Cough and expectoration a Coughing is an essential defense mechanism that it prevents the airways from the foreign substance and clear the excretion of respiratory tract Coughing is a reflex. permanent and frequent coughing indicates an abnormality
Cough and expectoration ◼ Coughing is an essential defense mechanism that it prevents the airways from the foreign substance and clear the excretion of respiratory tract. ◼ Coughing is a reflex. permanent and frequent coughing indicates an abnormality
Mechanism a Extrathoracic cough receptors( located in nose oropharynx larynx and upper trachea) intrathoracic cough receptors( located in low trachea and large central bronchi a Afferent( vague, trigeminal, superior laryngeal glosso-pharyngeal nerves ■ Efferent a recurrent laryngeal nerve -- closure of glottis a corticospinal tract and peripheral nerves ---- contraction of thoracic and abdominal musculature
Mechanism ◼ Extrathoracic cough receptors ( located in nose oropharynx larynx and upper trachea) ◼ intrathoracic cough receptors ( located in low trachea and large central bronchi) ◼ Afferent ( vague , trigeminal , superior laryngeal , glosso-pharyngeal nerves ) ◼ Efferent ◼ recurrent laryngeal nerve --- closure of glottis ◼ corticospinal tract and peripheral nerves ------- contraction of thoracic and abdominal musculature
The cough reflex a deep breath---glottic closure---relaxation of diaphragm, contraction of expiratory muscle- positive thoracic pressure--suddenly release of glottis open---thoracic positive pressure airflow out---cough reflex
The cough reflex A deep breath---glottic closure---relaxation of diaphragm, contraction of expiratory muscle--- positive thoracic pressure--suddenly release of glottis open---thoracic positive pressure airflow out--- cough reflex
Etiology ■ Respiratory pleural disease ■ cardioⅴ ascular disease central nerve system factor
Etiology ◼ Respiratory ◼ pleural disease ◼ cardiovascular disease ◼ central nerve system factor
Respiratory disease Stimulator -- extra and intrathoracic ---from nose, oropharynx ---bronchi---cough reflex such as 1. inhalation of foreign material 2. inflammation of respiratory tract 3. bleeding of respiratory tract 4. tumor of respiratory tract
Respiratory disease Stimulator --- extra and intrathoracic --- from nose,oropharynx --- bronchi --- cough reflex. such as: 1.inhalation of foreign material 2.inflammation of respiratory tract 3.bleeding of respiratory tract 4.tumor of respiratory tract