Respiratory System

Question 0

What does the distal end of the laryngotracheal diverticulum enlarge to become?

Answer 0

respiratory bud

Question 1

What does the laryngotracheal groove elongate ventrally to the developing foregut to become?

Answer 1

laryngotracheal diverticulum

Question 2

When longitudinal tracheoesophageaal folds folds fuse, what do they form?

Answer 2

tracheoesophageal septum

Question 3

what forms ventrally of the tracheoesophageal septum?

Answer 3

laryngotracheal tube

Question 4

What does the laryngotracheal tube give rise to?

Answer 4

larynx, trachea, bronchi, and lungs

Question 5

The communication between the laryngotracheal tube and the pharynx is restricted to what?

Answer 5

primordial laryngeal inlet

Question 6

Where is the larynx epithelium derived from?

Answer 6

endoderm of laryngotracheal tube

Question 7

After rapid proliferation and temporary occlusion of laryngeal lumen, what remains after the lumen recanalizes?

Answer 7

vocal fold and vestibular fold

Question 8

What happens if thee lumen doesnt fully recanalize?

Answer 8

atresia (complete blockage) or stenosis (narrowing) of lumen

Question 9

Where is the epiglottis derived from?

Answer 9

hypopharyngeal eminence (arches 3&4)

Question 10

Where are larynx cartilages and mm derived from?

Answer 10

arches 4&6 (CNX innervation)

Question 11

What gives rise to the epithelium and glands of the trachea?

Answer 11

endoderm of laryngotracheal tube

Question 12

The splanchnic mesoderm gives rise to what in terms of the trachea?

Answer 12

cartilage, CT and mm

Question 13

What is a tracheoesophageal fistula?

Answer 13

abnormal persistent connection between trachea and esophagus

due to defective tracheoesophageal septum

Question 14

From what do primary bronchial buds grow from?

Answer 14

respiratory bud on medial wall toward developing pleural cavity

Question 15

Where do pleuropericardial folds form?

Answer 15

on lateral wall of pleural cavity superior to bronchial buds

Question 16

What fuses medially with the septum transversum?

Answer 16

pleuropericardial folds

Question 17

Pleuropericardial folds contribute to the formation of what?

Answer 17

mediastinum

Question 18

Where do pleuroperitoneal folds form?

Answer 18

form on lateral wall of pleural cavity inferior to bronchial buds

Question 19

What fuses transversely with septum transversum?

Answer 19

pleuroperitoneal folds

Question 20

What does the pleuroperitoneal folds form?

Answer 20

thoracic diaphragm

Question 21

On R side, the secondary buds will supply what?

Answer 21

upper = upper lobes
lower = middle and lower lobes

Question 22

What do segmental bronchi supply?

Answer 22

bronchopulmonary segments

Question 23

Respiratory bronchioles are present when what have formed?

Answer 23

17 orders of dichotomous branches

Question 24

How many dichotomous branches will form after birth?

Answer 24

7

Question 25

Where doe the thoracic diaphragm form initially?

Answer 25

opposite cervical somites 3-5

Question 26

Myoblasts draw innervation from cervical somites 3-5 to cause what kind of innervation to the thoracic diaphragm?

Answer 26

phrenic nerve innervation

Question 27

Where does the thoracic diaphragm move as embryo grows?

Answer 27

caudally

Question 28

What is the pseudoglandular stage of lung maturation

Answer 28

bronchial tree has formed but NO alveoli present!

NO respiration

Question 29

What is the Canalicular stage?

Answer 29

upper parts of the resp system develop prior to lower parts
bronchial tree lumen is enlarging
tissue becoming highly vascular
resp bronchioles with 3-6 alveolar ducts and some alveolar sacs present = respiration possible!

Question 30

What is the terminal sac stage?

Answer 30

many alveolar sacs form
- type I pneumocytes line rudimentary alveoli
- type II pneumocytes produce surfactant
capillaries invade interalveolar septa
respiration possible

Question 31

What is the alveolar stage?

Answer 31

type I pneumocytes thin
interalveolar capillaries bulge into alveolar lumen
lungs well developed
mature alveoli develop after birth

Question 32

Why is fetal breathing important?

Answer 32

• causes aspiration of amniotic fluid in lungs = absorption and turnover of amniotic fluid through placental exchange
• mvmt essential for normal lung development

Question 33

At birth fluid is removed by what three mechanisms?

Answer 33

1) through mouth/nose in response to thoracic pressure
2) absorption into pulmonary vasculature
3) absorption into pulmonary lymph

Question 34

Initial breathing is likely due to what?

Answer 34

• decrease in O2 and Increase in CO2
• cutaneous stim
• cold air stim

Question 35

When is rhythmic breathing established? how many breaths/min?

Answer 35

about 1 minute and 40 breaths/min

Question 36

What is oligohydraminos?

Answer 36

insufficient amount of amniotic fluid

- retarded lung development and compromised fetal breathing mvmts

Question 37

What is respiratory distress?

Answer 37

insufficient surfactant levels => labored breathing

Question 38

What is agenesis of the lung?

Answer 38

failure of development of resp bud

- unilateral = compatible with life
- bilateral = incompatible

Question 39

What is lung hypoplasia?

Answer 39

reduced lung volume and hypertrophic smooth mm in pulmonary aa.

- pulmonary hypertension
- pulmonary blood flow compromised