Week 1

Question 1

What portions of the body encompasses the upper respiratory tract?

Answer 1

nose, nasopharynx, and oropharynx

Question 2

How is the lower respiratory system formed in early development?

Answer 2

Laryngotracheal diverticulum start to bud, then the lungs bud and finally the bronchials bud. Afterwards, the tracheoesophageal septum separates the laryngotracheal tube from the esophagus.

Question 3

What layer of the embryo derives the laryngotracheal tube and esophagus?

Answer 3

visceral mesoderm

Question 4

what layer of the embryo do the laryngeal epithelium and glands arise from?

Answer 4

endoderm

Question 5

what layer are laryngeal muscles derived from?

Answer 5

somitomeric mesoderm of pharyngeal arches 4 and 6

Question 6

what layer is the laryngeal connective tissue and cartilage derived from?

Answer 6

mesoderm

Question 7

what layer is the tracheal epithelium and glands derived from?

Answer 7

endoderm

Question 8

what layer is the tracheal cartilage, smooth muscle and connective tissue derived from?

Answer 8

mesoderm

Question 9

what is an tracheoesophageal fistula? clinical features?

Answer 9

a connection between the trachea and the esophagus. excessive accumulation of saliva or muscus in the nose or mouth; episodes of gagging and cyanosis after swallowing milk; abdominal distention after crying; reflux of gastric contents into lungs causing pneumonitis.

Question 10

what is the most common type of tracheoesophageal fistula?

Answer 10

esophageal atresia with a distal ended tracheoesophageal fistula.

Question 11

what is the diagnostic features of tracheoesophageal fistulas?

Answer 11

inability to pass a catheter into the stomach and x-rays demonstrate air in the infant’s stomach.

Question 12

what is tracheal stenosis and atresia

Answer 12

are rare malformations of narrowing or closure of tracheal lumen and is usually associated with TE fistula.

Question 13

what is a tracheal diverticulum?

Answer 13

is a rare malformation in which a blind bronchus-like projection occurs off the trachea

Question 14

what does the visceral mesoderm and somatic mesoderm become in bronchial development in an embryo?

Answer 14

visceral mesoderm: visceral pleura

Somatic mesoderm: parietal pleura

Question 15

what is congenital neonatal emphysema?

Answer 15

overdistention with air of one or more lobes of the lung due a bronchi being collapse because bronchial cartilage development failed. air can be inspired but not expired.

Question 16

what is congenital bronchial cysts (bronchiectasis)?

Answer 16

caused by dilation of bronchi; cysts may be solitary or multiple, filled with air or fluid; honeycomb on x-ray

Question 17

what are the periods of lung development in embryo?

Answer 17

glandular period

canalicular period

terminal sac period

alveolar period

Question 18

Describe what occurs during the glandular period of lung development?

Answer 18

weeks 5-17: branching of endodermal tubules that have the air conducting system, but gas exchange cannot occur yet therefore no respiration can occur. premature fetus dies during this period.

Question 19

what occurs during the canalicular period of lung development in an embryo?

Answer 19

weeks 13-25: respiratory bronchials and terminal sacs develop; premature fetuses born less than 20 weeks rarely survive.

Question 20

what occurs during the terminal sac period?

Answer 20

terminal sac and vascularization increases greatly. differentiation of TYPE 1 Pneumocytes (blood-air barrier cells) and TYPE 2 pneumocytes (produce surfactant) begins.

capillaries make contact with type 1 pneumocytes which allows respiration

premature fetuses born between 25-28 weeks can survive with ICU but need surfactant

Question 21

What occurs during the alveolar period in lung development?

Answer 21

week 29-8 years old: by age 8 adult complement of alveoli is reached, terminal sacs develop into mature alveolar ducts and alveoli; mature blood-air barrier is established.

Question 22

What is respiratory distress syndrome?

Answer 22

it is caused by a deficiency or absence of surfactant

Question 23

What is pulmonary agenesis?

Answer 23

is complete absence of lungs, bronchi, and vasculature due to rare condition where bronchia buds fail to develop.

Question 24

what is pulmonary hypoplasia?

Answer 24

is a poorly developed bronchial tree with abnormal histology,