SEE Exam Questions with 100%
Correct Answers
Motor innervation to larynx Correct Answer: External superior laryngeal=
cricothyroid
Recurrent laryngeal= everything else
Sensory innervation to larynx Correct Answer: Internal superior laryngeal= above
vocal cords
Recurrent laryngeal= below vocal cords
What does the Posterior CricoArytenoid membrane do? Correct Answer: Pulls
the cords apart- ABDUCTS. "Please Open Airway"
What does the Lateral CrycoArytenoid membranes do? Correct Answer: Pulls
the cords together- ADDUCTS
What does the CricoThyroid membrane do? Correct Answer: tenses vocal
cords. "Cords Tense"
What does the ThyroArytenoid membrane do? Correct Answer: relaxes vocal
cords. "They Relax"
What muscle is the barrier to regurgitation? Correct Answer: Crycopharyngeus
muscle
Recurrent laryngeal nerve anatomy Correct Answer: concern with
thyroid/parathyroid surgery
if injured one side- hoarse voice
,if injured bilaterally- can cause complete airway obstruction due to inability to
abduct vocal cords
Laryngeal innervation Correct Answer: The recurrent laryngeal nerve (RLN) and
the superior laryngeal nerve (SLN) are branches of the vagus nerve (CN X). Injury
to them may occur during thyroid surgeries. The SLN (external branch)
innervates the cricothyroid muscle, which tenses and adducts the vocal cords.
Injury to the nerve can produce changes in voice quality, but is generally not
dangerous. Injury to the RLN is of more consequence, as it innervates all of the
intrinsic muscles of the larynx, except for the cricothyroid muscle which is
innervated by the SLN. A unilateral RLN injury produces abductor vocal cord
paralysis, so the affected cord assumes a paramedian position which causes
postoperative hoarseness (may be a delayed presentation of a few weeks).
Bilateral vocal cord paralysis, on the other hand, can manifest as partial vs.
complete airway obstruction. Symptoms include respiratory distress with stridor.
The situation often necessitates emergent reintubation or tracheostomy.
Oxyhemoglobin dissociation curve Correct Answer: Right shift unloads 02 from
blood (Right release)
-increased pC02, increased H+ acidosis, VA, increased temp, increased 2-3
DPG, sickle cell anemia, maternal hgb
Left shift increases 02 affinity loading (Left is locked)
-decreased pc02, decreased H+ alkalosis, decreased 2-3DPG, decreased
temp, CO poisoning (carboxyhemoglobin), fetal hgb, methemoglobin
(prilocaine, nitroprusside which change Fe2+ ferrous into Fe3+ ferric)
Bohr effect Correct Answer: Pac02 affects oxyhemoglobin dissociation curve
Right shift- how acidemia and hypercarbia affect unloading of 02 off of
hemoglobin
,CO2 + H2O ⇆ H2CO3 ⇆ H+ + H+CO3-
Haldane effect Correct Answer: How pa02 affects c02 dissociation curve
The Haldane Effect results from the fact that deoxygenated hemoglobin has a
higher affinity (~3.5 x) for CO2 than does oxyhemoglobin. Deoxygenated
hemoglobin has a higher affinity for CO2 because it is a better proton acceptor
than oxygenated hemoglobin. Therefore, when hemoglobin is deoxygenated
(i.e., at tissues) there is a right shift of the carbonic acid-bicarbonate buffer
equation to produce H+ which in turn increases the amount of CO2 which can
be carried by the blood back to the lungs to be exhaled. Then, with
oxygenation at the lungs CO2 dissociates more readily from hemoglobin.
