Immune System Flashcards
What does the immune system defend against ?
Bacterial Infection ; Viruses ; Fungi ; Metazoan Parasites ; Foreign Proteins and Peptides ; Debris and Proteases from Dead Cells ; Cancerous Cells
What are the two defenses that the immune system can be divided into?
Innate (nonspecific) defenses ; Adaptive (specific) defenses
What are Innate (nonspecific) defenses?
barriers that keep out foreign invaders; mechanisms that destroy invaders in a nonspecific fashion. These are present whether the body has encountered the threat before or not.
What are adaptive (specific) defenses?
Mechanisms that respond to specifiic threats in a particular way. Require priming by a prior encounter with a threat for maximum effectiveness.
How do innate defenses defend against things?
Surface barriers (skin and mucosae) ; Defensive cells (phagocytes natural killer cells) Defensive chemicals ; inflammation ; fever
What are surface barriers?
the first line defense against damage is a barrier between the inside of the body and the environment
Is lumen a type of surface barrier?
Yes; the lumen of the digestive tract and the respiratory organs are all technically outside the body
How is skin a surface barrier?
The keratinized layers of skin resist acidic, basic, and enzymatic attack by bacteria
Keratin acts as what?
A water resistant layer
What does Stratum Corneum do?
sloughs off, taking harmful material with it
How is sebum a skin barrier?
Sebum from hair follicles traps material and prevents it from entering the body
What does mucosae do?
produce proteoglycan mucins that form when hydrated (combined with water)
What does mucus do?
Trap material which can then be transported to the exterior by peristalsis or ciliated cells
What else do mucosae cells produce?
acid ; digestive enzymes (pepsin , lysozyme) , or simply water
