Lungs: Fine-tuning Flashcards
What happens to pH of the blood as it passes through systemic capillaries
It decreases
How is the efficiency of O2 transmission to cells affected as blood passes through systemic capillaries
The oxygen dissociation curve shifts which causes MORE O2 to be delivered to the cells
Is the airway involved in the swallowing reflex and vomiting reflex. If so, how?
They are:
Swallowing reflex - Respiration is INHIBITED to prevent aspiration of food
Vomiting Reflex - Oesophagus relaxes and the glottis is CLOSED
What happens to the amount of surfactant as the lungs inflate and why is this the case
The amount of surfactant decreases to prevent OVERINFLATION
What happens to the amount of pulmonary surfactant when blood flow is interrupted
The amount of surfactant decreases when pulmonary blood flow is interrupted as this occlusion causes the lungs to collapse
How does lung residual volume vary as people age?
The lung residual volume INCREASES
Tidal Volume DECREASES
How does the lung volume level at which small airways start to close during expiration change with age
Increases with age
At what stage of inspiration is INTRAPLEURAL PRESSURE is lowest?
End of inspiration
At what stage of inspiration is INTRAPULMONARY PRESSURE lowest?
mid-inspiration
At what stage of inspiration is INTRAOESOPHAGEAL PRESSURE lowest?
end of inspiration
An increase in CO2 uptake causes an equal increase in HCO3- and H+. True or False?
False
H+ is largely buffered by haemoglobin so it doesn’t enter the blood while HCO3- is
What has the highest conc in arterial blood, CO2 or O2
CO2
What is usually bigger, the rate of perfusion or the rate ventilation
Rate of perfusion
What receptors bring about bronchoconstriction
M3
Describe the hering-breuer inflation reflex
- Stretch receptors found throughout the bronchi and bronchioles send impulses down the vagi to the DRG when stretched
- Stops APs being transmitted to inspiratory muscles, causing them to RELAX
Describe the flow-volume curve
Flow into the lungs increases as volume increases initially until we reach a peak called the peak expiratory flow. The flow rate begins to decrease as we reach the end of inspiration
We then reach FVC
Flow reaches a lower peak during inspiration (the peak inspiratory flow)
What does the volume-time curve of a spirometer show
FEV1 + volume of air breathed out during maximal exhalation
What kind of receptor is M3
G-coupled
What do M3 receptors cause in the bronchioles
Increased intracellular Ca2+ - BRONCHOCONSTRICTION
What do M3 receptors cause in the endothelium
Increased release of NO - VASODILATION
What binds to beta-2 receptors
adrenaline
When is beta-2 receptor binding adrenaline released
When noradrenaline binds to the adrenal glands - BRONCHODILATION
When is compliance of lung greatest (spirometer wise)
Within the normal range of the tidal volume
What happens to the rate of ventilation at high altitudes
Increases
What happens to the blood pH at high altitudes
Increased ventilation causes respiratory alkalosis (increased pH)
What is the difference between the right and left main bronchus
Right is wider, shorter and more vertical than the left
Is the right or left bronchus more prone to aspiration
Right as it’s more vertical
At what level do the trachea divide into the left and right main bronchus
T5 (Carina)
How many branches of the left bronchi are there
2
How many branches of the right bronchi are there
3
What does the main bronchi divide into
Lobar bronchi
What does the lobar bronchi divide into
Segmental bronchi
What does the segmental bronchi divide into
Terminal bronchi
What does the terminal bronchioles divide into
respiratory bronchioles
How many segmental bronchioles are there in the right and left lung
Right - 10
Left - 8
At what vertebral level does the trachea begin at
C6
What innervates the vocal folds
Vagus nerve
Where are the vocal folds located
Larynx just under the trachea
What structure do the vocal folds belong to
Rima Glottidis
What is the rima glottidis
The opening between the true vocal cords and arytenoid cartilage of the larynx
What muscles cause the closure of the rims glottides
Lateral cricoarytenoid and arytenoid muscles
What is the rima glottides opened by
Posterior cricoarytenoid muscle
How do the vocal folds produce noise
They are brought close enough together that air pressure begins to build up below the larynx
Eventually the sub glottal pressure pushes the folds apart producing sound
What cartilage is the corniculate made of
Elastic cartilage
What cartilage do the corniculate articulate with
Arytenoid
What is the role of the corniculate
Prolong cartilage posteriorly and medially
Where can we find the corniculate cartilage
In the aryepiglottic fold
What structure is attached to the arytenoid
Vocal cords
Role of the arytenoid
Allow vocal cords to be tensed and relaxed
What cartilage is the cuneiform made of
Elastic
Where are the cuneiform cartilage found
Aryepiglottic fold
What is the laryngeal inlet
An opening that connects the pharynx to the larynx
What forms the border of the laryngeal inlet
Anteriorly by the epiglottis
Posteriorly by arytenoid and corniculate
Inferiorly by the aryepiglottic fold
Define ‘functional residual capacity’
The volume of gas PRESENT in the lungs when respiratory muscles are completely relaxed
How does standing upright affect the distribution of air in the lungs
Alveoli at the apex recieve more air than those at the base due to gravity
How does the size of the alveoli in the lungs vary
Those further towards the apex are larger than those closer to the base - due to gravity
At what level is FiO2 supplied to patients and why can’t it be higher than this
0.5, can’t be higher because oxygen toxicity can occur.
What muscle fixes the 12th rib during inspiration
Quadratus Lumborum
