Alterations to Respiration Flashcards
1
Q
What is the role of the Respiratory System?
A
- sense of smell
- speech
- acid-base balance
- fluid balance
- gas exchange
2
Q
What is Ventilation?
A
Movement of gases between the lungs and the environment
3
Q
What is Perfusion?
A
Movement of blood through the lungs
4
Q
What is Diffusion in the respiratory system?
A
Movement of gases between the lungs and the blood
5
Q
What is the purpose of the lower airway?
A
ventilation and gas exchange
6
Q
What is the purpose of the upper airway?
A
filter, warm and moisten incoming air
- allows better gas exchange and diffusion through the alveoli
7
Q
What does the upper airway compose of?
A
- nose
- sinuses
- pharynx (throat)
- larynx (voice box)
8
Q
What are Anterior Nares?
A
Are lined with hair follicles which trap foreign particles and stops them from entering the lungs
9
Q
What are Turbinates?
A
Tree bony projections which protrude into the nasal cavity
- they increase SA = more trapping of pathogens
- covered in mucous and trap pathogens that have not filtered by the vibrissae
10
Q
What are Cilia?
A
- Lines the bronchus and bronchioles
- Hair-like projections that push pathogens/debris in the mucous up the airways - where it is cough out
- If respiratory secretions thicken, the cilia may be prevented from moving freely thus impairing the protective function of the mucociliary defence system
11
Q
What is the Pharynx?
A
Tube or cavity that connects mouth and nasal passages with the oesophagus
- It is divided into three parts
Nasopharynx
Oropharynx
- both air and food through
- extends posteriorly from the soft palate to the epiglottis
- any obstruction leads to immediate cessation of ventilation
Laryngopharynx
- connects the oropharynx to the trachea
- when air contains foreign substances, the laryngeal muscle close the airway and a cough reflex is initiated
12
Q
What is the Epiglottis?
A
Leaf shaped structure
- during swallowing the edges of the epiglottis moves down to cover the larynx thus routing food and drink to the oesophagus
13
Q
What does the lower airway consist of?
A
- Trachea
- Two main stem bronchi
- lobar segmental, and subsegmental bronchi
- Bronchioles
- Alveolar ducts
- Alveoli
14
Q
What is the tracheobranchial tree?
A
consists of trachea bronchi & bronchioles
- branching network of tubes
- approx. 23 levels of branching, increasingly narrower tubes
15
Q
What is the Trachea?
A
- Windpipe
- connects larynx with major bronchi of the lungs
- carina has sensitive mucous and will initiate coughing if irritated
- walls supported by C-shaped rings of hyaline cartilage - this prevents the trachea from collapsing when the pressure of the thorax becomes negative
16
Q
What is the Bronchi?
A
- primary bronchi has similar to the trachea
- smallest of the conducting airways
- no cartilage present and there is an increase in smooth muscle and elastic fibres
- bronchospasm can cause contraction of the smooth muscle which narrow the bronchioles and impairs airflow
17
Q
What is the function of the lungs?
A
- gas exchange
- inactivate vasoactive substances e.g. Bradykinin
- convert angiotensin 1 to angiotensin 2
- reservoir for blood storage
- heparin producing cells are in abundance in the capillaries of the lungs to prevent small clots
18
Q
What are respiratory lobules?
A
- where gas exchange takes place
- each loluble is the smallest functional unit of the lung
- supplied by a terminal bronchiole, arteriole, pulmonary capillary and a venule
- gas exchange takes place in the terminal respiratory bronchiole, alveolar ducts and alveoli
19
Q
What are alveolar ducts and alveoli?
A
- alveolar ducts are lined with simple epthelium
- alveoli are cup shaped, thin wall structures
- 300 million in adult lung
2 types of alveolar cells
- type 1 - allows gas exchange to occur
- type 2 - produce surfactant to prevent alveoli from collapsing
20
Q
Describe the gas exchange process
A
oxygen moves from alveoli to pulmonary capillaries as dissolved gas
- moves down partial pressure gradient
Oxygen
- Alveoli PO2 is 100mmHg – venous end of pulmonary capillary PO2 is 40mmHg
Carbon dioxide
- pulmonary capillary PCO2 is 45mmHg
- alveoli PCO2 is 40mmHg
21
Q
Describe lung circulation
A
- has a dual supply
pulmonary and bronchial circulation - distributes blood to the conducting airways and supporting structure of the lungs
- warms and humidifies air in conducting airways
- bronchial blood vessels are the only ones to undergo angiogenesis when vessels in the pulmonary circulation are obstructed
- Pulmonary circulation brings deoxygenated blood from the right of the heart via the pulmonary artery
- Oxygenated blood returns via the pulmonary veins into the left artium
22
Q
What is the Pleura?
A
Thin and double layered serous membrane
- space between is the pleural cavity contains small amount of fluid
- surface tension of the pleural fluid also brings the lungs surfaces with the chest wall close together –> allows greater inflation of the alveoli during respiration
23
Q
What happens during inspiration?
A
- chest cavity increases due to the movement of the respiratory muscles expanding the chest cage
- intrathoracic pressure become negative
- air is drawn into the lungs
24
Q
What happens during expiration?
