Resporstory Flashcards
Within the larynx, what anatomical feature would you typically expect to find at C3 vertebral level?
Hyoid
Within the larynx, what anatomical feature would you typically expect to find at C4 vertebral level?
Top of thyroid cartilage
Within the larynx, what anatomical feature would you typically expect to find at C6 vertebral level?
Cricoid cartilage and thyroid
What anatomical feature would you typically expect to find at T2 vertebral level?
Suprasternal notch
What anatomical feature would you typically expect to find at t4/5 vertebral level?
Carina
Where would you typically create a surgical tracheostomy
2nd and 3rd tracheal rings
How many lobes in left lung
2
How many lobes in right lung
3
What cranial nerves supply the larynx via the pharyngeal plexus
IX Glossopharyngeal
X Vagus
XI accessory
Name the two nerves that supply the larynx
Superior laryngeal nerve (SLN)
Recurrent laryngeal nerve (RLN)
Name the blood supply to the larynx
Superior and inferior laryngeal artery
Where does the trachea start
Below the cords / C6
What vessels follow airways
Pulmonary arteries follow airways, veins don’t
Inspiration muscles:
Sternocleidomastoid (elevates sternum)
Scalenes (elevate upper ribs)
External intercostal muscles
Interchondral muscles (inner half of chest wall)
Diaphragm
Active expiration muscles
Mostly passive
Active:
Internal intercostal
Abdominal
External and internal oblique
Describe tidal volume
Volume of breath during normal breathing (6-8ml/kg)
Describe inspiratory reserve volume
Excluding TV, volume that can be inhaled with maximum effort
Describe expiratory reserve volume
Excluding TV, volume that can be exhaled upon maximum effort
Describe residual volume
Volume left in lungs following maximum exhalation
Describe vital capacity
Total volume that can be inhaled and exhaled
Total lung capacity
Total volume that the lungs can bare, including vital capacity and residual volume
Inspiratory capacity:
Volume including normal tidal volume and inspiratory reserve volume
Functional residual capacity
Volume left in lungs after normal exhalation (TV)
Describe dead space
An area that is ventilated but does not partake in gaseous exchange
Anatomical dead space: mouth and trachea (& equipment)
EXAMPLE:
PE, ETT, ventilator
Describe shunt
Blood passed through the lung/tissue without gaseous exchange
Perfused but not ventilated
EXAMPLES:
Pneumonia, pulmonary oedema
Describe Ventilation-Perfusion (V/Q) mismatch
Presence of shunt / dead space causing pathological discrepancy between ventilation and perfusion
Describe shunt fraction
Percentage of cardiac output from the left ventricle not oxygenated
Name the 3 gas laws
Boyles
Charles
Gay Lussacs
Describe boyles law
Constant = temperature
Pressure & volume inversely proportional
Describes Charles law
Constant - pressure
Temp & volume directly proportional
Describe Gay Lussacs law
Constant - mass/volume
Pressure & temperature are directly proportional to
Describe atmospheric pressure
1 ATM = 101KPa = 760 mmHg
Describe a gas
Substance in gaseous form above critical temperature
Describe critical temperature
Temperature below which gas cannot be liquified with pressure alone
Describe Dalton’s law
In a mixture of non-reactive gasses, total pressure is equal to the sum of all individual gasses
(Gas1+gas2=total pressure)
Describe Henry law
Quantity of gas dissolved in liquid is proportional to:
-partial pressure
-solubility
Describe oxygen cascade
Progressive reduction in partial pressure of oxygen in the blood as it travels through the body.. starting at 21% air..
Name 2 methods of oxygen transportation in the blood
Bound to haemoglobin (97%)
Dissolved in the blood (3%)
How many oxygen molecules can bind to a haemoglobin molecule
4
Oxygen binding is cooperative - easier to bind as more are attached
Fully saturated haemoglobin:
describe huffners constant
1.34ml of oxygen per Gram of HB
Deoxyhaemoglobin is what type of structure and affinity
Tight structure with low affinity for oxygen
As oxygen binds it relaxes and increases affinity / desire for more oxygen to bind
Which part of haemoglobin does oxygen bind to
Iron atom on the haemoglobin
Describe oxygen dissociation curve
Represents the association between partial pressure of oxygen pa02 and saturated haemoglobin sa02 with respect to changes in physiology.
Shift to the right / left..
Causes of a RIGHT shift of the oxygen dissociation curve
(Reduced affinity)
LOW ph
HIGH c02 - bohr effect
High Temperature
High 2, 3 DPG
Describe bohr effect
Excess c02 that dissolves in the blood combines with 02 to create hydrogen ions and reduce PH
Reduces haemoglobin affinity to oxygen
Causes of shifting oxygen dissociation curve to the LEFT
(Increase affinity)
HIGH PH
LOW C02
LOW Temperature
LOW 2,3 DPG
THINK: Hypothermia lowers metabolic drive and thus requirement for oxygen, HB still saturated so higher affinity
How is carbon dioxide carried in the blood?
- As bicarbonate (H20 + C02 = H2C03)
- Carbamino compounds (C02 binds with proteins including Hb)
- Dissolved (C02 is 20x more soluble than 02 in plasma)
Symptoms of superior laryngeal nerve injury:
Cricothyroid paralysis causing hoarseness
Symptoms of recurrent laryngeal nerve injury:
Cord paralysis
Unilateral hoarseness
Bilateral stridor
What are the central controllers of breathing in the brain stem
Medulla and Pons
What chemoreceptors respond to paC02
Central chemoreceptors (medulla)
What chemoreceptors respond to pa02 and blood ph
Peripheral chemoreceptors (carotid/aortic arch)
