Pulmonary Histology Flashcards Preview

Histology Exam III Material > Pulmonary Histology > Flashcards

Flashcards in Pulmonary Histology Deck (67):
1

The respiratory system consists of a ______ portion and a _____ portion

Conducting, gas exchange

2

Respiratory mucosa lines the respiratory passageway and consists of

- Pseudostratified ciliated columnar epithelium:
- Respiratory epithelium
- Lines most of conducting structures
- Lamina propria
- Thin layer of loose CT
- Submucosa
- Dense irregular CT

3

Respiratory epithelium structure

Pseudostratified ciliated columnar epithelium

4

The lamina propria of respiratory mucosa is

thin layer of loose CT

5

The submucosa of respiratory system

dense irregular CT

6

Respiratory epithelium lines

most of the conducting structures

7

Epithelium of the nares/Nostrils composition

-Stratified squamous epithelium continuous with epidermis
- Contains sebaceous glands, sudoriferous glands, and hair follicles

8

Respiratory/nasal mucosa begins where in the nose

at the level of nasal septum

9

Nasal mucosa includes:

-Respiratory epithelium
- basement membrane
- Lamina propria (blends with underlying bone or cartilage)
- Depending on location, mucosa may be called mucoperiosteum, mucoperichondrium, or the Schneiderian membrane)

10

Where is olfactory epithelium located

in the nasal cavity roof

11

composition of olfactory epithelium

-pseudostratified columnar epithelium without goblet cells
- no distinct basement membrane

12

Cell of olfactory epithelium

-Sustentacular cells (supporting cells) with pigment granules
- basal cells with pigment granules:
- Stem cells-give rise to immature olfactory cells
- Olfactory cells:
- Bipolar neurons
- Apical end projects into nasal cavity as a knoblike ending with nonmotile cilia
- Cilia possess G-protein-linked odor-specific receptors
- Basal end of the cell extends as an unmyelinated axon, bundled with other similar axons, through the ethmoid plate to mitral cells located in the olfactory bulb
- Olfactory cells senesce and are replaced from basal cells
- olfactory glands of bowman:

13

Where are olfactory glands of bowman located

in the lamina propria of olfactory mucosa

14

What do olfactory glands of bowman secrete

odorant-binding protein, which binds to odorant molecule in nasal cavity

15

Generation of AP in Olfactory system

odorant-binding protein+ odorant molecules---> binds to odorant receptor protein (G protein) on olfactory cell cilium---> G-protein activated adenyl cyclase---> G-protein activated adenyl with ATP ----> cAMP---> Opening of Na+ channels ----> AP

16

What are the only neurons that can repopulate

Olfactory cells

17

mucosa of the nasopharynx

-Respiratory epithelium
- Lamina propria with FECT, mucous glands, serous and mixed glands, and diffuse lymphatic tissue

18

Submucosa of Nasopharynx

-Loose CT
- MALT (mucosa-associated lymphoid tissue)

19

What is Waldeyer's ring

-Located in the Nasopharynx
- Ring of lymphoid tissue around nasopharynx
- Includes Tonsils and Adenoids

20

What is FECT

Fibrous-elastic Connective Tissue

21

Histology of the Larynx components

Epiglottis
False vocal cords (vestibular folds)
True vocal cords
- Remainder of the larynx is covered with pseudostratified ciliated epithelium

22

Epiglottis

-sits above the opening to the trachea
- Lingual surface: covered with stratified squamous epithelium
- Lamina propria with loose CT and elastic fibers
-Pharyngeal surface:
- Covered with pseudostratied ciliated epithelium
- Lamina propria with tubuloacinar seromucous glands
- Core of the epiglottis consists of elastic cartilage

23

False vocal cords (vestibular folds)

-Covered with pseudostratified ciliated epithelium
- Lamina with seromucous glands

24

True vocal cords

-Covered with stratified squamous epithelium
- Lack seromucous glands in lamina propria

25

Tissues found in the layrnx

-Epithelium
- Respiratory epithelium (pseudostratified ciliated columnar)
- Stratified squamous epithelium (in 2 places)
- Cartilage
- Hyaline cartilages:
- Thyroid, cricoid, arytenoids
- Elastic cartilages:
- Corniculates, cuneiforms, tips of arytenoids, epiglottis
-Muscle
- Skeletal muscle

26

Composition of the Trachea

-Mucosa:
- Respiratory epithelium with thick basement membrane
- Lamina propria with delicate FECT and lymphatic tissue
- Submucosa
- many sero-mucous glands
- Adventitia
- 16-20 horseshoe-shaped cartilages interconnected by FECT
- opening between arms of horseshoe-shaped cartilages closed by: FECT, Mucous membrane, and smooth muscles (Trachealis muscles)
- mixed glands and capillaries

27

The right lung has how many lobes

3

28

Lungs refers to

all respiratory system components distal to the trachea

29

each lobe of the lung is divided into a number of lobules called

bronchopulmonary segments

30

The trachea divides into ____ primary bronchi

two, one to each lung

31

Each primary bronchus divides into _____ (to the right lung) or____ (to the left lung) secondary bronchi, also referred to as segmental bronchi

3, 2

32

each bronchus divide into

secondary bronchi, also referred to as segmental bronchi

33

The primary bronchi lie

outside the lung and are referred to as extrapulmonary

34

The bronchi resemble the trachea except

for a smaller diameter, and the cartilage ring that reinforces them are circular rather than horseshoe-shaped

