Blood Types Lecture Notes

Overview

• Blood transfusions have been performed for centuries.
• Discovery 120 years ago: antigens on erythrocytes determine blood compatibility.
• Blood types are A, B, AB, and O.
• Different antigens (flags) on red blood cells determine blood type.

Antigens and Blood Types

• Blood Type A: Has A antigen (sugar) on the surface.
• Blood Type B: Has B antigen.
• Blood Type AB: Has both A and B antigens.
• Blood Type O: No antigens on the surface.

Antibodies and Immune Response

• Blood types have specific antibodies:
  • Type A Blood: Has anti-B antibodies.
  • Type B Blood: Has anti-A antibodies.
  • Type AB Blood: No anti-A or anti-B antibodies.
  • Type O Blood: Has both anti-A and anti-B antibodies.

Blood Donation Compatibility

• Type A: Can receive A or O blood.
• Type B: Can receive B or O blood.
• Type AB: Universal acceptor; can receive A, B, AB, or O blood.
• Type O: Universal donor; can only receive O blood.

Rhesus Factor (Rh Factor)

• Adds complexity to blood typing (positive or negative).
• Positive: Presence of D antigen (Rh factor).
• Negative: Absence of D antigen; creates anti-D antibodies.

Rhesus Factor and Receiving Blood

• Positive blood type: Can receive both positive and negative blood of the same type.
• Negative blood type: Can only receive negative blood.
• Example: B negative can only receive B negative or O negative blood.

Conclusion

• Understanding blood types and antibodies is crucial for safe blood transfusions.
• Rh factor adds another layer of complexity to blood compatibility.