Module 2 Exam Flashcards
How much of our water intake is expected to come from fluids?
80%
How much of our water intake is expected to come from foods?
20%
How much of plasma is comprised of water?
91.5%
How much of body water is intracellular in infants?
46%
What is water a solvent for?
minerals, vitamins, glucose, and other small molecules
What does water do?
give body shape and form
maintain blood volume and blood pressure
regulate body temp by absorbing heat produced by fever and metabolic processes
form the structure of large molecules
transports nutrients to and waste away from cells
What is the ultimate destination of nutrients in the body?
cells
What is sensible water loss?
loss through the skin as perspiration
What is insensible water loss?
breathing, vomiting, etc
How much of water is lost daily via insensible water loss?
800 to 1000 mL
What is the main means of dissipating the body’s heat produced by exercise?
evaporation
In extreme cases, at what rate may a person perspire?
2 L per hour
What environmental conditions increase the amount of water lost?
high temps, high altitudes, and low humidity
How much water does obligatory excretion eliminate?
400 to 600 mL per day
What happens if gastric juices are lost?
hydrogen ions in the hydrochloric acid are lost, putting the person at risk for alkalosis
What does rapid breathing caused by anxiety trigger?
paresthesia, peripheral tetany (stiffness of fingers or arms), fainting
Why does tetany occur?
because respiratory alkalosis causes both hypophosphatemia and hypocalcemia
What does first aid recommend for hyperventilation from anxiety?
breathing through one nostril with the mouth closed
What can breathing into a paper bag cause?
hypoxia
What ions provide the most movement across cell membranes to maintain osmotic pressure and fluid balance?
sodium, phosphate, and chloride
What can abnormal levels of potassium produce?
cardiac arrest
What does blood pressure depend on?
volume of blood, nutrients, and water pushed out through capillaries into interstitial fluid by hydrostatic pressure supplied by the heart
What does magnesium regulate?
nerve stimulation and normal muscle action
What is bicarbonate?
an important extracellular fluid buffer
What constricts arteries to increase blood pressure?
ADH
What does aldosterone cause?
sodium ions to be returned to the bloodstream by the kidneys rather than to be spilled into urine, and water follows it
What is the most influential extracellular ion?
sodium
What happens during diabetes insipidus?
the hypothalamus does not secrete ADH or the kidneys do not respond appropriately
What do special sensors in the hypothalamus monitor?
osmotic pressure as the blood circulates in the brain
When the hypothalamus detects an increase in osmotic pressure, what happens?
the gland triggers a desire to drink