5.09 x 10 to the 6th power
Your outer skin is your epidermis, so just look at your arm
After the macrophage fails the Helper T Cell stimulates the B cells if pathogen is extracellular and Cytotoxic T Cells if the pathogen is intracellular. Once the pathogen is killed the B Cells create Memory B Cells and the Killer T Cells create memory T Cells.
<span>Cardiovascular / Circulatory system: ...Digestive system / Excretory system: ...Endocrine system: ...Integumentary system/ Exocrine system: ...Lymphatic system / Immune system: ...Muscular system/Skeletal system: ...Nervous system: ...<span>Renal system / Urinary system:</span></span>