Final Exam Review Flashcards
Adult larynx anatomic location
Anterior to C3-C6
At birth larynx anatomic location
C3-C4
Larynx lies between ___ and ___
Pharynx and trachea
Normal A-O extension
35 degrees
Mallampati Classification
Pt sitting, neck extended, mouth fully opened, tongue protruded, no phonation
MP Classes 1-4
MP Class 1
Full view of uvula and tonsillar pillars, soft palate
MP Class 2
Partial view of uvula or uvular base, partial view of tonsils, soft palate
MP Class 3
Soft palate only
MP Class 4
Hard palate only
Sphenopalatine ganglion—middle division of CN ___ and innervates what 4 structures?
Middle division of CN V
- Nasal mucosa
- Superior pharynx
- Uvula
- Tonsils
Glossopharyngeal nerve innervation
CN IX
- Posterior 1/3 of tongue
- Pharyngeal, tonsillar nerves
- Oral pharynx
- Supraglottic region
Internal branch of superior laryngeal nerve
CN X
- Mucus membrane above the vocal cords
- Glottis
Recurrent laryngeal nerve
CN X
-Trachea below the vocal cords
Superior laryngeal nerve is a branch of what cranial nerve?
Vagus nerve (CN X)
The superior laryngeal nerve divides into what two nerves?
- Internal superior laryngeal nerve
- External superior laryngeal nerve
Internal SLN
- Provides sensation to supraglottic and ventricle compartment
- Stimulation causes laryngospasm!
Stimulation of internal SLN causes ___
LARYNGOSPASM
External SLN provides ___ innervation to what muscle?
Motor innervation to cricothyroid muscle
Recurrent laryngeal nerve is a branch of what cranial nerve?
Vagus nerve (CN X)
Left RLN passes @ ___
Aortic arch
Recurrent laryngeal nerve provides sensory innervation to ___
Infraglottis
Recurrent laryngeal nerve provides motor innervation to all of the larynx except for the ___ muscle
Cricothyroid muscle
Stimulation of the recurrent laryngeal nerve causes ___
Abduction of vocal cords
Damage to the recurrent laryngeal nerve causes ___
Vocal cord adduction
What is the trachea?
Flexible cylindrical tube supported by 20-25 C-shaped cartilages
Diameter of the trachea
18-20 mm diameter
Length of trachea
12.5-18 cm length
Trachea extends from ___ to ___
C6 to T5
Where does the trachea divide into 2 bronchi?
At carina (level T5-T7); 25 cm from teeth
Inspiration is the ___ phase of breathing cycle
Active phase
What nerve transmits motor stimulation to diaphragm?
Phrenic nerve—C3, C4, C5
What nerves send signals to the external intercostal muscles?
Intercostal nerves (T1-T11)
The act of inhaling is ___
Negative-pressure ventilation
Transpulmonary pressure is the pressure difference between ___ and ___
Alveolar pressure and pleural pressure on outside of lungs
Alveoli tend to collapse together while the pleural pressure attempts to pull outward
What is recoil pressure?
