Embryology of respiratory system

Question 1

When does primordium of resp system appear?

Answer 1

4 weeks from ventral wall of foregut

Question 2

Where does epithelium of internal lining of larynx and trachea derive from?

Answer 2

Endoderm

Question 3

Where are the muscular and cartilaginous components of trachea and lungs derived from?

Answer 3

splanchnic mesoderm

Question 4

laryngeal orifice

Answer 4

Allows open communication between respiratory primordium and pharynx

Question 5

Esophagotracheal septum

Answer 5

divides foregut into dorsal portion for esophagus and ventral portion for trachea and lung buds

Question 6

Esophagotracheal ridges

Answer 6

Sep diverticulum from foregut

Question 7

What results in laryngeal orifice changing shape?

Answer 7

Rapid proliferation of mesenchyme

Question 8

Laryngeal ventricles form when

Answer 8

vacuolization and recanalization occur

Question 9

False and true vocal folds

Answer 9

Formed by folds of tissue that bind laryngeal ventricles

Question 10

Superior laryngeal nerve

Answer 10

innervates 4th branchial arch

Question 11

Recurrent laryngeal nerve

Answer 11

innervates 6th branchial arch

Question 12

Lung buds penetrate into this cavity

Answer 12

Pericardioperitoneal canal

Question 13

Pleuropericardial folds

Answer 13

Sep canals from peritoneal and pericardial cavities

Question 14

Mesoderm develops into

Answer 14

Visceral pleura

Question 15

Somatic mesoderm develops into

Answer 15

Parietal pleura

Question 16

Alveolar epithelial cells (type 1)

Answer 16

become gradually thinner so that surrounding capillaries protrude into alveolar sacs forming blood air barrier

Question 17

Alveolar epithelial cells (type 2)

Answer 17

surfuctant producers which lower surface tension at air-alveolar interface

Question 18

When does the amount of surfactant increase significantly?

Answer 18

Last 2 weeks before birth

Question 19

Respiratory distress syndrome

Answer 19

Insufficient surfactant, air blood tension becomes too high, alveoli collapse

Question 20

Hyaline membrane diseases

Answer 20

Partially collapsed alveoli contain fluid with high protein content, many hyaline membranes

Question 21

Stillborn infant

Answer 21

Lung fluid is not resorbed

Question 22

Ectopic lung lobes

Answer 22

arise from trachea or oesophagus-additional resp buds of foregut which dev independently

Question 23

Congenital cysts of lung

Answer 23

dilation of terminal or larger bronchi

Question 24

Supernumerary lobules

Answer 24

Abnormal divisions of bronchial tree