Respiratory System Flashcards
1
Q
Thorax vs thoracic cavity
A
thorax = boney; includes thoracic cavity & intra-thoracic part of abdominal cavity
thoracic cavity = separated from abdominal cavity by diaphragm
2
Q
Nasal cavity is b/w what structures
A
external nares & choanae
has respiratory & olfactory functions
3
Q
Extent of diaphragm
A
T7 to T13
4
Q
Innervation of diaphragm
A
phrenic nerve
from C5 & C6 ventral primary branches
5
Q
Fiber direction for external intercostal muscles
A
caudoventral to craniodorsal
inspiratory
6
Q
Fiber direction for internal intercostal muscles
A
caudodorsal to cranioventral’
expiratory
7
Q
Accessory muscles of inspiration
A
serratus ventralis & dorsalis cranialis
scalenus
rectus thoracis
abdominals (help support trunk)
8
Q
Accessory muscles of expiration
A
transversus thoracis
abdominals
9
Q
What is the pleura
A
serous membrane lines thoracic cavity & covers lungs secretes fluid capillary action allows for smooth gliding of lungs against body wall
10
Q
What is the pleural cavity
A
potential space b/w pleura
11
Q
Costo-diaphragmatic recess
A
from pleura changing directions
lungs do not extend into this space
12
Q
Line of pleural reflection
A
continous serous membrane makes an abrupt turn as it travels from he ribs (costal pleura) to the diaphragm (diaphragmatic pleura)
13
Q
Auscultation triangle
A
diagonal line from tip of T5 to top of T11
ventral to epaxial muscles
caudal to thoracic limb
avoids heart & trapezius muscles (so that lungs can be heard)
14
Q
Thoracentesis
A
needle into 7th to 10th intercostal spaces
must go cranial to ribs, not caudal (arteries & veins)
angle towards body wall to enter space
15
Q
Clinical relevance of the line of pleural reflection for thoracocentesis
A
cranial to line = pleural cavity
caudal to line = peritoneal cavity
16
Q
Type of epithelium for typical respiratory epithelium (TRE)
A
pseudostratified ciliated columnar epithelium w/ goblet cells
17
Q
Cell junctions are affected by what
A
pathogens, autoimmune disease, & cancers
18
Q
Tight junction
A
seal
19
Q
Adherens
A
attachment (contact inhibition)
20
Q
Desmosomes
A
lightly hold cells together
21
Q
Hemidesmosome
A
holds cells lightly to basal lamina
22
Q
Cell types in TRE
A
goblet, basal, ciliated, neuroendocrine, & brush
height & cell types of TRE change throughout dif regions
23
Q
Goblet cells
A
no cilia
nuclei on basal surface
mucus produced & secreted towards apical surface
24
Q
Basal cells
A
triangular/polyhedral shape
near basal lamina
contain desmosomes & hemidesmosomes
replace damaged cells
25
Ciliated cells
columnar
microvilli & vital organelles
escalator of mucus
26
Neuroendocrine cells
secrete pharmacologically active substances (calcitonin & hormones/chemicals)
diffuse endocrine system
granules face basal side to travel through blood
sense environment
involved in growth of respiratory sys cells
27
Brush cells
microvilli
| sensory receptors for trigeminal nerve
28
Nasal vestibule is the transition from
skin to respiratory
external keratinized squamous epithelium (w/ or w/out hair) to non-keratinized & thin to cuboidal/ non-ciliated pseudostratified columnar epithelium
29
Glands, cartilage, & other present in nasal vestibule
serous & sweat glands
hyaline and/or elastic cartilage
nerves, blood vessels, & immune cells (propria submucosa)
30
Epithelium of caudal 2/3rd of nasal cavity proper (excluding olfactory region)
TRE
31
Function of nasal cavity
humidification & warming by thin walled veins & glands
32
Constriction of nasal cavity by
alpha-adrenergic stimulation via sympathetic nervous sys
33
Other features of nasal cavity
nerves
lymphatic nodules
P450 enzymes for detoxification
34
Olfactory region epithelium
high pseudostratified epithelium
35
Cells in olfactory region
olfactory, supporting, & basal
36
Olfactory cells
```
bipolar neuron (axon & dendrite)
perikarya in basal zone
dendrites extend into lumen to sample odorant molecules
non-myelinated
lamina propria
```
37
Supporting (sustentacular) cells
protective
glial-like
occluding/ tight junctions
oval-shaped nucleus is closest towards the lumen
microvilli
wider on apical side & narrower on basal side
anchored to neighboring cells via tight junctions
38
Basal cell
tight junction
| regenerate olfactory cells/ neurons & support/ sustentacular cells
39
Glands in olfactory region & function
olfactory/ Bowman's glands
propria submucosa
secrete watery secretion that enhances the solubility of the odorant molecule & cleanse the cilia, allowing for the re-use of receptors for the next odorant molecule to be sampled
40
Pigmentation of olfactory region
lipofuscin
41
Location of olfactory region
dorso-caudal portion of nasal cavity
| includes parts of ethmoidal conchae, dorsal nasal meatus, & nasal septum
42
How to olfactory cells allow for the sense of smell
club-like dendritic bulb has 10-30 non-motile cilia that contain olfactory receptors
when an odorant molecule arrives at the site, secretions from the olfactory gland solubilize the odorant molecule, leading to an action potential & odor sensation
axons from olfactory cells reach olfactory bulb of brain & leave as non-myelinated nerve fibers through the cribriform plate of the ethmoid bone
43
Location of vomeronasal organ
ventral portion on both sides of nasal septum
44
What is the vomeronasal organ
blind-ended tubes w/ internal epithelial ducts, propria submucosa, & J-shaped hyaline cartilage
45
Vomeronasal organ opens where
in most species (not horses), incisive duct opens caudal to the upper central incisors
46
Epithelium of vomeronasal organ
medial side = neurosensory cells, sustentacular/support cells, basal cells, & vomeronasal glands
lateral side = pseudostratified ciliated or non-ciliated epithelium
47
Function of vomeronasal organ
chemoreceptors of liquid born substances
sexual behavior
maternal instinct
fetal interaction w/ amniotic fluid
48
Function of muco-ciliary escalator
beat in one direction (towards pharynx) to clear the mucus into the exterior (via sneezing/spitting) or into the GI tract (via swallowing)
