1
Q
What are the 2 main portions of the respiratory system?
A
Respiratory Portion
Conducting Portion
2
Q
Which part is the conducting portion?
A
Mouth–>terminal bronchioles
3
Q
Which part is the respiratory portion?
A
respiratory bronchioles–>alveoli
4
Q
What is the pathway of air from mouth to alveoli?
A
Mouth Nasal Cavity Pharynx Larynx Trachea Lobar Bronchi Segmental Bronchi Bronchioles Terminal Bronchioles Respiratory Bronchioles Alveolar Ducts Alveolar Sacs Alveoli
5
Q
What are the main tissues that are found in the conducting system?
A
cartilage, elastic, collagen, smooth muscle fibers
6
Q
As the diameter of the airways gets smaller, what happens to the elastic fiber concentration?
A
Diameter decreases
Elastic fiber concentration increases
7
Q
Where are the elastic fibers in the airway? What direction do they run?
A
They are found in the lamina propria.
They run longitudinally.
8
Q
Where are the smooth muscle fibers in the airway? What direction do they mainly run?
A
They are in the muscle section of the airway
They mainly run circularly.
When this contracts, the lumen actually opens.
9
Q
Where is the general respiratory epithelium found? What are the 6 cell types that make it up?
A
Nasal Cavity-->Respiratory Bronchioles Ciliated Columnar Cells Columnar Cells Mucous Goblet Cells Brush Cells Diffuse Endocrine or Small Granule Cells Basal Cells or Immature Cells
10
Q
Describe the ciliated columnar cells of the general respiratory epithelium.
A
these are the most predominant cell types in the epithelium.
continues until respiratory portion of the airway.
**the cilia beat bad stuff towards the mouth
**also called pseudo stratified ciliated epithelium
11
Q
Describe the columnar cells of the general respiratory epithelium.
A
- *these don’t have cilia
* *they secrete serous fluid
12
Q
Describe the mucous goblet cells of the general respiratory epithelium.
A
Their population decreases as you go down toward the terminal bronchiole. After the terminal bronchiole, they aren’t there anymore.
- *synthesizes mucinogen
- *the mucinogen is hydrated & turns into mucous.
- *they trap & remove bacteria & particles
13
Q
Describe the brush cells of the general respiratory epithelium.
A
**there are no cilia, but there are many microvilli
2 Flavors
1. acts like mucous goblet cells & releases mucinogen…this one doesn’t have nerve endings
2. has nerve endings on basal surface…sensory receptor for gas volume & O2/CO2 conc’n
intraepithelial receptor for the trigeminal nerve & the sneeze reflex
14
Q
Describe the diffuse endocrine or small granule cells of the respiratory epithelium.
A
- *these cells have the smallest granules
- *they control the serous & mucous secretions.
- *they also control the vessel diameter
- *considered an endocrine cell of the respiratory system
15
Q
Describe the basal cells or immature cells of the general respiratory epithelium.
A
rest on the basement membrane & don’t reach the surface…
these are considered stem cells…
they extend from the nasal cavity to the respiratory bronchioles…
these cells make everything appear pseudo stratified…
16
Q
What is metaplasia?
A
the transformation of adult cells from one form to another abnormal form…
**this can happen in response to disease, or a physical or chemical event…
17
Q
What is the metaplasia that occurs in a smoker’s lung?
A
There are more mucous goblet cells b/c of pollutants.
There are fewer cilia b/c of CO.
18
Q
What is the metaplasia that occurs w/ breathing in of second hand smoke?
A
An increase in the amount of mucous goblet cells b/c of the pollutants.
19
Q
What leads to the smoker’s cough?
A
the increase in mucous goblet cells & the decrease in cilia
20
Q
What is the function of the conducting portion of the respiratory system?
A
provides a conduit to transfer air
conditions the air (cleans, moistens, & warms)
21
Q
What is the vestibule of the nasal cavity?
A
the anterior portion of the nasal cavity
22
Q
What does it mean that the nasal cavity is corrugated on its lateral surface?
A
There are 3 concha. Superior, middle, inferior
23
Q
What is important about the area b/w the middle & inferior conches?
A
In this area is the openings to the maxillary sinus.
**when you have a sinus infection, there is discharge from this opening.
24
Q
What is underneath the respiratory epithelium/nasal cavity mucosa?
A
the superficial venous plexus.
this is a good site for legal & illegal drug delivery.
25
Aside from your nasal cavity, what is another site of a superficial venous plexus?
underneath the tongue.
26
What are the 2 types of mucosa of the nasal cavity? What is their function?
Olfactory & respiratory mucosa
| air is filtered, warmed, humidified by the nasal mucosa
27
What are the vibrissae in the nasal cavity?
these are short, thick hairs that humidify the air & remove dust particles from the air.
28
What is a more general term for the superior, middle, & inferior concha?
Nasal fossa (depressions in the bone)
29
What is the function of the nasal cavity?
it filters, warms & humidifies air
30
What is significant about the plasma cells located in the lamina propria of the nasal cavity?
These plasma cells secrete IgA & IgE.
31
Which are our friends: IgA or IgE?
IgA are our friends.
IgE is our friend when we deal w/ parasites.
Otherwise, IgE is binding to the receptors on mast cells & basophils & causing the release of their inflammation mediators.
32
What is the function of swell bodies in the nasal cavity?
They are located in the superficial venous plexus.
They close off the passageway at a rate of every 30 minutes. They alternate whether the left or right passage is occluded. This keeps the nostrils from getting dried out & gives them a chance to rest.
33
When do you feel the alternating opening of nasal airways during a cold--the thing that swell bodies cause?
Only when you are starting to recover from your cold...
34
Which concha is associated w/ a cranial nerve?
The superior concha is associated w/ Cranial Nerve I: the olfactory nerve, which sits on top of it.
35
Where is the olfactory epithelium located in the nasal cavity?
on the roof of the nasal cavity & on the superior nasal concha
36
Which 4 cell types make up the olfactory epithelium?
1. olfactory cells
2. sustentacular cells/supporting cells
3. basal cells
4. brush cells
37
Describe the olfactory cells.
They are bipolar neurons.
Near the basilar surface there is the axon.
Near the apical surface is a dendrite that becomes an olfactory vesicle & terminates as 6-20 nonmotile modified cilia. (participate in the smelling)
Synthesize odor receptor molecule on cilia.
Triggers impulse when bound to odor binding protein to the bulb of the bipolar neuron.
38
Explain the olfactory cell's role in smelling.
The modified cilia on the apical surface of the bipolar neuron produce an odor binding protein. The odor dissolved in the serous fluid binds an odor-binding protein that is produced by the Bowman's glands.
When these things all bind together the threshold is reached to send an impulse along the bipolar neuron to the olfactory bulb.
39
Where are the nuclei for the sustentacular cells?
near the apical surface
40
Where are the nuclei of the basal cells located? What is their function?
near the basolateral surface.
| they are the stem cells--help w/ regeneration.
41
What is the location of the bipolar neurons' nuclei?
In the middle! B/w the basal cells & the sustentacular cells.
42
Where are the axons of the olfactory cells located?
They pierce through the cribriform plate of the ethmoid bone into the olfactory bulb.
43
Where are the brush cells located? What is their function?
They are either before or @ the olfactory epithelium. They are responsible for the sneeze reflex.
44
What are 2 cool functions of the olfactory epithelium?
spatio-temporal patterning
| olfactory adaptation.
45
What's the deal w/ the Bowman's glands?
They are located in the nasal cavity.
They are located in the lamina propria.
They secrete odor binding protein
They secrete serous fluid that cleans the surface of the nasal cavity & dissolves the odors.
46
What are the paranasal sinuses? What is their function? What are they lined w/?
They are air-filled spaces in the cranium. It makes it less heavy. They are lined w/ respiratory epithelium.
47
What are the different paranasal sinuses?
```
frontal sinus
maxillary sinus
anterior ethmoid sinuses
posterior ethmoid sinuses
sphenoid sinus
```
48
What 2 main structures does the larynx connect?
the trachea & the pharynx
49
The larynx has a relatively small/large amount of elastic cartilage & a relatively small/large amount of hyaline cartilage.
Small amount of elastic cartilage
| Large amount of hyaline cartilage
50
What are the 2 main functions of the larynx?
phonation via vocal cords
| prevents entry of food into the respiratory system
51
What are the 2 main structures of the larynx?
epiglottis
| vocal cords--false & true
52
How does the epiglottis keep food from entering the respiratory system?
When you swallow the epiglottis swings down & covers the larynx. this directs the food into the esophagus.
53
Describe the tissues of the epiglottis.
It has an elastic cartilage core.
It has a lingual side w/ stratified squamous epithelium
It has a laryngeal side w/ respiratory epithelium.
54
What is the first set of vocal cords you run into going down from the epiglottis?
the false vocal cords
55
What type of epithelium are the false vocal cords covered in?
respiratory epithelium
56
Do the false vocal cords have glands? Muscle?
They do have glands (serous mucous), but no glands.
57
What do you find underneath the false vocal cords?
A cul de sac depression called a laryngeal ventricle.
58
What do you find underneath the laryngeal ventricle?
The true vocal cords.
59
What type of tissue is found on the true vocal cords?
stratified squamous epithelium.
60
Are there glands or muscle associated w/ the true vocal cords?
No glands
| There is skeletal muscle (vocalis muscle)
61
What is an example of normal metaplasia?
When a baby is born & cries...the respiratory epithelium on the true vocal cords becomes stratified shamus epithelium.
62
Where is the vocal ligament?
These are the elastic fibers associated w/ true vocal cords. Called vocal ligament.
63
What is Reinke's edema?
This is edema (fluid collection in the lamina propria of the space near the vocalis ligament of the true vocal cord). This causes hoarseness.
64
What causes laryngitis?
This is caused by the infection of the laryngeal ventricle. There is inflammation associated w/ this.
65
How many rings does the trachea have?
16-20 rings
66
What does the trachea become?
L & R primary bronchi.
| Right bronchus is more vertical.
67
What type of epithelium is found in the trachea? What are some of the cell types that are found here?
```
Respiratory Epithelium
Columnar Ciliated Cell
Goblet Cell
Basal Cell
Endocrine Cell
```
68
What is the relationship b/w the trachea & seromucous secretions?
The trachea b/c of all its glands is an important regulator of the proportion of serous to mucous secretions...this affects the actions of the cilia.
69
Why is it an advantage to have the muscle close off the back of the trachea instead of more hyaline cartilage?
b/c when there is a huge bolus of food going down the esophagus...it can safely push into the trachea & continue on its course.
70
What is the order of tissues in the esophagus? From the inside to the outside...
Lumen
Mucosa:
Respiratory Epithelium
Thick Basement membrane (rigid structure)
Lamina Propria w/ seromucous glands & well-defined elastic lamina w/ elastic & collagen fibers
Submucosa:
extensions of the seromucous glands of the LP
Adventitia: C-shaped hyaline cartilage rings closed off in the back by tracheal is muscle
71
The perichondrium in the adventitia fuses w/ the _____ & _______.
Submucosa
| Adventitia
72
The bronchial tree comes in which 2 flavors?
```
Extrapulmonary bronchi (before entering the parenchyma of the lung)
Intrapulmonary bronchi (after entering the parenchyma of the lung)
```
73
Describe the structure of the extra pulmonary bronchi? What do they divide into?
They resemble the trachea & are more rigid than the intrapulmonary bronchi.
Their cartilagenous rings are irregular.
Their smooth muscle spirals can be seen b/w the submucosa & cartilage.
**the R extra pulmonary bronchi trifurcate into the secondary pulmonary bronchi (these are straighter) & the L extra pulmonary bronchi bifurcate into the secondary pulmonary bronchi.
74
What is another name for secondary & tertiary intrapulmonary bronchi? What do they supply?
Secondary: Lobar Bronchi **the lobes
Tertiary: Segmental Bronchi **the bronchopulmonary segments.
75
Describe the structure of the intrapulmonary bronchi.
They have respiratory epithelium & LP & submucosa.
They have a lot of elastic fibers.
They have spiral smooth muscle.
They have seromucous glands located b/w the cartilage plates & the smooth muscle.
76
What does the terminal bronchiole supply?
a pulmonary lobule
77
What does the respiratory bronchiole supply?
a pulmonary acinus (alveolar sacs etc)
78
What causes wheezing?
The constriction of the bronchioles.
79
What causes rhonchi?
the constriction of the bronchi
80
What does the spiral smooth muscle of the bronchi do?
It diminishes their diameter, but doesn't necessarily constrict them.
81
Where is the vasculature found in the bronchi?
It is located in the submucosa.
82
What does hyaline cartilage stain w/? Elastic cartilage?
Hyaline Cartilage: H & E
| Elastic Cartilage: Elastic Stain
83
What are the tissue layers (inside to outside) of the bronchi?
```
Mucosa (including resp epithelium)
Muscularis (w/ spiral smooth muscle)
Submucosa (w/ vasculature)
Cartilage Layer (w/ hyaline)
Adventitia
```
84
What is the rough size of the diameter of the bronchioles?
1 mm or less.
85
Why don't you want a lot of mucous in the bronchioles?
B/c we are getting near the respiratory portion & we don't want to clog things up. Thus the bronchioles lack seromucous glands.
86
T/F The bronchioles have cartilage, but no seromucous glands.
False.
| They don't have either.
87
What is the relationship b/w goblet cells & Clara cells in the bronchioles?
As you descend, the goblet cells decrease & the Clara cells increase.
88
Describe the epithelium & lamina propria of the bronchioles.
Epithelium: ciliated columnar cells w/ goblet cells -->ciliated columnar & cuboidal cells w/ Clara cells
LP: Plenty of smooth muscle & elastic fibers
**no cartilage or seromucous glands.
89
What's the deal w/ Clara cells?
they have microvilli, but no cilia
secrete glycoprotein that helps protect mucosa
degrades airborn toxins thru sER p450 cytochromes
Stem cells-->divide to regenerate the epithelium
**also, they appear dome-shaped!!
90
What is the most common chronic illness affecting children? What types of drugs are used to treat it?
Asthma
| Drugs that mimic sympathetic innervation--cause bronchodilation.
91
What happens when you have an asthma attack? What causes it?
Often caused by an allergic reaction
Causes widespread constriction of the smooth muscle in the bronchioles
See Wheezing: difficulty expelling air
Also some difficulty inspiring
92
What are the types of innervation of the bronchioles? What is their effect?
Sympathetic: Bronchial Dilation
Parasympathetic: Bronchial Constriction
93
What happens to the epithelium as you progress from the trachea to the respiratory portion of the respiratory system?
Its height decreases. The type of epithelium also changes.
94
What are the 2 things that continue all the way from the trachea to the end of the respiratory portion?
Smooth muscle
| elastic fibers
95
What are 3 things that stop at the level of the bronchi?
Goblet cells
Hyaline Cartilage
Seromucous Glands
96
What is the organization of the respiratory portion of the respiratory system?
Respiratory Bronchioles
Alveolar Ducts
Alveolar Sacs
Alveoli
97
Describe the tissue of the respiratory bronchioles.
Epithelium: simple ciliated cuboidal w/ clara cells
| Lamina Propria: very thin smooth muscle & elastic fibers opening up to the alveoli
98
Describe the tissue of the alveolar ducts.
Epithelium: squamous epithelium, mainly Type I pneumocytes
| Lamina Propria: lots of smooth muscle & elastic fibers
99
Describe the structure of the alveoli.
They are pouch-like evaginations.
| Separated by an interalveolar wall or septum
100
Describe the tissue of the inter alveolar wall or septum.
it is lined primarily by Type I & Type II pneumocytes.
101
When do most alveoli develop? What are the implications of this when considering the dangers of second hand smoke?
85% of alveoli develop after birth. Until the age of 10...
| Clearly, second hand smoke is dangerous b/c it can affect young kids who are developing!!
102
Elastic fibers are oriented ______, while smooth muscle fibers are oriented ________.
elastic fibers-->longitudinally
| smooth muscle fibers-->concentrically...
103
Describe the Type I pneumocytes.
They are made of simple squamous epithelium.
Very stretched out/attenuated-->allows for good gas exchange
can NOT regenerate
make up 95% of the alveolar surface.
104
Why is it particularly important that Type I pneumocytes are so attenuated?
b/c there are no fenestrations in the capillaries...they are continuous so it is important that they are thin...
105
Describe Type II pneumocytes.
cuboidal epithelium
CAN regenerate
produces surfactant
5% of the alveolar surface
106
How are Type I & Type II pneumocytes connected?
thru occluding jcns
107
How do burn victims or smoke inhalation victims recover?
It takes time!!
Makes gas exchange more challenging.
Type II can repair eventually, but it takes time.
108
What's the deal w/ surfactant?
```
It reduces surface tension.
released by Type II pneumocytes.
stored in lamellar bodies
present at 26-28 weeks in amniotic fluid
keeps the walls from sticking together!!
```
109
What is one of the breathing issues of premature births?
If the surfactant isn't present at birth, the kid will have problems breathing; their alveoli will collapse -->Respiratory Distress Syndrome
Treatment: injection of glucocorticoids in the mom to induce baby to make surfactant
110
What are the 2 main sections of the inter alveolar septum & the function of each?
THIN portion: exchange of gases
| THICK portion: removal of fluid
111
What makes up the thin portion of the inter alveolar septum? From the outside to the inside?
```
Blood Gas Barrier
Outside-->Inside
Surfactant
Type I pneumocyte (attenuated)
Fused basal lamina
Capillary Endothelium (also thin)
```
112
Why is it important that the Type I pneumocyte & the capillary endothelium of the thin portion of the inter alveolar septum are attenuated or thin?
B/c this area is used for gas exchange. Need a short distance to travel ideally.
113
How does the body get rid of excess fluid near the alveolar sacs?
Wicking action.
It gets the extra fluid in the interstitium to the level of the respiratory bronchioles where there are lymphatics again to properly get rid of the fluid.
Note: wicking action super duper important b/c there are no lymphatics after the level of the resp bronchioles.
114
What all is found in the thick portion of the inter alveolar septum?
continuous capillaries
elastic, collagen, reticular fibers
fibroblasts, macrophages, mast cells
NO Lymphatics
115
What are the 2 types of macrophages that are found in the inter alveolar septum? What is another name for the macrophage of the respiratory system?
Dust cells
Fixed: associated w/ the wall
Free: they roam around
116
What do the dust cells produce?
Elastase--it breaks down the elastin foundation of the respiratory system.
117
What are the pores of Kohn?
These are alveolar pores found b/w the alveoli in the inter alveolar septum. They allow for the movement of macrophages. They also allow for collateral ventilation if the bronchioles are constricted. They equilibrate the pressure b/w the alveoli.
118
T/F There is a continuous layer of Type I pneumocytes in the alveoli.
True.
119
What is an important distinguishing feature of Type II pneumocytes?
abundant apical microvilli...
120
What are heart failure cells?
These are macrophages in the respiratory system in a person with congestive heart failure. B/c of the pulmonary edema w/ heart failure...the route of the roaming macrophages b/w the alveoli thru the pores of Kohn is messed w/ & they digest RBCs. They stain positive for hemosiderin (Fe) from their blood meal.
121
When do the alveolar pores develop?
At 3-4 years of age.
122
What are the 2 main blood supplies of the lungs?
Pulmonary Artery that follows the bronchial tree & carries deoxygenated blood.
Bronchial Artery that follows the bronchial tree & carries oxygenated blood & branched off the thoracic aorta
123
What is the pressure of the pulmonary artery to the lung?
Systolic: 15-25 mmHg
124
What is the pressure of the bronchial artery to the lung?
Systolic: 110-135 mmHg
125
What happens to the pulmonary artery after it follows the bronchial tree?
It terminates at the level of the respiratory bronchiole & then forms the alveolar capillary plexuses in the alveoli.
126
What happens to the bronchial arteries after it follows the bronchial tree?
it anastomoses w/ the pulmonary vein plexus
127
What's the deal w/ the lymphatics of the lungs?
Location in the lung: @ the bronchi, bronchioles, blood vessels, septa
Links to: superficial lymphatic plexus, hilum drains into main lymphatic vessels
128
What do the alveolar capillaries drain into?
pulmonary vein plexuses-->venules-->pulmonary vein
129
Where does the pulmonary vein go? What does it carry?
Back to the heart. It carries oxygenated blood.
| Travels thru the CT septa
130
What defines the boundaries of a pulmonary lobule?
The connective tissue septum that carries the pulmonary vein.
131
What makes up the visceral pleura of the lung?
Fibroelastic CT
| Simple Squamous Mesothelium.
132
What is the fourth leading cause of death in the US?
Emphysema
133
What can cause emphysema?
Usually smoking.
| Sometimes genetic...defective alpha 1 antitrypsin enzyme
134
Are patients w/ emphysema considered pink puffers or blue bloaters?
Pink Puffers
| You have enough air, not "blue". You just can't move your air appropriately. Not enough elastin.
135
What's the deal w/ Bronchitis? Are these patients considered pink puffers or blue bloaters?
Blue Bloaters
bronchiole constriction--not enough oxygen can get in...
"blue" b/c cyanotic...
136
What is the specific mechanism that causes emphysema? How does this relate to smoking & genetic causes?
Destruction of the inter alveolar septum.
Loss of ability for the alveoli to recoil b/c they have lost their elastin.
Smoking & some genetic causes inhibit alpha 1 anti-trypsin. This enzyme inhibits elastase. Elastase is produced by dust cells (macrophages) & breaks down elastin.
If elastase can roam free & break stuff down you lose your elasticity. Can't move air appropriately.
Block 2; Week 6
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