E3 Respiratory System Dev

Question 1

At approximately week 4, the _____ (lung bud) appears as outgrowth of foregut

Answer 1

Respiratory diverticulum

Question 2

The inner lining of larynx, trachea, bronchi, and lungs have a ____ origin

Answer 2

Endoderm

Question 3

The cartilaginous, muscular, and connective tissue components of the trachea and lungs are from ____ mesoderm

Answer 3

Splanchnic

Question 4

As the lung bud grows caudally, _____ begin to separate the lung bud from the foregut. They will fuse to form the _____.
The dorsal portion becomes the ____.
The ventral portion becomes the ___.

Answer 4

Tracheoesophageal ridges

Tracheoesophageal septum

Esophagus

Trachea and lung buds

Question 5

Abnormalities in partitioning of esophagus and trachea by tracheoesophageal septum result in ____ with or without tracheoesophageal fistulas (TEFs)

Answer 5

Esophageal atresia

Question 6

The respiratory diverticulum maintains communication with the pharynx thru the _____. Laryngeal cartilages and musculature arise from pharyngeal arch pair(s) ____.

Answer 6

Laryngeal orifice

4 and 6

Question 7

Mesenchyme of the 4th and 6th arch transform into:

Epiglottis forms from mesenchyme of the ____

Answer 7

Thyroid Cartilage
Cricoid Cartilage
Arytenoid Cartilage

Caudal Hypopharyngeal eminence

Question 8

Laryngeal mm arising from 4th arch are innervated by ____

Laryngeal mm arising from 6th arch are innervated by ____

Answer 8

Superior Laryngeal n

Recurrent laryngeal n

Question 9

Lung bud divides to form 2 primary bronchial buds.

1. The right forms ____
2. The left forms ____

Answer 9

1. 3 secondary bronchial buds, 10 tertiary bronchial buds

2. 2 secondary bronchial buds, 8 tertiary bronchial buds

Question 10

____ gives rise to the visceral pleura of the lungs.

____ lining the thoracic body wall gives rise to the parietal pleura.

Answer 10

Splanchnic mesoderm

Somatic mesoderm

Question 11

Respiratory tree produces small branches called ___. These will then divide into ___. At the end of these will be the formation of ____.

Answer 11

Terminal bronchioles

Respiratory Bronchioles

Terminal Sacs (primitive alveoli)

Question 12

Describe the 4 stages of lung maturation (fetal-childhood):

Answer 12

1. Pseudoglandular Period- branching -> terminal bronchioles
2. Canalicular Period- terminal bronchioles -> respiratory bronchioles -> alveolar ducts
3. Terminal Sac Period- terminal sacs form, capillaries establish close contact
4. Alveolar Period- mature alveoli have well-developed epithelial endothelial contacts

Question 13

At 26 weeks, lining the terminal sac walls is a single layer of simple squamous cells, most of which are ____ cells through which gases diffuse. Scattered among these are a few ____ cells that produce, store, and secrete pulmonary surfactant.

Answer 13

Type 1 alveolar

Type 2 alveolar

Question 14

___ counteracts surface tension and prevents alveolar collapse.

Answer 14

Surfactant