RESPIRATORY SYSTEM

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dr. Sunanto Roewijoko, M.S, Sp.A

dr. Fifinela Raissa, M.Kes

DEPT OF HISTOLOGY

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THE RESPIRATORY SYSTEM

LUNGS SYSTEM OF TUBE

VENTILATION MECHANISMPhysiology

- Thoracic cage

- Intercostal muscle

- Diaphragm

- Elastic & collagen (of the lungs)

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NASOFARING

PLICA VOCALIS

CONUS ELASTICUS

Tonsil

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PRINCIPLE REGIONS

CONDUCTING PORTION

RESPIRATORY PORTION

CONDUCTING PORTION Nasal cavity Nasopharynx Larynx Trachea Bronchi Bronchioles Terminal bronchioles

RESPIRATORY PORTION Gas exchange:

- Resp. bronchioles

- Alveoli ducts

- Alveoli

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MAIN FUNCTIONS OF THE CONDUCTING PORTION

Conveys air to and from the respiratory portion of the respiratory system

To condition the inspired air Cleansed/filteredMoistened and warmed

by:Respiratory epitheliumMucous and serous glandsA rich vascular network

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RESPIRATORY EPITHELIUMCiliated pseudostratified Columnar epitheliumwith goblet cells

5 Cells (with EM): Ciliated columnar cells Mucous goblet cells Columnar brush cells Basal cells Small granule cells

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NASAL CAVITY

VESTIBULE NASAL FOSSAE

• Nares (nostril)• Vibrissae• Sebaceous &

sweat glands

• Nasal septum• Conchae:

- sup, mid, inf.• Venous

plexuses (of Kiesselbach)

OLFACTORY EPHITELIUM ORGANIZATION

Modified pseudostratified columnar epitheliumBipolar neurons cellsSustentacular cells: supportBasal cells

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MUCOUSSECRETION

OLFACTORY EPHITELIUM ORGANIZATION

Mechanism of smell Odor discernment Poorly understood

Odor molecules stimulate receptors

Transduction process

Toward the central nervous system

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PARANASAL SINUSES

Frontal, Maxillary, Ethmoid, Sphenoid Thinner respiratory epithelium Few goblet cells Few small glands Thinner lamina propria fused with periosteum

Sinusitis :

Inflammatory process of the sinus

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Acute

Chronic

PHARYNX

Connects nasal cavity with larynx Nasopharynx

Respiratory type epithelium

OropharynxSquamous type epithelium

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LARYNX

Laryngeal cartilages

Hyaline cartilages:- Thyroid- Cricoid- Inferior arytenoid Elastic cartilages:- Epiglottis- Cuneiform and corniculate

- Superior arytenoid

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EPIGLOTTIS

Lingual surfaceStratified squamous epithelium

Laryngeal surfaceRespiratory epitheliumMixed mucous and serous glands

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LARYNX

Consists of 2 pairs of mucous folds

The upper pair:False vocal cords: (vestibular folds)Respiratory epitheliumLamina propria: Seromucous glands

The lower pair:True vocal cords: (vocal fold)Vocal ligament (elastic fiber)Stratified squamous epitheliumVocalis muscle (+)

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TRACHEA

Respiratory epithelium C-shape rings of hyaline cartilage

(pars. cartilaginea) Pars membranacea:

Fibroelastic ligamentSmooth muscleMixed mucous-serous glands

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Bronchial tree

Bronchi extra pulmonal (primary bronchi) Bronchi intra pulmonal (secondary bronchi) Bronchioli (terminal bronchioles)

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Bronchi

Folded appearance of the bronchial mucous (observed in histologic section)

Respiratory epithelium Mucous and serous gland Spirally arranged smooth muscle Rings / isolated plate of hyaline cartilage Extrapulmonary: Identical with trachea, smaller

diameter, thinner wall Intrapulmonary: Isolated plates of hyaline

cartilage

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Primary Bronchus

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Bronchiole

Diameter of 5 mm/less Ciliated pseudostratified columnar ciliated

simply columnar / cuboidal epithelium Smooth muscle + elastic fiber in the lamina propria Have neither cartilage nor glands in their mucous

layer Goblet cell: occasionally(large bronchiole)/ none

(terminal bronchiole)

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Bronchiale Asthma

The musculatur (both the bronchi and the bronchioles) is under the control of the vagus nerve and the sympathetic N.S.

Stimulation of The vagus contraction The parasympathetic relaxation

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Asthma Attacks

Dispnoe (increased airway resistance) Wheezing sounds

Decreases the diameter of the lumenHypersecretion of the mucous / serous glands +

goblet cells

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Respiratory Bronchioles

Respiratory portion Their walls numerous saccular alveoli Ciliated cuboidal epithelium Smooth muscle + elastic C.T.

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Alveolar Ducts

Squamous alveolar cells Smooth muscle cells”knob” Matrix of elastic and collagen

Atria

Alveolar sac.

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ALVEOLI

Terminal portions of the bronchial tree Inter alveolar septum:

CapillariesFibroblastElastic and collagen fibersMacrophages

Blood-Air barrierCytoplasm alveolar type I cellFused basal laminaeCytoplasm endothelium(continuous)

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TYPEs OF ALVEOLAR CELL

Type I cells (squamous alveolar/

Pneumocyte type I)Type II cells

(Septal cells/

Pneumocyte type II)

• Thin/squamous • Permeable to gases

• Cuboidal• Vesicular cytoplasm• Secretory cells

Pulmonary surfactant (to lower alveolar surface tension)

ALVEOLAR PORES

10-15 m in diameter Connecting neighboring alveoli Equalize pressure in the alveoli Enable the collateral circulation

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PLEURA

Serous membrane covering the lung Parietal and visceral layer Mesothelial cells Connective tissue (collagen + elastic) Pleural cavity + lubricantPathology: Pleuricy Pneumothorax Pleural effusion / haemothorax

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DEFENSE MECHANISM

Vibrissae (screening) Mucous-coated ciliated epith. (trapped) Cough reflex (expectoration) Alveolar macrophages Lymphoid tissues

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REFERENCES Gartner LP, Hiatt JL. Color textbook of

histology. 3rd ed. Saunders Elsevier. 2007 Bloom, Fawcett. Concise histology.

Pictures were taken from: http://www.meddean.luc.edu/lumen/mede

d/histo/frames/h_fram15.html http://www.ouhsc.edu/histology http://www.technion.ac.il http://histology.leeds.ac.uk

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THAT’S ALL FOLKS…

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