35

Segmental bronchi are mostly

intrapulmonary

36

Secondary/segmental bronchi are reinforced by

circular rings of hyaline cartilage that transition to irregular plates

37

As the bronchi become smaller there is a ________ in height of the epithelium, a _______ in cartilage and glands, and an ______ in the proportion of elastic fibers and smooth muscles

decrease, decrease, increase

38

General histology of the intrapulmonary bronchi

-Mucosa
- Similar to trachea and extrapulmonary bronchi
- mucosal folds may be present due to smooth muscles
- Elastic fibers are prominent
-Submucosa
- Characterized by loose CT and lymphatic tissue
- Contains mixed glands and mucous glands
- Adventitia
- Contains hyaline cartilage plates surrounded by dense FECT

39

General characteristic of bronchioles

-Absence of cartilage
- Absence of glands
- Sparse goblet cells, especially in terminal bronchioles
- Large amount of smooth muscle tissue
- Diameter ranges from 1 mm to about 0.3 mm
- Epithelium transitions form ciliated columnar with a few goblet cells to ciliated cuboidal with no goblet cells (terminal bronchioles)
- Smallest brochioles are the terminal bronchioles
- Each terminal bronchiole branches to form two or more respiratory bronchioles

40

general characteristic of respiratory bronchioles

-Diameter

41

Alveolar ducts

-continuations of respiratory bronchioles
- cone-shaped
- squamous epithelium
- Wall consists of smooth muscle with FECT

42

Alveolar sacs

each sac is composed of several alveoli

43

Alveoli within alveolar sacs are separated by

alveolar septa

44

Walls of the alveoli and septa are thin and composed of

-Type I alveolar cells (type I pneumocytes)
- less numerous than type II alveolar cells
- Cover larges surface area
- Type II alveolar cells (type II pneumocytes)
- Cuboidal or rounded
- Serve as stem cells for type I and type II pneumocytes
- Macrophages (dust cells)

45

What are the pores of Kohn

openings between adjacent alveoli

46

Cell types in the respiratory epithelium and alveoli

-Ciliated columnar cells
- Nonciliated columnar cells
- have microvilli but no cilia
- Stem cells
- Basal cells of pseudostratified epithelium
- Replace themselves
- Goblet cells
- Mucous secreting cells
- Also stem cells; can replace other cells of epithelium
- Neuroendocrine cells (small granule cells)
- May be associated with sensory reception and are more prevalent in infant
- Release catecholamines

47

neuroendocrine cells (small granule cells)

-may be associated with sensory reception and are more prevalent in infants
- release catecholamines

48

Surfactant is secreted by

Clara cells and type II alveolar cells

49

Type II alveolar cells contain numerous

lamellar bodies

50

what is the function of surfactant

reduces surface tension on alveolar surface

51

Type II alveolar phagocytize

old surfactant

52

Type II alveolar cells contain numerous lamellar bodies, which

-are distinctive under EM
- Contain dipalmitoyl phosphatidylcholine (lecithin)
- secreted from apical domain of cells
- combine with proteins from clara cells

53

Type I pneumocytes (alveolar cells)

-very thin cytoplasm
- cover about 95% of the alveolar surface
- tight junctions connect with other type I cells
- Basal lamina may be fused with basal lamina of nearby capillaries

54

Type II pneumocytes (alveolar cells)

-Rounded cells that bulge into the alveolar lumen
- Cover about 5% of the alveolar surface
- Can divide and replace type I pneumocytes
- Produce phospholipid-protein surfactant that coats alveolar walls

55

Type II pneumocytes (alveolar cells ) produce

phospholipid-protein surfactant that coats alveolar walls

56

explain how odors lead to action potential

(odorant-binding protein + odorant molecule) -----> binds to odorant receptor protein (G protein) on olfactory cell cilium ------> G-Protein activated adenyl cyclase------- turns ATP to cAMP--------> opens Na+ channels -------> Action potential

57

Clara cells are only found in the

bronchioles

58

The number of Clara Cells in the bronchioles increases as

ciliated columnar cells decrease

59

What is the Histological identification characteristic of Clara Cells

can be identified by an apical surface that bulges into the lumen of the airway

60

Clara cells function

secrete surface-active lipoprotein that prevents collapse of terminal bronchioles during exhalation (surfactant)

61

Do Clara cells contain abundant SER

Yes

62

Dust cells are _____ and are derived from ____-

Macrophages, derived from monocytes

63

Function of dust cells

phagocytize particles such as pollutants, bacteria, and surfactant that are not trapped in the mucous and expectorated

64

What is the relation of dust cells to CHF (congestive heart failure)

- in CHF, fluid containing the breakdown products of hemoglobin (iron-containing hemosiderin) leak into alveolar spaces and are phagocytize by dust cells
- the iron-containing dust cells are referred to as heart failure cells

65

Iron-containing dust cells are referred to as

heart failure cells

66

List the components of the air-blood respiratory barrier

- Thin capillary endothelium (continuous endothelium)
- Thin epithelium of pneumocyte (type I)
- intervening basal lamina produced by both cell types

67

function(s) of blood-air barrier

permits gas exchange but does not allow fluids or cells to enter alveoli (normally)