PATHOLOGY

Detailed explanation-1: -Fluid that is forced out of the bloodstream during normal circulation is filtered through lymph nodes to remove bacteria, abnormal cells and other matter. This fluid is then transported back into the bloodstream via the lymph vessels. Lymph only moves in one direction, toward the heart.

Detailed explanation-2: -Lymph enters the node (arrow) through afferent lymphatic vessel(s) (Af). It then moves to subcapsular sinus (SCS), which can then go to either B cell follicles (BF) and T cell cortex (TC) through central path, or directly to medullary sinuses (MS) through peripheral path.

Detailed explanation-3: -The correct answer is option d because the lymphatic system is not a closed-loop like the circulatory system, it starts with lymphatic capillaries that drain into successively larger vessels that eventually drain out the lymphatic system through two lymph ducts into veins that lead towards the heart.

Detailed explanation-4: -There is no pump in the lymphatic system like the heart in the cardiovascular system. The pressure gradients to move lymph through the vessels come from the skeletal muscle action, respiratory movement, and contraction of smooth muscle in vessel walls.