[05/08 19:12] Satyendra Ojha sir:
Ch.Chi 18/ 7-9
Cough Reflex:
The bronchi and trachea are so sensitive to light touch that very slight amount of foreign matter or other causes of irritation initiate the cough reflex. The larynx and carina (the point where the trachea divides into the bronchi) are especially sensitive, and the terminal bronchioles and even the alveoli are sensitive to corrosive chemical stimuli such as sulfur dioxide gas or chlorine gas. Afferent nerve impulses pass from the respiratory passages mainly through the vagus nerves to the medulla of the brain. There, an automatic sequence of events is triggered by the neuronal circuits of the medulla, causing the following effect.
First, up to 2.5 liters of air are rapidly inspired.
Second, the epiglottis closes, and the vocal cords shut tightly to entrap the air within the lungs.
Third, the abdominal muscles contract forcefully, pushing against the diaphragm while other expiratory muscles, such as the internal intercostals, also contract forcefully. Consequently, the pressure in the lungs rises rapidly to as much as 100 mm Hg or more.
Fourth, the vocal cords and the epiglottis suddenly open widely, so that air under this high pressure in the lungs explodes outward. Indeed, sometimes this air is expelled at velocities ranging from 75 to 100 miles per hour. Importantly, the strong compression of the lungs collapses the bronchi and trachea by causing their non-cartilaginous parts to invaginate inward, so that the exploding air actually passes through bronchial and tracheal slits. The rapidly moving air usually carries with it any foreign matter that is present in the bronchi or trachea.
The above explanation holds true as a physiological as well as a disease process.
The main pathogenesis has 5 steps viz
(i) pratihatō vayu i.e obstruction or avarodh to the normal movement of vayu. It may occur due to the bronchospasm or due to mucus or due to tumour or any foreign body. As said by Chakrapani that kapha (mucus) etc are the cause for the obstruction to the natural movement of the vata.
(ii) urdhwa srota samasrita: this step explains the complete process of the afferent nerves taking the impulse to the cough centre leading to the epiglottis closure and shutting down of the vocal cords to entrap the air within the lungs.
(iii) udānabhāvamāpannaḥ: third and the important step is to gain bala to the urdhwa gati which is brought about by the contracture of abdominal muscle pushing against the diaphragm while other expiratory muscles, such as the internal intercostals, also contract forcefully.
(iv) khāni sarvāṇi pratipūrayan i.e. the pressure in the lungs rises rapidly. Khāni means srotas i.e air gets filled up in the complete pulmonary passage.
(v) vāyōḥ saraṁhasaḥ: Chakrapani comments on saraṁhasa as sa vegasya i.e. with full speed. The vocal cords and the epiglottis suddenly open widely, so that air under this high pressure in the lungs explodes outward. Secondly, the strong compression of the lungs collapses the bronchi and trachea by causing their noncartilaginous parts to invaginate inward, so that the exploding air actually passes through bronchial and tracheal slits.
The specificity of the sound depends on the obstruction caused to the movement of vayu (pratighāta viśēṣēṇa). The pratighātaviśēṣēṇa may be due to consolidation as seen in pneumonia, tuberculosis etc. Obstruction may also be caused due adenocarcinoma or by simple process of bronchospasm. The presentation on auscultation like fine crepts or rhonchii is nothing but the pratighāta viśēṣa which helps in diagnosis of the disease.
[05/08 19:14] Sanjay Lungareg Dr:
Nice interpretation गुरूवर्य।
[05/08 19:20] Satyendra Ojha sir:
प्रतिघात विशेष is very much clinically significant word..
[05/08 19:24] Satyendra Ojha sir:
Phonograms are based on pratighaata..
[05/08 19:24] +91 70102 87704:
Awesome interpretation of the facts, sir.
[05/08 19:27] Satyendra Ojha sir:
Thanks.. it's glory of charak samhita..
***********************************************************************************************************
Prof. Satyendra Narayan Ojha
MD PhD
(Kayachikitsa)
Director
Director
Yashwant Ayu. College & P.G.Training&Research Center
Kodoli, Kolhapur, Maharashtra, India.
Mobile No.- +91 9822177155
email: drsnojha@rediffmail.com
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