Which structural distinction separates spleen white pulp from red pulp?

Which structural distinction separates spleen white pulp from red pulp?

• A. White pulp contains venous sinusoids; red pulp contains periarterial lymphatic sheaths.
• B. White pulp contains splenic cords; red pulp contains lymphoid nodules.
• C. White pulp contains periarterial lymphatic sheaths and lymphoid nodules; red pulp contains venous sinusoids and splenic cords with red blood cells.
• D. White pulp contains B cell follicles; red pulp lacks vascular sinusoids.

Answer: (C)

The main concept here is that the spleen’s white pulp and red pulp are built for different tasks: white pulp is lymphoid tissue focused on immune responses, while red pulp is a vascular region specialized for filtering blood. In the white pulp, you find periarterial lymphatic sheaths (PALS), which surround the central arteries and are rich in T cells, plus lymphoid nodules that are B-cell–rich follicles. This organized lymphoid arrangement is what gives the white pulp its immune function. In contrast, the red pulp is a vascular area that contains splenic cords (the reticular tissue networks with macrophages and red blood cells) and venous sinusoids (specialized, loosely arranged capillaries through which blood cells pass). The sinusoids allow older or damaged red blood cells to be filtered out as they travel through the spleen. So, the distinguishing structural feature is that white pulp houses PALS and lymphoid nodules, while red pulp contains venous sinusoids and splenic cords filled with red blood cells.

The main concept here is that the spleen’s white pulp and red pulp are built for different tasks: white pulp is lymphoid tissue focused on immune responses, while red pulp is a vascular region specialized for filtering blood. In the white pulp, you find periarterial lymphatic sheaths (PALS), which surround the central arteries and are rich in T cells, plus lymphoid nodules that are B-cell–rich follicles. This organized lymphoid arrangement is what gives the white pulp its immune function.

In contrast, the red pulp is a vascular area that contains splenic cords (the reticular tissue networks with macrophages and red blood cells) and venous sinusoids (specialized, loosely arranged capillaries through which blood cells pass). The sinusoids allow older or damaged red blood cells to be filtered out as they travel through the spleen.

So, the distinguishing structural feature is that white pulp houses PALS and lymphoid nodules, while red pulp contains venous sinusoids and splenic cords filled with red blood cells.