Biomedicine: Human Sciences 

Lecture 4: 

Respiratory System 

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Learning Outcomes 

In today’s topic you will learn: 

⮚ The parts of the respiratory  

system including its structure  

and function in the human body. 

⮚ The signs, symptoms,  

investigation procedures and  

some mainstream treatments of  

common respiratory diseases. 

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Functions 

1. Gas exchange: Oxygen (O₂) and carbon dioxide  

(CO₂). 

⮚ O₂ is required for cell respiration.  

⮚ CO₂ is a waste product of cell respiration. 

⮚ By breathing, we inhale O₂ and exhale CO_2. 

2. Warming or cooling and moistening of air. 

3. Removal of inhaled particles (immunity): 

⮚ Removal of larger substances in nose. ⮚ Smaller substances by mucociliary escalator. ⮚ Alveolar macrophages in alveoli. 

4. Voice production and olfaction (smell). 

alveoli = air sacs in lungs macrophages = white blood  cells 

mucociliary escalator =  goblet cells and ‘hairs’ in the  respiratory tract that help  remove particles

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Respiratory System Structures 

Air flows through the following  structures in the respiratory system: - Nose. 

- Paranasal sinuses. 

- Pharynx (throat). 

- Larynx (voice box). 

- Trachea (windpipe). 

- Bronchi (left and right). 

- Bronchioles. 

- Alveoli (air sacs). 

Nose 

Pharynx 

Larynx 

Trachea 

Bronchi 

Bronchioles 

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Types of Respiration 

1. External respiration: 

• Exchange of gases between the  

blood and lungs (air). Pulmonary  

capillaries carry blood around alveoli. 

• Air is inhaled and exhaled — this is  

called ventilation. 

2. Internal respiration: 

• Exchange of gases between blood and cells. 

3. Cellular respiration: 

• Metabolic process whereby energy  

(ATP) is obtained by metabolising  

carbohydrates, fats and proteins. 

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Respiratory Tract Mucous Membrane 

The respiratory tract is lined with a mucous  membrane. This is a ciliated epithelial  membrane that contains mucus-secreting  goblet cells. 

• Mucus traps inhaled particles and acts  as a surfactant (lowers the surface tension  of a liquid, allowing easier spreading).  

It also has antimicrobial properties.  

• Cilia move the particle-laden mucus towards  the oesophagus where it can be coughed up  or swallowed, thus protecting the lungs from  inhaled pathogens. This mechanism is  

called the mucociliary escalator. 

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cilia = fine hairs 

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Nose and Nasal Cavity 

The nasal cavity is the first contact organ in  the respiratory system and it conditions air. 

• It is an irregular cavity, divided by a septum  (cartilage). Bordered posteriorly by skull bones. 

• The nasal cavity contains hairs that trap larger  particles. 

• Internally has three nasal concha (turbinates)  — shelves that increase surface area and  trap water during exhalation. 

• Contains olfactory receptors (interpret smell). 

• Internal nose lined by mucous membrane and  capillaries. 

conche = Greek for ‘shell’ olfactory = ‘smell’ 

septum = Latin for ‘enclosure’

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Nasal Cavity Functions 

1. Filtering air: 

• Hairs (larger particles) and cilia / mucus  (trap smaller particles, protect  

epithelium; cilia beat towards mouth). 

• Nasal concha (turbinates) spin air within the  nasal cavity; this filters air and encourages  particles to become trapped in the mucus. 

2. Warming air — strong vascularity of mucosa . 

Nose bleeds  

demonstrate how  vascular the  

nasal cavity is. Nasal cilia: 

3. Humidification — air travels over moist mucosa. 

4. Sneezing reflex — in case of mucosal irritation. 

5. Olfactory function — olfactory receptors. 

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Paranasal Sinuses 

para- = ‘beside’ nasal = ‘nose’ 

The paranasal sinuses are air-filled cavities within certain  facial and cranial bones. 

• They are lined with mucous membranes that are continuous with  the nasal mucosa lining. Secretions drain into nasal cavity. 

• Include: Frontal, ethmoid, sphenoid, maxillary. 

• The sinuses perform the following functions: 

1.Resonance in speech. 

2.Lightening of cranial mass. 

3.Nasolacrimal ducts drain tears from the eyes. 

4.Moistening / humidifying of the air. 

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Pharynx 

The pharynx is a straight muscular  

tube that connects the nose and throat. 

• The pharynx is roughly 13cm long  

and sits anterior to the cervical  

spine, terminating at the larynx.  

• Consists of the nasopharynx,  

oropharynx and laryngopharynx.  

• The pharynx contains the eustachian 

tubes, which connect the nasopharynx  

to the middle ear and allow equalisation  

of pressure in the middle ear. 

• Contains adenoids (nasopharyngeal tonsils). 

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Pharynx 

FUNCTIONS:  

1. Passageway for air and food. 

2. Warming and humidifying. 

3. Taste. 

4. Hearing. 

5. Equalisation of pressure in  

middle ear (eustachian  

tubes). 

6. Immune protection: Tonsils. 

7. Speech: Resonating  

chamber. 

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Nasopharyngeal  tonsils 

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Larynx 

The larynx is also known as the voice box and  

connects the laryngopharynx with the trachea. 

