The Respiratory System Flashcards
The Lungs 4 Functions
To extract O2 from the atmosphere and transfer it to the bloodstream in the lungs.
To excrete water vapour and CO2.
To maintain the normal acid-base balance of the blood.
To ventilate the lungs.
the exchange of gas occurs in 2 places
External respiration - in the lungs
Internal respiration - in the body tissues
process of gaseous exchange is called
diffusion - Movement from a high to low concentration.
External Respiration
the process of breathing where:
oxygen from inhaled air is absorbed into the blood via the capillaries of the lung.
CO2 is released from the blood into the lungs and is exhaled.
Internal Respiration
blood and the circulatory system carries O2 to the body cells. O2 is given off for use by the cells and CO2 is absorbed by the blood which is carried to the lungs.
2 respiratory movements
Inspiration - breathing in or inhalation
expiration - breathing out or exhalation
components of inspired air
O2 = 20% Nitrogen = 79% inert gas = 1% CO2 = 0.04% Water Vapour (variable)
components of expired air
O2 = 16% Nitrogen = 79% CO2 = 0.4% (100% increase) Water Vapour (to saturation/100% increase)
17 components of the respiratory system
Nose Mouth Soft Palate Pharynx Epiglottis Larynx Trachea Carina Parietal Pleura Serous Fluid Visceral Pleura right/left bronchus Bronchi Bronchioles Alveolar Ducts Alveoli Diaphragm
Structure of the Lungs
2 Spongy, Cone shaped Organs.
Right has 3 lobes.
Left has 2 Lobes.
The Pleura
is a serous membrane that surrounds each lung.
it has 2 layers: Parietal and Visceral
normal breathing rate for an adult
16 to 24 BPM
normal breathing rate for infants and children
24 to 40 BPM dependant on age. younger = faster
factors that can Increase breathing rates
Exercise
Fever
Clinical Shock
Conditions affecting the lungs (pneumonia, bronchitis)
factors that can Decrease breathing rates
Conditions which affect the brain (CVA, head injury) Certain drugs (Heroin, Methadone, Barbiturates)
Control of respiration - involuntary
rate & depth automatically controlled by the respiratory centre & various other receptors
Control of respiration - voluntary
concious control of breathing as in holding breath
Chemoreceptors
in the brain and aorta monitor levels of CO2 in the blood.
increase in CO2 = increase in breathing rate & depth
Dsypnoea
difficulty breathing
Apnoea
absence of breathing
Hypoxia
lack of O2 supplied to the tissues
Hypercarbia
too much CO2 in the blood
Obstructive Airways Diseases
Bronchitis
Emphysema
Asthma
Bronchitis - what is it?
inflammatory condition affecting the airways caused by viruses or bacteria.
usually a short lived infection
Common in young children and the elderly
Bronchitis - signs and Symptoms
Tachycardia (fast HR) Tachypnoea (fast breathing) Dyspnoea (Diff Breath) Cyanosis (blue bloater) Reduced O2 saturation (SpO2) BP normal or slightly raised Productive cough
Bronchitis - signs and Symptoms
Use of accessory muscles
Pupils may be dilated or slow to react
If hypoxia is severe LOC may be reduced
May be evidence of oedema (build up of fluid in tissue)
Auscultation (listening) usually reveals Rhonci ( coarse rattling) and wheezes
Emphysema - what is it?
distension of the alveoli
&
destructive changes in their membranes
Emphysema - signs and symptoms
usually thin Tachycardia (fast HR) Tachypnoea (fast breathing) cardiac dysrhythmias (irregular heart beat) Dyspnoea (diff breath) skin colour usually normal (pink puffer) use of accessory muscles difficulty in exhaling pursed lips on expiration
Emphysema - signs and symptoms
BP usually elevated
Cyanosis may be evident in acute attack
patient will appear to have have abnormally large chest (barrel chested)
Wheezing and crackles may be heard on auscultation - mainly on inspiration
possible evidence of oedema
Asthma - what is it?
A narrowing of the medium to smaller air passages due to muscle spasm.
Swelling and blockage by secretion of mucous from inflammatory cells.
Asthma - signs and symptoms
Tachypnoea Dyspnoea, respiratory distress, cyanosis sitting up, leaning forward, anxious use of accessory muscles usually and expiratory wheeze difficulty exhaling low peak flow reading
breathlessness/Dyspnoea
common symptom of respiratory disease including pneumonia, asthma and other COPDs
also common in non-respiratory conditions (cardiac failure, hypovolaemic shock)
breathlessness/Dyspnoea - management
Primary survey, provide O2 as appropriate
Position patient for comfort (usually sitting upright)
Evaluate whether any time critical features are present
peak flow
Hyperventilation - definition
A rate of ventilation higher than that required to maintain a normal level of plasma CO2
Hyperventilation - management
maintain a calm approach and manner at all times.
reassure the patient and try to remove the source of the patients anxiety if this is believed to be the cause of hyperventilation.
coach the patients respirations whilst maintaining a calm environment.
Hypoxic Drive
in patients with severe COPD the levels of CO2 in the blood is permanently raised.
They also have low levels of O2 in the blood (hypoxia) due to poor respiratory function.
As a result the respiratory centre in the brain utilises this hypoxia as the stimulus to breathe.
