Understanding Lymphocytes

Overview

• Lymphocytes are a type of white blood cell.
• Unlike phagocytes, you need to know their formation and maturation.
• Lymphocytes are formed in the bone marrow.

Formation and Differentiation

• Blood stem cells in the bone marrow divide continuously via mitosis.
• These stem cells differentiate into two types of lymphocytes:
  • Immature B Lymphocytes
  • Immature T Lymphocytes
• Differentiation is represented by different colors for clarity, not actual colors.

Maturation

• B Lymphocytes:
  • Mature in the Bone Marrow (B for Bone Marrow).
• T Lymphocytes:
  • Mature in the Thymus (T for Thymus).
  • Thymus is located behind the sternum, part of the lymphatic system.
• Maturation involves the growth of the cell and development of receptor proteins on their surface.

Importance of Receptor Proteins

• Mature lymphocytes have receptor proteins on their cell surface membrane.
• Each lymphocyte has receptors specific to one type of antigen.
  • Receptors are complementary to the shape of a specific antigen.
  • B and T lymphocytes are highly specific and respond only to particular antigens.

Specificity of Lymphocytes

• B Lymphocytes:
  • Have receptors that match specific antigens on pathogens.
• T Lymphocytes:
  • Also have receptors specific to one type of antigen.
• This specificity is crucial because it means lymphocytes only respond to foreign substances that match their receptors.

Key Differences Between B and T Lymphocytes

• Area of Maturation:
  • B Lymphocytes: Mature in bone marrow.
  • T Lymphocytes: Mature in the thymus.
• Immune Response:
  • B and T lymphocytes respond differently to antigens.
  • Details on their immune response strategies will be covered in the next video.

Exam Tips

• Know the formation and maturation locations of B and T lymphocytes.
• Understand the role and specificity of receptor proteins on lymphocytes.
• Remember the differences in maturation and immune response between B and T lymphocytes.