• Consists of nine pieces of cartilage (including  

the thyroid cartilage and epiglottis) and vocal  

cords. 

• The vocal cords are composed of mucous  

membrane foldings stretched horizontally. 

• Laryngeal muscles attach to the vocal cords  

and when contracted stretch them: 

• Relaxed muscles = loose cords = low tone • Contract muscles = tight cords = high tone  (vibrate rapidly). 

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Testosterone  

thickens and  

lengthens the  

vocal cords. 

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Larynx 

FUNCTIONS:  

• Production of sound (vocal cords) and  

speech (tongue, lips and cheeks). 

• Protection — the epiglottis closes off  

the trachea during swallowing and  

hence prevents food entering the  

lungs. 

• Air passageway. 

• Warming and humidifying. 

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Trachea 

The trachea (or windpipe) is roughly  

12cm long and is made of incomplete  

C-shaped rings of hyaline cartilage. 

• The incomplete rings of cartilage are  

connected by smooth muscle, which is  

called trachealis. 

• Sympathetic (fight or flight) response 🡪 

tracheal dilation. 

• Parasympathetic (rest and digest)  

response 🡪 tracheal constriction. 

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Trachea 

FUNCTIONS: 

1. Air flow: Rings keep trachea  

open and unobstructed. 

2. Mucociliary escalator: 

Trapping inhaled particles and  

removing them from the  

respiratory tract. 

3. Cough reflex. 

4. Warming, humidifying, filtering 

(it is usually warm and humid  

by this point). 

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Coughing Reflex 

1. Epithelial receptors in the respiratory tract are  

highly sensitive to mechanical and chemical  stimuli. The coughing reflex starts when  irritation of the mucous membrane occurs. 

2. Stimulates sensitive nerve endings in the larynx, trachea, bronchi. 

3. A nerve impulse is sent via the vagus nerve  to the respiratory centre in the brain stem. 4. This causes deep inhalation and closure of  the glottis (and vocal cords). 

5. Contraction of the abdominal / respiratory  muscles to increase pressure. 

6. Forced removal of irritation. 

Coughing is a  reflex that can  reach speeds of  up to 60 miles/hr... 

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Bronchi 

The trachea divides into left and right  bronchi at the vertebral level of T5.  • The bronchi deliver air into the lungs.  • Bronchi contain cartilage rings that  

maintain an open airway. Bronchi are  lined with ciliated epithelium. 

• The right bronchus is more vertical, shorter  and wider. Hence an aspirated object is  more likely to enter the right lung. 

• Where the trachea divides into the two  bronchi, an internal ridge called the carina is formed (this is the most sensitive structure  in the system and it triggers the cough  

carina means ‘ridge’

reflex). ¹⁷ © CNM: Human Sciences – Respiratory System. BQ/MC

Bronchioles 

The bronchioles are continuations of the bronchi. 

• Bronchioles have no cartilage in their structure and  

instead contain more smooth muscle.  

• The bronchioles lead directly into the  

alveoli, where gas exchange occurs.  

Control of air-entry via: 

• Sympathetic nervous system  

(SNS: Fight or flight) = bronchodilation. 

• Parasympathetic nervous system 

(PSNS: Rest and digest) = bronchoconstriction. 

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Alveoli 

Alveoli are small hollow cavities that make up  most of the lung volume. They act as the  sites of gas exchange in the lungs. 

• The bronchioles terminate into alveolar sacs.  

• Alveolar gas exchange is maximised  by the following:  

- A large surface area (approximately 80m²)  created by 250 million alveoli in each lung. - Alveolar walls are very thin  

(single-layered). 

- Surrounded by many blood capillaries.  - Alveolar surfaces are moist (gases  

exchange more easily when in water). 

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Alveolus = Latin  for ‘hollow cavity’ 

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Alveolar Gas Exchange 

In alveoli, oxygen and carbon dioxide are  

exchanged between air and blood 

• Gas exchange occurs between alveoli  

and capillaries.  

• Oxygen moves from the alveoli (after  

breathing in), into the blood. This causes  

the blood to become oxygenated. 

• Carbon dioxide moves from the blood  

(having been delivered via the pulmonary  

artery), into the alveoli, to be exhaled.  

• The movement of both gases occurs via  

diffusion (down the concentration gradient). 

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Alveolar Cells 

Type I alveolar cells: 

• These are simple epithelial cells, covering  

90% of the alveolar surface and are  

very thin to support gas exchange. 

Type II alveolar cells: 

• Secrete alveolar fluid that contains  

pulmonary surfactant.  

• Pulmonary surfactant reduces alveoli  

surface tension, preventing alveolar collapse.  

• The fluid allows gases to diffuse through it. 

Alveolar macrophages: 

• These are strategically located white blood  cells (leukocytes) that engulf and destroy  microbes entering the alveoli. 

surfactant = 'surface' and  'active substance' 

gestation = time when  foetus develops 

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Pulmonary Surfactant 

Surfactant is a mixture of lipids and proteins that forms a  surface film in alveoli. 

• The protein part is hydrophilic and resides in the alveolar fluid,  whilst the lipid component is hydrophobic and faces the air.  • Through this structure, surfactant  

reduces the surface tension within  

the alveoli, preventing them from  

collapsing and reducing the pressure  

required to re-inflate them. 

