Respiratory Pathology Flashcards

Question

What is Pulmonary Hypertension?

Answer 1

Due to pulmonary vasoconstriction leads to increased pulmonary artery pressure. In time, pulmonary arteries develop intimal proliferation and narrowing. Pulmonary hypertension leads to right ventricular hypertrophy.

Answer 2

Due to stimulation of erythropoietin release from the kidney. This can lead to increased blood viscosity and predispose increased risk of thrombosis. Hypercapnia, when severe, causes tremor of the outstretched hands, a bounding pulse, vasodilation and increased cardiac output & confusion leading to coma.

Answer 3

ATELECTASIS

Answer 4

Several conditions lead to atelectasis which has important respiratory consequences: Obstruction of an airway leads to reabsorption of air from the lung distal to the obstruction. Scarring in the lung may cause contraction of parenchyma and collapse. Loss of normal surfaces leads to generalized failure of lung expansion.

Answer 5

Pulmonary Hypertension Pulmonary Oedema Pulmonary Emboli

Answer 6

COR PULMONALE

Answer 7

Increased pulmonary arterial pressure in pulmonary hypertension causes irreversible structural changes in pulmonary arteries. The leads to increased demand for work on the right side of the heart Which causes right ventricular hypertrophy And eventually right sided heart failure  COR PULMONALE In long standing pulmonary hypertension, structural changes develop in the lung, including medial hypertrophy in muscular arteries and pulmonary veins. There is narrowing or occlusion of the lumina of pulmonary arteries by intimal proliferation. Abundance of alveolar macrophages infiltrate Fibrosis in the interstitium of the lung eventually develops. The clinical effects of pulmonary hypertension are breathlessness and the development of right sided cardiac failure.

Answer 8

Pulmonary Edema is caused by an accumulation of fluid in the alveolar wall (pulmonary interstitium). If severe, this will affect the alveolar spaces. This leads to impaired gas exchange  lead to respiratory failure. The main cause of pulmonary edema is left ventricular failure Which causes increased pressure in the alveolar capillaries Fluid leaks from capillaries into the pulmonary interstitium, and there is an increase in the flow or fluid into the pulmonary lymphatics. This increases the stiffness of the lungs, giving rise to a subjective sensation of dyspnea. This can remain stable for a long time In severe left ventricular failure, fluid also leaks into alveolar spaces, resulting in severe acute impairment of respiratory function. Capillary rupture leads to leakage of RBC into the interstiutium, as well as into the alveoli. Haemoglobin is phagocytosed by macrophages, which accumulate iron pigment, and lie in the alveoli & interstitium

Answer 9

Direct damage to the lung parenchyma trauma, inhilation of toxic gases, ARDs, choking on a foreign body, neoplasms causing lymphatic obstruction within lungs Fluid Overload Renal Failure, Iatrogenic Decreased albumin in the blood Liver disease, nephrotic syndrome, poor nutrition

Answer 10

Head injury Unclear why, thought to be due to a raised intracranial pressure Opiate overdose Can cause severe hypoventilation causes hypoxia then ARDs. Altitude Sickness Leaking capillary alveolar membranes

Answer 11

Very common, preventable cause of death Most emboli arise in the deep leg veins (known as deep vein thrombosis) and pass in the venous circulation through the right side of the heart and lodge in the pulmonary arteries. The outcome of the pulmonary thromboembolism depends on the size of thrombus.

Answer 12

Long period of immobilization of an extremity Long car or plane journeys Right sided congestive heart Failure Hyper- coagulable states Cancer, post severe burns, severe trauma Pregnancy, Oral contraceptives Damaged endothelium Intravenous central lines

Answer 13

Increase in pulmonary arterial pressure Which puts a strain on the right side of the heart Ischaemia of the lung With ventilated areas not being perfused by blood. If 60% of the pulmonary vasculature is suddenly blocked, the heart cannot pump blood through the lungs  causes rapid death (about 5% of PE cases) 10% of all PE cases, blockage of middle sized pulmonary arteries- causing chest pain & breathlessness. Most cases, blockage of small vessels- may be asymptomatic or experience breathlessness & pleuritic chest pain.

Answer 14

Asthma is a very common and the main reversible cause of airflow limitation It is characterized by: Functional obstruction of small airways- by a combination of bronchospasm & mucus plugging Which fluctuates with time Is frequently reversible with bronchodilator drugs A complex inflammatory response involving eosinophils, mast cells and lymphoid cells – whatever the underlying cause. It is an inflammatory conditions that has both acute and chronic components affecting different structural elements in the airways. A variety of triggers stimulate acute exacerbations.

