Innate Immunity Flashcards

Lecture 30-32

1
Q

What are the two systems the immune system is made of?

A

Innate system- non-specific

Adaptive system- very specific

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is the innate immune system? When does it develop?

A

The innate immune system protects humans from most infectious diseases. It develops at birth, so it is not learned system but one developed by nature.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What does the innate immune system consist of?

A
Physical barriers  
Chemical defenses 
Cellular defenses  
Molecular defenses  
Physiological processes
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What do pathogens prefer to initiate infection? What is this based upon?

A

A specific body site- this is based upon metabolic and nutritional needs of the pathogen.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

At a specific body site what is the mechanism pathogens like to use? Give an example.

A

They like to use the mechanism of spreading
Aerosol vs. blood/bodily fluids
Ex) Clostridium tetani can be ingested or can enter into deep wounds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Every species has natural host resistance, but susceptibility to pathogens varies from one species to another. What are two examples of this?

A

Anthrax causes fatal blood infection in cattle and cutaneous infection in humans
HIV can infect human cells but not mice or guinea pigs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Which physical barrier prevents invasion by microbes and is rich in tough protective protein?

A

Skin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is keratin?

A

The tough protective protein on skin- it is a fibrous protein forming the main structural constituent of hair, feathers, hoofs, claws, horns, etc.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

True or False: Skin has a slightly acidic ph of 5 and a high [NaCl]-periodic drying.

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Some fungal infections can grow right on the skin, but what do most require to infect the host?

A

Broken skin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Which physical barrier lines tracts in the body, like the respiratory tract, digestive tract, reproductive tract, and urinary tract?

A

Mucous Membrane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is mucous produced by? What does it do and what does it contain?

A

Goblet Cells- a column-shaped cell found in the respiratory and intestinal tracts, which secretes the main component of mucus.
It traps microbes preventing infections and contains antimicrobial secretions.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

In the mucous membrane of the respiratory tract, what does it contain?

A

It contains the mucocilliary escalator and mucosal epithelial cells. Both contain cilia.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is the function of the cilia in the respiratory tract?

A

Using the cilia’s sweeping motion they filter incoming air and remove of mucous and trapped microbes from the lungs.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

In the mucous membrane of the gastrointestinal tract, what are the characteristics of the stomach?

A

Strongly acidic: pH~2
Contains proteases- breaks down proteins and peptides
Few microbes are able to survive in this environment

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

In the mucous membrane of the gastrointestinal tract, what does the small intestine contain?

A

It contains pancreatic juice that buffers acidity of incoming contents from the stomach: pH ~7
Contains pancreatic enzymes
Contains bile from the liver
It’s very difficult for microbes to maintain cellular integrity in this harsh environment.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

In the mucous membrane of the gastrointestinal tract, what does the large intestine contain?

A
It contains the normal microbiota  
It also contain normal resident bacteria that live symbiotically inside of the colon 
-Uses attachment sites to persist 
Consume undigested nutrients 
Produce antimicrobial compounds
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

In the large intestine, how does it consume undigested nutrients and produce antimicrobial compounds?

A

In order:
Competitive Exclusion- inevitable elimination from a habitat of one of two different species with identical needs for resources
Microbial Antagonism- method of using established cultures of microorganisms to prevent the intrusion of foreign strains. Invasive bacteria usually do not thrive.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

In the mucous membrane, what is the difference between male and female genitourinary tracts?

A

While genital and urinary tracts are joined in males, they are separate in females.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What does the urinary tract (in both male and females) contain? What is its function?

A

The urinary tract contains urine which includes many toxins that are intolerable by bacteria. The action of urinating physically removes contaminating microbes.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What does the female reproductive tract contain? Give an example of a microbe that lives in the female reproductive tract.

A

The female reproductive tract contains normal microbiota. Glycogen secreted by vaginal epithelial cells supplies nutrients for microbial growth.
Ex) Lactobacillus acidophilus
-Ferments glucose to lactic acid
-Local pH ~4.5

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Which innate system is composed of organs and vessels that allow immune cells to contact foreign antigenic material?

A

The lymphatic system

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What is the term used to describe foreign material that is able to activate cells of the immune system?

A

An antigen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What is the lymphatic system composed of?

A

Lymphatic Vessels and Primary and Secondary Organs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What is the function of the lymphatic vessels? What do they contain? What do they not contain?

