Deck 14: Water

Question 1

In relation to body water which of the following statements is TRUE:

A) half is turned over each day
B) it is obtained from foods and beverages
C) interstitial water and extracellular water are the same
D) obligatory urine output is about 600 mL/day
E) osmosis is required for solute transport across cell membranes

Answer 1

B

Question 2

Which of the following statements about water in the body is FALSE?

A) In an average adult, water comprises about 60% of body weight.
B) Most of water (about 60% of total body water) in the body is inside cells.
C) In humans, a developing fetus has the highest water content of about 95% by weight.
D) Apart from in the blood, water can be found in the heart, brain, lungs, kidneys, skin and bones.
E) Fatty tissue contains more water than lean tissue.

Answer 2

E

Question 3

In order to maintain an extracellular pH of 7.32 - 7.42:

A) most intracellular anions are bicarbonate
B) carbonic acid is removed as carbon dioxide
C) the kidneys excrete volatile acids
D) hyperventilation is required
E) alkaline foods must be consumed

Answer 3

B

Question 4

Which minerals are mostly involved with maintaining the body's fluid and acid-base balance?

A) chlorine, sodium, potassium
B) sodium, potassium, zinc
C) potassium, magnesium, selenium
D) chlorine, phosphorous, magnesium
E) selenium, phosphorous, zinc

Question 5

Water in the human body is NOT a:

A) medium for biological reactions
B) component of all body cells
C) transport medium for nutrients and waste
D) regulator of body temperature
E) regulator of body fluid volume

Question 6

Which of the following statements about water balance is FALSE?

A) An average adult may be expected to consume about 1.5-2 litres of water daily from food and drink.
B) Environmental temperature and level of physical activity can affect water requirements.
C) Aquaporin and vasopressin are two major hormones that control water content in the body.
D) Urine output is primarily determined by the frequency and amount of water consumed.
E) Urine is required for the regulation of tissue electrolytes and for the elimination of metabolic end products such as urea, uric acid and creatinine.

Question 7

Which of the following is regular obligatory water NOT lost through?

A) lacrimation and menstruation
B) sweating and salivation
C) urination and defecation
D) epidermal loss and respiration
E) seborrhoeic loss and ejaculation

Question 8

Which of the following statements about body water is FALSE?

A) Thirst is an important mechanism triggered by a lack of fluids or an increase in osmotic concentration in tissue fluids.
B) The body can tolerate a loss of up to 10 per cent of body water without significant impairment of function.
C) The two main sources of water losses from the body are urine and sweat.
D) The body regulates water balance through the adjustment of urinary volume.
E) Dehydration can occur with excessive sweating, prolonged diarrhoea, vomiting and excessive urine production.

Question 9

Which of the following statements about dehydration is FALSE?

A) The body can tolerate up to 2.5 per cent of body water without any adverse symptoms.
B) Infants and the elderly are more at risk of dehydration compared to other age groups.
C) In addition to fluid from food sources, we need to drink water at least eight glasses (about 2 litres) a day; this is to prevent dehydration.
D) The elderly are at risk of dehydration due to the reduction in their thirst perception, renal concentration ability and vasopressin effectiveness.
E) Death can occur with a loss of over 20 per cent of body water.

Question 10

Why is dehydration more common in infants and the elderly? (8 marks: 4 each for infants and elderly)

Question 11

In normal situations, electrolyte imbalance