CO2 + H2O ⇆ H2CO3 ⇆ H+ + H+CO3-
The following is the general equation of the Haldane Effect
H+ + HbO2 ←→ H+Hb + O2
How pa02 correlates to sa02 Correct Answer: pa02 40 %satshgb 70
50 80
60 90 (hypoxemia)
, 90 97
26 50
Calculating Dissolved 02 (Henrys law) Correct Answer: Dissolved 02= 0.003x Pa02
(units mls 02/100ml blood)
Calculating 02 bound to hemoglobin Correct Answer: (1.34 x hgb)(sa02)=
Total arterial oxygen content Ca02 calculation
Oxygen delivery calculation D02
Oxygen consumption calculation V02 Correct Answer: CaO2=(1.34 X Hgb X
SaO2) + (0.003 X PaO2)
Normal Ca02 ~20
DO2=CO x CaO2 x10
-amt 02 delivered to capillaries per minute
Normal 520-720ml/min
V02= CO (Ca02-Cv02)
Correct Answers
Motor innervation to larynx Correct Answer: External superior laryngeal=
cricothyroid
Recurrent laryngeal= everything else
Sensory innervation to larynx Correct Answer: Internal superior laryngeal= above
vocal cords
Recurrent laryngeal= below vocal cords
What does the Posterior CricoArytenoid membrane do? Correct Answer: Pulls
the cords apart- ABDUCTS. "Please Open Airway"
What does the Lateral CrycoArytenoid membranes do? Correct Answer: Pulls
the cords together- ADDUCTS
What does the CricoThyroid membrane do? Correct Answer: tenses vocal
cords. "Cords Tense"
What does the ThyroArytenoid membrane do? Correct Answer: relaxes vocal
cords. "They Relax"
What muscle is the barrier to regurgitation? Correct Answer: Crycopharyngeus
muscle
Recurrent laryngeal nerve anatomy Correct Answer: concern with
thyroid/parathyroid surgery
if injured one side- hoarse voice
,if injured bilaterally- can cause complete airway obstruction due to inability to
abduct vocal cords
Laryngeal innervation Correct Answer: The recurrent laryngeal nerve (RLN) and
the superior laryngeal nerve (SLN) are branches of the vagus nerve (CN X). Injury
to them may occur during thyroid surgeries. The SLN (external branch)
innervates the cricothyroid muscle, which tenses and adducts the vocal cords.
Injury to the nerve can produce changes in voice quality, but is generally not
dangerous. Injury to the RLN is of more consequence, as it innervates all of the
intrinsic muscles of the larynx, except for the cricothyroid muscle which is
innervated by the SLN. A unilateral RLN injury produces abductor vocal cord
paralysis, so the affected cord assumes a paramedian position which causes
postoperative hoarseness (may be a delayed presentation of a few weeks).
Bilateral vocal cord paralysis, on the other hand, can manifest as partial vs.
complete airway obstruction. Symptoms include respiratory distress with stridor.
The situation often necessitates emergent reintubation or tracheostomy.
Oxyhemoglobin dissociation curve Correct Answer: Right shift unloads 02 from
blood (Right release)
-increased pC02, increased H+ acidosis, VA, increased temp, increased 2-3
DPG, sickle cell anemia, maternal hgb
Left shift increases 02 affinity loading (Left is locked)
-decreased pc02, decreased H+ alkalosis, decreased 2-3DPG, decreased
temp, CO poisoning (carboxyhemoglobin), fetal hgb, methemoglobin
(prilocaine, nitroprusside which change Fe2+ ferrous into Fe3+ ferric)
Bohr effect Correct Answer: Pac02 affects oxyhemoglobin dissociation curve
Right shift- how acidemia and hypercarbia affect unloading of 02 off of
hemoglobin
,CO2 + H2O ⇆ H2CO3 ⇆ H+ + H+CO3-
Haldane effect Correct Answer: How pa02 affects c02 dissociation curve
The Haldane Effect results from the fact that deoxygenated hemoglobin has a
higher affinity (~3.5 x) for CO2 than does oxyhemoglobin. Deoxygenated
hemoglobin has a higher affinity for CO2 because it is a better proton acceptor
than oxygenated hemoglobin. Therefore, when hemoglobin is deoxygenated
(i.e., at tissues) there is a right shift of the carbonic acid-bicarbonate buffer
equation to produce H+ which in turn increases the amount of CO2 which can
be carried by the blood back to the lungs to be exhaled. Then, with
oxygenation at the lungs CO2 dissociates more readily from hemoglobin.
CO2 + H2O ⇆ H2CO3 ⇆ H+ + H+CO3-
The following is the general equation of the Haldane Effect
H+ + HbO2 ←→ H+Hb + O2
How pa02 correlates to sa02 Correct Answer: pa02 40 %satshgb 70
50 80
60 90 (hypoxemia)
, 90 97
26 50
Calculating Dissolved 02 (Henrys law) Correct Answer: Dissolved 02= 0.003x Pa02
(units mls 02/100ml blood)
Calculating 02 bound to hemoglobin Correct Answer: (1.34 x hgb)(sa02)=
Total arterial oxygen content Ca02 calculation
Oxygen delivery calculation D02
Oxygen consumption calculation V02 Correct Answer: CaO2=(1.34 X Hgb X
SaO2) + (0.003 X PaO2)
Normal Ca02 ~20
DO2=CO x CaO2 x10
-amt 02 delivered to capillaries per minute
Normal 520-720ml/min
V02= CO (Ca02-Cv02)