49
Describe stroke of cilia
forward (power) stroke followed by a backward (recovery) stroke
No contact w/ mucus on recovery stroke
Energy from mitochondria
50
Damage to muco-ciliary escalator due to toxins or other defects results in
cilia unable to remove bacteria, allergens, & dust trapped in the mucus bilayer (gel & soluble layers)
51
Structure of muco-ciliary escalator
9 peripheral & 2 central microtubules
peripheral tubules held by nexin protein to prevent sliding & ensure unity
inner & outer dynein protein arms of the peripheral generate a sliding motion using ATP
52
Cause of primary ciliary dyskinesia
immotile ciliary syndrome or Kartagner syndrome
| autosomal recessive genetic disorder -> defect in coding of the dynein protein
53
Result of primary ciliary dyskinesia
excessive mucus build up -> chronic respiratory & middle ear infections
sitrus inversus totalis
sitrus ambiguous or heterotaxy syndrome
reproductive failures
inner, outer, or both dynein arms affected
54
Diagnosis & treatment of primary ciliary dyskinesia
electron microscopy of nasal/ bronchial epithelium
| no treatment, but remove from breeding
55
Horses are obligate nasal breathers w/ a long soft palate. What diseases commonly affect them
dorsal displacement of the soft palate, laryngeal hemiplegia, & pharyngeal collapse
56
Epithelium of nasopharynx & larynx
TRE excluding epiglottis & vocal folds
57
Lamina propria of nasopharynx & larynx has what
loose CT & seromucous glands
58
Epithelium of epiglottis
oral side & tip = stratified squamous epithelium (non-keratinized)
tracheal side = TRE
59
Glands & cartilage of epiglottis
no glands
| elastic cartilage
60
Epithelium of vocal folds
stratified squamous epithelium (non-keratinized)
61
Glands & cartilage of epiglottis
none
62
Club cells/ bronchiolar exocrine cells
no cilia
secrete glycosaminoglycan
stem cell
metabolize xenobiotics
club cell secretory protein is a biomarker
contain tryptase & activate hemagglutinin of influenza A
63
Trachea epithelium
lumen lined w/ TRE & supported by c-shaped hyaline cartilaginous rings
64
Structure of trachea allows for what
semi-flexible & semi-collapsible tube
| permits bending/ rotating of neck w/out affecting ventilation
65
Glands & cartilage of trachea
sero-mucous/ sub-mucosal glands
| hyaline cartilage
66
Trachealis muscle & function w/ swallowing
smooth muscles
faces esophagus on dorsal side, allows for shape change of trachea when food passes through the esophagus
trachea can flatten & expel air when coughing
cartilage provides rigidity to prevent collapse
67
Tunica adventitia of trachea has
loose CT & longitudinal elastic fibers
68
Hyaline cartilage of trachea has
chondrocytes, matrix, & type II collagen fibers
69
Tracheal collapse
"goose honk" coughing
common in toy breeds
sound occurs primarily in expiration
50% collapse = 16x increase in airway resistance
70
Treatment of tracheal collapse
medical management is a temporary fix
| surgical treatment w/ a stent is necessary
71
Epithelium of bronchi
TRE w/ goblet cells
72
Cartilage of bronchi
in pieces/ plates
73
Intra-pulmonary bronchi changes how
height decreases & glands become sparse
74
Bronchi & trachea smooth muscle comparison
bronchi has more
75
Bronchioles epithelium
simple columnar/ cuboidal epithelium (ciliated or non-ciliated)
+/- goblet cells
76
Smooth muscle of bronchioles
circular & oblique fascicles
77
Glands & cartilage of bronchioles
none
78
Functional blood
pulmonary trunk & left/right pulmonary veins
| gas exchange
79
Nutritional blood
bronchial artery branches supply pulmonary lymph nodes, bronchi, & bronchioles w/ oxygenated blood
80
Smaller airways do not need nutritional blood b/c
do fine on just functional blood
81
Deoxygenated blood from the nutritional blood goes where
into pulmonary vein, mixing w/ oxygenated blood
82
Pulmonary art
thin
deoxygenated blood
low pressure
both internal & external elastic laminae
83
Bronchial art
thick
oxygenated blood
high pressure
only internal elastic laminae
84
Pulmonary vein
thin
| only external elastic laminae
85
Pulmonary lymphatics
thin
valves
no erythrocytes
86
Pulmonary hypertension
may affect veins or arteries
results from inflammatory lung disease (asthma or COPD) that leads to thickening of the pulmonary artery branches
could occur from a left atrioventricular valve defect that backs blood into pulmonary veins
87
Terminal bronchiole is considered what portion
conducting portion
| no alveoli or gas exchange
88
Epithelium of terminal bronchiole
simple cuboidal epithelium (ciliated or non-ciliated)
| no goblet cells
89
Glands & cartilage of terminal bronchiole
none
90
Smooth muscle in terminal bronchioles
greatly reduced
| directly below the lining epithelium
91
Respiratory bronchiole is considered what portion
respiratory portion or transitional zone
92
Epithelium of respiratory bronchiole
simple cuboidal epithelium (few ciliated)
no goblet cells
some alveoli
93
Type I alveolar epithelial cells
```
squamous cells
only nuclei well seen
cover 95% of alveolar area
very thin blood-gas barrier
tight junctions
```
94
Type II alveolar epithelial cells
```
large round cells/ cuboidal
granular
cover 5% of alveolar area
mostly in corners of alveoli
produce surfactant
act as stem cells for Type I AEC
```
95
Pathological conditions like chronic inflammation may result in thickening of the respiratory membrane, leading to
decreased efficiency of gas diffusion
96
Alveolar macrophages are found where
in air spaces w/in alveoli
97
Function of alveolar macrophages
guard against invading pathogens & their products
98
Appearance of macrophages when they ingest foreign bodies (dust particles or bacterial products) or dead cells
foamy cytoplasm
| may be due to the processing of internalized materials w/ the help of enzymes present in lysosomes
99
Are there other immune cells in the lungs except for alveolar macrophages
no, unless there is a danger signal (bacteria) -> neutrophils
100
Surfactant
contained is osmiophilic lamellar bodies
reduce surface tension
allow alveoli to stay open
