Unit 1 bio, Buzz words to remember. May 2012 PP

1) When a pathogen enters the body it may be destoryed by phagocytosis. Describe how. 

• Phagocyte recongizes antigen
• Pathogen is engulfed 
• Enclosed in vesicle in phagocyte
• Fuses with lysomes 
• Lysome contains digestive enzymes 
• Pathogen digested 

2) The heart controls and coordinates the regular contraction of the atria and venticles. Describe how. 

• SAN node is pacemaker, sends electrical impluses over atria 
• To AVN to bundle of his 
• Atria contract
• Non-conductive tissue in between
• Delay at AVN
• Atria empty…