• Surfactant is not produced until 24-28  

weeks’ gestation, so consider lung  

development in a premature baby. 

• Two-thirds of the work of breathing is to overcome surface tension. 22 

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Lung Anatomy 

Two cone-shaped lungs, separated by the heart. 

Surfaces: 

• Apex (extends above clavicle). 

• Base (over diaphragm). 

• Costal (rib) surface. 

• Medial surface. 

Lobes: 

• Right lung: Three lobes. 

• Left lung: Two lobes (due to the heart). Blood supply: 

• From the pulmonary artery (left and right). 

apex = Latin for tip / peak

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Pleura and Pleural Cavity 

The pleura are serous membranes that  

surround the lungs. 

• The pleura contain a visceral and a parietal  

layer, with a pleural cavity in between. 

• The visceral and parietal pleura form a  

double layer separated by 5 - 10ml of  

serous fluid that prevents friction. 

• The pleura adhere to the lungs so that the  

lungs are sucked to the pleura (‘passive  

dilation’) — helps expansion of the lungs. 

• A pneumothorax occurs when damage to  the pleura allows air into the pleural cavity. 

visceral = pertaining to organs parietal = walls of a cavity 

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Ventilation 

ventus = Latin for ‘wind’ 

Ventilation is the process through which O₂ and  

CO₂ are transported to and from the lungs.  

• A normal cycle of ventilation during quiet  

breathing involves 12 - 15 breaths per minute.  

• Ventilation involves two main phases: 

1. Inhalation (approx. two seconds). 

2. Exhalation (approx. three seconds) 

(followed by a brief pause). 

• Breathing can come from two areas: 

- Abdominal (diaphragmatic) breathing — 

where most breathing should come from. 

- Upper rib breathing. 

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Muscles of Ventilation 

Two types of ventilation muscles: primary  

and secondary. 

Primary muscles: 

• Intercostal muscles (internal and external): 

• Attached between ribs at right angles. 

• Contraction pulls ribs upwards (inhalation)  

expanding outward and increasing size of rib cage. 

• Diaphragm: 

• Attached to the lower ribs, sternum and  

lumbar spine. A domed muscle that  

separates the thoracic and abdominal cavity. 

• Contraction moves the diaphragm into the  

abdomen and draws air into the lungs. 

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Muscles of Ventilation 

The secondary muscles of ventilation  

(also called accessory muscles)  assist in breathing. 

• These muscles are often over-recruited in patients suffering with breathlessness  (e.g. asthmatics). They can become  shortened and fatigued. 

• Most accessory muscles are located  around the neck and chest. 

The scalenes:

• Examples of secondary muscles of ventilation include the  trapezius, sternocleidomastoid, and the scalenes. 

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Ventilation 

Inhalation: 

• Inhalation is an active process requiring muscles. 

• Negative pressure in the thoracic cavity causes air  

to enter lungs down a pressure gradient.  

Exhalation: 

• Exhalation is typically a passive process — 

muscles relax. 

• This occurs through the elastic recoil of the lungs. 

• Should only be active during forceful breathing. 

• If elasticity is lost, for example, in pulmonary  

fibrosis, exhalation can become active with the  

recruitment of internal intercostal and abdominal  

muscles. 

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Lung Volumes 

The average pair of human lungs  

can hold about six litres of air. 

• However, only a small amount of this  

capacity is used during normal  

breathing (as highlighted in the image). 

• The tidal volume represents the normal  

volume of air that enters the lungs during  

inspiration when no extra effort is applied.  

• A normal tidal volume is about 500ml. 

• Men generally have larger lung volumes, as  

do taller individuals, non-smokers,  

athletes and those living at higher altitudes. 

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Gases 

Inspired air contains a large  quantity of nitrogen and oxygen. • As oxygen has a strong affinity  

(attraction) for haemoglobin, oxygen  will readily enter the blood and bind  with haemoblogin molecules.  

• Haemoglobin is the key component  of red blood cells and transports  oxygen in the blood. 

Atmospheric Gases: 

• Nitrogen doesn’t bind to haemoglobin. _{Furthermore, nitrogen is not used or}  

created in the body, so any nitrogen  

that has dissolved in the blood will  

remain at the same concentration. 

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Gases in Blood: Oxygen 

98.5% of oxygen in the blood is transported  by haemoglobin (Hb) in red blood cells. • 1.5% of oxygen is dissolved in plasma  (oxygen dissolves poorly in water). 

• Haemoglobin changes colour depending on  how much oxygen is bound to the molecule. • Oxyhaemoglobin is when plenty of oxygen is bound to Hb. Deoxyhaemoglobin is Hb  that lacks oxygen. 

• Oxygen is an essential gas in the body.  Cells use oxygen to create the energy that  is required for various processes.  

oxy- = oxygen 

haem- = blood 

globus = a spherical protein

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Gases in Blood: Carbon Dioxide 

Carbon dioxide diffuses into the  

blood from respiring cells easily. It  

is transported in the following  

ways: 

• 70% found in plasma as HCO^3- (bicarbonate). 

• 23% carried in RBCs (bound to  haemoglobin). 

• 7% dissolved in plasma (the  water component of blood). 

