Study your flashcards anywhere!

Download the official Cram app for free >

  • Shuffle
    Toggle On
    Toggle Off
  • Alphabetize
    Toggle On
    Toggle Off
  • Front First
    Toggle On
    Toggle Off
  • Both Sides
    Toggle On
    Toggle Off
  • Read
    Toggle On
    Toggle Off

How to study your flashcards.

Right/Left arrow keys: Navigate between flashcards.right arrow keyleft arrow key

Up/Down arrow keys: Flip the card between the front and back.down keyup key

H key: Show hint (3rd side).h key

A key: Read text to speech.a key


Play button


Play button




Click to flip

24 Cards in this Set

  • Front
  • Back
what are electrolytes?

Water and electrolytes in the body must be in balance. What does this mean?
molecules that release ion in water.

the amounts entering the body must equal the amounts leaving it.
How water and electrolyte balance interdependent?
Electrolytes are dissolved in water of body fluids. Anything that changes the water concentration changes the electrolyte concentration and vice versa.
The body is what percentage of water by weight?

Water in the body is distributed into which two compartments? Describe these compartments
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.
How do intracellular and extra cellular fluids differ in composition?
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.
Movement of fluid between compartments is regulated by what three things?
1)hydrostatic pressure
2)colloid osmotic pressure
3)sodium ion concentration

How does hydrostatic pressure help regulate fluid movement between compartments?

How does colloid osmotic pressure help regulate fluid movement?
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
Water intake comes from what sources? what is water of metabolism

How is water lost?

what inhibits thirst?
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.
How is water intake regulated? by what mechanism?

What regulates water output? How?
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.
Which electrolytes are the most important to cellular functions?

How do we get these?
sodium, potassium, calcium, magnesium, chloride, sulfate, phosphate, bicarbonate, hydrogen ions.

2)as byproducts of metabolism

How is electrolyte intake regulated?

A severe definciency of electrolytes may produce what?
hunger and thirst

salt craving
How are electrolytes lost?

What can affect the rate of loss?
2)perspiration, feces, urine

body temperature and physical exercise
How does the adrenal cortex help in sodium and potassium concentrations?
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)

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

Calcitonin, thyroid gland, LOWERS blood calcium

How are negatively charged ions regulated?
by the same mechanisms as the positively charged ions.
what are acids?

what are bases?

what importance is pH in the body?
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)
List the five sources of hydrogen ions in body fluids, and NAME an acid that originates from each source.
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.
water 17
Distinguish between a strong and a weak acid, and give an example of each.

Bases vary in strength also
strong acid ionizes more easily, eg. hydrochloric acid.

weak acids ionize less completely eg. carbonic acid.

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

Name three important acid-base buffer systems in the body
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.

How does the bicarbonate buffer system work?

How do proteins act as buffers?
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.

How does the respiratory center contribute to acid base balance?
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).
How does the kidney help in pH balance?

How are chemical and physiological buffers different?
Kidney nephrons secrete hydrogen ions to regulate pH.

Chemical buffers act more rapidly. Physiological buffers act less rapidly.
Respiratory acidosis results from increases in concentration of _____ _____ and _____ _____

How is it different from metabolic acidosis?
carbon dioxide, carbonic acid

Metabolic acidosis results from accumulation of OTHER ACIDS, or LOSS of bases.
Respiratory alkalosis results from ____ of carbon dioxide and carbonic acid.

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

loss, gain

How does the body compensate for acidosis?

For alkalosis?
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