Final Embryo - Respiratory Development

Question 1

This appears in the floor of the caudal pharynx

Answer 1

laryngotracheal groove

Question 2

The laryngotracheal groove protrudes ventral forming an endodermal outgrowth from the foregut called what

Answer 2

lung bud (respiratory diverticulum)

Question 3

This develops, separating the lung bud (ventrally) from the foregut (dorsally)

Answer 3

tracheosophageal septum

Question 4

The respiratory diverticulum retains a connection with the pharynx where

Answer 4

primordial laryngeal inget

Question 5

What abnormalities can occur during respiratory development and what risk is associated with them

Answer 5

tracheoesophageal fistula and esophageal atresia

risk of polyhydramnios

Question 6

The lung bud develops to form what

Answer 6

larynx, trachea, respiratory tree, and lungs

Question 7

This germ layer forms the epithelial lining and glands of the airway

Answer 7

endoderm

Question 8

This germ layer forms the smooth muscle and CT of the airway

Answer 8

splanchnic mesoderm

Question 9

This developed as the portion of the foregut immediately caudal to thy pharynx

Answer 9

esophagus

Question 10

Which pharyngeal arch pairs give rise to the laryngeal cartilage and musculature

Answer 10

4 and 6

Question 11

What forms the epiglottis

Answer 11

mesenchyme of the caudal hypopharyngeal eminence

Question 12

Laryngeal muscules arising from the 4th arch are innervated by hat

Answer 12

superior laryngeal nerve

Question 13

Laryngeal muscles arising from the 6th arch are innervated by what

Answer 13

recurrent laryngeal nerve

Question 14

The lung bud divides to from what

Answer 14

the primary bronchial buds (future primary bronchi)

Question 15

This type of mesoderm gives rise to the visceral pleura of the lungs

Answer 15

splanchnic mesoderm

Question 16

This type of mesoderm lining the thoracic body gives rise to the parietal pleura

Answer 16

somatic mesoderm

Question 17

The primary bronchial buds divide for form what

Answer 17

secodnary (lobar) bronchial buds

Question 18

How many secondary (lobar) buds are there

Answer 18

3 on the right

2 on the left

Question 19

The secondary bronchial buds divide to form what

Answer 19

teritiary (segmental) bronchial buds

Question 20

What consists of a bronchopulmonary segment

Answer 20

tertiary bronchus + surrounding tissue

Question 21

How many tertiary (segmental) buds are there

Answer 21

10 on the right

8 or 9 on the left

Question 22

What stage of lung development happens during weeks 6- 16

Answer 22

pseudoglandular

Question 23

What stage of lung development happens during weeks 16-26

Answer 23

canalicular

Question 24

What stage of lung development happens from week 26 until birth

Answer 24

terminal sac

Question 25

What stage of lung development happens from week 32 until 8 years of age

Answer 25

alveolar

Question 26

In this stage of lung development all major lung structures have developed except for the most distal portions where gas exchange takes place

Answer 26

pseudoglandular stage

Question 27

What does the lung tissue look like during the pseudoglandular stage

Answer 27

it appears histologically as a collection of exocrine glands

Question 28

Can a fetus born during the pesudoglandular stage survive?

Answer 28

No

Question 29

In this stage of lung development respiration is possible near the end where each terminal bronchiole has split into 2+ respiratory bronchioles developing primitive alveolar ducts

Answer 29

Canalicular stage

Question 30

What becomes of the lung tissue during the canalicular stage

Answer 30

it becomes highly vascular

Question 31

Can a fetus born during the canalicular stage survive?

Answer 31

At the end, possibly; although many die

Question 32

In this stage of lung developments more terminal sacs develop and capillaries arrive firing the blood-air barrier; will see type I and type II alveolar cells

Answer 32

termninal sac stage

Question 33

What is the purpose of type I alveolar cells

Answer 33

This is through which the gasses diffuse

Question 34

What is the purpose of type II alveolar cells

Answer 34

they produce, store, and secrete pulmonary surfactant

Question 35

This lines the inner walls of alveolus, reducing surface tension at the air-alveolar interface preventing alveolar collapse upon exhaling

Answer 35

pulmonary surfactant

Question 36

When do type II alveolar cells begin producing surfactant

Answer 36

20-22 weeks, the amount though is insufficient for survival until weeks 26-28

Question 37

What could a baby suffer from is born between 24-26 weeks due to insufficient surfactant

Answer 37

respiratory distress syndrom

Question 38

In this stage of lung development, the alveoli are fully functional

Answer 38

alveolar stage

Question 39

What percentage of mature alveoli develop postnatally continuing until 8 years of age

Answer 39

95% (most within the first three years)