The Hyoid bone is located at what vertebral level
C3
Whats this
epiglottitis
Describe what would happen in V/Q mismatch when there is reduced perfusion (i.e. embolism)
decreased ventilation via bronchoconstriction
Which law describes how air flows down a pressure gradient
What breathing pattern can be described as that which exceeds metabolic demand?
hyperventilation or tachypnea?
hyperventilation
Identify the internal intercostal muscles
middle layer in an 'A' orientation
A stridor is an indication of
partial airway obstruction (where it is heard can indicate location)
Are mucous glands innervated? How are they important to lung protection?
yes (by vagus nerve). Important for mucous secretion
Why does pulmonary edema lead to an increase work of breathing (relating this to the Ficks law)?
According to Ficks law, diffusion is dependent on surface area, concentration gradient, diffusion distance and diffusion coefficient. In pulmonary edema, there is increased diffusion distance.
Explain why sinusitis can often cause toothaches and facial pain
Nerve supply of sinuses is shared by nerves that supply face and teeth (trigeminal nerve V1-2)
Name the paired sinuses
4 paired sinuses: frontal, maxillary, ethmoidal + sphenoidal.
Other = paranasal
Name histological findings of squamous cell carcinoma (often found in URT)
prominant nucleoli
pleomorphic nuclei
keratin pearls
abdundant eosinophilic cytoplasm
lymphocytic infiltration
Name the sensors of the respiratory system (and therefore provide input to the brainstem about altering RR) [5]
central chemoreceptors
peripheral receptors
lower airway receptors
upper airway receptors
skeletal muscle receptors (proprioreceptors)
If the partial pressure of oxygen in the alveoli were to decrease, what would you expect to happen to oxygen solubility in the alveolar capillary blood?
Henry's law dictates that the concentration of gas in liquid (blood) is proportional to its partial pressure above the liquid (in alveoli). Hence, a decrease in partial pressure of oxygen would cause a decrease in solubility. A decreased solubility can also occur in warming (which can bubble out of a solution and cause an air embolism)
Intrinsic laryngeal muscles are innervated by the vagus nerve. The cricothyroid muscle is innervated by which branch?
superior laryngeal nerve
Name the muscles of the suprahyoid and their function as a group
Geniohyoid, Mylohyoid, Digastric, Sytlohyoid (Geese, my dad's stylish)
function = elevate hyoid assisting in opening mandible
What is sinusitis? what are potential Cx?
sinusitis (inflammation that causes blockage)
Cx: polyp, retention cyst, abscess
Draw a feedback loop for forced breathing including DRG/VRG, nerves and muscles used
insp: DRG and inspiratory centre of VRG active, expiratory VRG inactive --> inspiratory muscles contract (external intercostals via T1-11, diaphragm via phrenic, scalenes, SCM and maybe pec major too) while expiratory relax (internal intercostals, abdominal muscles i.e. rectus abdominus, obliques, transverse abdominus) --> inspiration
exp: DRG and inspiratory centre of VRG inactive, expiratory VRG active
Draw the respiratory volumes and capacities
all respiratory muscles functional - so wouldn't
cough reflex also intact (above T12 is diff story tho)
Label the function of the intrinsic laryngeal muscles:
cricothyroid
thyroartenoid
posterior, and lateral cricoarytenoid
oblique and transverse arytenoid
cricothyoid = tenses vocal lig by pushing cricothyroid forward
thyroartenoid = relaxes vocal ligament by pulling cricothyroid back
posterior cricoarytenoid = abduction (connected posteriorly, hug cricothryoid)
rest = adduction
Premmie babies have a hard time breathing. Why might this be?
Often don't have a lot of surfactant --> surfactant is important for decreasing surface tension and eases alveolar inflation
Lungs also not fully developed
What are the adaptive mechanisms (acute and chronic) of being at high altitude? Why is this potentially bad?
main issue = decreased Patm = decrease FiO2 = decreased PAO2 = decreased PaO2 = hypoxemia
acute
hyperventilation --> decreased PCO2 --> increased pH [respiratory alkolosis]
increased sensitivity of chemoreceptors
chronic
increased HCO3 reabsorption with decreased H excretion
increased EPO
increased 2-3 DPG (to decrease affinity)
Explain how inspiration is possible (talking about thoracic pressure, intrapulmonary pressure, atmospheric pressure and intrapleural pressure). Bonus (brownie) points for what nerves and brain centres are involved.
1. C3-5 causes the diaphragm to contract while T1-T11 activate the external intercostal muscles (these are stimulated by the DRG). This causes an increase in thoracic volume and therefore a decrease in pressure.
2. Intrapleural pressure decreases as parietal pleura is pulled away
3. This causes a decrease in intrapulmonary pressure
4. Air flows in (down a concentration gradient) until pulmonary pressure = atmospheric pressure
Draw flow-volume loops for: normal person, restrictive lung disease + obstructive lung disease