W11- Lecture 56- Respiration physiology, Pathophysiology and Lung volumes

Question 1

describe how filtration of airways helps with immune function

any use for drug delivery ?
e.g

Answer 1

Turbulence in the upper respiratory tract and large surface allow inhaled particles to become trapped in the mucus lining the mucosa.

Smaller particles are trapped by mucus further down the branching respiratory tract.

Macrophages help clear any particles that may reach the alveoli.

Filtration has implications for drug delivery.
e.g inhalers

Question 2

describe how Mucocilliary Transport helps immune function

• direction of mucus

Answer 2

Cilia of mucosa beat in a rhythmic and coordinated way and carry trapped particles towards the pharynx and the digestive tract.

In the digestive tract, swallowed particles are then broken down by a combination of the low pH in the stomach and pepsin.

Question 3

explain the use of Tonsils and adenoids

Answer 3

Tonsils and adenoids are rich in lymphatic tissue - fixed and wondering macrophages ingest particles and function as antigen-presenting cells and so activate the immune system.

Question 4

what are the signs of respiratory disease ?

Answer 4

Cough, sneeze, difficulty in breathing (dyspnoea), cyanosis(blue discolouration due to poor circulation )

Question 5

describe the use of a cough as a reflex response against resp infections

• process
• speed of air expulsion
• cause

Answer 5

Reflex response that helps to clear congestion in the lower respiratory tract. A common sign of a respiratory disorder.
Involves - Inspiration
- Closure of epiglottis and vocal chords
- Forceful contraction of abdominal muscles
- Opening of glottis and vocal chords
- Expulsion of air under pressure

Air can be expelled at 75-100 km/h.
Caused by irritation of lower respiratory tract.

Question 6

what is Dyspnoea

• caused by
• what can this lead to ?

Answer 6

Difficult or laboured breathing - shortness of breath (air hunger).
May result from airway obstruction.
Can be caused by reduced lung compliance.

Question 7

what us Cyanosis

caused by

when does this become evident ?

Answer 7

Blueness of the skin associated with low blood PO2 in the capillary beds. side effect of Dyspnoea

Most peripheral cyanosis caused by peripheral vasoconstriction - often seen as response to extreme cold.
Can be caused by respiratory disorders resulting in blood supply exceeding ventilation rate - increased concentration of reduced haemoglobin, thus an increased physiological shunt.

Becomes evident when deoxygenated haemoglobin rises to 5g/dl in the arterial blood.

Question 8

name the three types of respiratory tract diseases

Answer 8

Infections - due to pathogens

Obstructive lung disease – narrowing of air passages

Restrictive lung disease – loss of lung compliance

Question 9

describe respiratory tract diseases used by infections

• what can increase this risk ?

effects of infections

current treatments

Answer 9

Due to pathogenic microorganisms.

Poor ventilation of the lungs can cause increased incidence of respiratory infections.

Infections lead to inflammation – a term ending in an ‘itis’ usually indicates inflammation, i.e., rhinitis, pharyngitis, bronchitis, etc.

Use of antibiotics and vaccinations has greatly reduced respiratory infection-related mortality - flu jab!

Question 10

name examples of
Upper respiratory tract infections:
Lower respiratory tract infections

Answer 10

Upper respiratory tract infections:

Common cold:
Viral
Affects nose, throat, sinuses
Symptoms: cough, runny nose, sneezing, sore throat, (fever), muscle ache, fatigue, headache, etc.
Sinusitis, tonsillitis, otitis media, pharyngitis

Lower respiratory tract infections

Tuberculosis:
Affects the lungs
Caused by bacteria Mycobacterium tuberculosis

Pneumonia:
Inflammatory, affects alveoli
Caused by bacteria Streptococcus pneumoniae (usually), but can also be caused by viruses and fungi

Question 11

Immune Response to Covid 19 and Vitamin D

on other sheet

Answer 11

Normal response - Helper T cells activated by viralproteins on antigen presenting cell membrane.

Helper T cells help activation of Killer T cells and B cells so they can target the virus and infected cells.

In vitamin D deficiency - Over activation of immune response.

Helper T Cells allow activation of abnormal and normal B cells.

Abnormal B cells produce autoantibodies and these target self cells.

If Not Vitamin D Deficient
Immune cells regulate their own activation of vitamin D. Vitamin D seems to play a part in activating regulatory B cells which play a part in inhibiting TH1 and TH17 Helper T cells associated with autoimmune and

Question 12

tb (on other sheet ) tuberculosis

Answer 12

Following inhalation, infection of alveolar macrophage
Internalised into phagasome and mycobacterium protected by lypoglycans particularly the lipoglycan lipoarabinomannan (ManLAN).
Mycobacterium replicate within the macrophage.
In immunocompetent individuals macrophages and lymphocytes accumulate around infected macrophages giving rise to granulomas in which accumulations of macrophages shield the mycobacteria from the adaptive immune system.
In immunoincompetent individuals the primary infection site (Ghon focus) granulomas increase in size as more macrophages are infected, within the centre of the larger granulomas cells undergo necrosis giving rise caseous granulomas some of which open into cavities from which infected material can drain into a bronchi and be expelled. Mycobacteria escaping the granulomas can infect other pulmonary regions(secondary granulomas) and other organ via the bloodstream and lymphatic systems.