Bicarbonate 

CO₂ + H₂O ↔ H₂CO₃ ↔ H⁺ + HCO₃- Carbonic acid 

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Gases in Blood: Carbon Dioxide 

Bicarbonate buffer reaction (to control blood pH): 

• CO₂ diffuses down its concentration  

gradient from tissues into the blood. 

• Because of the high-water content  

of blood, CO₂ combines with water  

to produce carbonic acid (H₂CO₃). 

• As carbonic acid is unstable, it decomposes  

immediately into bicarbonate and H⁺. 

• Hydrogen is exhaled and excreted in  

urine to reduce the acidity. In addition,  

the bicarbonate formed is alkaline, which  

buffers the acidity of blood to keep pH stable.  

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Respiratory System: Blood pH 

pH is the measure of acidity, alkalinity and neutrality.  • Blood pH needs to be controlled within very narrow limits. • Low pH = elevated H⁺ion concentration (more acidic). 

• High pH = more alkaline.  

What causes a low pH (acidity) in the blood? 

• 🡹 CO₂: When CO₂ dissolves in the blood, it  

causes an increase in H⁺ions and thus an increase  

in acidity. This leads to respiratory acidosis. 

• It is not just CO₂that causes acidosis; exercise  

produces lactic acid, and fasting produces ketoacids  

which enter the blood. This is called metabolic acidosis. 

• Ventilation helps to lower the acidity of body fluids via  

exhalation of CO_{2. 34} © CNM: Human Sciences – Respiratory System. BQ/MC

Regulating Blood pH 

Increase in acidity is managed in three ways: 

1. Buffer systems 

• Temporarily bind to H⁺ removing  

them from solution (i.e. proteins,  

bicarbonate). 

2. Increased exhalation of CO₂  

3. Kidney excretion of H⁺ 

• Slow mechanism. 

• Kidneys can also synthesise new  

bicarbonate and reabsorb  

bicarbonate, thus influencing pH. 

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buffer = to lessen or  moderate the impact of  something 

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Cell Respiration 

Cell respiration describes the process  of energy production (ATP) within cells. • Glucose is the primary organic molecule  

metabolised for ATP production although fats and proteins are also used.  

Energy is produced by either:  

1. Aerobic respiration (with oxygen) 38 ATP (total yield) + water + CO_2. 2. Anaerobic respiration (no oxygen) 2 ATP (total yield) + lactic acid. 

Remember: ATP is 

adenosine triphosphate,  the energy currency in the  body.  

The oxygen availability of cells depends on the functioning of the respiratory  system (breathing and gas exchange), as well as circulation to deliver oxygen. 

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Ventilation Control 

The control of ventilation is primarily involuntary. 

• The respiratory centre is in the brainstem (medulla  

oblongata and pons). This receives  

inputs from different parts of the body. 

• Chemical receptors found in the brainstem 

measure CO₂ and acidity (H⁺ concentration). 

• Chemical receptors in the aorta and carotid  

artery measure CO₂, O₂ and acidity levels.  

• Stretch receptors in the walls of the bronchi  

and bronchioles detect over-inflation. 

• If receptors detect high arterial CO₂, this triggers  

hyperventilation (to excrete / exhale excess CO₂). 

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Summary Quiz: 

1) Name the TWO gases that are exchanged in alveoli. 

2) Where does internal respiration take place? 

3) How many lobes does the left lung have? 

4) Name the artery that supplies the lungs. 

5) Indicate the location of the respiratory centre in the brain. 6) List THREE functions of the nasal cavity. 

7) Is exhalation generally an active or passive process? 

8) Name TWO primary muscles of ventilation. 

9) Describe the function of the mucociliary escalator. 

10) Explain the effect of high blood concentrations of carbon  dioxide on blood pH. 

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Smoking and the Respiratory System 

Smoking cigarettes significantly increases  

the risk of lung diseases. 

• Cigarettes contain substances known as  

carcinogens. Carcinogens are substances  

that can cause cancer.  

• Smoking also damages the delicate cilia that  

line the respiratory tract. Normally these cilia  

would sweep trapped particles out of the lungs. 

• Following cilia damage, mucus and trapped  

particles build up in the lungs, causing a  

smoker’s cough, whilst also increasing the risk  

of pulmonary infections, bronchitis and emphysema.  

Research has shown that 15 cigarettes smoked = one genetic mutation 39 

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Respiratory Investigations: 

Common Signs and Symptoms 

• Congestion. • Runny nose. • Sneezing. 

• Cough. 

• Sputum. 

• Wheezing.  • Chest pain. • Breathlessness. 

ortho = straight/upright dys- = difficulty 

-pnoea = breathing

Cyanosis: 

Inadequate oxygenated blood in an area. Due to: 

• Dyspnoea (difficulty breathing). • Orthopnoea (breathless when lying down). 

• Hyperventilation (over-breathing). • Cyanosis. 

1. A peripheral arterial disease  (i.e. blockage). 

2. Lung disease (poor gas exchange). 3. Heart failure (inability to deliver  oxygenated blood). 

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Sputum Differential Diagnosis 

The following table describes the key appearances of  sputum and what each appearance might indicate: 

purulent = containing  pus 

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Investigations 

^{Medical investigations:} • Blood test (i.e. white blood cell count,  

inflammatory markers). 