101
Epithelium of pleura
simple squamous epithelium (mesothelium) w/ underlying CT & vessels
102
Pleuritis
may result in pain & affected individuals could sense gliding of their lungs against the body wall in the affected area
103
Respiration processes involve
ventilation (movement of air)
diffusion
transportation
tissue delivery & return
104
At higher elevations, how does amount of air & % composition change
amount of total air decreases
| % composition stays the same
105
Air composition at a higher altitude may accentuate certain pathological conditions or physiological performances like
patient w/ lung disease moved to a higher elevation may not be able to perform strenuous activities & experience breathing difficulties
healthy human/animal may have sub-optimal performances when moved to a higher elevation w/ less O2
106
Upper respiratory tract includes
nares, nasal conchae, pharynx, larynx, trachea, & principle bronchi
107
Species w/ most & least pliable nostrils
horse - most
| pig - least
108
Function of upper respiratory tract
conditions air
warms it to body temp
entraps inhaled substances in mucus
109
Nasal conchae (turbinate bones) function
```
create laminar (slow) slow
help trap dust
```
110
Other accessory structures of upper respiratory tract
auditory tube, guttural pouches, vomeronasal organ, nasolacrimal duct, & paranasal sinuses
111
As airways branch, what happens
total cross-section area increases & resistance to flow decreases
112
Ventilation definition
process of inhaling & exhaling air to acquire O2 & expel CO2
113
Ventilation is dependent on
pressure differences b/w atmosphere & inside of thoracic cavity
114
Neg pressure ventilation
created by respiratory muscles
115
Expiration is usually passive, but can be affected by
pathological conditions like heaves or physiological conditions like strenuous exercise
requires aid of abdominal muscles
116
Pos pressure ventilation
created by O2 devices used when anesthetizing an animal
117
VE = VT * f
```
VE = total amount of air breathed per min
VT = volume of each breath during normal breathing
f = respiratory frequency; # of respiratory cycles per min
```
118
Dead space
no gas exchange
conducting portion
respiration wasted
119
Anatomic dead space
nostril, mouth, trachea, auditory tube, guttural pouches, & paranasal sinuses
120
Equipment dead space
endotracheal tube
121
Alveolar dead space
poor or no perfusion of alveoli
| caused by hydrostatic pressure failure, embolus, emphysema, or pre-capillary constriction
122
Function of dead space
eliminates heat (panting in dogs)
123
Drawback of dead space
shallow & higher frequency breathing is not desired due to the increase in the amount of total ventilation wasted in the dead space
could lower the amount of effective gas reaching the alveoli
124
VEdot = VAdot + VDdot
```
VEdot = tidal volume per min
VAdot = alveolar ventilation per min
VDdot = dead space ventilation per min
```
125
Primary symbols
physical quantities to be measured
| uppercase
126
Name these primary symbols:
| P, V, S, F, Q, R, & D
```
P = pressure
V = volume
S = saturation w/ O2
F = fractional conc of gas
Q = blood volume
R = resistance
D = diffusing capacity
```
127
Secondary symbols
indicated location of gas
128
Name these secondary symbols:
| a, V, & A
```
a = arterial
V = venous
A = alveolar
```
129
Final symbol
refers to the gas being measured
130
Describe these symbol modifications:
dot above
bar secondary symbol
prime sign after secondary symbol
dot = quantity measured w/ respect to time
bar = mean or mixed sample
prime sign = end of a structure/ end of expiration or inspiration
131
Respiratory cycle
one inspiration & one expiration
| except horses have two of each
132
Respiratory pattern waveform
smooth & symmetrical
133
Complementary breathing cycle (sigh)
deep rapid inspiration & expiration
not seen in horses
created using a breathing bag
134
Types of breathing
```
abdominal = most common (except during peritonitis)
costal = rib movement (not during pleuritis)
```
135
Eupne
normal, quiet breathing
136
Dyspnea
difficulty breathing
137
Hyperpnea
increased depth & rate
138
Polypnea
rapid & shallow (panting)
139
Apnea
temporary cessation in breathing
140
Tachypnea
excessive rapidity of breathing
141
Bradypnea
abnormal slowness of breath
142
Respiratory frequency
```
# of respiratory cycles/min
indicates health status of animal
```
143
What increases respiratory frequency
pregnancy, digestive tract fullness, lying down, & diseases
144
What decreases respiratory frequency
low temp & sleeping
145
Normal sound of lungs is due to
air movement through tracheobronchial tree (turbulent air flow)
146
Adventitious lung sounds are
extrinsic to normal breath sounds
147
Crackles
edema & exudates
148
Wheezes
airway narrowing
149
Lung volume
air w/in lung or breath
| all are measured except residual volume (only assessed)
150
Tidal volume (VT)
volume of each breath
151
Inspiratory reserve volume (IRV)
extra volume that can still be inhaled after a normal breath (VT)
152
Expiratory reserve volume (ERV)
extra volume that can still be expired after a normal breath (VT)
153
Residual volume (RV)
amount of air remaining in lungs after most forceful expiration
154
Lung capacity
combination of volumes
| all are inferred
155
Inspiratory capacity (IC)
VT + IRV
156
Functional residual capacity (FRC)
ERV + RV
157
Vital capacity (VC)
IRV + VT + ERV
158
Total lung capacity (TLC)
IRV + VT + ERV + RV
VC + RV
IRV + VT + FRC
159
FRC is affected by
position, sex, diseases, & body condition
| only source of O2 during apnea
160
Ex of restrictive lung diseases & what they are characterized by
fibrosis, muscular diseases, sarcoidosis, & chest wall deformities
fibrotic processes in lung parenchyma -> restrictive inspiration
161
Volumes & capacities indicating restrictive lung disease
decreased VC, TLC, RV, & FRC
162
Ex of obstructive lung diseases & what they are characterized by
emphysema, chronic bronchitis, & asthma
| inflammation of bronchioles & bronchiolar smooth muscle that contracts upon expiration -> restrictive expiration
