Host Barriers Flashcards
1
Q
skin
A
- physical/mechanical barrier
- chemical agents
- normal flora
2
Q
physical/mechanical barrier
A
- closely connected cells called keratinocytes with cross-linked keratin
- high turn over rate
- prevents evaporation
3
Q
antimicrobial agents of the skin
A
- cathelicidins
- defenses
- dermicidin
- propionic acid
4
Q
pH of the skin
A
- acidic pH
- create an environment where bad bacteria don’t want to live
5
Q
normal flora
A
- commensals
- bacteria in the epidermis that do no harm
- and in some cases possibly benefit
6
Q
Langerhans cells location
A
- dendritic cells located among keratinocytes
7
Q
Langerhans cells origin
A
- derived from the bone marrow
8
Q
Langerhans cells function
A
- function as antigen presenting cells in immune responses to contact antigens (like skin allergies) and some skin grafts
9
Q
what do Langerhans cells contain?
A
- contain birbeck granules
10
Q
organization of mucous membranes
A
- mucosa
- submucosa
- muscular externa
- external layer
11
Q
mucosa composed of
A
- epithelium
- lamina propria
- muscularis mucosae
12
Q
lamina propria
A
- loose connective tissue with glands
13
Q
muscularis mucosae
A
- smooth muscle
14
Q
submucosa
A
- dense irregular connective tissue
15
Q
muscularis externa
A
- inner smooth muscle
- outer smooth muscle
16
Q
external layer
A
- adventitia
- serosa
17
Q
adventitia
A
- loose connective tissue
18
Q
serosa
A
- loose connective tissue
- mesothelial lining from peritoneum
19
Q
intercellular junctions
A
- tight junction
- zonula adherens
- desmosome
- gap junction
20
Q
desmosome composed of
A
- desmoplakins
- plakoglobins
21
Q
tight junction type of junction
A
- an occludens junction
22
Q
tight junction composed of
A
- Claudins
- occludins (protein)
- Claude sounds like the name of someone who is uptight
23
Q
tight junction function
A
- prevents leaking between cells
- prevents movement of membrane proteins
24
Q
zonula adherens type of junction
A
- adherens junction
25
zonula adherens composed of
- cadherins
26
zonula adherens function
- binds to actin of the terminal web (cytoskeleton)
27
desmosome type of junction
- adherens junction
| - macula adherens or spot desmosome
28
desmosome composed of
- desmoplakins and plakoglobins
29
desmosome function
- join keratinocytes at cell-cell junctions
| - join side to side or up to down
30
gap junction type of junction
- communicating junction
31
gap junction composed of
- connexins
32
hemidesmosome type of junction
- adherens junction
| - NOT AN INTRACELLULAR JUNCTION
33
hemidesmosome function
- join cells in basal layer to basement membrane
34
mucosal immunity in intestine
- epithelial products
- antimicrobial factors
- normal flora
- lymphoid tissue
- peristalsis
-
35
epithelial products in intestine
- acidic pH in stomach
- pancreatic enzymes
- bile
- intestinal secretions
- mucus
36
antimicrobial factors in intestine
- lysozyme
37
what makes lysozyme in the intestine
- Paneth cells
| - full of secretory vesicles
38
goblet cell
- secretes mucus precursors to surface of intestine
39
mucosal immunity in intestine
- antigens in gut bound by M cells and undergo transcytosis into their intraepithelial pockets
- dendritic cells take up antigen, process it, and present to helper T lymphocytes
- B lymphocytes stimulated to differentiate into plasma cells which secrete igA antibodies
- IgA transported to gut lumen where it binds its antigen on the surface of microorganisms, neutralizing potentially harmful invaders before they penetrate the mucosa.
40
antigens in gut - mucosal immunity
- bound by M cells
| - undergo transcytosis into their intraeplial pockets
41
dendritic cells - mucosal immunity
- take up antigen
- process it
- present to helper T lymphocytes
42
B lymphocytes - mucosal immunity
- stimulated to differentiate into plasma cells
43
plasma cells - mucosal immunity
- secrete IgA antibodies
44
IgA - mucosal immunity
- transported to gut lumen
- binds antigen on surface of microorganism
- neutralizes potentially harmful invaders before they penetrate the mucosa.
