Airway Host Defence Flashcards
(125 cards)
1
Q
2 types of defense mechanisms
A
physical, chemical, cellular
2
Q
physical defense
A
cough, barrier function, MCC
3
Q
chemical defense
A
mucous composition and viscocity, antimicrobial peptides
4
Q
cellular defense
A
phagocytosis by macrophages, immune response
5
Q
WHat are the major atomspheric pollutants
A
carbon monoxide, nitrogen oxides, sulphur oxides, hydrocarbons, photochemical oxidants, particulate matter
6
Q
largets pollutant by weight
A
carbon monoxide
7
Q
binds to Hb with 200X greater affinity than O2
A
CO
8
Q
what is produced when fossil fuels are burned at high temps in power stations and cars
A
nitrogen oxides
9
Q
nitrogen oxides cause:
A
inflammation of eyes and upper RT
10
Q
what is a corrosive and posionous gas produced when sulphur containing fuels are burned
A
sulphur oxides
11
Q
inflammation of eyes and upper RT are symtpoms of
A
sulphur oxide exposure
12
Q
what is the product of unburned fuel waste
A
hydrocarbons
13
Q
hydrocarbons are not usually toxic at _____
A
concentrations found in atmosphere
14
Q
sunlight can trigger concersion of ___ into photochemical oxidants
A
hydrocarbons
15
Q
examples of photocehmical oxidants
A
ozone, peroxacyl nitrates, aldehydes, and acrolein
16
Q
high concentrations of photochemical oxidants cause
A
pulmonary edema
17
Q
what are sources of particulate matter
A
power stations and industrial plants
18
Q
why is cigarette smoke an important pollutant
A
because it is inhaled = higher concentrations
19
Q
smoke contains ___ which produced tachycardia and hypertension and sweating
A
nicotine
20
Q
what is associated with increase risk of chronic bronchitis, emphysema and heart disease
A
cigarette smoking
21
Q
some chemicals in cigarettes
A
nicotine, carbon monoxide, acetone, methanol, acetic acid, butane, ammonia, etc
22
Q
____ is deposition of large particles in nasopharynx
A
impaction
23
Q
_____ is gradual settling of medium particles in small airways
A
sedimentation
24
Q
____ is random movement of particles in alveoli
A
diffusion
25
Cough is a ______ that removes foreign material and secretion from airways
protective reflex
26
how long does cough take to develop
1 month
27
cough is initiated by:
airway obstruction, mechanical irritation, dust, cigarette smoke, chemical fumes, etc
28
where are specialized cough receptors located
under airway epithelium
29
what are the 4 phases of cough
deep and rapid resp effort, deep inspiration and immediate compression and activation of diaphargm and chest wall msucles, sudden openning of glottis reuslts in high exp airflow, relaxaion of muscles and reversal of pressures
30
barrier function by
bronchial epithelia: ciliated, pseudostartified, columnar epithelium
31
what do tight junctions do
provide structual support, inhibit movement of material via paracellular space (barrier funciton), and seperate apical and basolateral domains (fence function)
32
what are sources of mucous?
submucousal glands and goblet cells
33
mucous has 2 layers, what are they
top gel layer and bottom sol layer
34
cilia ___ in synchronized manner
beat
35
tips of cilia interact with ))))
gel layer
36
what do cilia do?
properl mucous in one direction
37
mucoscilary clearance is a ____ processes of protection
physical
38
end point of MCC
pharynx = swallowed
39
cilia are found down to the ___ bronchial division
16th
40
each ciliated cell has approx ____ cilia
200
41
cilia have a _____ arrangement
9+2
42
subfiber ___ is a complete microtubule and subfibre ___ shared part of ____
A, B, A
43
rest position, cilia bend sideway and back = ____ storke
recovery
44
what stroke account sofr 3/4 of cycle time
recovery
45
cilia move perpendicular to cell surface = ____ stroke
effective
46
during the ___ stroke, tip of cilia engage with mucous and sweep it in a cephalic direction
effective
47
overlying mucous penetrated by cilia tips in ____ only
effective stroke
48
____ of PCL layer is critical for effecttive MCC
thickness
49
ciliary movement coordinated by _____
metachronal waves
50
human cilia in the nose beat with what frequency?
