A&P / Blood & Immunity

spleen

• blood reservoir

• forms blood cells during fetal stage

• destroys worn out / old blood cells

Tonsils

• masses of lymphoid tissue

• trap and remove bacteria and other foreign materials

• lateral to the uvula

Thymus

• specialized organ of the lymphatic system that matures T-lymphocytes (T-cells) (= T-cells gain autoimmunocompetence here)

• located behind sternum

• shrinks w age

Adenoids

• roof of nasopharnyx

• trap + remove bacteria

Peyer’s Patches

• wall of small intestine

• capture + destroy intestinal bacteria

1st Line of Defense

• cilia of respiratory tract

• nasal hair

• Lysozyme in tears, saliva, mucus, and breastmilk (kills bacteria by damaging cellular membrane; “lyses” cells)

2nd Line of Defense

• Phagocytes (such as macrophages)

• Inflammatory response

• Interferons

• Pyrogen

• Natural Killer Cells (direct attack against infected cells but don’t depend on antigens)

3rd Line of Defense

• Macrophages

• Killer T cells

• Helper T cells

• Memory B cells

• Plasma B cells

Antibodies

• produced by Plasma-B cells