^{• Biochemistry tests. • Sputum analysis and microbiology.} • Imaging — chest x-ray, MRI, CT. 

Physical examination: 

• Percussion (tapping to the thoracic  

cage) and auscultation. 

• Respiratory function tests — measure  

inspiration / expiration of lungs and  

gaseous exchange in the lungs / circulation.  

Naturopathic investigations (later in the course). 

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Respiratory Examination 

Finger clubbing: 

Lung cancer, COPD or cystic fibrosis

^Percussion: Chest  deformity:  

‘Barrel chest’  

(seen in COPD) 

_{Auscultation:} X-Ray – lung tumour: 

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Respiratory Pathologies: _{rhin- = nose} 

Rhinitis  

Rhinitis is inflammation of the nasal mucosa.  

• The inflammation leads to mucosal swelling  and an increase in the volume and viscosity  of nasal secretions (mucus). 

CAUSES: 

• Immune compromise (leading to viral, bacterial or  fungal infections); i.e. related to emotional stress,  medications, diet etc. 

• Allergic rhinitis (e.g., due to pollen, spores, mites)  — IgE stimulates mast cells to release histamine. 

-itis = inflammation 

Rhinitis can be  acute or  

chronic... 

• Non-allergic rhinitis (associated with environmental  and lifestyle changes; e.g. pollution, diet, drugs  

such as NSAIDs, stress, etc). 

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Rhinitis  

SIGNS AND SYMPTOMS:  

• Itchy runny nose, sneezing, stuffy nose, ↓ smell. 

COMPLICATIONS:  

• Nasal polyps, ear infections, loss of smell. 

TREATMENT:  

• Allopathic: Anti-histamines, decongestants,  steroid nasal sprays. 

• Natural: Nutritional (immune modulation and  anti-inflammatory) — raw honey, apple cider  vinegar, quercetin, probiotics.  

Herbs (e.g. echinacea, nettle), homeopathy,  

Echinacea 

acupuncture. ₄₅ © CNM: Human Sciences – Respiratory System. BQ/MC

Common Cold  

Infection of the upper respiratory tract. 

• Those with lower immunity become infected with virus.  

SIGNS AND SYMPTOMS: gradual onset, lasting two to seven days: • Rhinorrhoea (runny nose), sneezing, sore throat and mild fever. 

ALLOPATHIC DRUG TREATMENT:  

• Symptomatic: Painkillers, decongestants.  

NATURAL TREATMENT:  

• Nutritional (immune support) — vitamin C in high  

doses, zinc, vitamin D, steam inhalations with mint, thyme,  eucalyptus, colloidal silver, rest. Acupuncture and homeopathy. • Herbal medicine, e.g., echinacea, elderberry. 

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Influenza (Flu) 

Influenza is an acute respiratory disease,  

associated with various strains of the flu virus. 

• Incubation period: One to four days (time  

between microbial exposure and first symptoms). 

• Symptoms tend to be systemic, more severe  

and last longer. 

• Flu vaccinations often don’t provide effective  

immunity as the virus mutates (the vaccine  

also produces significant adverse effects). 

SIGNS AND SYMPTOMS:  

• Sudden onset: Fever and shivering, malaise,  

muscle and joint pain, rhinitis, sore throat. 

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Influenza (Flu) 

ALLOPATHIC TREATMENT:  

• Antiviral drugs — reduces viral shedding. To be taken within  48hrs, but very poor effectiveness and adverse effects. 

• Antibiotics to prevent secondary bacterial  

infection (adverse effects: Lowered immunity,  

diarrhoea, poor digestion and thrush). 

• Flu vaccine in vulnerable populations. 

NATURAL TREATMENT:  

• Herbal medicine (immune system support and anti-viral herbs). • Homeopathy, nutritional (immune support) — garlic,  

vitamin C in high doses, zinc, vitamin D, quercetin,  

steam inhalations with mint, thyme, eucalyptus, rest. 

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Flu Complications 

• Secondary infections while the immune system  

is depleted due to primary flu infection.  

• Post-viral syndrome (chronic fatigue syndrome)  

following compromised immune system. 

• Morbidity / mortality — influenza pandemics such  

as the pandemic of 1918 which is estimated to have  

killed between 50-100 million people (2.7-5.4% of the  

world population - consider that this pandemic followed  

the huge loss and distress of World War 1. 

• Pigs are known as mixing reservoirs as they can  

host both human and non-human viruses, potentially  

allowing the mixing of viral genes creating a new virus. 

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Cold v. Flu  

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Sinusitis 

Inflammation of the membranous lining of one  or more of the sinuses (rhinosinusitis). 

sinus = sinuses -itis = inflammation 

• Sinusitis can be acute or chronic (> three months). 

• Often associated with immune compromise. - - - Frequently follows a respiratory infection.  

An infected tooth may cause  

the sinuses to become infected also. 

SIGNS AND SYMPTOMS: 

• Pain over affected sinus and congestion. 

• Sinus headaches. 

• Fever, nasal drip, change in tone of voice, reduced sense of smell. 

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Sinusitis 

ALLOPATHIC DRUG TREATMENT:  

• Painkillers, decongestants. 

NATURAL TREATMENT:  

• Nutritional (vitamin C in high doses,  

zinc, vitamin D, steam inhalations  

with mint, thyme, eucalyptus). 

