Final answer:
An infant's blood pressure typically increases gradually over the first year. This is a result of the ongoing development and growth of the infant's heart and blood vessels post-birth, with further rapid changes occurring during adolescence.
Step-by-step explanation:
An infant's blood pressure typically increases gradually over the first year of life. At birth, an infant's circulatory system undergoes significant changes as the infant begins to breathe air, and the fetal circulation patterns are replaced by postnatal circulation patterns. The heart and blood vessels, which are among the earliest organs to develop and function, continue to grow and adapt as the infant grows. While the increase in size and capacity of the heart and lungs is most rapid during the adolescent growth spurt, there is also a steady increase in these systems throughout infancy.
Adjustments After Birth
Immediately after birth, changes such as the first breath inflating the lungs, the cutting of the umbilical cord altering circulation, and the activation of brown adipose tissue for temperature regulation all impact blood flow and pressure. Additionally, factors such as the establishment of bacterial flora in the gastrointestinal tract can affect overall health and development, including cardiovascular development.