Page 180 - 84 human physiolofy part-1
P. 180
Chapter 9
new cells "phagocytes", in Greek meaning "devouring cells."
This discovery was very important since it helped scientists how the body defends itself against
disease. If the phagocyte encountered anything foreign, they absorb and destroy it. Phagocytes also
play an important part in activating the immune response in the rest of the body.
Paul Ehrlich and the Side-chain Theory
Ehrlich supposed that living cells have side-chains. These side chains can link with a particular
toxin, just as Emil Fisher said enzymes must bind to their receptors "like a key in a lock."
He theorized that a cell under threat grew additional side-chains to bind the toxin, and that these
additional side chains broke off to become the antibodies that circulate through the body. It was these
antibodies that Ehrlich first described as "magic bullets" in search of toxins.
Ehrlich figured that if a compound could be made that selectively targeted a disease causing
organism, then a toxin for that organism could be delivered along with the agent of selectivity. Hence, a
"magic bullet" would be created that killed only the organism targeted.
Ehrlich predicted autoimmunity calling it "horror autotoxicus".
In 1908, Ehrlich and Mechnikov received the Nobel Prize.
Review Questions
1-When neutrophils and macrophages squeeze out of capillaries to fight off infection it is called:
A) phagocytosis
B) hemolysis
C) interleukin
D) diapedesis
E) folliculitis
2-During a great battle between your WBC's and an aggressive microbe, an inflammatory response has
been initiated. Reddness and edema has kicked in what else does the body do to protect itself?
A) Histamine cause vasodilation
B) Hypothalmus raises the thermostat
C) Neutrophils engulf and destroy the microbe
D) Living and dead WBC and bacteria accumulate
E) All of the above
3-Specificity and memory are associated with which body defense mechanism?
A) inflammatory response
B) phagocytosis by macrophages and neutrophils
C) interferon
180 | Human Physiology
