(a) Tonsils — Tonsils are lymph glands located on the sides of the neck. They tend to localize the infection and prevent it from spreading it in the body as a whole.
(b) Spleen — The spleen is a large lymphatic organ. The spleen acts as a blood reservoir in case of emergency such as haemorrhage, stress or poisoning. It produces lymphocytes and destroys worn out RBCs.
(c) Hepatic portal vein — The hepatic portal vein is a blood vessel that carries blood from the gastrointestinal tract, gallbladder, pancreas and spleen to the liver. This blood contains nutrients and toxins extracted from digested contents.
(d) Basophils — Basophils are a type of white blood cells. They are the least common type of granulocyte which release chemicals called histamine for inflammation which dilate blood vessels.
(e) S.A.N. — The sinoatrial node (SAN) is a region of cardiac fibres located in the right atrium. The electrical wave of stimulation is initiated here and extends over the two atria, causing them to contract. It is often referred to as the pacemaker of the heart.