
what are electrolytes?

Water and electrolytes in the body must be in balance. What does this mean?

Back 1

molecules that release ion in water.

the amounts entering the body must equal the amounts leaving it.

Front 2

water2
How water and electrolyte balance interdependent?

Back 2

Electrolytes are dissolved in water of body fluids. Anything that changes the water concentration changes the electrolyte concentration and vice versa.

Front 3

water3
The body is what percentage of water by weight?

Water in the body is distributed into which two compartments? Describe these compartments

Back 3

approx. 60%

1)extracellular fluid compartment - the fluid outside the cells, in tissue spaces (interstitial fluid); blood vessels (plasma); lymphatic vessels (lymph)
2)intracellular fluid compartment - enclosed by cell membranes. This is the larger of the two components.

Front 4

water4
How do intracellular and extra cellular fluids differ in composition?

Back 4

1) Extracellular fluids have high concentrations of SODIUM, CHLORIDE, BICARBONATE, CALCIUM ions. (Plasma contains more protein than interstitial fluid or lymph)

2)Intracellular fluid contains more potassium, phosphate, magnesium, and sulfate ions than extracellular fluid.

Front 5

water5
Movement of fluid between compartments is regulated by what three things?

Back 5

1)hydrostatic pressure
2)colloid osmotic pressure
3)sodium ion concentration

Front 6

water6

How does hydrostatic pressure help regulate fluid movement between compartments?

How does colloid osmotic pressure help regulate fluid movement?

Back 6

1)forces fluid out of plasma.
2)drives fluid into lymph vessels

a)returns fluid to plasma
b)regulates fluid movement in and out of cells

Front 7

water7
Water intake comes from what sources? what is water of metabolism

How is water lost?

what inhibits thirst?

Back 7

1)MOST water comes from consuming liquids or moist foods.
2)SOME water comes from oxidative metabolism (water of metabolism)

Water is lost through
1)urine, feces, sweat
2)evaporation from skin and lungs

drinking and resulting stomach distension inhibit thirst.

Front 8

water8
How is water intake regulated? by what mechanism?

What regulates water output? How?

Back 8

Thirst is the primary regulator of intake. As water in body decreases, osmotic pressure of ECF (extracell. fluid) increases, stimulating receptors in thirst center in hypothalamus.

Urine production. Distal convoluted tubules and collecting ducts of the nephron regulate water output. ADH increases water reabsorption and reduces urine production.

Front 9

water9
Which electrolytes are the most important to cellular functions?

How do we get these?

Back 9

sodium, potassium, calcium, magnesium, chloride, sulfate, phosphate, bicarbonate, hydrogen ions.

1)food/beverages
2)as byproducts of metabolism

Front 10

water10

How is electrolyte intake regulated?

A severe definciency of electrolytes may produce what?

Back 10

hunger and thirst

salt craving

Front 11

water11
How are electrolytes lost?

What can affect the rate of loss?

Back 11

1)kidneys
2)perspiration, feces, urine

body temperature and physical exercise

Front 12

water12
How does the adrenal cortex help in sodium and potassium concentrations?

Back 12

adrenal cortex secretes ALDOSTERONE, which
1)increase sodium reabsorption in distal convoluted tubules and collecting ducts of the kidneys' nephrons
2)causes tubular secretion of potassium ions (decreasing potassium in blood)

Front 13

water13

How does the parathyroid gland help in calcium ion output?

What other hormone affects calcium, and where is this hormone produced? What effect does it have?

Back 13

Parathyroid hormone increases the concentrations of calcium and phosphate ions in extracellular fluids.

Calcitonin, thyroid gland, LOWERS blood calcium

Front 14

water14

How are negatively charged ions regulated?

Back 14

by the same mechanisms as the positively charged ions.

Front 15

water15
what are acids?

what are bases?

what importance is pH in the body?

Back 15

acids are electrolytes that ionize in water and release hydrogen ions.

Bases combine with hydrogen ions.

body fluid pH must remain within a certain range, for adequate functioning (eg of enzymes)

Front 16

water16
List the five sources of hydrogen ions in body fluids, and NAME an acid that originates from each source.

Back 16

1)aerobic respiration of glucose - carbonic acid
2)anaerobic respiration of glucose - lactic acid
3)incomplete oxidation of fatty acids - acidic ketone bodies
4)oxidation of sulfur-containing amino acids - sulfuric acid.
5)hydrolysis of phosphoproteins and nucleic acids - phosphoric acid.

Front 17

water 17
Distinguish between a strong and a weak acid, and give an example of each.

Bases vary in strength also

Back 17

strong acid ionizes more easily, eg. hydrochloric acid.

weak acids ionize less completely eg. carbonic acid.

Front 18

water18

What do buffer systems do? Why are they important in the body?

Name three important acid-base buffer systems in the body

Back 18

buffer systems convert strong acids into weaker acids, or strong bases into weaker bases. They help MINIMIZE pH CHANGES in body fluids.

1)bicarbonate buffer system
2)phosphate buffer system
3)protein buffer system.

Front 19

water19

How does the bicarbonate buffer system work?

How do proteins act as buffers?

Back 19

bicarbonate combines with hydrogen ions underacidic conditions to produce carbonic acid.

Under alkaline conditions, carbonic acid release hydrogen ions, and the pH decreases.

H+ + HCO3- = H2CO3 and vice versa

Protein molecules can function as BASES by accepting hydrogen ions in their AMINO groups. They can function as ACIDS by releasing hydrogen ions from their CARBOXYL groups.

Front 20

water20

How does the respiratory center contribute to acid base balance?

Back 20

Respiratory center controls the RATE and DEPTH of breathing, and is sensitive to hydrogen ion concentration in the cerebrospinal fluid. For example, during exercise, body cells INCREASE CO2, and CARBONIC acid. This stimulates the respiratory center which causes increase in RATE and DEPTH of breathing to breath off CO2 (which comes from carbonic acid).

Front 21

water21
How does the kidney help in pH balance?

How are chemical and physiological buffers different?

Back 21

Kidney nephrons secrete hydrogen ions to regulate pH.

Chemical buffers act more rapidly. Physiological buffers act less rapidly.

Front 22

water22
Respiratory acidosis results from increases in concentration of _____ _____ and _____ _____

How is it different from metabolic acidosis?

Back 22

carbon dioxide, carbonic acid

Metabolic acidosis results from accumulation of OTHER ACIDS, or LOSS of bases.

Front 23

water23
Respiratory alkalosis results from ____ of carbon dioxide and carbonic acid.

Metabolic alkalosis results from ______ of hydrogen ions or _____ or bases

Back 23

loss


loss, gain

Front 24

water24

How does the body compensate for acidosis?

For alkalosis?

Back 24

1)chemical buffer systems, which accept hydrogen ions
2)respiratory center increases breathing rate and depth
3)kidneys excrete more hydrogen ions.


A)chemical buffers, eg hemoglobin, release hydrogen ions
B)respiratory center stimulation is decreased, inhibiting hyperventilation
C)kidneys secrete fewer hydrogen ions