Question 13

what is Obstructive Lung Disease

e.g

Answer 13

Describes a group of diseases associated with narrowing of the air passages.

Asthma, bronchitis and emphysema are common obstructive lung diseases.

In general, obstructive lung diseases do not greatly affect vital capacity, but significantly decrease airflow during expiration

Question 14

Asthma

type of resp disease

symptoms

treatment

Answer 14

Is an obstructive (inflammatory, chronic) lung disease.

Recurrent, reversible airway obstruction, caused by bronchial hyper-responsiveness.

Has an allergic component.

Symptoms: Wheeze, shortness of breath, nocturnal cough.

Bronchial muscles contract (there is bronchospasm) so it is difficult for air to reach the lungs.

Can be treated with bronchodilators and anti-inflammatory drugs.

Status asthmaticus: severe acute asthma; a medical emergency.

Question 15

what is Emphysema

symptoms

effect

cause

Answer 15

Is a chronic obstructive pulmonary disease (COPD), alongside chronic bronchitis and chronic obstructive airways disease.

Symptoms: breathlessness, cough, phlegm, frequent chest infections.

Caused by loss of elastin.

Smoking is the main cause of COPD (smoking causes elastin loss in emphysema, resulting in loss of normal elasticity).

Question 16

effect of smoking on resp tract

Answer 16

Smoking allows the inhalation of nicotine, which accumulates in the pulmonary epithelial cells.

Nicotine can act directly on alveolar macrophages and neutrophils, inducing them to increase the secretion of the enzyme elastase and oxygen radicals.

Question 17

what is elastase

type of enzyme

produced by

effect on alpha 1-antitrypsin activity

Answer 17

A serine protease that targets the extracellular matrix material elastin.

Elastin gives the lungs their elastic properties, so destruction of elastin decreases the elasticity of the lungs.

Elastase is produced by neutrophils and macrophages and is normally deactivated by the serine protease inhibitor 1-antitrypsin.

1-antitrypsin activity is inhibited by oxygen radicals.

Question 18

Susceptibility for alpha 1-antitrypsin activity variation

Answer 18

Gene for alpha 1-antitrypsin is polymorphic.

Three major alleles, M, S and Z. About 95% have normal MM genotype

< 01% ZZ individuals have 10-15% normal 1-antitrypsin activity

0. 1% SZ individuals have 30-35% normal 1-antitrypsin activity
1. 1% SS individuals have 50-60% normal 1-antitrypsin activity; does not cause disease

4% MZ individuals have 50-60% normal 1-antitrypsin activity; does not cause disease

Question 19

what is Restrictive Lung Disease

effects

lung capacity/ vital capacity change

commonly caused by

Answer 19

There is usually pulmonary fibrosis.

Lung compliance decreases.

Vital capacity drops.

Peak flow rate remains high.

Can be caused by elastic tissue being replaced by inelastic tissue.

Typically caused by asbestos, silica and coal dust.

Question 20

resp tract diseases
Malignant tumours
Pleural cavity diseases
Pulmonary vascular disease

Answer 20

Malignant tumours
(e.g., small cell lung cancer, mesothelioma) and benign tumours
Some cancers (colon, prostate) can metastasize to the lungs

Pleural cavity diseases
Pleural mesothelioma
Pleural effusion (fluid in pleural cavity)
Pneumothorax (hole in the pleura)

Pulmonary vascular disease
Pulmonary embolism
Pulmonary arterial hypertension
Pulmonary oedema
Pulmonary haemorrhage, inflammation, capillary damage, etc.

Question 21

what are the Effects of Aging on the Respiratory System ?

Answer 21

Elastic tissues deteriorate
Altering lung compliance and lowering vital capacity

Arthritic changes
Restrict chest movements
Limit respiratory minute volume

Emphysema
Affects individuals over age 50
Depending on exposure to respiratory irritants (e.g., cigarette smoke)

Question 22

what are the Commonly-used tests to diagnose respiratory disease

Answer 22

Spirometry
The Vitalograph
Peak flow meters
Blood gas and pH measurements

Question 23

what pulmonary volumes can a spirometer measure ?

Answer 23

Resting) Tidal volume
Inspiratory reserve volume
Expiratory reserve volume
Residual volume

Question 24

how can you measure Blood Gas/pH Analyses

Answer 24

Achieved by the measurement of the partial pressures of carbon dioxide and oxygen and also pH in blood samples.

Simple and quick and may only need small amounts of blood (a drop or two).