The immune system (chapter 21) Flashcards
The ability of the body to defend itself against “unfamiliar” microorganiams
immunity
Physically prevent pathogens from entering body
surface barriers
tought fibrous protein resistant to weak acids, weak bases, bacterial enzymes
keratin
sweat and sebum on skin surface are slightly acidic
acid mantle
line all body cavities that open to the exterior (digestive, respiratory, and reproductive tracts)
Mucous membranes
traps microorganisms in respiratory and digestive tracts
mucus
traps microorganisms in nasal cavity
nasal hairs
takes mucus (with trapped microorganisms) and propels it away from nasal cavity and respiratory tract (bath and forth rapidly)
cilia
stomach: secretes very acidic gastric juices
Vagina: acidic nature prevents bacterial and fungal growth in reproducitve tract
Acid mantle
- cleanses eyes and mouth
- contains lysozymes to destroy bacteria
tears and saliva
acidic in nature, physically removes bacteria during urination
urine
used when surface barriers are breached
cellular and chemical defenses
- proteins found on cells of the innate immune sysytem
- recognize potentially harmful substances by presence of a molecule with a certain shape found on pathogen, but NOT normal human cells
patter recognition receptors
- target cancerous cells and virus infected cells
- non specific
Natural Killer (NK) cells
natural killer cells release perforin. What is perforin?
creates pores in the membrane of cell
process by which cells engulf and destroy pathogenic cells of substances
Phagocytosis
capable of traveling through tissue to search for pathogens
Free macrophage
Permanent location in tissue of a particular organ
fixed macrophages
substance that binds to pathogen surface which allows the phagocytes to recognize an bind pathogen easily
opsonins
nonspecific localized response to tissue injury
inflammation
- released by basophils
- effect: vasodilation, increase permeability of local capillaries
histamine
- derived from plasma protein kininogen
- effect: vasodilation, attracts other leukocytes, induces pain
Kinins
- generated by neutrophils, basophils, mast cells, etc
- Vasodilation, neutrophil chemotaxis, induces pain
prostaglandins
increase number of white blood cells in the blood
leukocytosis
- released by injured/damaged cells
- cause WBCs to migrate to blood
Leukocytosis-inducing factor
phagocytosis cling to inside of endothelial wall of capillaries at the injury site
margination
cells clinging to wall will squeeze between cells of endothelial wall
Diapedesis
inflammatory chemicals are chemotactic agents
chemotaxis
protein that can attack microorganisms directly or interfere with their reproduction (work independently of cells)
Antimicrobial proteins
released by cells infected by a virus to protect surrounding noninfected cells
interferons
- group of 20 plasma proteins synthesized by the liver
- normally inactive in blood (if healthy)
- stimulates vasodilation, pain perception, stronger response
Complement
- body wide systemic response to pathogens
- characteristics abnormally high body temperature
- leukocytes and macrophages release pyrogens
Fever