Patho Chapter 40

Elevated levels of CO2 produce _______ of cerebral blood vessels, causing headache, blurred vision, irritability, muscle twitching, and psychological disturbances.

vasodilation

Physiologically, these acids fall into two groups: the ______ acid H2CO3 and all other _______ acids.

volatile, nonvolatile

The enzyme _____ metabolizes methanol and ethylene glycol until their toxic metabolites.

alcohol dehydrogenase

The_______ buffer system is the principle extracellular fluid buffer,

bicarbonate

The body has built-in compensatory mechanisms that take over when correction of pH is not possible or cannot be immediately achieved. What are these compensatory mechanisms considered?

(b) Interim measures that permit survival

Metabolic acidosis has four main causes. Which laboratory test is used to determine the cause of metabolic acidosis?

(c) Anion gap

To calculate the H2CO3 content of the blood, you need to measure the PCO2 (partial pressure of CO2) by its solubility coefficient. What is the solubility coefficient of CO2?

(a) 0.03

There are both metabolic and respiratory effects on the acid-base balance in the body. How do metabolic disorders change the pH of the body?

(a) Alter the plasma of the HCO3

The body regulates the pH of its fluids by what mechanism? Mark all that apply.

(a) Chemical buffer systems of the body fluids (c) Lungs (e) Kidneys

Respiratory alkalosis is caused by hyperventilation, which is recognized as a respiratory rate in excess of that which maintains normal plasma PCO2 levels. What is a common cause of respiratory alkalosis?

(a) Hyperventilation syndrome

Respiratory acidosis occurs when the plasma pH falls below 7.35 and arterial PCO2 rises above 50 mm Hg. Because CO2 easily crosses the blood-brain barrier, what signs and symptoms of respiratory acidosis might you see? Mark all that apply.

(a) Irritability (b) Muscle twitching (c) Psychological disturbances

Acid

(a) Molecule that can release H+.

Excess base loading

(b) Acute increases in HCO3⁻.

By reabsorbing HCO3 from the glomerular filtrate and excreting H+ from the fixed acids that result from lipid and protein metabolism, the kidneys work to return or maintain the pH of the blood to normal or near-normal values. How long can this mechanism function when there is a change in the pH of the body fluids?

(c) Days

Metformin

(c) Mitochondrial inhibitor

Laboratory tests give us valuable information about what is happening in the body. What laboratory test is a good indicator of the how the buffer systems in the body are working?

(d) Base excess or deficit test

A change in the pH of the body affects all organ systems. When the pH falls to less than 7.0, what can occur in the cardiovascular system? Mark all that apply.

(d) Cardiac contractility can decrease, causing cardiac dysrhythmias.

Base

(d) Ion or molecule that can accept H+.

Amphoteric

(e) Can function as acid or base.

Hypercapnia

(f) Increases in plasma PCO2.

Dissociation constant

(g) Degree to which an acid or base in a buffer system dissociates.

Difference between Na+ and Cl-/ HCO3-

(h) Anion gap of urine

Whole-blood buffer base

(i) Measures the level of all buffer systems of the blood.

Carbonic anhydrase

(j) Catalyzes bicarbonate reaction.

______ acts in the collecting duct to stimulate H+ secretion, while increasing Na+ reabsorption and K+ secretion.

Aldosterone

Normally, the concentration of body acids and bases is regulated so that the pH of extracellular body fluids is maintained within a very narrow range of ___________ to _____________.

7.35 to 7.45

The terms ___ and ___ describe the clinical conditions that arise because of changes in dissolved CO2 and HCO3⁻ concentrations.

Acidosis, alkalosis

_______ and __________ are the major protein buffers in the vascular compartment.

Albumin, plasma globulins

________ disease is the most common cause of chronic metabolic acidosis.

Chronic kidney

_____ provide a means to control pH when correction is impossible or cannot be immediately achieved.

Compensatory mechanisms

The kidney regulated pH by excreting excess __ and reabsorbing ___.

H+, HCO3-

The ______ content of the blood can be calculated by multiplying the partial pressure of CO2(PCO2) by solubility coefficient.

H2CO3

Excessive loss of ___ occurs with sever diarrhea; small bowel, pancreatic, or biliary fistula drainage; ileostomy drainage; and intestinal suction.

HCO3⁻

The plasma pH can be calculated using an equation called the______.

Henderson-Hasselbalch equation

______ is the potent stimulus for H+ secretion and HCO3- reabsorption.

Hypokalemia

_______ involves a decreased plasma HCO3⁻ concentration, along with a decrease in pH.

Metabolic acidosis

______ is a systemic disorder is caused by an increase in plasma pH due to a primary excess in HCO3⁻.

Metabolic alkalosis

Respiratory _____ occurs in acute of chronic conditions that impair effective alveolar ventilation and cause an accumulation of PCO2.

acidosis

Respiratory _____ is caused by hyperventilation or a respiratory rate in excess of that needed to maintain normal plasma PCO2?.

alkalosis

There are two important intratubular buffer systems: the phosphate and _____ buffer systems .

ammonia

The ___ describes the difference between the plasma concentration of the major measured cation (Na+) and the sum of the measured anions (Cl⁻ and HCO3⁻).

anion gap

It has been estimated that as much as 40% of buffering of an acute acid load takes place in ____?.

bone

A ___ consists of a weak base and its conjugate acid pair.

buffer system

The metabolism of ________ and other substances results in the generation of fixed or nonvolatile acids and bases.

dietary proteins

Most cases of ___ acidosis are caused by inadequate oxygen delivery, as in shock or cardiac arrest.

lactic

Metabolic alkalosis also leads to a compensatory ____ with development of various degrees of ____ and respiratory acidosis.

hypoventilation, hypoxemia

An overproduction of _____ occurs when carbohydrate stores are inadequate of when the body cannot use available carbohydrates as a fuel.

ketoacids

Acids are continuously generated as byproducts of ______ processes.

metabolic

The H+ concentration is commonly expressed in terms of the ________.

pH

The ___ cross the blood-brain barrier and directly stimulate the respiratory center, causing hyperventilation and respiratory alkalosis.

salicylates

Arterial blood gases are used for blood gas measurements due to venous blood gas ___, depending on metabolic demands.

variability