163
Volumes & capacities indicating restrictive lung disease
decreased VC
| increased TLC, RV, & FRC
164
Atmospheric pressure
760 mmHg at sea level
165
At higher elevations, why does atmospheric pressure decrease
less air
166
Gauge pressure
pressure measured against atmospheric pressure at a particular location
167
Absolute pressure
atmospheric pressure + gauge pressure
168
Dalton's law
total pressure = sum of individual gases in a mixture
169
Boyle's law
pressure & volume are inversely proportional
170
Charle's law
w/ constant pressure, volume & temp are directly proportional
171
Moles law
at constant temp & pressure, volume of a sample of gas is directly proportional to the number of moles of gas in the sample
172
Ideal gas law
pressure is directly proportional to moles & temp of gas
| pressure is inversely proportional to volume of gas
173
When PAW < PB, what happens
| PAW = pressure w/in airways; PB = atmospheric pressure
air flows in until PAW = PB
174
When PAW > PB, what happens
| PAW = pressure w/in airways; PB = atmospheric pressure
air flows out until PAW = PB
175
Breathing creates what pressure
neg pressure
176
A ventilator creates what pressure
pos pressure
177
Transpulmonary pressure gradient (PAW - Ppl) is important for what
(PAW = pressure w/in airways; Ppl = pressure in pleural cavity)
inspiration & expiration
| if Ppl increases (ex: pneumonothorax), then lungs do not expand
178
Function of thin film of fluid in pleural cavity
allows pulmonary/visceral pleura & parietal pleurato have a vacuum-like seal but still be able to slide
179
How is neg pressure created in the pleural cavity
chest wall & alveoli try to recoil
180
What happens to intrapleural pressure & alveolar transmural pressure during inspiration
intrapleural: becomes more neg
| alveolar transmural: increases
181
During inspiration, what do the alveoli do
expand so pressure w/in them decreases
| air flows in until pressure w/in alveoli = atmospheric pressure
182
What happens to intrapleural pressure & alveolar transmural pressure during expiration
intrapleural: becomes less neg
| alveolar transmural pressure: decreases
183
During expiration, what do the alveoli do
alveoli return to normal size by elastic recoil
| air flows out until pressure w/in alveoli = atmospheric pressure
184
What aides in lung recoil
elastic & collagen fibers
| surface tension of alveolar fluid lining/ air-fluid interface
185
When water molecules at the air-liquid interface pull towards each other to try to collapse the alveoli, what counteracts this
surfactant molecules cut the H bonds of water to nullify this effect due to surface tension
186
Law of LaPlace states that what feature of alveoli should be true if they have a smaller diamter
have high pressure & thus be likely to empty or burst into a larger alveoli
187
What keeps small alveoli from popping
surfactant molecules in a higher density compared to large alveoli, which helps to equalize the pressure
188
Describe alveolar interdependence
recoil effect of surrounding alveoli can pull the collapsing alveoli back to stabilize it
189
Alveolar interdependence is altered by what
emphysema since many alveoli are destroyed
190
Compliance
opposite of elasticity
191
What diseases affect compliance
emphysema: increases
fibrosis: decreases
192
Poiseulle's law
resistance is directly proportional to viscosity of gas & length of airway
resistance is inversely proportional to pi*r^4
193
Compare pressure b/w pulmonary & systemic circulation
pulmonary < systemic
194
Why is it advantageous that the pulmonary system has a lower pressure
less work for the heart
thin blood-gas membrane/ alveolar respiratory membrane can be protected
lower chance of edema
195
Compare density of capillaries b/w pulmonary & systemic
pulmonary has a dense capillary network around alveoli
196
Describe pulmonary vessels
neg pressure
sm amount of smooth muscle & vasomotor n's
great distensibility & compliance
197
Compare hypoxia in pulmonary vs systemic
```
pulmonary = vasoconstriction (to redirect blood flow towards other alveoli that are well ventilated)
systemic = vasodilation
```
198
Describe recruitment & distension
meets demand of increased blood through the lungs w/out an increase in arterial pressure
results in a decrease of pulmonary vascular resistance
199
Why is the equation for pulmonary vascular resistance an estimation
blood is not a Newtonian fluid
| pulmonary blood flow is pulsatile
200
Alveolar vessels are found where
w/in wall of alveoli
201
What happens to alveolar vessels as the alveoli expand
capillaries are crushed & pinched
202
Alveolar vessels on pulmonary vascular resistance graph
high PVR from FRC -> TLC
203
Extra-alveolar vessels are found where
in the corner of alveoli
204
What happens to extra-alveolar vessels as the alveoli expand
get pulled open
205
Extra-alveolar vessels on pulmonary vascular resistance graph
high PVR from RV -> FRC
206
When is pulmonary vascular resistance the lowest
during FRC
207
Hypoxic conditions affect pulmonary vascular resistance according to what relationship
directly proportional to the amount of smooth muscle present in the wall of the pulmonary art & branches
208
Which species are more susceptible to hypoxic vasoconstriction
cattle & pigs
209
Where is hypoxic vasoconstriction more likely to occur
high elevations
210
Brisket edema is the word for hypoxic vasoconstriction in cattle due to high elevations; what are the clinical signs
right ventricular hypertrophy, dilation, & failure
distension of system veins & edema of brisket region
low exercise intolerance, tachycardia, jugular pulse, & pulmonic 2nd heart sound
211
Brisket edema treatment
return to low elevation
| O2 therapy
212
Exercise induced pulmonary hemorrhage occurs when
horses exercise at a high intensity, which increases blood flow/ pressure & leads to RBCs entering the alveoli
213
Treatment of exercise induced pulmonary hemorrhage
nasal strips - hold tissue around nasoincisive notch open so horse can breathe better, which decreases the pressure
