During puberty, which change is most characteristic regarding hematologic values?

During puberty, which change is most characteristic regarding hematologic values?

• A. Increase in respiratory rate
• B. Increase in number of neurons
• C. Increase in neural connections
• D. Increase in serum iron, hemoglobin, and hematocrit

Answer: (D)

Puberty brings a surge of androgens, especially testosterone, which stimulates the bone marrow to produce more red blood cells. This increased erythropoiesis raises hemoglobin concentration and hematocrit. Iron is required for hemoglobin synthesis, so circulating serum iron can also rise to support the greater red cell production. In contrast, the other options reflect changes that aren’t hematologic—respiratory rate can vary with activity or illness, and changes in neuron number or neural connections are neurodevelopmental processes not specific hematologic shifts of puberty. The androgen-driven boost in red-cell production, yielding higher Hb and Hct (and often higher serum iron as part of that process), is the characteristic hematologic change during adolescence, especially in boys.

Puberty brings a surge of androgens, especially testosterone, which stimulates the bone marrow to produce more red blood cells. This increased erythropoiesis raises hemoglobin concentration and hematocrit. Iron is required for hemoglobin synthesis, so circulating serum iron can also rise to support the greater red cell production. In contrast, the other options reflect changes that aren’t hematologic—respiratory rate can vary with activity or illness, and changes in neuron number or neural connections are neurodevelopmental processes not specific hematologic shifts of puberty. The androgen-driven boost in red-cell production, yielding higher Hb and Hct (and often higher serum iron as part of that process), is the characteristic hematologic change during adolescence, especially in boys.