a&p chapter 25 quiz and homework

The bicarbonate buffer system is one of the chemical buffer systems of the body. How would the bicarbonate buffer system work if sodium hydroxide were added to a solution?

A hydrogen on carbonic acid would dissociate and join the hydroxyl group on the base to form water and sodium bicarbonate.

Mrs. Frykholm is experiencing diabetic ketoacidosis, which causes metabolic acidosis. She has experienced damage to her kidneys from diabetes mellitus. Predict how her body compensates to return her blood pH to normal.

Hyperventilation

Determine the effect of hypokalemia on resting membrane potential.

Hypokalemia causes the membrane potential to become hyperpolarized.

Which of the following statements about ECF is correct?

It is made up of fluids such as plasma and interstitial fluid.

If the Pco2 in the plasma increases, what effect will this have on plasma pH?

The pH will decrease.

Which of the following represents appropriate compensation for metabolic acidosis?

The retention of bicarbonate ions in the kidneys

There are other medications that are used to treat acid reflux. These have a longer duration of effects. One type of medication is known as a proton pump inhibitor. This medication inhibits the pumping of protons (H+). These medications are not as quick acting as the OTC antacids, but have other advantages. What do you think the mechanism is for these medications?

They interfere with the formation of HCl to decrease the acidity of the stomach secretions.

Plasma has much higher protein content than interstitial fluid.

True

The most important chemical buffer system in the blood is the carbonic acid-bicarbonate ion buffer system, which consists of the weak acid carbonic acid and its weak conjugate base, the bicarbonate ion.

True

Which hormone influences the concentration of hydrogen ions in the filtrate formed by the kidneys?

aldosterone

Which hormone promotes the reabsorption of water from the kidneys back into the ECF by osmosis?

antidiuretic hormone (ADH)

Which of the following is NOT a possible cause for metabolic acidosis?

asthma

The primary role of the phosphate buffer system is to __________.

buffer intracellular fluid (ICF)

A patient present with severe metabolic alkalosis. The appropriate respiratory compensation would be __________.

decreased respiratory rate

This electrolyte imbalance is normally caused by hyperparathyroidism.

hypercalcemia

Aldosterone inhibitors are prescribed to patients with advanced heart failure. A common side effect of these drugs is __________.

hyperkalemia

This electrolyte imbalance can be caused by renal failure, aldosterone insufficiency, cellular destruction from severe burns or trauma, and accidental administration or ingestion of excess potassium salts.

hyperkalemia

The most common cause of this electrolyte imbalance is dehydration.

hypernatremia

A patient is admitted to the hospital with the following plasma values: pH = 7.2, pCO2 = 25 mmHg, and HCO3 −− = 18 mEq/L. What is the acid base imbalance?

metabolic acidosis with respiratory compensation

The normal range of blood pH is __________.

7.35 to 7.45

Severe anxiety would cause which type of acid-base disturbance? What would be the compensation?

respiratory alkalosis; kidneys would excrete HCO3

Hyperventilation causes __________, and hypoventilation causes __________.

respiratory alkalosis; respiratory acidosis

The respiratory system is one of the three systems that regulate acid-base balance in the body. How does it work to decrease an acidosis?

Carbonic acid is broken down into water and CO2; the CO2 is then exhaled.

Why are chlorine ions important?

Chlorine ions are involved in the production of stomach acids.

Which of the following ions is found primarily in the ECF?

HCO3−

A friend has acid indigestion after eating a big meal. Which of the following would act as a buffer and help ease his pain?

milk of magnesia, with a pH of 10

Increased water volume causes the hydrostatic pressure in plasma to increase and the osmotic pressure to decrease; as a result, water will __________.

move from the ECF to the ICF

What ion concentration is linked to calcium ion concentration and regulated by vitamin D3 (calcitriol)?

phosphate ions

What is the normal range for the partial pressure of carbon dioxide in the blood?

35 - 45 mm Hg

Identify the role of the urinary system in acid-base balance.1. The kidneys can secrete bicarbonate ions when the pH of the blood rises.2. The kidneys contribute to acid-base balance by excreting fixed acids that the lungs cannot excrete.3. The kidneys can manufacture new bicarbonate ions when the pH of the blood falls.4. The kidneys contribute to acid-base balance by controlling the concentration of bicarbonate ions in the blood

1, 2, 3, 4

Which of the following would have the greatest effect on the pH of a solution?

A strong acid

Determine the effect of hypocalcemia on the heart.

As a result of hypocalcemia, the plateau phase of the cardiac muscle cell action potential is lengthened.

Which of the following substances is the most acidic?

Gastric juice with a pH of 2

CO2 + H2O ↔ H2CO3 ↔ __________

H+ + HCO3−

Over-the-counter (OTC) antacids are chemicals that neutralize acidity to relieve a painful reflux. Which of the following chemical reactions correctly shows this process?