• Herbal medicine (immune system  

support, antiviral and decongestant  

herbs; e.g. eyebright, echinacea).  

• Homeopathy, acupuncture. Netty pot drainage. 

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Nasal Polyps 

Nasal polyps are soft, non-cancerous (benign)  masses of oedematous nasal mucosa. 

CAUSES / RISKS:  

• The end-product of chronic inflammation, due to: • Viral, bacterial or fungal. 

• Allergies - chronic rhinitis. 

PATHOPHYSIOLOGY: 

• Chronic inflammation causes the blood  vessels in the lining of the nose and  

sinuses to become more permeable,  

allowing water to accumulate in the cells. • Over time, as gravity pulls on these waterlogged  tissues, they may develop into polyps. 

© CNM: Human Sciences – Respiratory System. BQ/MC

oedema = fluid swelling 53 

Nasal Polyps  

SIGNS AND SYMPTOMS: 

• Difficulty breathing, runny nose, persistent  

stuffiness. 

• Chronic sinus infections, reduced sense of smell. 

^{• Dull headaches, snoring, mouth breathing.} • Can cause sleep apnoea. 

ALLOPATHIC TREATMENT: 

• Intranasal steroids (adverse effects). 

• Anti-histamines, anti-fungals, surgery.  

NATURAL TREATMENT: 

• Treat the cause. Nutrition and herbal  

medicine for immune modulation / support. 

• Homeopathy and acupuncture (relieve blockage). 

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^{tonsill = tonsils} Tonsillitis -itis = inflammation 

Tonsillitis describes inflammation of the tonsils. 

• Common type of infection in children  

5–10 years and 15–25 years. 

• Viral (common cold or flu virus) or  

bacterial (streptococci). 

• Short incubation period. 

SIGNS AND SYMPTOMS:  

• Sore throat that becomes worse when swallowing. • Fever over 38^oC. 

• Coughing, headache and red / inflamed tonsils. © CNM: Human Sciences – Respiratory System. BQ/MC

Tonsils are  

immune /  

lymphoid tissue  positioned in the  oral and nasal  passageway as a  first line of  

defence. 

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Tonsillitis 

COMPLICATIONS: 

• Middle ear infection, quinsy (abscess). 

ALLOPATHIC TREATMENT:  

• Painkillers, antibiotics (adverse effects: Lowered  

immunity, disturbed gut function (diarrhoea, bloody  

stools, poor digestion and absorption, candida). 

• Surgery (tonsillectomy) — loss of immune tissue. 

NATURAL TREATMENT: 

• Nutritional (support immune system and reduce  

inflammation), lozenges, gargles, colloidal silver. 

• Herbal medicine — anti-microbial, immune  

support; i.e. echinacea, calendula, sage. 

• Homeopathy and acupuncture. 

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Quinsy (peritonsillar abscess) 

An abscess that has formed around the  tonsils, occurring as a result of tonsillitis.  

• Mostly affecting adolescents and young adults. 

SIGNS AND SYMPTOMS:  

• Severe unilateral throat pain, dysphagia,  unilateral earache, trismus (limited mouth  opening), fever, swollen lymph nodes. 

TREATMENT: 

• Allopathic: Antibiotics, pus drainage, surgery. • Alternative: Herbal medicine, nutritional  support, lozenges, gargles, colloidal silver.  Homeopathy and acupuncture. 

peri- = Greek for around tonsillar = of the tonsils abscess = collection of  pus 

dys- = difficulty  

-phagia = swallowing  

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Pharyngitis 

An acute inflammation of the mucous  membrane of the pharynx. 

• Usually accompanies colds and tonsillitis and  is often accompanied by swollen lymph nodes. 

ALLOPATHIC TREATMENT:  

• Painkillers for virus (adverse effects). • Antibiotics — adverse effects. 

NATURAL TREATMENT:  

pharyng- = pharynx -itis = inflammation.  

• Herbal medicine (anti-microbial, immune support),  nutritional (support immune system and reduce  

inflammation), lozenges, gargles, acupuncture. Homeopathy. 

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Laryngitis 

Laryngitis describes inflammation of the  larynx. 

• Can be acute or chronic: 

• Acute: Viral, bacterial. 

• Chronic: Overuse — repeated strain,  irritants (smoke, fumes), acid reflux. 

SIGNS AND SYMPTOMS:  

• Hoarseness, weak voice or voice loss. • Sore / dry / tickly throat. 

• Dry cough. 

• Difficulty breathing (in children). 

laryng- = relating to larynx -itis = inflammation. 

Again, you must  

consider why the  

host immune system  is failing to prevent  

disease… 

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Laryngitis 

ALLOPATHIC TREATMENT:  

• Antibiotics (consider adverse effects). 

• Avoid smoking and smoke,  

maintain oral hygiene. 

NATURAL TREATMENT:  

• Herbal medicine (anti-microbial,  immune support); i.e., echinacea,  boswellia, turmeric, ginger, red sage.  

• Nutritional (support immune system  and reduce inflammation) — garlic,  onions, steam inhalations. Homeopathy  and acupuncture. 

Boswellia 

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Asthma 

Asthma is a chronic airway disease with  

reversible narrowing of the bronchi and  

bronchioles. 

