Red — Mature

: Mature red blood cells lack a nucleus and most organelles (like mitochondria) to maximize space for hemoglobin, the protein that carries oxygen.

: In ultrasound Doppler flow studies, red color on the display typically indicates blood flowing toward the ultrasound transducer, which doctors use to evaluate blood flow in a post-term (mature) fetus. mature red

: They develop from stem cells in the bone marrow. During the final stages of maturation, they shed non-functional proteins and undergo "membrane microvesiculation," a regulated process that removes old or damaged components. : Mature red blood cells lack a nucleus

: As these cells age, signals on their surface trigger their removal from the bloodstream by the spleen and liver. Other Related Contexts During the final stages of maturation, they shed

: Immediately after birth, a woman experiences "lochia rubra," which is bright red vaginal bleeding that typically lasts for the first 3–4 days.

Depending on your specific interest, "red" and "mature" can appear in other medical or biological topics: