9.2 - Lab + Lecture Notes Flashcards

1
Q

Describe a distinguishing aspect of the lamina propria in the trachea

A
  • rich in elastic fibers

- no glands in this layer

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

Describe the tracheal Hyaline Cartilage and its distinguishing aspects

A
  • stacked C-shaped rings
  • openings point away from ventral surface
  • location of tracheal is muscle
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is BALT?

A

= bronchial associated lymphoid tissue (a type of MALT)

- congregations where motile CT cells are likely to encounter foreign antigens

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

What are the intrapulmonary bronchi?

A

= largest of respiratory airways –> surrounded by lung tissue

  • easiest to recognize because they retain cartilage in wall
  • end of branching of these bronchi into smaller structures are the bronchioles
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Describe the bronchioles

A
  • exhibit a change in epithelium from pseudo stratified to domed cuboidal/low columnar cells –> called Clara Cells
  • the epithelium of Clara cells still functions as a conducting epithelium
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are Clara cells and where are they found?

A
  • Clara cells are found starting in the bronchioles and represent a shift in the epithelium from pseudo stratified in high airways to their characteristic domed cuboidal shape
  • secrete a serous fluid that better traps fine particles that penetrate deep into the lung
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Where in the respiratory system will you find a pseudostratified epithelium known as the “respiratory epithelium”

A
  • refers the the conducting airway portions of the lung (nose, trachea, bronchi)
  • does not refer to respiratory portions (they have an alveolar epithelium)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

List the airways that pass from the bronchiolar to the alveolar epithelium

A

1) Terminal bronchi
2) Respiratory Bronchi
3) Alveolar Duct
4) Alveolar Sac

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

Describe the terminal Bronchiole

A
  • last airway completely lined witha conduction (Clara cell) epithelium
  • connects the bronchi/bronchioles to the respiratory bronchiole
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Describe the Respiratory bronchiole

A
  • passageway lined mostly with a Clara cell epithelium,
  • but containing patches of alveolar epithelium
  • Connects terminal bronchiole to the alveolar duct
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Describe the Alveolar Duct

A
  • passageway lined completely with alveolar epithelium

- Connect respiratory bronchiole to the alveolar sac

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

Describe the alveolar sac

A
  • terminal passageway of the lung
  • lined by alveolar epithelium
  • connected to rest of airways by alveolar duct (and by alveolar pores?)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Describe the Alveolar Morphology (Dust Cell)

A
  • normally recognized by inclusions
  • not permanently attached to the epithelium
  • crawl using pseudopodia
  • when end useful life accumulate in corners of CT near significant collagenous tissue
  • are good example of supra vital staining
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What are the 4 resident cells of the alveolar epithelium

A

Endothelial Cells
Type I pneumocytes
Type II pneumocytes
Alveolar Macrophages

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

What are two classification of emphysema

A

1) Centriolobular

2) Panacinar

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

Describe Centrilobular emphysema

A
  • affects the centers of the lung’s lobules

- -> near the respiratory airways

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

Describe panacinar emphysema

A
  • affects all levels of airways
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Describe the morphology of a deflated + fixated lung

A
  • would see minimal or no air spaces between alveolar septa
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Fibrosis

A

= accumulation of fibrous tissue

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

When does embryonic stage of development end, and on what day does is the lung bud formed?

A
  • Embryonic stage ends on day 56
  • on Day 22 the ventral foregut forms the respiratory diverticulum (the lung bud) - which begins growing inside the splanchnic mesoderm
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Where is the epithelium of the lung derived from and what does it give rise to?

A
  • Endoderm derived epithelium of lung
  • Gives rise to
    Larynx, Trachea, Bronchi, Bronchioles (proximally), parenchymal cells (distally)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What does the splanchnic mesoderm form WRT lung development

A
  • Condensation of splanchnic mesoderm gives rise to cartilage, muscle, CT, vascular network around the lung
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Describe what occurs when the respiratory diverticulum separates from the foregut

A
  • the lung bud forms the trachea + 2 main bronchial buds
  • mesoderm covering outside of lung develops into visceral pleura
  • mesoderm covering body wall develops into parietal pleura
  • pleural cavity develops in space between the pleura
  • the bronchi then continue developing and divide repeatedly forming secondary and tertiary bronchi
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Describe the difference between right and left main stem bronchi that can be seen from early on in development

A
  • Right main stem bronchi is a little more vertical and has a larger diameter than the left
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Give a brief overview of the sequences of development after embryonic period and indicate whether gas exchange is possible at the end of embryonic development

A
  • By end of embryonic period no gas exchange sites have developed yet
  • Respiratory tree continues branching to form terminal bronchioles, which then give rise to respiratory bronchioles
  • respiratory bronchioles give rise to terminal sacs (also known as primitive alveoli)
  • mesodermal CT becomes highly vascularized and lymphatic capillaries develop close to the primitive alveoli
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What are the 4 stages of lung development following the embryonic period and what is the time frame for each?

A

1) Pseudoglandular period (6-16wks)
2) Canalicular Stage (16-26wks)
3) Terminal Saccular Period (26wks-birth)
4) Alveolar Period (32 wks - 8 years)

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

Describe the Pseudoglandular Period of Lung development, mention the possibility of fetal birth during this stage.

A
  • timeframe: 6-16 weeks
  • no gas exchange sites have formed
  • thus, respiration is not possible
  • fetal birth is not compatible with life
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Describe the Canalicular Stage of Lung development, mention the possibility of fetal birth during this stage.

A
  • timeframe: 16-26 weeks
  • primordial alveoli have formed
  • respiration is possible near the end of this period 24-26 weeks
  • fetal birth would allow life, but serious complications requiring extensive long care would result
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Describe the Terminal Saccular Period of Lung development, mention the possibility of fetal birth during this stage.

A
  • timeframe: 26 week - birth
  • CT is thinning and surfactant production begins increasing very the very small amount that is being produced beginning at weeks 22-24
  • depending on immaturity of lungs and how early the baby is born the lack of production of surfactant can cause respiratory distress such as NRDS (Hyaline membrane disease)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Describe the Alveolar Period of Lung development

A
  • Timeframe: 32 weeks - 8 years

- at 8 years lung development is considered complete

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Describe Neonatal Respiratory Distress Syndrome (NRDS)

A
  • Immaturity of lungs and lack of surfactant is key concept
  • infant is almost always preterm
  • associated with NRDS and male gender and maternal diabetes
  • increased work of breathing results in cascade of events that cause hyaline membrane disease
  • surfactant production increases with birthing process –> so see increased incidence with c-sections
  • Surfactant synthesis is modulated by glucocorticoids (and other factors)
32
Q

Describe the clinical course for NRDS treatment

A
  • Delay labor
  • assess fetal lung maturity
  • induce maturation of fetal lung through antenatal corticosteroid treatment
  • post-natal surfactant therapy + CPAP
33
Q

Give an overview of the anatomy of the respiratory system

A
  • vital organs of respiration are located in thoracic cavity
  • 2 lungs are completely separated by the mediastinum = central partition or middle septum
  • apex of lung projects into root of neck
  • base of lung sits on diaphragm
34
Q

Compare the anatomy of the right and left lungs

A
  • Right lung is larger than left (heart bulges into left) and is slightly more vertical
  • Right lung has 3 lobes (superior, middle, inferior)
  • Right lung has 2 fissures (oblique, horizontal)
  • Left lung has 2 lobes (superior, inferior)
  • Left lung has an oblique fissure separating two lobes
35
Q

What is aspiration and what effect does the anatomy of the lungs have on it?

A

= breathing in something other than air

  • when something is aspirated it is always found on the right side due to more vertical orientation and larger diameter
  • if in supine/sitting position will be found in right lower lobe
  • if in prone position might be found in right upper lobe
36
Q

Explain a mediastinal shift

A
  • is an exception to the idea that damage to 1 lung does not affect the other
  • if 1 lung (ex. the left lung) is hyper inflated because it is doing the work of both lungs it will push against the mediastinum and will see a mediastinal shift
  • the shift will push into the space of the other lung and affect its inflation
37
Q

How are the lung attached to mediastinum and what occurs there

A
  • attached to mediastinum by root of lungs where structures are entering and exiting:
  • bronchial artery, bronchi, pulmonary arteries, pulmonary plexus of nerves, lymphatic vessels, 2 pulmonary veins from each side
38
Q

What is the hilum of the lungs

A

= a wedge-shaped area on medial aspect of lungs through which structures enter and exit

  • the root of the lungs? connecting to mediastinum?
  • pulmonary ligament is off of it
39
Q

What is the lung roots and what is special about it

A
  • is the site of connection of the lungs to the mediastinum

- it is enclosed in an area of continuity between visceral and parietal layers of the pleura (serous membrane) CT

40
Q

Describe the characteristics of the pleural cavities

A
  • each contains only a thin layer of serous fluid
  • each is lined by a pleura = a single layer of mesothelium and associated underlying CT
  • each is a potential space enclosed between visceral and parietal pleurae
41
Q

Describe the parietal pleura

A

= associated with walls of body cavity

- has larger space than the visceral pleura making it a more likely location for fluid accumulation

42
Q

Describe the visceral pleura

A
  • adheres to and covers the surface of the lung and is continuous with the tissue there
43
Q

What is a Pneumothorax

A
  • entry of air into pleural cavity
  • results in lung collapse
  • puncture causing it is pierces both the thoracic wall and parietal pleura
  • also maybe a puncture of the lung and visceral pleura to admit air into the space
44
Q

What is a hemothorax

A
  • blood in pleural cavity
45
Q

What is a pleural effusion

A
  • accumulation of fluid in pleural cavity
46
Q

What is meant by the term dual blood supply WRT the lung

A
  • the lung contains both functional vessels and nutrient vessels serving different functions
47
Q

What are the functional vessels of the lung

A
  • Pulmonary arteries - carrying deoxygenated blood
  • Pulmonary veins (2 per lung) - carrying oxygenated blood
  • these vessels do not nourish the lung tissues
48
Q

What are the nutrient vessels of the lung

A
  • bronchial arteries that carry oxygenated blood and nourish the lung tissue
  • Branch from the aorta –> thoracic aorta –> bronchial arteries
49
Q

Where do you find pulmonary arteries

A
  • travel adjacent to airway

- branch along side the airway to the level of the respiratory bronchiole

50
Q

Where do you find pulmonary veins

A
  • travel in CT septa

- will no have larger airways around them

51
Q

Where do you find bronchial arteries

A
  • travel in wall of airway
52
Q

Where do you find capillary plexus

A
  • in the alveoli/ at sites of gas exchange (i.e. respiratory portions of the lung)
  • lungs have largest capillary network in body
  • only have continuous capillaries
53
Q

Describe the overall changes associated with bronchial branching

A
  • progressive decrease in diameter
  • progressive increase in cross-sectional area
  • more branching will se more profiles of areas
54
Q

What is senile emphysema

A
  • change in elastic property of lung as a specific impact due to aging
55
Q

Describe the structure, function, and location of the conducting portion of the respiratory system

A

Structure:
- Varying levels of wall thickness with structures that warm, filer, humidify incoming air
Location:
- portions outside and inside of lung: from bronchiole up
- terminal bronchiole marks end of conducting zone
FXN:
- conduct and condition air

56
Q

Describe the structure, function, and location of the respiratory portion of the respiratory system

A
Structure:
- thin walled for efficient gas exchange
Location:
Only in lungs: respiratory bronchiole is the first part of the respiratory zone, alveolar duct, alveoli
FXN:
- Gas exchange
57
Q

Describe the 3 tracheal wall layers

A

1) Mucosa - psuedostratified epithelium, elastic rich lamina propria (also contains BALT), no muscularis mucosae
2) Submuscosa - contain “tracheal seromucous glands”
3) Adventitia/Cartilage - 16-20 hyaline cartilage rings that open posteriorly - bridged by trachealis muscle

58
Q

Characterize the tracheal epithelium, include relevant cells types

A
  • the tracheal epithelium is a pseudostratified (“respiratory”) epithelium
  • contains 5 cells types, which have an important ratio of presence between them, and incorrect amounts are related to cystic fibrosis among other disorders (needs to be more ciliated cells)
  • 5 cells types of the tracheal epithelium (in order of most present to least)
    1) Ciliated Cells
    2) Mucous Cells
    3) Basal Cells
    4) Brush Cells
    5) Small Granule Cells
59
Q

Describe the ciliated cells of the tracheal epithelium

A
  • produce a percilliary fluid = a serous fluid

- this fluid rests on top of ciliated cells allowing for them to beat evenly and easily

60
Q

Describe the mucous cells of the tracheal epithelium

A
  • produce mucous (like the goblet cells of intestine)
  • the mucous floats on serous perciliary fluid
  • both fluids are moved by cilia toward the oral cavity and function in clearing debris from airway
61
Q

Describe the basal cells of the tracheal epithelium

A
  • stem cell for all cells of tracheal epithelium

- will not touch the lumen of the trachea

62
Q

Describe the brush cells of the tracheal epithelium

A
  • have sensory role because are associated with nerve endings
  • sometimes called receptor cells
  • do not have cilia, but have microvilli instead
63
Q

Describe the small granule cells of the tracheal epithelium

A
  • need a special stain to see
  • have varying functions that might include development of respiratory system, regulation of diameter of airways, nervous system functions
64
Q

Describe metaplasia in the human respiratory system

A
  • Pseudostratified epithelium changes to SSNK epithelium (often due to inhaled irritant - i.e. smoking)
  • change is reversible if irritant eliminated
  • removal of mucous is impairs –> results in more mucous cells than ciliated cells + hypertrophy of mucous secreting glands of the submucosa in the trachea + large bronchi
  • excessive mucous secretions result in lumen of respiratory tree
  • individuals must cough to clear secretions
65
Q

Describe the bronchi, and their morphological identification

A
  • identified commonly by plates of cartilage + circular smooth muscle (Note: extra pulmonary bronchus still has the c-shaped rings, but intrapulmonary bronchi have plates - we will not be tested on distinguishing the two)
  • Bronchi 4 layers in their walls
    1) Mucosa
    2) Muscularis
    3) Submucosa
    4) Adventitia/Cartilage plates
66
Q

Describe the 4 layers of Bronchial Walls

A

1) Muscosa - same pseudostratified epithelium as trachea
2) Muscularis - regulates diameter of airway
3) Submucosa - submucosa seromucous glands are present
4) Adventitia/Cartilage plates - are not c-shaped (intrapulmonary bronchi) - as move down airway walls the plates are smaller and have decreasing diameter

67
Q

Describe the characteristics of Bronchioles

A
  • airways that measure 1mm or less
  • branch repeatedly
  • will give rise to terminal bronchioles that mark end of conducting zone
  • have simple columnar/cuboidal epithelium comprised of some clara some ciliated cells
68
Q

What characteristics allow you to identify bronchioles

A
  • no glands
  • no cartilage
  • simple epithelium of clara/ciliated cells
  • increase in elastic fibers
69
Q

What are clara cells

A
  • mitotically active stem cells (cuboidal/columnar shaped)
  • primarily found in bronchioles (no glands in bronchioles)
  • apical aspect = domed morphology
    FXN:
  • release a surface active agent that is surfactant-like but is not surfactant
70
Q

Characterize terminal bronchioles

A
  • smallest most distal portion of conduction portion of respiratory system (mark the end of it)
  • no gas exchange is possible at this point
  • epithelium has Clara Cells and some ciliated cuboidal cells
71
Q

Characterize Respiratory Bronchioles

A

= start of respiratory zone - first region where gas exchange occurs

  • walls are interrupted with alveoli
  • smooth muscle + elastic tissue is below epithelium
  • epithelium is dominated by clara cells (some ciliated cells are present)
  • leads to alveolar ducts –> alveolar sacs
72
Q

Describe the structure, function, and location of type I pneumocytes

A

Structure:
- squamous, attenuated cells, many organelles clustered around the nucleus
- cytoplasm is free for gas exchange
FXN:
- provide barrier of minimal thickness that is permeable to gases
Location:
cover 95% of alveolar surface (account for only 40% of lining cells?)

73
Q

Describe the structure, function, and location of type II pneumocytes

A

Structure:
- rounded cells that bulge into lumen
- apical cytoplasm contains lamellar bodies
FXN:
- undergo mitosis to regenerate themselves + type I pneumocytes
- continually produce surfactant to prevent collapse of alveoli
Location:
- interspersed among type I pneumocytes (often at alveolar corners)
- occupy 3-5% of surface area

74
Q

Describe Alveolar Macrophages

A

= Dust cells
- made in bone marrow derived from monocytes
Location:
- in septum and airspaces of of alveoli
FXN:
- phagocytose material and then are either
A) passed up bronchial tree in mucous to reach pharynx (thus contributing to mucociliary transport system)
B) Migrate to CT of larger airways where they may stay with particles for life of individual - these particles increase likelihood of lung damage

75
Q

Describe the mucociliary Escalator (Transport)

A
  • FXNs as a defense mechanism for the lungs
  • traps and removes debris/bacteria/particles
  • moves the paticles/toxic substances from distal to proximal
    Components of the system include:
    1) Cilia
    2) Serous fluid (perciliary fluid produced by ciliated cells)
    3) Mucous layer (produced by mucous cells and submucosal seromucous glands)
  • also dust cells contribute to the defense characteristics of this system my digesting particles and being removed from airways themselves