A

Lymphatic vessels carry lymph from the tissues to the lymph nodes

  • Unidirectional (always away from tissues)
  • Lymph is rich in leukocytes (white blood cells)
  • Free of erythrocytes (red blood cells)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What are the primary lymphatic organs? What do they contain?

A

Bone marrow
-Leukocytes are produced here (white blood cells)
Thymus gland
-Some leukocytes (T-wbc) mature here

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What are the secondary lymphatic organs? What do they contain?

A

Lymph nodes
Spleen
Mucosa associated lymphatic tissue (MALT)
-All contain a high concentration of leukocytes
-Incoming lymph is filtered

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What does MALT stand for? What is its function?

A

MALT- Mucosa associated lymphatic tissue

-associated with all mucous membranes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What does GALT stand for? What is its function?

A

GALT- Gut associated lymphatic tissue

-Leukocytes present here are constantly phagocytosing material in their surroundings in search of foreign content

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

In the innate system what is the cellular defense? What are the two sub-categories in this defense.

A

The bodies cellular defense is leukocytes- white blood cells. They are split into two broad categories:

  • Granulocytes
  • Agranulocytes
31
Q

What are the function(s) of leukocytes?

A

Circulate in the blood and the lymphatic system
Reside in the tissues and the lymph nodes
Play a role in both innate and adaptive immunity

32
Q

What are granulocytes? What is their function?

A

They are large, visible granules in the cytoplasm that are reactive. They can:
Can kill microbes
Can serve as signaling molecules to recruit and activate other components of the immune system

33
Q

Granulocytes can be split into three categories that spell out the acronym ‘BEN’. What does BEN stand for?

A

Basophils and Mast Cells- stores histamines
Eosinophils- destroys large parasites
Neutrophils- professional phagocytes

34
Q

What is a neutrophil? What does it contain?

A

A cytoplasmic granule that contains:

  • lysozome
  • Defensins
35
Q

What is a neutrophil’s function?

A

They circulate in the blood
Exit the capillaries during periods of infection
Strongly phagocytic
Very important cells of the innate immune system

36
Q

What is an eosinophil? What does it contain? When are their levels in the blood high?

A

A non-phagocytic cells. It has Cytoplasmic granules that will stain with acidic dyes.
-The amount of eosinophils in the blood increase during an allergic reaction

37
Q

What is an eosinophil’s function?

A

They work to destroy large parasitic cells.
Protozoa and parasitic worms
Secrete extra-cellular enzymes and reactive oxygen species
-H2O2, OH, O
Can also exit the capillaries into infected tissues

38
Q

What is are basophils and mast cells? What do they contain?

A

They are cytoplasmic granules that stain with basic dyes. They’re not strongly phagocytic.

  • Basophils circulate in the blood
  • Mast cells reside in mucosal tissue
39
Q

What is a basophil and mast cell’s function?

A

Degranulate (release) in response to appropriate stimuli
Release histamine
Important part of the allergic response
Causes vasodilation locally
Causes life threatening vasodilation and bronchiolconstriction when released systemically
Ex) someones throat closing up during a peanut allergy

40
Q

What are agranulocytes? What is their function?

A

Contain cytoplasmic granules that are much smaller and more difficult to view than granulocytes.

41
Q

Agranulocytes can be broken down into two sub-categories- what are they?

A

Monocytes and Leukocytes

42
Q

Referring to agranulocytes, what are monocytes? What is their function?

A

Monocytes circulate in the blood. Once in the tissues they are very strongly phagocytic. They present foreign antigen to other cells of the immune system.

43
Q

Monocytes migrate to different tissue and can mature into two different cells- what are they called?

A

Macrophages and Dendritic Cells

44
Q

Which cell that a monocyte can mature into is located in the tissues (lungs, connective tissue, spleen, liver)?

A

Macrophage

45
Q

What is the function of a macrophage? What do they contain?

A

They contain special surface receptors that allow them to recognize many pathogens with one receptor- Toll-like Receptors (TLRs).
Recognize things like LPS, peptidoglycan, elements of the fungal cell wall, and what to kill/not kill.
Binding of the toll-like receptor to antigen induces phagocytosis.

46
Q

What cell that a monocyte can mature into is located in tissues that are often sites of entry for infectious materials and in the mucus membranes of the nose, the lungs and the intestines? What is another name for this cell?

A

Dendritic cell

-in the skin they are referred to as Langerhan’s Cells

47
Q

What is the function of the dendritic cell? What do they contain?

