Microbiology CH 12 Flashcards
What is the study of immune systems called?
Immunology
What are specific defenses used to protect the body from pathogens identified by the body?
Acquired defenses
What are non-specific defenses used to protect the body from any general pathogenic attack?
Innate defenses
What 2 main lines of defense do innate defenses include?
- Barriers to prevent infection
- Systems to combat infections
What is the purpose of the first line of defense? What barriers does it involve?
Prevent pathogens from infecting the body
Chemical or Physical Barriers
What do the barriers ALSO defend against? List 2 examples
Non-living foreign agents
1. Dust
2. Smoke
What is the most apparent physical barrier? Most things exist _________ and can’t _______
Skin
Most things exist outside the body and can’t get in
What 2 things in the respiratory system trap and then push out inhaled particles?
Cilia and mucus
What can the microbiome do?
Physically occupy space to prevent pathogens from attaching to body surfaces
What is a chemical found in tears and saliva that hydrolyzes cell walls called?
Lysozyme
What does lysozyme do?
Makes it harder for pathogens to invade through the eyes or digestive tract
What is one of the reasons the body produced chemicals?
Prevent pathogen access
What allows the body to kill most microbes that make it to the digestive tract?
Stomach acid at low pH
What do salts secreted by sweating do?
Creates an environment that is hypertonic and hostile to anything you might come in contact with
Urine, vaginal secretions, and semen all contain?
Compounds that are microbicidal to reduce risk of infection
When does the second line of defense kick in?
When a pathogen gets beyond the first line
Where does the second line of defense occur? Via what?
(HINT: Include examples)
Blood
Cells - Phagocytes
Chemicals - interferons and Complement system
Processes - inflammation and fever
What type of response is the second line of defense?
Chemical response
What 7 substances can be found in plasma?
- Water
- Electrolytes
- Dissolved gases
- Nutrients
- Proteins
- Antibodies
- Clotting Factors
What is blood composed of?
- Plasma
- Formed elements
Are formed elements soluble? What 3 ‘substances’ can be found in formed elements?
No
- Erythrocytes
- Leukocytes
- Platelets
What are leukocytes that contain large granules that are visible during staining of blood?
Granulocytes
What WBCs make and release histamines?
Basophils
What 2 WBCs perform phagocytosis and diapedesis?
- Eosinophils
- Neutrophils
What is diapedesis?
Movement of WBCs outside the blood vessels
What are leukocytes that do not contain any large granules called?
Agranulocytes
What WBCs mature into macrophages?
Monocytes
What WBCs are responsible for specific immune response?
Lymphocytes
What are the 3 lymphocytes/cells part of the immune response? Which one is part of the NONSPECIFIC immune response?
- B-Lymphocytes
- T-Lymphocytes
- Natural Killer cells - NONSPECIFIC response
What is a test to measure the ratios of WBCs?
Differential White Blood Cell Count
What do changes from the normal count of WBCs indicate?
Disease or infection
What indicates allergies or parasitic worm infection?
Eosinophilia
What does increased leukocytes overall but especially neutrophils indicate?
Bacterial infection
What does increased lymphocytes indicate?
Viral infection
What are the 5 mechanisms of the second line of defense?
- Phagocytosis
- Extracellular killing by leukocytes
- Nonspecific chemical defenses
- Inflammation
- Fever
What is the process by which cells of the immune system engulf invading cells to break them down?
Phagocytosis
What are the 5 steps of Phagocytosis?
- Chemotaxis
- Adherence
- Ingestion
- Digestion
- Elimination
What is the movement of a cell in response to a chemical stimulus?
Chemotaxis
What do phagocytes use to move towards invading microbes?
(HINT: Make sure to describe what they are)
Pseudopods - extensions of the membrane and cytosol
Phagocytes/Macrophages are attracted by what 4 things?
- Microbial waste products or secretions
- Components of damaged cells or tissues
- Chemotactic factors
- Cytokines
What are cytokines?
Chemicals released by white blood cells during an immune response
What are chemotactic factors?
Specific chemicals in the complement system
What does PAMP stand for?
Pathogen-Associated Molecular Pattern
What is the recognition and attachment of the phagocyte to the invading cell?
Adherence
What are PAMPs ‘function’?
Things that might be recognized by a receptor protein on the macrophage
What do PAMPs include?
(HINT: List 3)
- Bacterial Flagella
- Peptidoglycan
- Lipopolysaccharide
What is indirect recognition? What cells can recognize these?
‘Tags’ that have been attached to an invader by the immune system; Phagocytes
What is when pseudopods extend from the phagocyte to surround the microbe?
Ingestion
What is formed after ingestion?
Phagosome
What is when the macrophage breaks down the invader that it swallowed?
Digestion
What does Digestion involve?
Fusing of the phagosome with a lysosome containing a variety of chemicals that damage the invader
What happens after digestion is completed?
Macrophages eliminate the debris by exocytosis
What will phagosomes do during digestion?
Phagosomes fuse with the cell membrane, spilling the broken down pathogen out of the cell
Why do macrophages “display” broken pieces of a pathogen after digestion?
To alert the immune system
What do eosinophils target? How do they kill invaders?
Eosinophils mainly attack parasitic worms
Eosinophils will attach to the surface of the worm and secrete toxins to kill the organism
What targets are too big to engulf?
Parasitic worms
How do Natural Killer cells kill invaders? What do Natural Killer cells target?
(HINT: 2)
NK cells secrete toxins into human cells that are displaying “strange” patterns on the surface
1. Tumor cells
2. Virus-infected cells
Chemicals free-floating in blood will _____ or _______
attack invaders or help with the immune response
What 2 things are part of nonspecific chemical defenses?
- Complement system
- Interferon
What is a series of proteins that come together to form a MAC that perforates the membrane of invading bacteria?
Complement system
What does MAC stand for?
Membrane Attack Complex
The complement system is generally more effective against what kind of bacteria?
Gram-Negatives
What is a chemical that is used during a viral infection?
Interferon
What are interferons released by?
Released by cells infeeted by a virus as an ‘alarm bell’
What 2 things do interferons do?
- Stops translation in neighboring cells so virus can’t spread
- Summons phagocytes to attack the infected cells
A lot of infections lead to?
Local or systemic inflammation
What are the symptoms of inflammation?
(HINT: 4 symptoms)
- Redness
- Heat
- Swelling
- Pain
What happens during inflammation? Why does this happen?
(HINT: Include 3 things for “why”)
Blood vessels dilate (open up)
1. Stimulates migration of phagocytes so it’s more likely a pathogen will be killed
2. Summons defense cells and chemicals such as complement system proteins and antibodies
3. Results in tissue repair
Why can inflammation be a bad thing?
Chronic inflammation is long-term, can lead to tissue damage over time
What are the 3 types of pyrogens?
- Bacterial Toxins (O-antigen on Lipopolysaccharide)
- Cytoplasmic contents of bacteria released by lysis
- Certain interleukins (chemicals released by lymphocytes)
What is when the body temperature over 37 C?
Fever
What chemicals trigger the hypothalamus to increase body temperature?
Pyrogens
Why can fever be good?
(HINT: Include 3 points)
- Increases activity of Interferon
- Inhibits growth of mesophilic microbes
- May enhance performance of certain immune cells
Why can fever be bad?
(HINT: Include 2 points)
- Too high for too long can damage host cells
- Organisms prefer a slightly-warmer-than-us temperature