45
why can IgA coexist with proteases in the gut lumen
- it is resistant to proteolytic enzymes
46
how many bacterial species in oral cavity
- 400
47
mucosal immunity in oral cavity
- epithelium
- lamina propria
- saliva
48
epithelium - mucosal immunity in oral cavity
- physical barrier as in skin
| - cells slough off and prevent biofilm formation
49
epithelium contains - mucosal immunity in oral cavity
- contains Langerhans cells and intraepithelial lymphocytes
50
lamina propria contains - mucosal immunity in oral cavity
- macrophages
| - dendritic cells
51
dendritic cells - mucosal immunity in oral cavity
- project dendrites into the epithelium
- uptake antigens
- migrate to secondary lymphoid tissue and draining lymph nodes
52
saliva contains
- lysozyme
- lactoferrin
- histatins
- salivary IgA
- myeloperoxidase
53
lysozyme - mucosal immunity in oral cavity
- cleaves bacterial cell walls
54
salivary IgA
- aggregates oral bacteria
| - prevents formation of dental plaques
55
pemphigus vulgaris
- acontholytic (loss of intercellular connections) in persons aged 30-60
56
pemphigus vulgaris cause
- autoimmune attack of desmosomes
57
pemphigus vulgaris result
- formation of severe intraepidermal bullae starting in oral cavity and spreading to skin
- can be fatal
58
bullous pemphigold vs pemphigus vulgaris
- resembles pemphigus vulgaris but less severe
59
bullous pemphigold cause
- autoimmune attack of hemidesmosomes
60
bullous pemphigold result
- sub epidermal bulael with characteristic inflammatory infiltrate of eosinophils
61
diffuse lymphoid tissue located
- located in mucosa
| - unless seen in submucosa known as Peyer's patches
62
two forms of diffuse lymphoid tissue
- loose clusters of lymphoid cells
| - lymphoid nodules
63
where are lymphoid nodules found
- in lamina propria of mucosa throughout gut
64
Peyer's patches
- found in ileum
| - large and press outward to submucosa
65
respiratory tract
- turbulent airflow and humidification causes large particles to land on mucosal surfaces
66
layer of mucus respiratory tract
- flows toward pharynx for expectoration or swallowing
67
swallowing is what kind of mechanism?
- cleansing mechanism
68
mucus clearance aided by
- coordinated secretion of mucin and proteins
- sufficient water for hydration
- beating cilia
- sneezing and coughing
69
protective antimicrobial factors in respiratory tract
- antioxidants
- defensins
- lactoferrins
- lysozyme
70
sentinel cell
- alveolar macrophage
| - first line of defense
71
epithelium in vagina secretes
- epithelium secretes glycogen
72
normal flora in vagina
- convert glycogen to lactic acid
- creates acidic pH
- unfavorable for pathogens
73
normal urine
- sterile
74
normal urine pH
- bactericidal due to pH and urea
75
Tamm-Horsfall protein
- comes from kidney
| - binds bacteria and prevents attachment to urinary tract lining
76
frequent urination
- rinses lower urinary tract with urine 4-8 times a day
| - eliminates pathogenic organisms
77
pathogens that can bind to urinary tract epithelial cells
- N. gonorrhea
| - E. coli
78
longer male urethra benefit
- passive protection
| - longer route for bacterial to travel to bladder
79
Eye protections
- blinking
- lacrimal glands
- meibomian glands
- ciliary gland
- bacteriostatic/cidal tear film
80
lacrimal glands
- tears
81
meibomian glands
- sebaceous glands on eyelid
82
ciliary gland
- aporcrine sweat glands on eyelid
83
tear film comes from
- glandular secretions of conjunctiva and cornea
84
constant bathing of eyes with tears
- dilutes and clears foreign substances via tear ducts into nasal passage
85
tears contain
- lysozyme
86
lipid oil layer of eye
- lubricates and prevent evaporation
87
aqueous water layer of eye
- nourishes and protects cornea
88
mucin layer of eye
- adheres tear to eye
89
presence of innate immune defenses
- present intrinsically without previous stimulation
90
specificity of innate immune defenses
- limited specificity
91
innate immune defenses repeated exposure
- not enhanced by repeated exposure
92
diversity of expression of innate immune defenses
- limited diversity of expression