12-15 Hz
51
Basal ciliary beat frequency can increase in repsonse to
insult
52
neuropeptide Y ____ CBF by ____
inhbit , reducing intracellular calcium
53
rises in ____ inccrease CBF
calcium
54
mechanical stimulation ___ CBF response
increases
55
factors affecting MCC in healthy individuals
age, sex, sleep, exercise, gravity
56
CBF is higher in ___ and lower in____
neonates and teens, adults
57
MCC is slower in
males
58
MCC is decreased during ___
sleep
59
exercise ____ MCC
increases
60
another name for primary ciliary dyskinesia
immotile cilia syndrome
61
primary ciliary dyskenesia caused by
absence of dynein arms normally found in 9 peripheral microtubule doublets
62
common clinical findings of immotile cilia syndrome
increased resp illnesses, bronchitis, rhinitis, sinusitis, repeated infection, infertility
63
Bronchiectasis
abnormal widening of bronchi
64
local damage to the resp tract epithelium due to infection is thought to result in ____
defective MCC
65
cycstic fibrosis results in ___
defective MCC
66
name 3 diseases affecting MCC
primary ciliary dyskenesia, bronchiectasis, CF
67
2 ways of clearance of inhaled particles
MCC, alveolar macrophages
68
phagocytose particles migrate to what 2 places
small airway to load on MCC escalator or leave via lmymphatics
69
phagocytes contain ___ so can directly kill bacteria
lysozyme
70
macrophage activity is imparied by
cigarette smoke, alcohol, alevolar hypoxia, ozone, radiation
71
What is respiratory mucous made up of
water with high molecular mass cross lunked glycoproteins and serum and cellular proteins = glycoproteins and water
72
glycoproteins and water give ____ properties
viscoelastic gel
73
mucins are
gigantic biopolymers of glycoproteins characterised by presence of one or more large region rich in serine and thronine - ++ carbohydrates
74
human reps tract is a mix of what
MUC5AC and MUC2
75
mucins provide _____ of defense barrier, prevent _____, present carbohydrate sites which ___ can attach to
defense barrier, dehydration, pathogens
76
airway mucous is a mix of proucts from
alveolar liquid, secretory products from cells lining the surface epithelium, submucousal galdn products, serum transudate
77
clara cells may transform into
goblet cells
78
when secreoty granule docks with the plasma membrane what forms
a secreotry pore
79
the secretory pore has a hih ionic conductance and ___ iside the granule is exchanged for extracellular ___
Ca, Na
80
this ion exchange triggers a ______ transition, when the mucin polymer matrix undergoes extensive swelling and goes into a ___ state
polymer-gel phase, hydrated
81
what are the physical properties of mucous
viscoelastic, adhesivity, wettability, spinnability
82
viscoelastic material is characterized by __ and ____ flow
nonlinear and time-dependent
83
due to ____ mucous has both viscous and elastic properties
cross linking of glycoproteins
84
viscocity is
resistance to flow and the capacity of a material to absorb energy when moving
85
elasticity is
capacity of a material to store energy used to move or defortm it
86
mucous repsond to stress as a combination of both ___ and ___
viscocity and elasticity
87
mucous exhibits
shear thinning
88
what is shear thinning
high shear forces then shows a decreased viscocity at lower shear forces
89
mucous is ___
non newtonian = viscocity decreases as applied force increases
90
more forcefully the cilia beat, the ___ the mucous moves
easier
91
what is adhesivity
ability of the mucous to bind to a solid surface
92
adhesivity of mucous depends on
mucous surface tension, hydration, wettability, and contact time
93
wettability is
ability to spread when deposited onto a solid plannar surface
94
degree of wettability is characterized by the ___ between the solid and the liquid at equilibrium
contatc angle
95
the ____ the contatc angle, the greater the wettability
lower
96
Spinnability is
the thread forming capacity of mucous under the influence of large amplitude elastic formation
97
spinnability gives informaiton on the _______ and ____
internal cohesive forces and elasticity
98
___ correlates positively with MCC
spinnability
99
characteristics of the physical properties (rhology) of mucous focus on 2 properties
viscocity and elasticity
100
viscocity is
the extent to which the gel resists the tendency to flow
101
elasticity is
the tendency for the gel to recover its original shape following stress induced deformation
102
what is phlegm
purulent secretion that is a product of airway inflammation
103
what does phlegm contain
breakdown products of inflammatory and epithelial cells, DNA and actin fragments, cell debris and mucins
104
when phlegm is expectorated it is called
sputum
105
What is another name for Sol layer
periciliary liquid
106
periciliary liquid has ___ viscocity to facilitate _____
low, ciliary beating
107
PCL contains _____ like lysozyme, lactoferrin, human beta defensins, cathelecidin LL-37
antibacterial factors
108
hydration of mucous and depth of sol layer is controlled by ____
transepithelial movement of ions and water
109
when excess PCL is present _____ absorption via ___ is dominant
Na, ENaC
110
When PCL volume is low ___ is inhbited which makes the apical membrane potential more ____ generating a force for ___ secretion
ENaC, negative, Cl
111
Antimicrobial peptides (AMPs) are part of
innate host defence mechanisms
112
AMP are generally
cationic, allows binding to negatively charged prokaryotic cell membranes
113
after AMPs bind to microbial surface, they lead to ______
cell wall distruction
114
activity of many AMPs is inhbited by ______
high levels of salt or serum proteins
115
where are AMPs secreted from
surface epithelial cells and submucosal glands
116
human airways has what 2 types of AMPs
defensis and cathelicidins
117
name a defensin
human beta defensin
118
which Hbeta D is constitutively secreted into the PCL
hBD-1
119
other hBD are induced in response to ____
pathogens, inflammatory cytokines
120
what is the only human cathelicidin
LL-37
121
name 2 large AMPs
lysozyme and lactoferrin
122
lysozyme secreted from ____ and ____
epithelial cells and SMG
123
what does lysozyme induce?
lysis of gram positive bateria
124
lactoferrin is activated by ____ and ____
inflammatory and infectious stimuli
125
what does lactoferrin do
sequesters iron from microbes
