Which areas in a secondary lymphoid organ allows intimate contact between blood and the lymphocytes?

White pulp of the spleen

Explanation:

The white pulp of the spleen is that region found in the spleen which appears white in color.

It appears whiter than the surrounding red pulp on the gross section which consitutes to about 25% of the whole splenic tissue.

This area has antigen presenting cells and dendritic cells and macrophages. Some of the cells there are known as metallophillic mcrophages which helps in keeping the body free from diseases.

1. amino acid refers to the fundamental building block of proteins, comprising of an amino group and a carboxyl group.

2. catalyst refers to any substance, which increases the rate of chemical reaction without being used up in the reaction.

3. a complex molecule containing he genetic code is dna or deoxyribonucleic acid.

4. an enzyme refers to a molecule of protein, which is unique in accelerating up a particular chemical reaction in the biological systems.

5. nucleic acid refers to an sequence of sugars, phosphates, and nitrogenous bases, for example, dna and rna.

6. a protein refers to a large, composite organic molecule comprising of a huge number of amino acids associated together with the of peptide bonds.

7. rna refers to a nucleic acid that takes part in the production of proteins.

8. substrate refers to a compound, which takes part in a chemical reaction, and is chemically modified by the reaction.