test 2: lecture 12 respiratory

Question 1

two types of epithelium in the lungs

Answer 1

airway- more complex- goblet, basal, fibroblasts and smooth muscle- Conduct airflow
alveolar- AT2 and AT1 gas exchange

Question 2

Lung epithelium is derived from ___

Answer 2

the endoderm (definitive endoderm)

Question 3

Endoderm is surrounded by visceral ___, derived from the lateral plate mesoderm

Answer 3

“splanchnic” mesoderm

Question 4

What is expressed to cause lungs to bud and divide from forget endoderm

Answer 4

Nkx2.1

Question 5

how does respiratory diverticulum develop

Answer 5

Nkx2.1 expressed

1. Starts as laryngotracheal groove in the ventral pharynx between the fourth pharyngeal arches.

then the tracheo-esophageal ridge

then the respiratory diverticulum

Question 6

___ becomes the lining of the trachea, the two bronchi, and the alveoli of the lungs.

Answer 6

Laryngotracheal endoderm

Question 7

Proper trachea / esophogeal separation requires precise levels of the transcription factor___

Answer 7

Sox2

Question 8

atresia

Answer 8

dead end- errors in Sox2 and Nkx2.1 that lead to premature stop of esophagus

usually can be surgically fixed

Question 9

tracheoesophageal fistula

Answer 9

error in trachea and esophagus when they are attached to each other

Question 10

5 stages of branching morphogenesis of lungs

Answer 10

embryonic

pseudo-glandular

canalicular

saccular

alveolar

Question 11

embryonic branching morphogenesis of lung

Answer 11

1st stage

Appearance of right and left lung buds

Question 12

pseudoglandular branching morphogenesis of lung

Answer 12

2nd stage

Complete structure of the human airway tree is complete

Question 13

canalicular branching morphogenesis of lung

Answer 13

3rd stage

3 more rounds of branching to produce future alveolar regions

Question 14

saccular branching morphogenesis of lung

Answer 14

4th stage

Branching done. Epithelial growth and differentiation continues

Question 15

alveolar branching morphogenesis of lung

Answer 15

Secondary septation: subdivision of alveoli to increase surface area for gas exchange

Continues for 21 years!

Question 16

subdivision of alveoli to increase surface area for gas exchange

Answer 16

secondary septation

happens last stage of branching of lungs- up to 21 years in humans

Question 17

___ to be expressed in the region of the embryonic foregut endoderm that will bud into the lung

Answer 17

•First transcription factor (TTF1 Nkx2.1)

Question 18

___ are expressed in the ventral anterior mesoderm surrounding the region of the anterior foregut endoderm and induce expression of Nkx2.1

Answer 18

Wnt2 and Wnt2b

no Wnt, no lungs

Question 19

expression of Wnt leads to expression of ___ in the lungs. expression of ___ inhibits to Sox2 which will inhibit ___

Answer 19

Nkx2.1

BMP4 Nkx2.1

Question 20

•BMP4 from the mesoderm ___ Sox2 in the anterior foregut endoderm, thus allowing expression of ___

Answer 20

suppresses/inhibits

Nkx2.1

•(in humans, BMP2 and BMP7 seems to be more important than BMP4)

Question 21

FGF10 and lung branching

Answer 21

Fgf10 is not required for stereotypic branching

Fgf10 is a permissive factor

not really fully understood

Question 22

cells that will differentiate into airway cells of the lungs will

Answer 22

turn down Sox2

express Nkx2.1

then turn Sox2 back on

Question 23

cells that will differentiate into alveolar cells of the lung will

Answer 23

turn down Sox2

express Nkx2.1

then turn on Sox9 and Id2

distal endoderm progenitor lineage

Question 24

progenitor cells in the developing lung will turn into

Answer 24

proximal progenitors: Sox2

goblet cells, basal cells, ciliated cells ect

distal progenitors: Sox 9, Id2

AEC 1 or 2 (alveolar type 1 (secretory) or type 2 (gas exchange))

Question 25

goblet cell in the developing lung develop early or late in development?

Answer 25

late

Question 26

Mechanical forces generated from the inhalation of ___ by ___ movements are essential for AT1 cell differentiation

Answer 26

amniotic fluid

fetal breathing

Question 27

alveolar cells that move down into the underlying connective tissue by fetal breathing is a ___

Answer 27

alveolar type 2 cell

Question 28

differences in mouse and human lung development

Answer 28

human alveolar tissue express Sox 2 and Sox 9 until canalicular stage when they express only Sox9

Humans need retinoic acid to differentiate

Mice need ROCK inhibitor to differentiate

Question 29

the lung professor research does :

Answer 29

Transplantation of human iPSC-derived alveolar type 2 cells into immunocompromised mice

Question 30

The presence of both the pulmonary arteries and the pulmonary veins in the absence of lung development suggests that ___ contribute to the generation of these structures.

Answer 30

cardiac progenitors

Question 31

The cardiac progenitors closest to the anterior foregut where the lung arises are defined by expression of ___ and are referred to as the ___

Answer 31

Isl1

second heart field (SHF)

Question 32

The cardiac progenitors (CPP) cells do not generate ___

Answer 32

alveolar capillaries - still don’t know where these come from

Question 33

aerocyte

Answer 33

cells that sit on alveolar type 1 cells that help with gas exchange into blood

found in alveoli of lungs

Question 34

Bronchopulmonary Dysplasia

Answer 34

chronic pediatric lung disease, characterized by impaired gas exchange and respiratory distress

lack surfactant

premature babies are placed on ventilator and oxygen therapy to help breathe but can result in making this disease worse by decreasing alveolar development

Question 35

you can mimic the effects of Bronchopulmonary Dysplasia by ___ which shows ___

Answer 35

exposing mice to hyperoxia (too much oxygen leads to simplified alveoli)

loss of alveoli type 1 cells- cells revert into type 2 cells in presence of too much O2

Question 36

pulmonary fibrosis

Answer 36

issue with Alveolar type 2 cells

issue with surfactant production (SFTPC)

Question 37

Alveolar Type 2 Cell Maturation Promotes __

Answer 37

Parturition (labor)

Question 38

•Lung maturation is the primary determinant of the ___

Answer 38

timing of labor

Question 39

•Steroid receptor coactivators 1 and 2, ____, drive expression of Surfactant Protein A and Platelet Activating Factor (an inflammatory phospholipid)

Answer 39

SRC-1 and SRC-2,