• An inflammatory condition combined with  

bronchial hyper-responsiveness with  

varying degrees of immune cell infiltration. 

• Airflow obstruction due to oedema, mucus buildup and  smooth muscle proliferation (= problems exhaling). 

• Asthma can develop at any age, but most  

commonly affects children under 10 years of age,  

with another peak in the elderly. 

• Leukotrienes are key chemical inflammatory  

mediators in asthma. They are bronchoconstrictors.  

© CNM: Human Sciences – Respiratory System. BQ/MC ⁶¹

Asthma 

The prevalence of asthma is increasing.  

Possible reasons for this include: 

• Earlier weaning. 

• Inadequate exposure to pathogens in  

childhood. 

• Inherited dysbiosis (imbalance of gut flora)  

and antibiotic use in children. 

• Food additives. 

• Leaky gut syndrome. 

• Nutritional deficiencies’ i.e., C, D, E, magnesium. 

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Asthma 

ASTHMA CLASSIFICATION: 

• Extrinsic (or atopic) asthma: 

• Affecting children typically, immunologically  

mediated with an increase in IgE antibodies. Brought on  by exposure to allergens e.g., pollen, dust, animal dander. 

• Intrinsic asthma: 

• A bronchial reaction that is not due to  

antigen-antibody stimulation. Adult onset typically. 

• Common triggers include anxiety, chemicals, exercise,  cold air, drugs (NSAIDs, beta blockers), stress, dust, etc. 63 

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Asthma 

This image highlights the pathological  

changes that occur in the bronchioles of  

an asthmatic patient. 

• Smooth muscle contracts and immune  

cells infiltrate the bronchioles as part of  

the inflammatory process, which  

obstructs the airways. 

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Asthma 

SIGNS AND SYMPTOMS: 

• Recurrent episodes of breathlessness  

and chest tightness. 

• Wheezing when exhaling.  

• Nocturnal coughing, occasionally with  

thick clear or yellow sputum. 

• Accessory muscles of ventilation are  

overused and can cause aching in  

the neck and upper back. 

DIAGNOSIS:  

• Based on signs / symptoms and history. 

• Spirometry. 

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Asthma 

ALLOPATHIC TREATMENT:  

• Bronchodilators (blue inhaler).  

• Corticosteroids (brown inhaler) — many adverse  

effects. 

NATURAL TREATMENT:  

• Nutritional — fruit and vegetables, antioxidants (e.g.,  

vitamin C and E, quercetin), onions and garlic, omega-3s,  magnesium (bronchodilator), eliminate food allergens.  

• Herbal medicine; e.g., boswellia, turmeric, astragalus,  

gingko, liquorice. 

• Homeopathy and acupuncture. 

• Avoid irritants (dust, smoke etc.) and allergens, allergy  treatment, breathing exercises, manual therapy. 

© CNM: Human Sciences – Respiratory System. BQ/MC ⁶⁶

Asthma Attack 

• An asthma attack can be life-threatening.  

• Do not hesitate to call for help. It is severe if  the patient cannot speak in sentences and has  more than 25 breaths per minute (tachypnoea). 

• Encourage the patient to sit down (not lie down)  and take slow, steady breaths. Try to keep the  patient calm. 

• Use inhaler (usually blue bronchodilator) every  30‒60 seconds, up to a maximum of 10 puffs.  

• CALL AN AMBULANCE IF YOU CANNOT  GET THE PATIENT’S SYMPTOMS UNDER  CONTROL. 

© CNM: Human Sciences – Respiratory System. BQ/MC

tachy- = rapid 

-pnoea = breath 67 

Bronchitis 

Bronchitis describes inflammation of  the bronchial tubes. Inflammation can  be acute or chronic.  

• Viral or bacterial infections can result from  compromised immunity (considered a  lower respiratory tract infection). Can be  associated with environmental irritants. 

• When an irritant enters the airways, goblet  cells secrete mucus to flush it out. If mucus  is overproduced, the respiratory system  attempts but struggles to clear it. 

• This can increase airway resistance and  cause breathing difficulties. 

bronch- = bronchi -itis = inflammation. 

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Bronchitis 

SIGNS AND SYMPTOMS: 

• Hacking unproductive cough, becoming  

productive within days (thick yellowy mucus).  

• Fever, sore throat, shortness of breath,  

headache, runny or blocked nose, muscle pain. 

• Signs: Crackles on auscultation, tachypnoea,  

tachycardia, cyanosis. 

TREATMENT APPROACHES: 

• Allopathic: Antibiotics (adverse effects). 

• Alternative: Herbal medicine (anti-microbial,  

immune support), nutritional (support immune  

system and reduce inflammation), avoid irritants.  

Homeopathy, acupuncture. 

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Chronic Obstructive Pulmonary Disease (COPD)  

COPD causes airflow limitation that is progressive  and not fully reversible. The airflow limitation is due  to airway and functional lung tissue damage.  

• A chronic inflammatory response of the  

lungs (usually to inhaled toxins). 

• COPD refers to a combination of two  

main pathologies (of varying proportions): 

- Emphysema 🡪 walls of the alveoli  

damaged and destroyed, leading to  

reduced gas exchange. 

- Chronic bronchitis 🡪 the bronchial lining is  

constantly irritated and inflamed 🡪 thick mucus. 

