Respiratory Flashcards
What does the respiratory system consist of and what are their functions?
Upper and lower airway.
Upper airway: filters, warm and moisten the air
Lower airway: ventilates and exchanges gas
Describe the lungs and its functions.
It is a soft spongy organ with the upper part being the apex and lower part the base.
Functions include: gas exchange, inactivate vasoactive substances, convert angiotensin I to angiotensin II, reservoir for blood storage and heparin producing cells located in the capillaries.
Where does gas exchange and how?
Gas exchange occurs in the respiratory lobules/Alveoli. Oxygen moves from the alveoli to pulmonary capillaries as dissolved gas.
This is able to occur due to a concentration gradient.
carbon dioxide also travels as along the concentration gradient.
Describe the dual blood supply to the lungs?
- Pulmonary circulation: brings DEOXYGENATED blood from the RIGHT side of the heart via the pulmonary artery. Oxygenated blood returns via the pulmonary veins into the LEFT.
- Bronchial circulation:
Distributes blood to the conducting airways and supporting structures.
Warms and humidifies air in the conducting airways. Bronchial blood vessels are the only ones to undergo angiogenesis when vessels in the pulmonary circulation are obstructed.
What is lung compliance?
How much the lungs can inflate. It is a measure of the change in lung volume that occurs with the change in intrapulmonary pressure.
Normal compliance in the average adult is 200ml.
It is determined by elastin, collagen fibres, water content, surface tension
List the common tests used to determine the presence of a respiratory disorder.
- Visual examination (cyanosis etc.) – Peak flow meters – Spirometry – Pulse oximeter – Auscultation (Breath sounds) – X-ray – Blood gases
Describe what normal breathing sounds like.
Normal breath sounds vary over different anatomical sites.
– Bronchial: loud, high pitched
– Bronchovesicular: medium pitched
– Vesicular: soft, low pitched, gentle, rustling sounds
Describe what abnormal breathing may sound like.
Abnormal/adventitious breath sounds may: – Be absent – Sound wet = pulmonary oedema – Be noisy: air passing past sputum = pneumonia – Be a wheeze: narrow airways = asthma
Define the term COPD
Chronic obstructive pulmonary disease – In COPD, less air moves in and out of the lungs because: – Air sacs have lost their elasticity – walls between air sacs are destroyed – airways are thick and inflamed – excessive mucus production clogs airways
Compare and contrast the clinical manifestations observed in a patient with bronchitis and with a patient with emphysema.
Chronic bronchitis
– Have a sputum producing cough
– Blue bloater: poorly oxygenated lung causing cyanosis
– Right sided heart failure due to pulmonary hypertension (Cor pulmonale)
resulting from constriction of pulmonary blood vessels
– Peripheral oedema due to right sided heart failure
– Acidosis resulting from CO2 retention
Emphysema
– Pink Puffer: oxygenated but strains to breath due to collapse of the airways
during expiration.
– Not cyanotic, therefore not blue in colour (except in extreme cases)
– Pursed lip breathing with rapid respiratory rate
– Barrel chest
Name the three common pathophysiological changes that occur in chronic bronchitis?
Chronic Bronchitis is the result of inflammation for more than 3 months in the bronchi and bronchioles. – Muscle spasm – Mucus production – Inflammation
Describe the complications associated with chronic bronchitis
- persistent inflammation with swelling and increased fibrosis/scarring
of the lining of the respiratory tract;
– increased number (hyperplasia) and size (hypertrophy) of both mucus- secreting glands and goblet cells—both of which contribute to the production of large volumes of thick mucus;
– variable degrees of bronchial smooth muscle hyperplasia; and
– increased bronchial wall thickness
– may lead to acidosis due to CO2 retention
– right sided heart failure due to pulmonary hypertension resulting
from constriction of pulmonary blood vessels
– peripheral oedema due to right sided heart failure
State two pathophysiological changes that occur in emphysema.
- Abnormal dilation of the
alveoli.
– Loss of lung elasticity.
Emphysema: is characterised by the loss of elastin and other major structural proteins in the lower airways, resulting in the
widespread destruction of alveoli.
-– The major pathophysiologic change that leads to this widespread destruction is the excessive release of proteolytic enzymes from neutrophils and alveolar macrophages.
Define ARDS and describe what it is.
- Acute respiratory disease
-prevents gas exchange - mostly associated with septicaemia
-Caused by a major lung injury e.g. inhaling chemicals, pneumonia,
septic shock, trauma.
– Creates oedema in the air sacs preventing gas exchange.
– Condition that gives rise to type 1 respiratory failure
symptoms fo ARDS
Difficulty breathing
– Low blood pressure and other organ failure
– Rapid breathing
– Shortness of breath
– Symptoms usually develop within 24 to 48 hours of the injury
or illness.
– Often, people with ARDS are so sick they cannot complain of symptoms.
Define pulmonary oedema and discuss how it develops.
Fluid accumulation in the tissue and air spaces – Leads to impaired gas exchange – Causes: – Cardiogenic (LVF/CHF leads to fluid backing up onto the lungs) – Non-cardiogenic (hypertensive crisis, upper airway constriction, neurogenic causes)