A

Regularly sample the surroundings and phagocytose antigens. The Phagocytosed antigen is carried to lymphoid organs
Presented to other cells of the immune system (T/B lymphocytes)
Activate the adaptive immune response

48
Q

Referring to agranulocytes, what is a leukocyte? What is their function?

A

Leukocytes the are involved in the adaptive immune response.

They Circulate through the blood and remain in the lymphoid organs.

49
Q

Leukocytes can be split into three sub-categories- what are they?

A

T-lymphocyte
B-lymphocyte
Natural Killer Cells (NK cells)

50
Q

Which leukocyte destroys abnormal cells in the body (cancer cells, infected cells)?

A

NK cells

51
Q

Which leukocyte has many Different types and forms the main component of cell mediated immunity?

A

T-lymphocytes (T-cells)

52
Q

Which leukocyte has antibody producing/secreting cells and forms the main component of humoral immunity?

A

B-lymphocytes (B-cells)

53
Q

What molecular defense(s) are secreted at mucosal sites? What are the defense(s) functions?

A

Lysozyme:
Cuts b-1,4 glycosidic bonds in peptidoglycan
-destruction of cell wall
Defensins:
Antimicrobial peptides that poke holes in bacterial cell membranes

54
Q

What is a function of phagocytosis?

A

Destroys pathogens that may have never before been encountered in the body

55
Q

What does phagocytosis include?

A

Involves leukocytes capable of phagocytosis

-Neutrophils and macrophages

56
Q

How does phagocytosis activate?

A

Recognize pathogen associated molecular patterns (PAMPs):

-Lipopolysaccharide, lipoteichoic acid, flagellin

57
Q

What happens in phagocytosis after PAMPs are recognized? What recognizes them?

A

PAMPs are recognized by TLRs located on the surface of phagocytic cells
TLRs are also called pattern recognition receptors (PRRs)
Interaction of PAMP with a TLR triggers phagocytosis

58
Q

What occurs in phagocytosis after phagocytes engulf the invading pathogen?

A

Cell membrane invaginates around a foreign particle Engulfs it into a phagosome
Phagosome fuses with a lysosome to form a phagolysosome

59
Q

What is a phagolysosome filled with?

A

Lysozyme and defensins
Proteases (degrade proteins)
Lipases (degrade phospholipids)
Nuclease (degrade nucleicacids)

60
Q

True or False: after the phagosome fuses with the lysosome to form a phagolysosome, that is the last oxygen-independent step.

A

True

61
Q

What is the first oxygen-dependent step in phagocytosis?

A

Activated phagocytes produce reactive oxygen compounds:
H2O2
O2
OH
HOCl
NO
This will kill ingested microbes by oxidizing cell components.

62
Q

What occurs in phagocytosis after the ingested microbes have been killed?

A

Neutrophils perform exocytosis- fragments are expelled from the cell

63
Q

In phagocytosis after exocytosis is performed, which cells become antigen presenting cells?

A

Macrophages and Dendritic cells

64
Q

What occurs in phagocytosis after the fragments of the intruder are expelled from the cell?

A

They trigger an adaptive immune response

65
Q

What Occurs non-specifically in response to tissue damage, toxins, and infectious material?

A

Inflammation

66
Q

What 5 signs are present when inflammation occurs?

A
Redness (erythema) 
warmth
pain 
swelling (edema) 
loss of function
67
Q

What is inflammation a response to? What do the blood vessels do?

A

It is response to infection injured tissue and leukocytes release pro-inflammatory cytokines.
Blood vessels dilate to allows more leukocytes to access the area

68
Q

When blood vessels dilate what happens to them? What does this allow?

A

Vessel walls become more permeable

Leukocytes can squeeze into tissues (Extravasation ) and attack invading pathogens.

69
Q

What can slow the growth of microbes and promotes faster healing of damaged tissues?

A

Temperature increase

70
Q

What does blood pooling into the tissues do? What does this action prevent?

A

Can clot to prevent the movement of pathogens.

71
Q

What is a fever? What controls it?

A

Fever is an increase in body temperature
It is controlled by the hypothalamus of the brain
It is triggered by toxins, LPS, and chemicals produced by the immune system
All of these things reset the bodies thermostat

72
Q

What action(s) does a fever result in?

A

Muscle contraction-shivering
Increased temperature-faster metabolism and promoted healing
Faster phagocytosis
Slower growth of microbes

73
Q

At 43 Celsius what can a fever cause?

A

Death

74
Q

What temperature does E. coli like to grow at? When does its growth slow?

A

Grows well- 37 Celsius

Growth slows- 40 Celsius