Respirastory system D L Kiss Anna Semmelweis University

Respirastory system D. L. Kiss Anna Semmelweis University Department of Anatomy, Histology and Embryology 2018.

• Extrapulmonar: – Nasal cavity - nasopharynx – Larynx – Trachea • Intrapulmonar: – Bronchi: principal lobar segmental – Bronchioles: terminals respiratory • Repiratory part: alveoli

Nasal cavity Olfactory area: receptors Regio respiratorica: pseudostratified ciliated epithelium (goblet cells) Vestibulum: skin

Regio respirtorica: vestibulum Propria: seros+mucus glands

Olfactory region cilia bulb-like ending supporting cell Receptors: primary sensory cells: bipolar cells • contain OBP (odorant binding protein) receptors on their plasma membrane receptor • axon-like processes - fila olfactoria – bulbus olfactorius • the number of them: 2 x 107 basal cells Schwann cells axon basement membrane • life time: 30 -60 days • more than 100 receptor molecules

nasopharynx tongue oropharynx soft palate laryngopharynx epiglottis

Nasopharynx

Waldeyer’s lymphatic ring Pharynx: pars nasalis: • tonsilla pharyngea+tonsillae tubariae (pseudostratified ciliated epithelium) p. oralis: • tonsilla palatina (stratified nonkeratinized epithelium) • tonsillae linguales (stratified nonkeratinized epithelium)

Larynx: epiglottis

Larynx epiglottis vestibular fold aryepiglottic fold vestibulum ventriculus vocal fold (vocal cord) infraglottic cavity

Histology of the larynx

Histology of the larynx

• lamina propria: fibers: fibroelastic membrane

Trachea anterior view Right posterior view left right Principal bronchi left

Trachea

Bronchus tree Principal bronchus lobal bronchus segmental bronchus bronchiolus terminal bronchiolus respiratoricus alveoli sacculus: ductus alveolaris

Histological changes in the respiratory system • cartilage disappears: gradually • glands are disappearing • smooth muscle becomes continuous (broncioles) and then disappears • epithelium becomes thin

Lung

Lung

Branches of the terminal bronchi, sacculi and alveoli Lobes : segments Segments: borders: veins artery + bronchioles (centrally)

Clara cells

Clara cells

Alveoli and alveolar septi macrophage alveolar entrance elastic fibers type I cells type II cells capillary macrophage in the septum

Alveoli: pneumocytes

Type I. and II. pneumocytes, alveolar makrophages

Pneumocytes: simple squamous epithelial cells Type I cells: flat, squamous cells: gass exchange Type II cells: surfactant secretion: decreases the surface tension

Surfactant Decreases the alveolar surface tension, actively participate in the clearance of foreign materials Low surface tension: increases the flexibility of the lung makes the alveoli stabil e Absence of the surfactant: alveoli collapse

Respiratory distress syndrome (RDS) – functional surfactant disorder • Fetal or neonatal RDS (IRDS): more frequent in premature infant 1. ) unmatured biosynthetic pathways 2. ) inactivation of the surfactant (intraalveolar coagulation) 3. ) increased use of surfactant caused by chronic respiratory mechanism 4. ) injury of the biosynthetic pathway (acidosis, decreased pulmonary blood flow) • Adult RDS (ARDS): acut respiratory insufficiency activation of neutrophyl granulocytes and alveolar macrophages release of permeability increasing substances (shock, trauma: . burning, infections, inhalation of toxic gases, overdosage of drogss etc)

Development of the lung 4 weeks embryo: respiratory diverticulum: outgrowth of the ventral wall of the foregut; • in the mesoderm retinoid acid production • • is increasing in the endoderm TBX 4 transcription factor production TBX 4: induces appearance, increase and differentiation of the lung primordia • epithelium: endoderm • connective tissue, cartilage and muscle: mesoderm

Development of the lung 1. ) respiratory diverticulum communicates with the foregut 2. ) Tracheoesophageal ridge: dorsal: esophagus ventral: trachea 3. ) 2 bronchus buds at the 5 th week: - right and left principal bronchi - then: right: 3 lobar brobnchi, left: 2 lobar bronchi - dichotomic division: segmental bronchi

Development of the lung

Development of the lung

The effect ot the fetal surfactant

Bibliography • Snell RS, Clinical Anatomy, Little, Brown & Co, • • • Boston, 1995 Moore KL, Dalley AF: Clinically Oriented Anatomy, Lippincott, 1999 Sobotta: Atlas of Human Anatomy Röhlich: Szövettan