A
- largely a passive process
- chest wall and lung structures recoil decreasing the size of the chest cage
25
Describe the concept of "Lung Compliance"
ability for the lungs to be inflated
- measure the change in lung volume that occurs with the change in intrapulmonary pressure
- determined by elastin and collagen fibres, water content, surface tension and compliance of the thoracic cage
26
Pulmonary Oedema
Fluid accumulation in the tissue and air spaces of the lungs
Leads to impaired gas exchange and may cause respiratory failure.
27
Hypoxaemia
Reduced concentration of oxygen in the blood
28
Hypercapnia
Increased concentration of CO2 in the blood
29
Dyspnoea
Feeling of breathlessness
- V/Q mismatches
- lung diseases
- may relate to stretch receptors
30
Hypoventilation
Decreased alveolar ventilation (leads to respiratory acidosis)
- inadequate ventilation to perform gas exchange
31
Hyperventilation
Increased alveolar ventilation (leads to respiratory alkalosis)
32
Haemoptysis
Coughing up bloodly mucous
33
Cyanosis
Bluish discolouration of the skin by desaturation of haemoglobin or peripheral vasoconstriction
34
What is lung consolidation?
region of lung tissue which usually contains gas is filled with fluid
it can be
- pulmonary oedema
- exudate
- pus
- inhaled fluids
- blood
35
What is pleural effusion?
- excess fluid in the pleural cavity
- compresses the lungs and restricts lung expansion during inhalation
fluid may be from
- pus
- blood
- serous fluid
- larger effusion may require an intercostal drain
36
Pneumothorax
condition where air enters the pleural cavity separating the visceral and parietal pleura destroying the negative pressure
- can be classified as primary and secondary
(fractured ribs and COPD)
37
What is a Shunt?
Perfusion without ventilation
- occurs when alveoli of the lungs are perfused with blood but there is not supply of air to the region of perfusion
- often from alveoli filled with fluid
- blood leaving area with low levels of oxygen and increased amounts of carbon dioxide
38
Dead air space
volume of inhaled air which does not take place in gas exchange either because:
- it is in the conducting zone
- it is in alveoli that are poorly perfused
poor perfusion can be caused by blood clot - pulmonary embolism
39
Coughing
- protective and neurally mediated reflex
- protects lungs from accumulation of secretions and foreign particles
- initiated by receptors in the tracheobronchial wall
- cough reflex may be impaired by diseases that impaired by diseases that impair or weaken the abdominal and respiratory muscles
40
Tissue hypoxia
- blood vessels in the pulmonary circulation undergo significant vasconstriction when exposed to hypoxia
- enables blood to redirected from areas with poor ventilation to areas with good ventilation to enable maximum oxygen delivery
- if alveolar oxygen falls below 60mmHg, marked vasoconstriction will occur and blood flow to the area may eventually cease
41
Chronic Obstructive Pulmonary Disease
Group of progressive respiratory disease that increase resistance to airflow
- cause of hypoxaemic and hypercapnic cases
- co-exist with emphysema, asthma, chronic bronchitis
e.g. bronchial asthma prevents airflow via constriction of the smooth muscle in the airways and mucous production
42
Chronic Bronchitis
Chronic inflammation of the bronchi
- Persistent cough which is productive (produces sputum & mucus)
- Chest x rays shows prominent vessels
Smoking is the most common cause
43
Emphysema
Alveoli are destroyed
- reduces SA for gas exchange and makes them unable to hold shape on exhalation
- Chest x ray shows hyperinflation
smoking is the most common cause
44
Asthma
chronic inflammatory disease characterised by reversible airway obstruction and bronchospasm
- mucous production blocks inflamed airway
- shortness of breath
- linked to genetic and environmental factors
45
Atelectasis
Incomplete expansion of the lung or a portion of the lung
- lung compression e.g. pneumothorax
- caused by pleural effusion
- increased lung recoil due to decreased surfactant
46
Acute Respiratory Distress Syndrome
severe lung syndrome caused by direct and indirect factors
- inflammation of the lungs leading to impaired gas exchange
- release of inflammatory mediators, hypoxaemia and multiple organ failures
often fatal and need intensive care
47
List some infections of the pulmonary system
influenza
Tuberculosis is caused by a bacterial infection causing scar tissue in the lungs
Bronchiolitis is an inflammation and obstruction of the small airways due to infection and most common in children
48
Pneumonia
Inflammation of the lung structures e.g. alveoli and bronchioles
- can be caused by bacteria, virus and gastric secretions
49
Obstructive Sleep Apnoea
Partial or complete airway obstruction during sleep
- disrupting sleep patterns and decreasing ventilation
it is developed from smoking, increased age, obesity and being male
50
What is Croup?
Acute inflammation of the upper respiratory tract
- occurs usually in children aged between 6 months to 5 years as they have smaller airways
- airway obstruction occurs (subglottic region) due to mucosal oedema and secretions related to the viral infection
- patient initially has a sore throat that develops into a barking cough
- usually resolves with 1 to 2 days
