Author Question: Which of the following is true regarding carboxyhemoglobin? a. Smokers have increased levels. ... (Read 117 times)

leilurhhh · **on:** Jun 25, 2018

Which of the following is true regarding carboxyhemoglobin?

a. Smokers have increased levels.
b. It has hydrogen sulfide added to hemoglobin.
c. Normal people have none.
d. Levels of 15 to 20 cause coma and death.

Question 2

Which of the following statements is true about Hb F?

a. It is the major hemoglobin during fetal life.
b. It is increased in concentration in children up to 2 years old.
c. It is evenly distributed at low concentration in all RBCs of an adult.
d. It has a low oxygen affinity.

nanny · **Reply #1 on:** Jun 25, 2018

Answer to Question 1

ANS: A
Smokers, depending on how much and what they smoke (e.g., cigarettes, cigars), may have as much as 20 carboxyhemoglobin in their blood. The concentration of carboxyhemoglobin in normal blood varies depending on the environment in which a person lives (more in an urban environment, for example, than in a rural location), but it is generally less than 1. Levels greater than 50 cause coma and death. The addition of hydrogen sulfide to hemoglobin forms sulfhemoglobin.

Answer to Question 2

ANS: A
Hb F is the major hemoglobin during fetal life and at birth, but its concentration decreases after birth so that by age 6 months it should be less than 1 of the total hemoglobin. It is distributed unevenly in the RBCs of an adult (F cells), meaning that it is only found in some RBCs (not in all of them). It has a high oxygen affinity to enable it to extract oxygen from the maternal circulation.