Week 1 .1 Flashcards
What are 4 main purposes of the respiratory system?
Gas Exchange
Acid-Base balance
Protection from Infection
Communication via Speech
Internal vs External Respiration?
Internal respiration is within cells, releasing energy via glycolysis or oxidative phosphorylation
External respiration is using CVS and Resp systems to move gasses from external environment to inside, between body’s cells
What is the net volume of O2 and CO2 exchanged in the lungs?
250 L/min O2 and 200 L/min CO2
What is the normal breathing rate?
12-18 breaths/min
What is an acronym to remember anatomy of respiratory system?
APELT B
Airways (nose)
Pharynx
Epiglottis
Larynx
Trachea
Bronchi
Describe the pharynx
Part of both resp and digestive (alimentary) system
Describe the Epiglottis
Small flap of cartilage tissue, usually open but closes when we swallow to prevent food entering the trachea
Describe the Larynx
The voice box
Where does the lower respiratory tract begin?
Trachea and below, inc. bronchi and alveoli
What is the conducting zone vs the respiratory zone?
Conducting zone is trachea and bronchioles as membranes are toot hick for diffusion to occur.
Respiratory zone is alveoli as gas exchange occurs directly here
How many secondary bronchi are there on either side, and how many times does it split?
Bronchi on right have 3 secondary bronchi, while only 2 on left
Bronchi split 22 times on each side
What is the surface area of the alveoli? How much gas can each lung fit?
80m^2 fitting 3L in each lung
Where does resistance occur most commonly in the lung?
In the upper airways, e.g. trachea, then bronchi. This is because we only have 1 trachea compared to 80 million alveoli. Cross sectional area of trachea is far smaller, followed by bronchi
What is tidal volume and its normal value?
Volume of air breathed in at each breath - 500ml in and 500ml out
What do ERV and IRV stand for?
Expiratory reserve value and Inspiratory reserve value - max volume of air that can be released or drawn in
What is the reserve value and why does it exist?
Amount of air left over after maximal expiration. Stops lung collapsing
How many lobes are found in the lung?
Right has 3 loves - superior, middle and inferior lobe
Left has 2 lobes - superior and inferior
What is the pleural membrane and what 2 parts are there?
Inner and outer membranes of each lung. Visceral is attached to lung directly and Parietal is attached to rib cage. Contains interpleural fluid
What movement does the pleural membrane allow?
Movement of lungs with rib cage and diaphragm
What is boyles law?
Pressure = 1/Volume - they’re inversely related
What is Dalton’s law?
The total pressure of a gas mixture is the sum of the individual pressures of each gas in the mixture
What muscles do we use to perform inspiration?
External intercostal muscles and Diaphragm muscles
What muscles do we use to perform expiration?
None - its a passive movement due to revoking of elastic fibres. HOWEVER during forced expiration - e.g. sneeze, cough - we use internal intercostal muscles and abdominal muscles
What happens to thoracic volume during inspiration and expiration?
Inspiration - volume increases and air flows in
Expiration - volume decreases and air pushed out
What is intra-thoracic pressure and its value during inspiration and expiration?
Pressure inside the thoracic cavity. In inspiration, it decreases as volume increases. In expiration, it increases as volume decreases
What is intra-pleural pressure and why is it relevant?
Pressure within the pleural cavity. Should always be negative to maintain proper inflation of lungs and prevent pneumothorax
What is trans-pulmonary pressure?
Difference between intra-thoracic and intra-pleural pressure. Should always be positive as intra-pleural is always negative
