Respiratory Histopathology

Question 1

respiratory epithelium

Answer 1

refers to pseudostratified ciliated columnar epithelium of trachea

Question 2

goblet cell

Answer 2

mucus producing, abundant in trachea

Question 3

type of cartilage in trachea

Answer 3

hyaline

Question 4

basal cell

Answer 4

stem cell

in trachea, replaces both respiratory epithelium and goblet cells

Question 5

brush cells

Answer 5

sparse ciliated columnar epithelium of trachea

most likely function is chemosensory

Question 6

small granule cells

Answer 6

sparsely scattered cells of trachea that secrete peptide hormones that might affect muscle tone, bronchial function and/or act as chemosensory receptors

may be responsible for small cell carcinoma

not well understood

Question 7

Kulchitsky cells

Answer 7

aka small granule cells
peptide secreting
trachea, bronchi, bronchioles (all the way through terminal bronchioles)
possibly small cell carcinoma

Question 8

cells of tracheal epithelium

Answer 8

respiratory epithelium (pseudo stratified ciliated columnar epithelium)
goblet cells (mucus)
basal cells (stem cells)
brush cells (chemosensory)
small granule cells/Kulchitsky cells (peptides)

Question 9

layers of trachea

Answer 9

epithelium
basement membrane
lamina propria (connective tissue, some seromucous glands, immune cells, MALT)
submucosa (even more seromucous glands, immune cells, MALT)
hyaline cartilage skeleton

Question 10

trends from trachea –> bronchi –> bronchioles

Answer 10

columnar –> shorter columnar –> cuboidal
progressively less pseudostratification
progressively less cilia
progressively fewer mucus-producing cells (goblet)
progressively less submucosa (immune cells, MALT, mucous glands)
club cells (surfactant producing) in terminal bronchioles
progressively less cartilage
progressively more elastin
progressively more smooth muscle

Question 11

cells of terminal bronchioles

Answer 11

cuboidal epithelium, some are ciliated
kulchitsky cells
no more goblet cells
club cells (surfactant producing)
very thin lamina propria
no cartilage
walls of 1-2 smooth muscle cell. layers

Question 12

club cells

Answer 12

secrete:

• surfactant
• enzymes that break down mucus
• enzymes to destroy pathogens
• inflammatory and anti-inflammatory cytokines

act as stem cells for surrounding epithelium

non-ciliated
granulated

Question 13

pores of Kohn

Answer 13

pores between neighboring alveoli of different bronchioles
stabilize pressure
in the event of an obstruction, ensure collateral circulation

Question 14

smooth muscle cells in alveoli

Answer 14

absent or pathologic

Question 15

elastin in alveoli

Answer 15

abundant

Question 16

type I alveolar cells

Answer 16

simple columnar epithelium

responsible for diffusion of respiratory gases

Question 17

type II alveolar cells

Answer 17

surfactant-producing

Question 18

pulmonary alveolar macrophages

Answer 18

found along and in between alveoli

Question 19

approx size of alveolus

Answer 19

200 micron

Question 20

emphysema histology

Answer 20

alveoli look “burst” due to permanent destruction (enlargement of air spaces and destruction of walls)
no obvious fibrosis

Question 21

chronic bronchitis histology

Answer 21

lymphocytic infiltration
mucous gland hyperplasia
squamous metaplasia (multi-layer squamous epithelium rather than simple squamous)

Question 22

COPD histology

Answer 22

generally includes features of both emphysema and chronic bronchitis
asthma would also be a type of COPD and does not have these histologic changes

Question 23

acute pneumonia histology

Answer 23

neutrophil infiltration and fluid consolidate

normal alveolar architecture

Question 24

“glandular” carcinoma prefix

Answer 24

“Adeno-“

Question 25

most long tumors are derived from ___

Answer 25

bronchial epithelium
(therefore are carcinomas)
small cell carcinomas only make up about 15% of these but have worse prognosis as they are generally inoperable

Question 26

adenocarcinoma histology

Answer 26

looks like glands in connective tissue
extensive fibrosis
very disorganized