Flashcards
Respiratory
Cards in this deck (58)
- 1What is the difference between functional residual capacity and residual volume?Functional residual capacity is the volume of air remaining in the lungs after passive expiration however residual volume is the amount of air remaining in the lungs after maximal exhalation
- 2What is the value for vital capacity?4.8L (4800ml)
- 3What is the value for functional residual capacity?2.2L (2200ml)
- 4What is the normal value for expiratory reserve volume?1.0L (1000ml)
- 5What is the value for inspiratory capacity?3.8L (3800ml)
- 6What does alveolar ventilation rate tell us?The amount of fresh gas avaliable for gas exchange
- 7How can compliance be measured graphically?By taking the gradient of a volume vs transpulmonary pressure graph
- 8What measurements cannot be taken using a spirometer?Functional residual capacity, total lung capacity, residual volume
- 9What is the normal value for tidal volume?0.5-0.6L (500-600ml)
- 10What is the value for vital capacity?4.8L ( 4800ml)
- 11What is the value for residual volume?1.2L (1200ml)
- 12What is the normal value for inspiratory reserve volume?3.2L (3200ml)
- 13What is the value for total lung capacity ?6.0 L (6000ml)
- 14What is happening if the VA:Q ratio is 0?Blood is passing through the lung without coming into contact with alveolar air
- 15Give two functions of the pulmonary circulation.Any two from:
provides nutrition to the alveoli and airways, acts as a blood reservoir, provides filtration of the blood and metabolises vasoactive substances - 16If a VA:Q ration is ∞, where is this?An anatomical dead space or ventilated alveolus that isn't perfused
- 17How are pulmonary arterial walls different from other arterial walls?They are very thin and contain little smooth muscle
- 18What are the responses that help maintain low pressure that dont require any muscle/nervous input?Recruitment of capillaries - act to increase the surface area of lungs and increase passage through lungs and distension of capillary segments- acts to reduce resistance
- 19What is the equation for vascular resistance?input pressure-output pressure
÷
blood flow - 20How is vascular resistance affected when the lungs are fully inflated?Vascular resistance decreases as the vessels are pulled open by surrounding lung parenchyma
- 21Name two things that can result from pulmonary hypertension?Hypertrophy of R.V which can lead to right ventricular heart failure and pulmonary oedema (blood goes out of vessels and into the lungs)
- 22What is the pressure difference between the top and bottom of the lungs?23mmHg or 30cm H₂O
- 23What does hypoxia mean?Reduced pO₂ levels, the fall below the usual 98mmHg- can occur at high altitude.
- 24What occurs in response to hypoxia?pulmonary vasoconstriction
- 25What does hypercapnia mean?Raised pCO₂ of >40mmHg. CO₂ dissolves in water to give H+ therefore it causes a drop in blood pH. It usually occurs where there is inadequate gas exchange e.g. breathing disorders
- 26What occurs in response to hypercapnia?Vasoconstriction
- 27How is RAW (airway resistance) affected by change in lung volume?Airway resistance increases with decrease in lung volume
- 28What is radial traction?As the lung expands, connective tissue pulls on bronchioles so their diameter expands and RAW (airway resistance) falls
- 29Where does dynamic compression occur?From the bronchioles downwards. It can only occur where there are no-cartilaginous rings holding the airways open
- 30Name two things that cause bronchioconstriction.Parasympathetic innervation (vagal stimulation), a fall in pCO₂, asthma, and irritants causing bronchioconstriction e.g. inflammation of airways
- 31Name two things that cause bronchiodilation.Autonomic stimulation, local mediators, sympathomimetic agents (β₂ agonists)
- 32Name two things that can increase RAW (airway resistance)?Mucus and inflammation (causes a narrowing and occlusion of the airways)
- 33What is the mean arterial pressure in the pulmonary circulation?25/10mmHg
- 34Why is the diaphragm the most important muscle for respiration?Because contraction of the intercostal muscles aren't sufficiently strong to change the volume of the thorax (damage to the phrenic nerve results in the need of a ventilator to breathe)
- 35What happens to intrapleural pressure when the volume of the thorax increases?It falls/becomes more negative allowing air to flow into the lungs as alveolar pressure < atmospheric pressure
- 36By what method can we estimate the anatomical dead space?Via Fowler's method of N₂ washout from the lungs
- 37By what method can we measure the physiological dead space?Via the CO₂ content of the expired and alveolar air via the Bohr equation
- 38Why is the work of inspiration greater than the work of expiration?Because of resisitive forces that oppose the airflow- energy is required to overcome the airways resistance (also pulmonary tissue resistance and inertia of air and tissues)
- 39Why is energy required for expiration so much less?Because the energy for expiration is largely derived from the stretching of the elastic elements in the lungs and chest during inspiration. Resistive forces asist airflow
- 40In a healthy person, what is the volume of air in the anatomical 'dead space'?150-180ml- this is the volume inside the upper respiratory tract to the terminal bronchioles (doesn't take part in gas exchange)
- 41What effects can diseases which increase the physiological dead space (e.g. damages to the chest wall and paralysis of respiratory muscles have on ventilation rate?They can cause hypoventilation
- 42What is meant by the term hyperventilation?Ventilation that is in excess of metabolic needs. CO₂ exhaled at a greater rate than production. pCO₂ falls <40mmHg and pO₂ rises >98mmHg.
- 43What conditions or under what cirumstances can hyperventilation occur?During an acute asthma attack or under conditions of stress or altitude and during forced expiration e.g. blowing a balloon or musical instrument
- 44What is meant by the term 'physiological dead space'?The sum of the anatomical and alveolar dead space. However in HEALTH all of the alveoli take part in gas exchange so physiological dead space EQUALS anatomical dead space
- 45What is meant by the term 'dead space'?A volume of the lung that doesn't participate in gas exchange e.g. the trachea
- 46What do we mean by air conditioning?Warming up of the air before it enters the lungs and the purifying of it. (cilia and mucus trap particulates preventing them from going onto gas exchange surfaces)
- 47What is the average breathing rate?12 breaths/min
- 48What is alveolar ventilation rate?(tidal volume-dead space)x breathing rate
- 49What is the normal value for tidal volume?500ml
- 50What is the conducting zone primarily made up of?Dead space
- 51What structures of the bronchial tree are found in the transitional and conducting zones?Respiratory bronchioles, alveolar ducts and alveolar sacs
- 52What is the normal value of O₂ in arterial blood?98mmHg (13kPa)
- 53What is the normal value for CO₂ in arterial blood?40mmHg (5.3kPa)
- 54What is the definition of hypoventilation?Inadequate ventilation of the lungs. CO₂ is being produced and isn't being expelled. O₂ is being used up but isn't being replaced
- 55What is used to reduce surface tension in the liquid lining of the alveoli?Surfactant. It is a special fluid produced in the lungs that acts as a 'detergent' to reduce surface tension in the liquid layer of the alveoli. Makes it alveolar collapse less likely at lower pressures
- 56What is meant by the term compliance?The elasticity or distensibility of the lung
- 57What is the equation for compliance?Change in volume ÷ change in pressure
- 58When is compliance reduced?When elasticity is impaired e.g. fibrous tissue in the lungs ad when surface tension is increased (decrease in the production of surfactant- premature birth) This keeps alveoli small
Information
- Description
- Flashcards on Respiratory, created by reynoldslaura on 02/05/2013.
- Created by
- reynoldslaura
- Views
- 166
- Rating