furosemide - diuretic drug that decreases total body fluid & pressure exerted by flood flow
214
Zone 1 where PA > Pa > Pv
no blood flow
seen w/ blood loss & +ve pressure ventilation
absent in healthy lungs
215
Zone 2 where Pa > PA > Pv
optimal hydrostatic pressure w/ intermittent flow
216
Zone 3 where Pa > Pv > PA
due to gravity, has continuous flow w/ distended capillaries
217
When does pulmonary fluid clearance increase
exercise (increased lymph flow) or left sided heart ailure
218
Steps leading to clinical edema
lymphatic capacity exhausted
proteoglycan bridges break
fluid enters alveoli & bronchioles
219
Why is pulmonary edema fluid foamy
mix of air, edema fluid, & surfactant molecules
220
Causes of pulmonary edema
decreased plasma oncotic pressure (hypoproteinemia/ inflammatory lung disease)
increased vascular permeability
inflammation
lymphatic obstruction
221
Lung edema impedes what
ventilation & oxygenation
222
Where is pleural fluid reabsorbed
through stromata (holes) on parietal pleura
223
Hypoxia
specific region or whole body is deprived of O2 at the tissue level
224
Hypoxemia
abnormally low level of O2 in the blood
225
Hypoxemia results from
```
hypoventilation
diffusion impairment
low P1O2/F1O2
R -> L shunt
VQ mismatches
```
226
What happens in hypoventilation
alveolar ventilation rate decreases to an abnormally low rate, then PAO2 decreases & PACO2 increases
227
Causes of hypoventilation
respiratory center depression (inflammation & morphine/barbiturates)
peripheral nerve injury (chest wall injury & dislocation of vertebrae)
neuromuscular disease
lungs resisting inflation (airway resistance, mucus, large endotracheal tube, dense gas, & deep diving)
228
Hypoventilation A-a gradient & 100% O2 therapy
normal A-a gradient
| responds to O2 therapy
229
What happens in diffusion impairment
decreased diffusion leads to decreased oxygenation
230
Causes of impaired diffusion
exercise
low P1O2 or low F1O2 (at high altitude)
abnormal lung (due to a pathogen) w/ a thickened alveolar gas-exchange area
231
Diffusion impairment A-a gradient & 100% O2 therapy
increased A-a gradient
| responds to O2 therapy
232
Normal physiologic shunts
bronchial circulation
| thebesian veins
233
Pathological shunts
```
arterial-venous anastamoses
absolute intra-pulmonary shunts
patent ductus arteriosus
foramen ovale
interventricular septal defects
```
234
R -> L shunt A-a gradient & 100% O2 therapy
increased A-a gradient
| does not respond to 100% O2 therapy
235
Why do R -> L shunts not respond to O2 therapy
limit to amount of O2 that can be carried by Hb
236
Normal lungs have an average V/Q ratio of .8 to 1.2, but certain parts of the lungs differ b/c why
gravity results in units w/ poor perfusion
| low compliance of alveoli results in units w/ poor ventilation
237
V/Q = 0
complete occlusion of an airway
| shunt
238
V/Q < .8
lungs are affected
239
V/Q > 1.2
pulmonary vessels are affected
240
V/Q = infinity
total occlusion of pulmonary circulation
| dead space
241
When are V/Q mismatches accentuated
under pathological conditions
242
V/Q mismatch A-a gradient & 100% O2 therapy
increased A-a gradient
| responds to O2 therapy
243
Physiological response to V/Q mismatches
```
hypoxic vasoconstriction
brisket disease
right side heart failure
pulmonary embolism
COPD
asthma
pneumonia
```
244
Clinical intervention for V/Q mismatches
anesthesia
| O2
245
External respiration
exchange of O2 & CO2 at the alveolar respiratory membrane or blood-gas exchange area
246
Internal respiration
individual cells of tissues that receive O2 & eliminate CO2
247
Kinetic motion allows for what
diffusion of O2 & CO2
248
What happens to gas at 0 K or -273 degrees C
no kinetic motion
| gas volume = 0
249
Composition of gas in the air
```
N2 = 78%
O2 = 21 %
Ar = .93 %
CO2 = .3 %
```
250
Air breathed in has what partial pressure once you take into account that the air is humidified
713 mmHg
| partial pressure of H20 = 47 mmHg
251
Partial pressure is dependent on
conc of dissolved gas
| solubility coefficient
252
Is CO2 or O2 more soluble
CO2
253
Since O2 is less soluble, what is required for diffusion across the membrane
higher pressure gradient
254
Under high pressure when scuba diving, N2 gets dissolved in the blood; if a diver comes up too quickly, what happens
N2 forms bubbles in various body tissues -> decompression sickness or bends
255
When helium is mixed w/ O2, the air is lighter so there is less what
airway resistance
256
Fick's law of diffusion
diffusion coefficient is directly proportional to solubility & inversely proportional to molecular weight of the gas
257
Area of diffusion is increased in what pathologic conditions
emphysema
258
Thickness of diffusion barrier is increased in what pathologic conditions
sepsis, lung edema, & lung inflammation
259
What effect does providing an increased % of O2 have on gas diffusion
increase P1; overcomes thickness of membrane
260
RBCs spend .75 sec in the capillaries to get oxygenated, so any increase in thickness does what
increases the distance & tine of diffusion -> reduces oxygenation
261
Hyperbaric O2 therapy involves what
O2 administered under high pressure (3-4 atms)
262
Hyperbaric O2 therapy is useful for treating what conditions
```
anaerobic bacterial infections
wound healing
stroke
heart conditions
CO poisoning
cerebral edema
gas embolism
bone infections
COPD
```
263
Hyperbaric O2 therapy increases the dissolved fraction of O2 in the blood, which is important b/c
overcomes limitation of O2 carrying capacity of Hb by raising the O2 portion carried in the plasma
264
Humidification is essential for what
getting inspired air ready for effective gas exchange
| for upkeep of mucociliary function
265
As body temp increases, what happens to vapor pressure & PO2
vapor pressure increases
| PO2 decreases
266
Why does water boil at decreased temps when there is increased elevation
decreased atmospheric pressure, so heat is able to counteract the atmospheric pressure faster
267
Percent of O2 bound to Hb
98.5%