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COPD 

CAUSES:  

• Smoking (accounts for 90% of COPD in Western countries). • Exposure to lung irritants (air pollution, industrial chemicals,  dusts, etc.), genetic susceptibility. 

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COPD 

• Smoking cigarettes and inhaling  

other irritants leads to high levels  

of oxidative stress in the  

respiratory tract. 

• Oxidative stress damages the  

delicate cilia and promotes  

chronic inflammation throughout  

the respiratory tract. 

• Cells are damaged and scar.  

This, as well as excess mucus  

production, leads to airflow obstruction. 

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COPD 

SIGNS AND SYMPTOMS:  

• Chronic cough with sputum, dyspnoea. 

• Prolonged expiration and wheeze. 

• Frequent infections. 

• Signs: Tachypnoea, breathlessness on  

exertion, pursed lips breathing, patients  

may lean forward and rest arms on the table,  

flapping tremor, cyanosis, hyperinflation of  

chest (barrel chest), clubbed nails. 

COMPLICATIONS:  

• Chronic hypoxaemia 🡪 pulmonary hypertension.  • Recurrent respiratory infections.  

• Respiratory failure. 

© CNM: Human Sciences – Respiratory System. BQ/MC

hypo = below normal  -ox = oxygen 

-aemia = blood 

tachy = fast / rapid -pnoea = breathing 

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COPD 

ALLOPATHIC TREATMENT:  

• Smoking cessation. Bronchodilators,  

corticosteroids, oxygen therapy. 

NATURAL TREATMENT: 

• Herbal medicine: 

- Anti-inflammatory and immune enhancing  

(i.e., echinacea, andrographis, cat’s claw). 

- Mucous membrane support (i.e., goldenseal, eyebright). • Nutritional (support immune system and reduce  

inflammation), i.e., vitamin C, zinc, quercetin, ginger.  

• Avoid irritants (dust, smoke, etc.) and allergens;  

allergy treatment, acupuncture and homeopathy. 

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COPD 

Emphysema chest  

NORMAL EMPHYSEMA 

CT scan:  

Dilation of alveolar sacs by  

destruction of alveolar wall 

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Pneumonia 

Pneumonia is an infection of the alveoli  

and terminal bronchioles, mostly bacterial.  

• Associated with an infiltration of neutrophils  

with inflammation and oedema. 

• Most common in infants, children and the elderly.  Higher risk if the patient is immune suppressed. 

SYMPTOMS AND SIGNS: 

^{• Cough and purulent sputum which may be blood} stained. 

• Breathlessness, fever, malaise. 

bronchiole 

fluid in bronchiole

• Signs: Tachypnoea, crepitations on auscultation. 

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pulmonary = of the lungs 

^{fibrosis = scarring} Pulmonary Fibrosis _{idiopathic = unknown cause} 

Gradual replacement of the one-layer-thick epithelial  cell lining in alveoli with fibrotic tissue.  

• Fibrotic (scar) tissues are less able to  

exchange oxygen and CO_2. 

CAUSES: 

• Idiopathic (IPF): Unknown, may be  

genetic, presents around 70 years.  

• Smoking, asbestos, some drugs, radiation  

therapy, accompanies some diseases (autoimmune, e.g. RA). 

SIGNS AND SYMPTOMS:  

• Progressive dyspnoea, chronic cough, fatigue,  

discomfort in the chest, loss of appetite, weight loss. 

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Pulmonary Fibrosis 

Currently no effective allopathic  treatments. 

NATURAL TREATMENT: 

• Herbal medicine (anti 

inflammatory, bronchodilators,  immune modulation). 

• Nutritional (support immune  system and reduce  

inflammation). 

• Avoid irritants (dust, smoke, etc.)  and allergens, allergy treatment. • Acupuncture and homeopathy. 

Normal lung  

histology: 

Pulmonary fibrosis  histology: 

Normal chest  

CT scan: 

Pulmonary fibrosis CT:

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Obstructive Sleep Apnoea 

a- = absence 

-pnoea = breathing 

Intermittent and repeated upper airway collapse during sleep  leading to interrupted breathing.  

• Causes / risks: Include obesity, male gender, middle-aged,  smokers, alcohol, sedatives, nasal obstruction (rhinitis, polyps).  

• Treatment with nasal continuous positive  

airway pressure (CPAP), lifestyle modification.  

It is essential to treat the cause.  

SIGNS AND SYMPTOMS:  

• Loud snoring, daytime sleepiness, morning headache, morning  drowsiness, nocturnal choking, reduced libido. Diagnosis by polysomnography.₇₉ © CNM: Human Sciences – Respiratory System. BQ/MC

Pneumothorax 

A pneumothorax describes air  

accumulation within the pleural cavity,  causing part, or all, of a lung to collapse. 

• Air enters via defect in visceral or parietal  pleura (e.g. rib fracture). 

• Can be simple (i.e. heart remains central)  or tension (unstable — progressive buildup  of air shifting the heart away). 

CAUSES: 

pneumo = lungs or air thorax = cavity under ribs  

• Spontaneous — rupture of cyst / pocket of air,  

tuberculosis, cystic fibrosis, emphysema. 

• Traumatic (damage to pleura) — fracture, surgical complication. 

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