The last lecture on respiratory system Ramray Bhat Ramray ... · Reason for coexistence This is...
Transcript of The last lecture on respiratory system Ramray Bhat Ramray ... · Reason for coexistence This is...
On the matter of the Clara cells
Bronchiolar exocrine cells
Immune, protective and progenitory properties
Also called Club cells and why?
Part of uterus, kidney prostate
Emphysema
Environmental/genetic (α1 antitrypsin deficiency
Dead air
Poor exchange
Emphysema
Chronic obstructive pulmonary disease
A combination of chronic bronchitis and emphysema
Definition of emphysema: morphological
Definition of chronic bronchitis: clinical features such as chronic
and recurrent cough and excessive mucus secretion
Both diseases have slightly different locales: emphysema occurs
more in acinus and chronic bronchitis in the bronchi
Reason for coexistence
This is because the major cause, cigarette smoking, especially long-
term, heavy tobacco exposure is common to both disorders.
In view of their propensity to coexist, emphysema and chronic
bronchitis often are clinically grouped together under the rubric of
chronic obstructive pulmonary disease (COPD).
The primarily irreversible airflow obstruction of COPD distinguishes it
from asthma, which, as described later, is characterized largely by
reversible airflow obstruction.
normal alveoli emphysemaCOPD - emphysema
Barrel chest, dyspnea, pink puffer, a problem of expiration
Defined by the occurrence of a persistent productive cough for at least 3
consecutive months in at least 2 consecutive years. In early stages of the
disease, the productive cough raises mucoid sputum.
COPD – chronic bronchitis
bronchus chronic bronchitis
Hypoxia, blue bloater
Obstructive and non
obstructive causes
Asthma is a chronic inflammatory disorder of the airways with recurrent episodes of wheezing, breathlessness, chest tightness, and cough, particularly at night and/or early in the morning.
The hallmarks of the disease are1. intermittent and reversible airway obstruction, 2. chronic bronchial inflammation with eosinophils,3. bronchial smooth muscle cell hypertrophy and hyperreactivity, and 4. increased mucus secretion.
Atopic (allergic rhinitis and eczema) or non atopic
Bronchial asthma
An attack of asthma is characterized by severe dyspnea with wheezing; The victim labors to get air into the lungs and then cannot get it out, so that there is progressive hyperinflation of the lungs with air trapped distal to the bronchi, which are constricted and filled with mucus and debris.
Histopathologic changes in bronchial asthma
Bronchial asthma
Gross pathology: overdistended and overinflated lungssmall areas of atelectasis. occlusion of bronchi and bronchiolesby thick, tenacious mucous plugs.
Bronchial asthma contd
Lung cancer
Introduction to cancer
Terminologies (cancer, neoplasm, tumor, benign malignant)
(parenchyma, stroma)
(benign: fibroma, chondroma, adenoma, cystadenoma)
Malignant: (sarcoma, carcinoma, adenocarcinoma, mixed tumor)
Lungs are the frequent sites of metastases from extrathoracic cancers,
Primary lung cancer is common 95% of primary lung tumors are carcinomas 5% includes carcinoids, mesenchymal malignancies, lymphomas,and a few benign lesions.
The most common benign tumor is a spherical, small (3 to 4 cm), discrete “hamartoma”: coin lesion on chest radiographs. It consists mainly of mature cartilage, admixed with fat, fibrous tissue, and blood vessels
Lung cancers
Types of carcinoma:Adenocarcinoma (NSCLC)Squamous cell carcinoma (NSCLC) (smoking)Small cell carcinoma (smoking)Large cell carcinoma (NSCLC)
Squamous cell carcinoma of bronchi
Keratinized pearls
Atelectasis
normal
SqCC
Small cell lung carcinoma
Small deeply basophilic cells uniformly present within parenchymaRoundish cells, big nuclei, scant cytoplasm, mitotic foci
Necrotic foci
More aggressive, detected after the spread unlike NSCLC
Hoarseness, congestion, chronic cough common primary symptoms