268
Percent of O2 dissolved in plasma
1.5%
269
Hemoglobin is the main component of RBC's & has what components
1 globin
| 4 heme
270
Globin in adult vs fetal
adult: 2 alpha & 2 beta chains
fetal: 2 alpha & 2 gamma -> greater affinity for O2
271
Site for O2 binding on the heme
Fe2+
272
Nitrate poisoning makes Hb unable to transport O2 by
converting Fe2+ -> Fe3+
273
Carbon monoxide poisoning occurs b/c
CO occupies the same site as O2 & has 200 times greater affinity
274
Treatment for CO poisoning
100% O2, CO2, & fluids
275
O2-Hb binding is reversible & follows what law
law of mass action
276
As O2 partial pressure increases, does O2 binding to Hb increase or decrease
increase
277
Describe allosteric conformational change properties of Hb
once the 1st O2 binds, then it is easier for the rest of the O2 to bind
278
O2-Hb saturation curve starts flattening at what saturation
90% saturation
279
At normal PaO2 of 100 mmHg, Hb has what saturation
97.5% saturation
280
PaO2 < 60 mmHg is considered hypoxemic b/c
this is 90% saturation
| any decrease beyond this leads to a significant reduction in O2
281
PaO2 = 25 mmHg has what saturation
50% saturation
282
PvO2 = 40 mmHg has what saturation & occurs when
72-75% saturation; occurs in tissues under extreme exercise/ hypoxia conditions
283
Each gram of Hb combines w/ how many mLs of O2
1.34 - 1.39 mL
284
Why is a range given for the mLs of O2 that a fully saturated Hb holds
presence of impurities may result in lower O2 binding
285
If patient becomes anemic due to a reduction in Hb conc, what happens to the O2-Hb curve
shape almost stays the same, but total O2 content will be reduced
286
Right shift O2-Hb curve means
Hb affinity for O2 decreases
| delivery of O2 is facilitated
287
Left shift O2-Hb curve means
Hb affinity for O2 increases
| delivery of O2 is difficult
288
Bohr effect
increased PCO2 or decreased blood pH reduces the affinity of Hb to O2
right shift
289
Why are pH & PCO2 related
CO2 can combine w/ H2O to produce H2CO3 & H
| rxn is favored in RBCs b/c they have carbonic anhydrase
290
2,3 DPG is a product of glycolysis w/in RBC's that has what effect on the O2-Hb curve
right shift
291
When does production of 2,3 DPG increase
in anemia & at high altitudes
292
Effect of 2,3 DPG is reduced when blood is
stored
293
Why must a CO-oximeter be used to diagnose CO poisoning
regular pulse oximetry does not distinguish b/w HbO2 & HbCO
294
PaO2 levels may look normal w/ CO poisoning, but tissues still experience what
hypoxia
| left shift
295
O2 therapy can help treat CO poisoning b/c
O2 knocks CO off from Hb
296
Why are fluids & 5% CO2 also necessary when treating CO poisoning
stimulate peripheral chemoreceptors to increase drive for ventilation
ensures that CO will be expired
297
CO2 is produced where
in metabolizing tissues
298
CO2 is removed b/c
high levels -> confusion, coma, death, & acidosis
| low levels -> alkalosis
299
Why is hydration rxn favored in RBCs
have carbonic anhydrase
300
Acetazolamide, a carbonic anhydrase inhibitor, is used to treat
glaucoma & metabolic acidosis
301
Why does Cl- move into RBCs after the hydration rxn occurs
to maintain electrical neutrality as HCO3- leaves
302
H+ formed are buffered by
oxyhemoglobin
303
CO2 is eliminated in the alveoli b/c of
partial pressure gradient
| hydration rxn in reverse
304
Modes of CO2 elimination
dissolved in plasma
transported as HCO3-
bound to hemoglobin
at lung alveoli
305
Describe haldane effect
reverse of Bohr effect
for a given PCO2, the content of CO2 increases as PO2 levels decrease (loading of CO2)
as PO2 levels increase, CO2 delivery increases
306
CO2 dissociation curve
steep
no cooperativity/ allosteric effect
lacks a plateau
307
Acid
donate [H+] to soln
308
Base
accept [H+] from soln
309
Buffer
mix of weak acid & its conj base
310
Strong acid/ base
dissociate completely in a soln
311
Weak acid/ base
do not dissociate
312
Relationship b/q pH & [H+]
inverse & exponential
313
Acids/ bases made by the body
food, digestion, & cellular metabolism (CO2)
314
Normal blood pH
7.35-7.45
315
Acidemia
blood pH < 7.35
316
Alkalemia
blood pH > 7.45
317
Define acidosis/ alkalosis
physical processes & chemical rxns that progress into acidemia or alkalemia
318
Normal PCO2
40 mmHg
319
High PCO2
acidosis
320
Low PCO2
alkalosis
321
ATOT
total weak non-volatile acids
322
High ATOT
acidosis
323
Low ATOT
alkalosis
324
High SID
alkalosis
325
Low SID
acidosis
326
Function of buffers
exchange strong acid or base for a weak one
| help prevent deleterious effects of increased or decreased [H+]
327
For Henderson-Hassalbalch eq, what do the kidneys/ lungs manage
kidney - base [HCO3-]
| lung - acid PCO2
328
Addition of a strong acid into a buffer yields
weak acid & salt
329
Addition of a strong base into a buffer yields
weak base & water
330
Bicarbonate buffer system (pK = 6.1)
NaHCO2 & H2CO3
| independently regulated by lungs & kidneys
331
Phosphate buffer system (pK = 6.8)
NaH2PO4 & Na2HPO4
major intracellular buffer
tubular fluid in kidneys
332
Protein buffer sys (pK = 6.6 if ox & 8.2 if deox)
carboxyls give up H+ & amino groups accept H+
| Hb has imidazole groups
333
Anderson-Devenport nonogram
normal PCO2 line plotted w/ intersections at pH = 7.4 & HCO3- = 24 mEq/L
334
Top left corner on Anderson-Devenport
respiratory acidosis w/ increased renal H+ excretion & retention of HCO3-
335
Bottom left corner on Anderson-Devenport
metabolic acidosis w/ decreased PCO2 & H+
336
Top right corner on Anderson-Devenport
metabolic alkalosis w/ increased PCO2 & H+
337
Bottom right corner on Anderson-Devenport
respiratory alkalosis w/ decreased renal H+ excretion & retention of HCO3-
338
Describe the central controller DRG
in dorsal medulla
inspiratory activity
basic rhythm of breathing
339
Input & output for DRG
input: vagus & glossopharyngeal n
ouptut: phrenic n to diaphragm
340
Describe the central controller VRG
in ventral medulla
expiratory & some inspiratory
inactive during normal, quiet breathing
active during exercise/ heaves
341
Input & output for VRG