NaHCO3 + HCl → NaCl + CO2 + H2O

Which of the following ions is a component of hydroxyapatite crystals in bone matrix?

PO43−

If the pH of a solution decreases, how will a buffer respond?

The base will remove H+ to increase pH.

In a respiratory acidosis the kidney would do which of the following?

The kidney would reabsorb bicarbonate and secrete hydrogen ions.

In what direction will water move when hypotonic fluids are present in the plasma?

Water is pulled from the interstitial fluid and plasma into the cell.

If a person exercises for a long time, lactic acid will start to build up in his or her muscles. Which of the following would you expect to happen as the lactic acid first starts to be formed?

Weak bases in the muscles will act as buffers and resist or minimize any pH change.

Tony is diagnosed with acid reflux. This is a condition in which stomach secretions which contain hydrochloric acid or HCl, regurgitate (reflux) out of the stomach and into the esophagus. Stomach secretions are very acidic with a pH around 2.0. The acids damage the esophagus and it is felt as heartburn. This painful condition can be treated with over-the-counter (OTC) antacids. What do you think these antacids are?

Weak bases such as sodium bicarbonate (NaHCO3) or calcium carbonate (CaCO3)

Substances that function to resist large swings in pH are called __________.

buffers

Together, which ions form hydroxyapatite crystals of osseous tissue?

calcium and phosphate ions

Determine the product formed when hydrogen ions from a strong acid are accepted by the bicarbonate ion.

carbonic acid

Overhydration will cause __________.

cells to gain water

Which of the following fluids has the greatest concentration of potassium ions?

cytosol

The following represents the main locations fluids are found in the human body. Rank these body fluids in order from the fluid that accounts for most in the human body to the fluid that accounts for the least.

cytosol (intracellular fluid), interstitial fluid, plasma

For which imbalance is the release of antidiuretic hormone (ADH) appropriate?

fluid and electrolyte imbalance

Which of the following solutions has the highest concentration of H+?

gastric juice with pH 2

Respiratory alkalosis is characterized by a blood pH _______.

greater than 7.45

The proper respiratory compensation for metabolic acidosis is ______________.

hyperventilation

This electrolyte imbalance is normally caused by diuretics.

hypokalemia

This electrolyte imbalance is caused by an abnormal decrease in the plasma sodium ion concentration.

hyponatremia

What condition accompanies overhydration, or hypotonic hydration?

hyponatremia

Which type of extracellular fluid (ECF) solution will cause a cell to gain water?

hypotonic

The appropriate response to hyponatremia is __________.

increased reabsorption of sodium ions in the kidneys

Which ions are critical for the activation of some enzymes?

magnesium ions

Diarrhea can lead to which acid/base disturbance? Assuming compensation, would it be a metabolic or respiratory compensation?

metabolic acidosis with respiratory compensation

Starvation would cause which of the following acid-base conditions? Also, determine what type of compensation (metabolic or respiratory) there would be.

metabolic acidosis with respiratory compensation

Ingesting too much antacid would cause which of the following acid-base disturbances?

metabolic alkalosis

The following has been determined from an arterial blood gas (ABG) sample: an elevated blood pH and an elevated bicarbonate ion level. Determine the acid-base imbalance.

metabolic alkalosis

Vomiting will cause which type of acid-base disturbance?

metabolic alkalosis

A patient is admitted to the hospital with the following plasma values: pH = 7.5, pCO2 = 45 mmHg, and HCO3 −− = 30 mEq/L. What is the acid-base imbalance?

metabolic alkalosis with no compensation

Of the three buffering mechanisms in the body, which is the strongest?

renal system

What is a major function of potassium ions in the body?

repolarization of neurons and muscle cells after action potential

A patient is admitted to the hospital with the following plasma values: pH = 7.2, pCO2 = 55 mmHg, and HCO3 −− = 30 mEq/L. What is the acid base imbalance?

respiratory acidosis with metabolic compensation

Emphysema can lead to which acid/base disturbance? What would be the compensation?

respiratory acidosis; kidneys will retain more HCO3 −− and excrete H+

Through what two systems is carbon dioxide eliminated from the body?

respiratory and urinary systems

A drowning victim presents with combined respiratory and metabolic acidosis. The appropriate renal compensation would be __________.

secretion of hydrogen ions

What is the most abundant extracellular cation?

sodium ion

An electrolyte is a __________.

substance that dissociates into ions when placed in water

Why was the breath held after the second hyperventilation?

to retain carbon dioxide

Hyperventilation can result in _______.

too little carbon dioxide in the blood

Which system is responsible for the most common route of water loss from the body?

urinary system