Answer 15

Aitiology Most common under age of 30 Caused by IgE production following exposure to environmental allergens e.g. house dust. T- Lymphocytes mediate some of this process. Intrinsic Asthma Same pathology as atopy, but cold exposure & exertion can trigger. Childhood Asthma Often stimulated by viral infections, improves with age. Occupational Asthma Triggers by work environment – chemical irritant, gases etc Aspirin Induced Asthma

Answer 16

A complex inflammatory response involving eosinophils, mast cells and lymphoid cells – whatever the underlying cause. It is an inflammatory conditions that has both acute and chronic components affecting different structural elements in the airways. A variety of triggers stimulate acute exacerbations.

Answer 17

Bronchoconstriction due to increased responsiveness of bronchial smooth muscle Hypersecretion of mucus leading to plugging of airways Mucosal edema leading to narrowing of airway lumen Extravasation of plasma in submucosal tissues due to leakage from vessels contributes to mucosal edema Infiltration of bronchial mucosa by eosinophils, mast cells, lymphoid cells & macrophages. Focal necrosis of airway epithelium Deposition of airway epithelium Deposition of collagen beneath bronchial epithelium in long standing cases

Answer 18

Type 1 Hypersensitivity response Mast cells are important feature in asthma, and whilst they release histamine, anti – histamines are not clinically useful in treatment. T Tells, in particular Th2 cells are prominent in mucosal cellular infiltrate – they release a variety of cytokines. Cytkoines orchestrate and amplify the inflammatory response. Eosinophils migrate to the mucosa in response, and release many mediators of inflammation. Leukotrienes constrict airways

Answer 19

A disease characterized by airflow limitation that is not fully reversible. Airflow limitation is usually progressive, and is due to one of 2 main reasons: Airway resistance is increased (normally due to narrowing) Outflow pressure is reduced (elastic recoil is lost) Three main pathologies contributing to COPD are: Emphysema, Bronchitis, and Bronchiolitis.

Answer 20

Permanent dilation of any part of the respiratory acinus with destruction of tissue in the absence of scarring. There is a loss of elastic recoil in the lungs As connective tissue in the alveolar walls is destroyed. Reduced oxygen uptake, but will try and maintain blood oxygen with a rapid respiratory rate.

Answer 21

Defined as as “Cough with productive sputum on most days, for 3 months of the year for at least 2 successive years” Due to hypersecretion of mucus associated with hyperplasia of mucous glands. Airway obstruction in chronic bronchitis is related to luminal narrowing and mucus plugging.

Answer 22

The most significant being lifetime smoking exposure Other risk factors include: Recurrent chest infections in childhood Asthma Occupational exposure

Answer 23

occurs when the lungs become severely inflamed from either an infection or injury e.g. pneumonia, flu, sepsis, pancreatitis, near drowning. The inflammation causes fluid to leak from the capillaries, into the alveoli which affects perfusion- making breathing difficult leads to hypoexemia Is an acute restrictive lung disease caused by restrictive lung disease caused by alveolar damage.

Answer 24

Autosomal recessive disorder A multisystem disease Associated with pancreatic exocrine dysfunction Cause by the production of an abnormally viscid mucus that cannot be cleared from the lungs and causes blockage in the main pancreatic ducts 40% of cases present with respiratory disease 30% present as failure to thrive and malabsobtion 10% present with liver disease Abnormally viscid mucus leads to: Obstruction & stagnation of secretions leads to repeated bouts of infection – particularly staphylococcus aureus Bronchiectasis is a frequent complication leading to hemoptyisis Hyperinflation of lungs due to are trapping behind mucin plugs increases risk of pneumothorax Hypoxia, scarring and destruction of the pulmonary vascular bed The median age of survival is just over 30 years.

Answer 25

CF gene In normal mucus secreting epithelia chloride channel open in response to increase concentration of cAMP  CFTR protein chanenel open and enables secretion of chloride, water & sodium In the mutated CF gene, the surface protein is not present and therefore chloride secretion cannot occur… and neither can water & sodium This means mucus is extremely viscid.

Answer 26

Carcinoma of the lungs is the most common cause of death from neoplasia. The incidence of lung cancer is related to the main causative factor of cigarette smoking and industrial carcinogens. Smoking increases risk of developing cancer with precursor lesions of metaplasia and dysplasia occurring in the respiratory tract after exposure to smoke. Exposure to radioactive material, asbestos, nickel, iron oxides and coal gas plants are all known to contribute to the development of lung cancer.

Answer 27

Excessive fibrosis leads to thickening of the alveolar walls and results in reduced gaseous exchange Causes: Idiopathic Occupational inhilation e.g. asbestos, silicon Cigarette smoking Autoimmune – rheumatoid, sarcoidosis Radiation to chest