input & output: vagus n
| innervates intercostal & abdominal m
342
Function of pontine respiratory centers & their names
modify output of medullary centers
| apneustic & pneumonotaxic center
343
Location of pontine respiratory centers
pons & medulla
344
Pontine respiratory centers input & output
input: chemoreceptors, lungs, cortex, & other receptors
output: diaphragm & respiratory m
Vagus n has neg feedback signals
345
Apneustic center does what
stimulates inspiratory neurons of DRG & VRG
| over-stimulation -> apneusis
346
Pneumotaxic center does what
stimulates inhibitory signals to DRG & VRG
fine tunes inspiration & expiration
increased signals increases the respiration rate
347
Central chemoreceptors are found where
ventral surface of the meddula
348
Central chemoreceptors respond to what by doing what
pH of ECF or CSF
if decreased pH, then inspiratory neurons are stimulated
leads to increased tidal volume & frequency of breathing
349
Peripheral chemoreceptors are found where
in carotid bodies at the bifurcation of common carotid art & aortic bodies near the aortic arch
350
Carotid bodies are innervated by
glossopharyngeal n
351
Carotid bodies are fast adapting receptors that respond to
decrease in PO2 & pH; increase in PaCO2
352
Aortic bodies are baroreceptors that sense changes in
partial pressures of O2 & CO2
353
Cell types in aortic bodies
Type I: contain dopamine
| Type II: sustentacular/supporting
354
Pulmonary stretch receptors are slow adapting & respond to what
increase in lung volume beyond a certain limit & inhibit inspiration (Hering-Breuer reflex)
355
Irritant receptors in the airway epithelium are rapidly adapting pulmonary stretch receptors that respond to
gases, dust, & cold air
356
Impulses from irritant receptors travel where
in vagus n to cause bronchoconstriction & hyperpnea
357
J receptors are endings of non-myelinated c fibers in the wall of the alveoli that respond to
injected materials in pulmonary circulation
358
Impulses from J receptors travel via what nerve, sense what, & result in what
vagus n
lung edema
rapid, shallow breathing & dyspnea
359
Bronchial C fibers are similar to J receptors & are supplied by
bronchial circulation
360
Bronchial C fibers lead to
rapid, shallow breathing, bronchoconstriction, & mucus
361
Nose & upper airway receptors are found where
nose, nasopharynx, larynx, & trachea
362
Nose & upper airway receptors respond to
mechanical & chemical stimuli w/ sneezing, coughing, & bronchoconstriction
363
Joints & muscle receptors stimulate
ventilation
364
Gamma system is found where & sense what
diaphragm & intercostals - sense elongation of muscle spindles
365
How does the gamma system respond to elongation of muscle spindles
controlling the strength of contraction
| important in sensing airway obstruction & efforts to overcome the resistance
366
Increased arterial blood pressure leads to what responds in arterial baroreceptors
hypoventilation or apnea through stimulation of aortic & carotid sinus baroreceptors
367
Decreased arterial blood pressure leads to what response in arterial baroreceptors
hyperventilation
368
Pain leads to
apnea -> hyperventilation
369
Heat leads to
hyperventilation
370
Compare fetal to adult circulation
Fetal: parallel, mixing of arterial & venous blood, placenta for gas exchange, anatomic shunts, & increased Hb O2 affinity
Adult: in series, no mixing of arterial & venous blood, lungs for gas exchange, shunts are abnormal, & decreased Hb O2 affinity
371
Describe gas exchange in the fetus
simple diffusion of simple molecules in the placenta
| transfer of O2 depends on uterine arterial PO2 levels
372
Placenta has passive & active transport
passive - glucose transport
| active - AAs & ions
373
Fetal Hb has a higher affinity for O2 than adult Hb; some species also have what in relation to Hb
higher Hb conc in fetal blood (human, sheep, & cows)
374
Relative to body mass, fetuses have a higher cardiac output than adults, which helps to
deal w/ hypoxia
375
Ruminant fetal Hb
increased O2 affinity is an intrinsic property
376
Pigs & horses fetal Hb
do not have it
377
Primates fetal Hb have the inability to do what
bind 2,3 DPG
378
In fetal circulation, is blood flow increased in the placenta or the lung
placenta
379
Pulmonary vascular resistance & Pa are higher in fetus or adult
fetus
380
Fetal lung is in a psuedo-glandular stage at birth w/ what type of cartilage
eosinophilc hyaline cartilage (does not have proteoglycans like adult lungs)
381
Important signals that a fetus experiences after birth
hypoxia & hypercapnia
fetus cools & fetal fluids evaporate
sensory input from mother
382
Describe the first breath
great inspiratory effort
not all alveoli open at first
surfactant is important
383
Carotid bodies in a newly birthed animal start to function & sense what
decrease in O2 & increase in PCO2
384
As lungs expand in a newly birthed animal, pulmonary vascular resistance
decreases
385
What vessels rupture upon birth
umbilical vessels
386
When to fetal shunts close
aortic pressure > Pa & LA pressure > RA pressure
387
Avian embryo is wrapped in
fetal membranes & chorioallantosis (CAM)
| in contact w/ egg shell
388
Egg shell internal & external sides
external: hard layer of CaCO3 coated by a thin cuticle
internal: two soft membranes
389
What connects the environment w/ the CAM & what does it allow for
10,000 pores
| diffusion
390
As the embryo in the egg grows, what happens
increase in CAM
increase in O2 affinity for Hb
increase in cardiac output & hematocrit values
increase in diffusion gradient
391
Heat stress in an egg leads to
hyperventilation & decrease in PCO2 -> decrease in HCO3- levels -> affects normal amount of CaCO3 -> poor eggshell quality -> dehydration of developing chick embryo
392
Describe the trachea of birds
size & shape varies across species
full circular cartilage
hyaline cartilaginous rings appear as double rings (telescoping)
wider & longer than mammals, but resistance is about the same
393
Large tracheal dead space is compensated by what in birds
1/3rd respiratory frequency
