What components are included in blood collected from a capillary puncture?

The correct answer encompasses the various components present in blood collected from a capillary puncture. During a capillary puncture, typically performed on a fingertip or heel, blood is drawn from tiny blood vessels known as capillaries. This process captures a mixture of blood elements that reflect the microvascular circulation.

In addition to blood from capillaries, the sample generally includes contributions from surrounding arterioles and venules, as well as tissue interstitial fluid. This rich blend allows for a comprehensive assessment of the patient's condition, as it represents both the cellular components of blood and solutes that may be present outside the blood vasculature, such as metabolites and electrolytes.

Understanding the composition of capillary blood is crucial in several clinical contexts, especially when considering that it can provide similar biochemical information to venous blood but may also reflect different physiological states due to its mixed source. This aspect is particularly valuable in pediatrics and situations where venous access is challenging, making capillary sampling a critical skill for phlebotomy technicians.