02c: Embryology

Question 1

List the stages of lung development.

Answer 1

1. Embryonic
2. Pseudoglandular
3. Cannicular
4. Terminal sac (saccular)
5. Alveolar

Question 2

Describe embryonic stage of lung development.

Answer 2

Respiratory diverticulum forms

Question 3

Describe pseudoglandular stage of lung development.

Answer 3

Branching to form terminal bronchioles

Question 4

Describe canalicular stage of lung development.

Answer 4

Respiratory bronchioles form

Question 5

Describe saccular (terminal sac) stage of lung development.

Answer 5

Capillary-epithelium interface matures

Question 6

Describe alveolar stage of lung development.

Answer 6

Increase in respiratory bronchioles and alveoli

Question 7

There’s an intense in-growth of blood vessels in (X) stage of respiratory system development.

Answer 7

X = Cannicular

Question 8

In (X) stage of respiratory system development, histological structure of the lung resembles a gland.

Answer 8

X = Pseudoglandular

Question 9

(Ventral/dorsal) (X) forms respiratory diverticulum.

Answer 9

X = ventral foregut endoderm

Question 10

Respiratory system development of vascular network from (X) tissue.

Answer 10

X = splanchnic mesoderm

Question 11

Tracheoesophageal septum develops and divides:

Answer 11

Trachea and lung buds from esophagus

Question 12

Respiratory system of fetus stops developing at week 7. (X) stage has halted. Does this fetus have terminal or respiratory bronchioles?

Answer 12

X = pseudoglandular;

No, has neither

Question 13

Primordial capillary airspace interface develops in (X) stage of respiratory system development.

Answer 13

X = Cannicular

Question 14

Toward end of (X) resp development stage, each (Y) bronchiole has given rise to at least two respiratory bronchioles.

Answer 14

X = Cannicular
Y = terminal bronchiole

Question 15

T/F: Fetuses born during pseudoglandular period of lung development are unable to survive.

Answer 15

True

Question 16

T/F: Fetuses born during cannicular period of lung development are unable to survive.

Answer 16

False - can survive with intensive care

Question 17

(X) resp development stage: formation of secondary crests, which are (Y) that subdivide into (Z).

Answer 17

X = saccular
Y =  ridges of epithelial lined mesenchyme 
Z = saccules (small sacs/pouches)

Question 18

In later stages of resp development, specifically (X) stage, interstitial tissue (thickens/thins).

Answer 18

X = saccular;

Thins

Question 19

(X) resp development stage: increase in elastic network around airways and between airspaces.

Answer 19

X = saccular

Question 20

T/F: Interstitial mesenchyme continues to thin postnatally.

Answer 20

True

Question 21

Growth of the lung continues for (X) after birth is, primarily consisting of increase in (Y).

Answer 21

X = 8-10 years
Y = number of respiratory bronchioles and alveoli

Question 22

Lung maturation is associated with which 4 things?

Answer 22

1. Saccule develop to alveoli
2. Surfactant production
3. Alveolar wall thins
4. Capillary bed expansion

Question 23

Measurable amount of surfactant during (X) weeks of resp development.

Answer 23

X = 24-28

Question 24

T/F: In Neonatal Respiratory Distress Syndrome, infant almost always preterm.

Answer 24

True

Question 25

Neonatal Respiratory Distress Syndrome: (X) results in a cascade of events that causes (Y) membranes to develop and line alveoli.

Answer 25

X = increase in work of breathing
Y = hyaline

Question 26

(X) is the most common congenital lesion of the lung. What’s the result?

Answer 26

X = pulmonary hypoplasia

Decrease in size and weight of lung

Question 27

T/F: Few cases of pulmonary hypoplasia are secondary to conditions that limit fetal lung growth. Most cases are primarily PH.

Answer 27

False - most are secondary

Question 28

Three major factors may lead to pulmonary hypoplasia. List them.

Answer 28

1. Congenital diaphragmatic hernia
2. Oligohydramnios
3. Decreased respiration during fetal period

Question 29

(X) is the most common malformation of the diaphragm, most frequently caused by failure of (Y) membranes to (Z).

Answer 29

X = Congenital diaphragmatic hernia
Y = pleuroperitoneal 
Z = close pericardioperitoneal canals

Question 30

In Congenital diaphragmatic hernia, the (X) cavities are continuous along (anterior/posterior) wall.

Answer 30

X = peritoneal and pleural

Posterior

Question 31

Oligohydramnios is usually to do (X) anomalies. Amniotic fluid is (reduced/in excess).

Answer 31

X = urinary

Reduced (swallowed, but not excreted)