Development of Respiratory System

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Development of Respiratory System

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• ??.?????? ?????????

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Development of RS

• Respiratory tract
• Upper respiratory tract
• Lower respiratory tract
• Upper respiratory tract
• - nose
• - nasal cavities
• - pharynx
• Lower respiratory tract
• - larynx
• - trachea
• - bronchi lung

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Development of nose and nasal cavities
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• ??????????????
• Week 4 nasal placode nasal pit
• Medial nasal prominence
• Lateral nasal prominence - alae
• Intermaxillary segment (merged medial nasal
  prominence)
• ???????????????
• ?????????????????????
• ??????????? maxilla
• Primary palate

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• ?????????????
• oronasal membrane
• primary palate
• secondary palate (lateral palatine process ????
  palatine shelves)
• nasal septum
• palate

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Development of conchae

• maxilloturbinal inferior concha
• ethmoturbinal middle concha superior
  concha
• nasoturbinal agger nasi
• Development of nasal epithelium
• - simple cuboidal epithelium
• - pseudostratified ciliated columnar epithelium

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Development of paranasal sinus

• Nasal epithelium diverticulate into maxilla,
  ethmoid, frontal and sphenoid.
• ??????????? 4-5 ????? ?????? sphenoidal sinus
• ?????????????? puberty

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Development of palate

• primary palate
• intermaxillary segment
• secondary palate
• maxillary prominence
• Nasal septum
• intermaxillary segment
• mesenchyme abnormality
• cleft palate

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Development of lower respiratory tract

• Week 4 ?? respiratory primordium (diverticulum)
• at floor of pharynx (caudal part)
• Larynx trachea bronchi lungs

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Development of larynx laryngotracheal groove
respiratory primordium esophagotracheal
septum esophagus (dorsal) trachea and lung
buds (ventral) laryngeal orifice ?? T-shape
- epiglottal swelling - arytenoid
swellings endoderm epithelial lining and
gland mesenchyme (BA.4,6) CNT, cartilage
(-epiglottis), smooth m. recanalization
laryngeal ventricle
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Laryngeal muscles BA.4 Laryngeal cartilage
BA.4
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Development of trachea, bronchi lungs

• respiratory diverticulum esophagotracheal
  septum
• trachea (at T4 vertebra) lung buds
• primary bronchus secondary bronchi tertiary
  bronchi

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• pericardioperitoneal canal (pleuroperitoneal
  folds pleuropericardial folds)
• pleural cavities
• pericardial cavity
• peritoneal cavity
• visceral mesoderm
• visceral pleura,
• CNT, smooth m.
• somatic mesoderm
• parietal pleura
• pleural cavity

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• ???????????? 6 bronchi - dichotomous - 17
  generations
• ??????????? 23-24 generations

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Maturation of lungs

• ???????? 7 cuboidal cells squamous cells
• ???????????? 6 alveolar epithelial cells
• (type II pneumocytes) ????? surfactant
• Life premature ??????
• primitive alveoli
• surfactant
• 2 ?????????????
• terminal sac
• ????????????????????
• ??? primitive alveoli ??? capillary

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• Surfactant ?????????? 2 ?????????????
• ??????? ?????????????????????????????????????
  capillary lymph capillary ?????????????????????
  ????
• ?????????? surfactant

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Development of lungs

• 1. Pseudoglandular period (5-17 weeks) 2.
  Canalicular period (15-25 weeks)
• 3. Terminal sac (24 weeks to birth) 4.
  Alveolar period (29 weeks 8 years)
• Pseudoglandular period (5-17 weeks)
• compound exocrine gland visceral mesoderm
  ?????????
• Canalicular period (15-25 weeks)
• ?? respiratory bronchiole primitive alveoli
• visceral mesoderm ???????? capillary ???

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• Terminal sac (24 weeks to birth)
• ?? terminal sac (primitive alveoli) ??? capillary
  ???
• ?? type I type II pneumocytes ??? premature
  baby (25-28 weeks) ??????
• Factors for life sufficient blood supply
  surfactant
• Alveolar period (29 weeks 8 years)
• 8 ?? ?? 300 ???? alveoli
• Terminal sac alveolar duct sacs
• X-ray - ????????????????????????????

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Clinical considerations

• 1. ????????????????????????????? ???
• lungs in premature infant
• lungs in stillborn infant
• lungs in normal infant
• 2. Lung abnormalities
• ectopic lung lobe
• congenital cyst of lung
• ankyloglossia
• cleft palate

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Clinical considerations