Respiratory Development

Question 1

endodermal part of lung

Answer 1

endoderm of respiratory diverticulum gives rise to the mucosal lining of bronchi and epithelial cells of alveoli (so, the wet stuff)

Question 2

mesodermal part of the lung

Answer 2

picked up as the lungs travel through mediastinum into pleural space…. everything else… mesoderm-muscle, cartilage supporting bronchi, visceral pluera covering lung)

Question 3

failure of tracheoesohageal folds to fuse

Answer 3

tracheosophageal septum isnt formed, tracheoesopogeal fistula (TEF), communication between foregut and esophagus. VACTERL assocation

Question 4

VACTERL

Answer 4

vertebral anomalies, anal atresia, cardiac defects, tef, ea, renal anomalies, limb anomalies

Question 5

dorsal and ventral portions of the foregut

Answer 5

ventral=trachea and lung buds, dorsal= esophagus

Question 6

respiratory primordium maintains communication with pharynx through

Answer 6

laryngeal orifice

Question 7

type c tef

Answer 7

polyhydroaminos, blind esophagus, respiratory distress, choking, secretions, tube doesn’t make it to the stomach, air in stomach. septum doesn’t form. foregut and trachea not completely separated. radiographic, endoscopic. air to stomach. sonogram

Question 8

type h tef

Answer 8

least symptomatic, no esophageal atresia, ng tube makes it to the stomach, chronic lung infections. aspiration pnuemonia

Question 9

precursor to the epithelial lining of larynx and the cartliages

Answer 9

epithelial–endoderm of respiratory diverticulum

cartliages–4th and 6th pharyngeal arches

Question 10

development of the canal in larynx

Answer 10

mesenchyme proliferates to make arytenoid swellings which make lumen into slit. laryngeal epithelial cells (endoderm) proliferate rapidly to close slit. recanalization occurs at week 10.

Question 11

what occurs during the recanalization process of the larynx

Answer 11

production of the laryngeal ventricles, and their folds create vocal folds and vestibular folds.

Question 12

clincal correlation of failure of recanalization of larynx

Answer 12

laryngeal atresia. CHAOS. distal to atresia or stenosis, airways are dilated, lungs enlarges and filled with fluid, diaphram is flattened or inverted, and fetal ascites/hydrops…edema.
incomplete atresia, incomplete recanalizaton. membranous web forms at vocal cords, partially blocking air.

Question 13

epiglottis formed by

Answer 13

hypopharyngeal eminence, proliferation of mesenchyme

Question 14

innervation of larynx

Answer 14

vagus, recurrent laryngeal branch. (myoblasts from 4th and 6th arches)

Question 15

endodermal lining of laryngotracheal tube

Answer 15

epithelium and glands of the trachea and pulmonary epithelium

Question 16

splanchnic mesenchyme surrrounding laryngotracheal tube

Answer 16

mesoderm. cartilage, connective tissue, and muscles

Question 17

what is the difference between the right and left main stem bronchus

Answer 17

embryonic right main bronchus is larger, more vertical

Question 18

development of bronchial tree

Answer 18

trachea–>r/l bronchial buds (two lungs and r/l primary bronchi)–>3 r secondary branches, 2 l secondary branches (lobes)–>10 tertiary bronchi, both sides (bronchiopulmonary segments of mature lung)–>terminal bronchioles–>respiratory bronchioles (highly vascularlized mesodermal tissue)–>craniocaudal branching of “stubby branches–>terminal sacs (primitive alveoli) surround terminal stubby branches–>mature alveoli

Question 19

differentiation of primitive alveoli to mature alveoli

Answer 19

continued thinning of sqaumous epithelial lining of the terminal sacs

Question 20

5 stages of lung development

Answer 20

EPCSA

Embryonic, psuedoglandular, canalicular, saccular (terminal sac), alveolar

Question 21

embyronic stage

Answer 21

respiratory diverticulum
three rounds of branching (two lungs, lobes, and bronchiopulmonary segments
trachea and larynx
26-6 weeks

Question 22

psuedoglandular

Answer 22

terminal bronchioles (14 branches)
at 16 weeks, all major elements of lung except gas exchange
think:pseudo is false... you think you can breath because you have all the structures, but you cant

Question 23

canalicular

Answer 23

terminal bronchiole to respiratory bronchioles (now respiration is possible)
respiratory vasculature (canal of blood)
epithelium differentiates
at end, respiration possible, terminal sacs have developed (primordial alveoli)
blood-air barrier
26 weeks

Question 24

limit of viability of premature infants

Answer 24

22-23 weeks. respiration only possible after blood air barrier. end of this period (canalicular) could survie, but ICU

Question 25

saccular

Answer 25

terminal sacs are formed completely division of respiratory bronchioles to produce terminal sacs capillaries bulge (alveoli) establishment of blood-air barrier type II pnuemoncytes secrete pulmonary surfacant (phospholipids and proteins) saccules-primordial alveoli

Question 26

purpose of surfactant during saccular stage

Answer 26

counteracts the surface tension at air-alveolar interface, facilitating the expansion of saccules, and preventing atelectasis

Question 27

alveolar

Answer 27

maturation of gas exchange structures and alveoli

Question 28

respiratory distress syndrome

Answer 28

inadequate production of surfactant AKA hyaline membrane disease, glassy or hyaline membrane provide steroids if afraid premature only premature babies. ground glass, peripherally extending air bronchograms.

Question 29

total surface area for gas exchanged depends on

Answer 29

number of alveoli and density of alveolar capillaries, need thin walls.

Question 30

which type of alveolar cells secrete surfactant

Answer 30

type II

Question 31

pulmonary surfactant composition

Answer 31

90% phospholipid 10% protein AD--hydrophilic, host defence BC--hydrophobic, surface-active properties of surfactant

Question 32

hereditary surfactant protein b deficiency

Answer 32

respiratory failure. autosomal recessive. complete absence or mutation of the genes. respiratory distress syndrom.

Question 33

pulmonary hypoplasia causes

Answer 33

oligiohydrominos (insufficient amniotic fluid) (bilateral renal agenesis) CDH

Question 34

bilateral renal agensis results in

Answer 34

potter's sequence. and oligiohydrominos. deformed limbs, wrinkly, dry dink. abnormal facial appearnce.

Question 35

CDH

Answer 35

failure of pleuroperitoneal canal to close during 6th week of development. eft side 4-8 times more, left pericardioperitoneal canal larger, closes later. posterolateral bochdalek hernia. lung hypoplasia. failure of diaphragm to completely form. push lungs and heart anteriorly. prolonged is lung underdevelopment. medial do not really result in lung hypoplasia

Question 36

presentation of newborn with CDH

Answer 36

respiratory distress, cyanosis, decreased bronchial breath, scaphoid abdomen. smaller lung on hernia side bowel gas in ches and shift of mediastinal structures

Question 37

proximal diverticulum

Answer 37

larynx and trachea