VT 1.7x larger
lg expansible volume
greater compliance of respiratory system (decreased work & energy of breathing)
394
Birds lack an epiglottis & use what to produce sound
syrinx (instead of larynx)
395
Describe the bronchial tree of birds
primary: extra pulmonary & intra pulmonary
secondary: 4 groups
tertiary: parabronchi
396
Basic unit of gas exchange in the bird
parabronchi
397
Air sacs are connected to what & function as
lungs & long (pneumatic) bones
bellows -> move air
do not exchange gas
398
Lungs of birds are
fixed in dorsal part of the body & cannot expand
399
Name the air sacs in birds
```
2 cervical
1 clavicular
2 cranial thoracic
2 caudal thoracic
2 abdominal
```
400
Describe neopulmonic parabronchi
in some species
accounts for 10-12 % of total lung volume if present
meshwork
401
Describe paleopulmonic parabronchi
present in all birds
unidirectional air flow
always in contact w/ fresh air
402
Each volume of air in birds w/ paleopulmonic parabronchi is
eliminated via 2 cycles of respiration
403
Arrangement of capillaries in paleopulmonic parabronchi
air capillaries are surrounding by blood capillaries
404
Paleopulmonic gas exchange is
cross-current & highly efficient as it allows for an increase in percent of O2 capture & elimination of CO2
405
A thin blood-gas exchange area in paleopulmonic parabronchi is advantageous according to
Fick's law
406
Type IVc collagen in the basement membrane of paleopulmonic parabronchi provides what
strength needed to keep the thin gas exchange area stable
407
Yaks live where O2 content is 33-66%, so they have what advantages
larger heart & lungs
persistence of fetal Hb
other genes for hypoxia & metabolism under low O2
408
Yaks do not do well in
temps above 59 degrees C or elevations below 1000 ft
409
How do fish breathe
using gills
extract dissolved O2 in water
countercurrent flow
410
Mammalian diving reflex
bradycardia -> from 125 bpm to 10 bpm
| peripheral vasoconstriction -> more blood can be used by heart & brain
411
Diving adaptations of seals to manage the pressure changes
compliant chest
ability to collapse alveoli followed by terminal bronchioles
cavernous sinuses to prevent rupture of middle ear
presence of cartilage in bronchioles & sometimes alveoli to help in collapse/re-inflation of alveoli
specialized surfactants to make re-inflation easier
412
Seals deal w/ N2 narcosis how
collapse lungs & hold air in dead space
switch to anaerobic metabolism
elastic aorta keeps blood pressure constant
413
Other adaptations of seals
```
aortic bulb & slender abdominal aorta
lg heart w/ glycogen store
increased muscle myoglobin
increase O2 in lungs, muscles, & blood
increased hematocrit values
lg spleen
lungs have great rigidity & elasticity
deep divers have small RV
```
414
Name the 3 forces that affect the settling of particles
sedimentation
inertial force
Brownian motion
415
Sedimentation
deposition due to gravity & mass of particles
| go to nasal cavity & tracheobronchial tree
416
Inertial force
due to velocity
| go to nasal cavity, pharynx, & tracheobronchial tree
417
Brownian motion
property of small particles
| go to small airways & alveoli
418
Respirable particles
less than 10 micrometers
| could end up in blood-gas exchange area
419
Non-respirable particles
more than 10 micrometers
| retained in dead space & processed through the mucociliary escalator
420
Upper respiratory tract clearance
for regions cranial to alveolar duct
| mucociliary escalator pushes particles to the pharynx, which are then sent to the GI system & deposited in the feces
421
Low respiratory tract clearance
for particles w/in alveoli
absorptive sites near alveolar ducts where particles accumulate & are cleared through lymphatics
fluid flow towards bronchiolar epithelium & cleared by mucocilary escalator
insoluble & microbial particles are phagocytized by alveolar macrophages
alveolar epithelial cells engulf particles & clear them through desquamation & mucociliary escalator
cleared to lymph nodes to be phagocytized
422
Panting is a response to increased core body temp that does what
increases dead space ventilation to cool off
| increases glandular secretions or vascular transudate
423
Inhalation & exhalation through nose
least cooling
resting dogs
running at slow speed in cold temps
424
Inhalation through the nose & exhalation through the nose & mouth
most cooling
exercise
resting at > 30 degrees C
425
Inhalation & exhalation through the nose & mouth
greatest alveolar ventilation
exercise
resting at > 30 degrees C
426
Purring results from
highly regular, alternating action of the diaphragm & intrinsic laryngeal m
frequency is 25x/sec
oscillating mechanism w/in CNS
427
Phases of purring
glottal closing
initiation of glottal opening & sound production
complete glottal opening (decreases resistance & increases air flow)
428
Purring may provide better ventilation during
shallow breathing
429
Sneeze reflex
foreign objects/irritation of nose mucosa
strong inspiration & vigorous expiration through the nose
defensive
430
Aspiration/sneeze reflex
foreign object/irritation of pharynx
| series of inspiratory efforts (reverse sneezing)
431
Swallowing reflex
food/drink pushes down on the soft palate
epiglottis bends to close the larynx
respiration continues once the bolus is in the esophagus
432
Filtration of lungs
particulate matter & blood clots can be handled in the lungs
433
Pulmonary intravascular macrophages
present in horses, cats, cattle, & pigs
| increases susceptibility to pulmonary inflammation
434
Lungs are a major source of arichiodonic acid metabolites, which are a site for
synthesis, metabolism, uptake, & release
435
Angiotensin-converting enzyme is produced where
pulmonary epithelium
converts Angiotensin I -> Angiotensin II
maintains blood pressure
436
Nonspecific lung defense mechanisms
```
surfactant proteins A & D
host defense particles
mucociliary escalator
cough/sneezing
alveolar macrophages
TLRs
```
437
Specific lung defense mechanisms
surface IGs
pulmonary dendritic & T cells
intranasal vaccines
