34. Differences between the blood groups A antigen A antibody b B AB O antigen B antigen A and B no antigen antibody a no antibodies antibody a and b (universal donor) (universal recipient) Note: Antigens represented by capital letters A and B Antibodies represented by small letters a and b Antibody in serum Antigen on RBC Blood group
Red blood cells move in single file through the capillaries. Each red blood cell is a biconcave disk containing many molecules of hemoglobin, the respiratory pigment. Hemoglobin contains four polypeptide chains (in blue). There is an iron-containing heme group in the center of each chain. Oxygen loosely combines with hemoglobin when oxygenated. Oxyhemoglobin is bright red, and deoxyhemoglobin is a dark maroon color.
Monocyte-derived macrophages are the body’s scavengers. They engulf microbes and debris in the body’s fluids and tissues, as illustrated in this colorized scanning electron micrograph. The macrophage is in red, and the bacteria are in green.
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