SEE Exam ACTUAL UPDATED Questions
and CORRECT Answers
Motor innervation to larynx - CORRECT ANSWERS External superior laryngeal=
cricothyroid
Recurrent laryngeal= everything else
Sensory innervation to larynx - CORRECT ANSWERS Internal superior laryngeal= above
vocal cords
Recurrent laryngeal= below vocal cords
What does the Posterior CricoArytenoid membrane do? - CORRECT ANSWERS Pulls the
cords apart- ABDUCTS. "Please Open Airway"
What does the Lateral CrycoArytenoid membranes do? - CORRECT ANSWERS Pulls the
cords together- ADDUCTS
What does the CricoThyroid membrane do? - CORRECT ANSWERS tenses vocal cords.
"Cords Tense"
What does the ThyroArytenoid membrane do? - CORRECT ANSWERS relaxes vocal
cords. "They Relax"
What muscle is the barrier to regurgitation? - CORRECT ANSWERS Crycopharyngeus
muscle
Recurrent laryngeal nerve anatomy - CORRECT ANSWERS 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 ANSWERS 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 ANSWERS 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 ANSWERS 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 ANSWERS 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 ANSWERS pa02 40 %satshgb 70
50 80
60 90 (hypoxemia)
90 97
26 50
Calculating Dissolved 02 (Henrys law) - CORRECT ANSWERS Dissolved 02= 0.003x
Pa02 (units mls 02/100ml blood)
Calculating 02 bound to hemoglobin - CORRECT ANSWERS (1.34 x hgb)(sa02)=
Total arterial oxygen content Ca02 calculation
Oxygen delivery calculation D02
Oxygen consumption calculation V02 - CORRECT ANSWERS 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)
normal 250ml/min
oxygen consumption pedi vs adult - CORRECT ANSWERS Pedi 7ml/kg/min
Adult 3-4ml/kg/min
Definitive values for hypoxia - CORRECT ANSWERS Pa02<60, sat <90
Normal pa02 - CORRECT ANSWERS 78mmhg (in elderly) to 95mmhg in adults
normal pv02 - CORRECT ANSWERS mixed venous blood 40mmhg
Where does CO go? - CORRECT ANSWERS liver 25%
kidneys 22%
CNS 15% (750ml)
Heart 5% (225ml)
Lungs (100%)
Control of ventilation - CORRECT ANSWERS Primary respiratory centers are DRG (the
inspiratory pacemaker) and VRG (only active in exercise) which are both located in medulla.
Secondary respiratory centers are apneustic center and pneumotaxic - both located in pons which
help control rate and depth
Neural control of breathing - CORRECT ANSWERS Central chemoreceptors in medulla
respond to increased H+
peripheral chemoreceptors respond to decreased 02, increased c02 and increased H+
and CORRECT Answers
Motor innervation to larynx - CORRECT ANSWERS External superior laryngeal=
cricothyroid
Recurrent laryngeal= everything else
Sensory innervation to larynx - CORRECT ANSWERS Internal superior laryngeal= above
vocal cords
Recurrent laryngeal= below vocal cords
What does the Posterior CricoArytenoid membrane do? - CORRECT ANSWERS Pulls the
cords apart- ABDUCTS. "Please Open Airway"
What does the Lateral CrycoArytenoid membranes do? - CORRECT ANSWERS Pulls the
cords together- ADDUCTS
What does the CricoThyroid membrane do? - CORRECT ANSWERS tenses vocal cords.
"Cords Tense"
What does the ThyroArytenoid membrane do? - CORRECT ANSWERS relaxes vocal
cords. "They Relax"
What muscle is the barrier to regurgitation? - CORRECT ANSWERS Crycopharyngeus
muscle
Recurrent laryngeal nerve anatomy - CORRECT ANSWERS 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 ANSWERS 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 ANSWERS 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 ANSWERS 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 ANSWERS 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 ANSWERS pa02 40 %satshgb 70
50 80
60 90 (hypoxemia)
90 97
26 50
Calculating Dissolved 02 (Henrys law) - CORRECT ANSWERS Dissolved 02= 0.003x
Pa02 (units mls 02/100ml blood)
Calculating 02 bound to hemoglobin - CORRECT ANSWERS (1.34 x hgb)(sa02)=
Total arterial oxygen content Ca02 calculation
Oxygen delivery calculation D02
Oxygen consumption calculation V02 - CORRECT ANSWERS 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)
normal 250ml/min
oxygen consumption pedi vs adult - CORRECT ANSWERS Pedi 7ml/kg/min
Adult 3-4ml/kg/min
Definitive values for hypoxia - CORRECT ANSWERS Pa02<60, sat <90
Normal pa02 - CORRECT ANSWERS 78mmhg (in elderly) to 95mmhg in adults
normal pv02 - CORRECT ANSWERS mixed venous blood 40mmhg
Where does CO go? - CORRECT ANSWERS liver 25%
kidneys 22%
CNS 15% (750ml)
Heart 5% (225ml)
Lungs (100%)
Control of ventilation - CORRECT ANSWERS Primary respiratory centers are DRG (the
inspiratory pacemaker) and VRG (only active in exercise) which are both located in medulla.
Secondary respiratory centers are apneustic center and pneumotaxic - both located in pons which
help control rate and depth
Neural control of breathing - CORRECT ANSWERS Central chemoreceptors in medulla
respond to increased H+
peripheral chemoreceptors respond to decreased 02, increased c02 and increased H+
