Correct! The thymus has a thin capsule that extends CT septa into the parenchyma separating the cortex and medulla into incomplete lobules. Can you label the following thymus slide? A) × Hint for A) A region with fewer and larger, more developmentally mature thymocytes that undergo negative selection (aka clonal deletion) B) × Hint for B) A thin connective tissue covering C) × Hint for C) Region where thymocytes undergo positive selection (aka clonal selection) D) × Hint for D) Extensions of the capsule separating the parenchyma into lobes The thymus is considered a ______ lymphoid organ. Primary Secondary Tertiary
