embryology of respiratory

Question 1

respiratory primordium is indicated by ____ at day ___

Answer 1

laryngotracheal groove
28

Question 2

laryngotracheal groove evaginates to form a pouch called ____, which will elongate to form the ____

Answer 2

laryngotracheal diverticulum
respiratory bud

Question 3

respiratory diverticulum

Answer 3

outgrowth from the ventral wall of the foregut

Question 4

lung bud appeareance depends on ____, which causes upregulation of ____ in the endoderm of gut tube.

Answer 4

retinoic acid
TBX4

Question 5

epithelium of the internal lining of respiratory tract is ____ origin.

Answer 5

endodermal

Question 6

cartilage, muscular, connective tissue of trachea and lungs are ____ origin

Answer 6

splanchnic (visceral) mesoderm

Question 7

initially lung bud is in communication with foregut by way of ____

Answer 7

tracheoesophageal ridge

Question 8

tracheoesophageal septum divides

Answer 8

dorsal: esophagus
ventral: trachea and lung buds

lung maintain communication with pharynx through laryngeal orifice

Question 9

esophagieal atresia

most frequent one

Answer 9

tracheoesophageal fistule with distal part of esophagus
*vomiting
*distended abdomen

Question 10

esophagieal atresia

communication of esophagus with trachea

Answer 10

*aspiration
cyanotic due to low O2

Question 11

____ accompanies tracheoesophageal fistule (TEF) in fetus

Answer 11

polyhydroamnions (defective swallowing of amniotic fluid)

Question 12

larnyx

internal lining origin

Answer 12

endoderm

Question 13

larnyx

cartilage and muscle origin of cricoid, thyroid and arythenoid

Answer 13

mesenchyme of 4th and 6th pharyngeal arches

Question 14

layrnx

epiglottis origin

Answer 14

hypopharyngeal eminence of 3rd and 4th arches

Question 15

lung bud from foregut forms the ____
two lateral outpocketing form the ___

Answer 15

trachea
bronchial buds

Question 16

intraembryonic cavity is divided in 3

Answer 16

pericardial
2 pericardioperitoneal canal
peritoneal cavity

Question 17

pericardioperitonal canals

Answer 17

spaces for lung
filled with expanding lung buds

Question 18

primitive pleural cavities :
visceral pleura –>
parietal pleura –>

Answer 18

visceral pleura –> mesoderm covering outside of long (splanchnic)
parietal pleura –>somatic mesoderm covering body wall

Question 19

True / false

bronchial tree reaches its final shape in fetus

Answer 19

False: additional divisions of tree occur during posnatal life

Question 20

branching is regulated by ___

Answer 20

epithelial-mesenchymal interactions

Question 21

steps of maturation of lungs

Answer 21

1.pseudoglandular period
2.canalicular period
3.terminal sac period
4.alveolar period

Question 22

pseudoglandular period

Answer 22

5-16 wk
terminal bronchioles present
no respiratory bronchiole

Question 23

canalicular period

Answer 23

16-26 week
respiratory bronchioles
multiple alveolar ducts

Question 24

terminal sac period

Answer 24

26 week to birth
terminal sac = primitive alveoli
capillaries establish close contact

Question 25

alveolar period

Answer 25

8 months - childhood
mature alveoli
epithelial-endothelial capillary contact –> air-blood barrier: Type I and type II cells

Question 26

End of ____ month since mature alveolar sacs and capillaries are present, premature infant is able to survive.

Answer 26

7th

Question 27

last 2 months ____ cells become thinner,
about 6th month ____develop.

Answer 27

type I alveolar epithelial
type II

Question 28

before birth lungs are full of fluid with ____

Answer 28

high Cl
little protein
mucus
surfactant

Question 29

amount of surfactant increases ____ (time)

Answer 29

last 2 week before birth

Question 30

absence or insufficiency of surfactant causes

Answer 30

RDS

Question 31

5/6 of alveoli form during ____

Answer 31

first 8-10 years of postnatal life

Question 32

in severe ____ pulmonary hypoplasia can occur

Answer 32

oligohydroamnions
(intentional aspiration of amniotic fluid can not occur)

Question 33

intentional aspiration of amniotic fluid is important for ____

Answer 33

stimulating lung development
conditioning of respiratory muscles

Question 34

when respiration begins at birth lung fluid is ____

Answer 34

1. resborbed by blood and lymph
2. expelled via trachea and bronchi
   –> vaginal delivery

Question 35

Hyaline membrane disease

Answer 35

RDS
1. hypoxia and hypercapnia
2. affected cells : alveoli, endothelial cells, basal lamina
2. inflammation –> fibrin clotting
3. proteinaceous fluid forming a membrane over respiratory surface
4. interference of gas exchange –> more hypoxia