The elastic forces which tend to collapse the lung during respiration
4 volumes of spirometry
- Tidal volume (TV)
- Inspiratory reserve volume (IRV)
- Expiratory reserve volume (ERV)
- Residual volume (RV)
Tidal volume (TV)
Amount of inspired air with a normal breath; amounts to about 500 ml in the avg adult male
Inspiratory reserve volume (IRV)
Extra volume of air that can be inspired over and above the normal tidal volume when the person inspires with full force; usually equals 3000 ml
Expiratory reserve volume (ERV)
Maximum extra volume of air that can be expired by forceful expiration after the end of a normal tidal expiration; about 1100 ml
Residual volume (RV)
Volume of air remaining in the lungs after the most forceful expiration; about 1200 ml
4 capacities of spirometry
- Inspiratory capacity (IC)
- Functional residual capacity (FRC)
- Vital capacity (VC)
- Total lung capacity (TLC)
Inspiratory capacity (IC) =
TV + IRV
The amount of air a person can breathe in, beginning at the normal expiratory level and distending the lungs to the maximum amount ~3500 ml
Functional residual capacity (FRC) =
ERV + RV
The amount of air that remains in the lungs at the end of normal expiration ~2300 ml
Vital capacity (VC) =
TV + IRV + ERV
The maximum amount of air a person can expel from the lungs after first filling the lungs to their maximum extent and then expiring to the maximum extent ~4600 ml
Total lung capacity (TLC) =
VC + RV
TV + IRV + ERV + RV
Max volume to which the lungs can be expanded with the greatest possible effort ~5800 ml
IC =
IRV + TV
FRC =
ERV + RV
VC =
IRV + ERV + TV
TLC =
IRV + TV + ERV + RV
TV ~
~500 ml
IRV ~
~3000 ml
ERV ~
~1100 ml
RV ~
~1200 ml
IC ~
~3500 ml
FRC ~
~2300 ml
VC ~
~4600 ml
TLC ~
~5800 ml
Spirometry cannot measure ___
Residual volume (RV)
Thus FRC and TLC cannot be determined using spirometry alone
FRC and TLC can be determined by ___, ___, and ___
- Helium dilution
- Nitrogen washout
- Body plethysmography
What are 3 main functions of surfactant?
- Lowers surface tension of alveoli and lung—increases compliance of lung; reduces work of breathing
- Promotes stability of alveoli—alveoli have tendency to collapse; surfactant reduces forces causing atelectasis
- Prevents transudation of fluid into alveoli—reduces surface hydrostatic pressure effects; prevents surface tension forces from drawing fluid into alveoli from capillary
What type of cells secrete surfactant?
Type II pneumocyte
Very important in neonates—maturation occurs at 24 weeks gestation
What forces air out of alveoli?
Elastic force caused by water tension attempts to force air out of alveoli
Poiseuille’s Law—reducing the radius by 16% will ___ the resistance
Double
Poiseuille’s Law—reducing the radius by 50% will increase resistance ___
16-fold (2^4)
If you double the radius, you reduce the resistance ___
16-fold (2^4)
Systemic circulation = ___ pressure, ___ flow, ___ resistance
High pressure, low flow, high resistance
Pulmonary circulation = ___ pressure, ___ flow, ___ resistance
Low pressure, high flow, low resistance
RA pressure
2-3 mm Hg
RV pressure
25 mm Hg
LA pressure
5-8 mm Hg
LV pressure
120 mm Hg
Mean pulmonary artery pressure
14-15 mm Hg
Mean systemic artery pressure
90-100 mm Hg (120/80)
Mean pulmonary capillary pressure
10-10.5 mm Hg
Mean systemic capillary pressure
20 mm Hg
What is recruitment?
Opening of previously closed vessels
What is distention?
Increase in caliber of vessels
What is the CHIEF mechanism for fall in pulmonary vascular resistance (PVR)?
Recruitment
However, both recruitment and distention are two mechanisms that decrease PVR
Increased CO ___ pulmonary vascular pressures but ___ pulmonary vascular resistance
Increases pulmonary vascular pressures but decreases pulmonary vascular resistance (occurs during periods of stress and increased tissue oxygen demand)
___% of alveolar surface area is covered by capillary bed
70-80%
Total capillary surface area almost equals alveolar surface area
Capillary volume increases by ___
Recruitment—opening closed segments
What is the normal capillary volume at rest?
70 ml (1 ml/kg body weight)
What is the maximal capillary anatomical volume?
200 ml
Distance RBCs have to travel through capillary network is ___
Small (600 to 800 micrometers)
Capillary network blood volume = ___ stroke volume
RV
Total blood volume from main pulmonary artery to left atrium is ___ ccs
500
Lung is ___% blood by weight
40-50%; this volume fraction > than any other organ
What is the capacitance reservoir for the left atrium?
The pulmonary vasculature—can act as a reservoir and alter its volume from 50 to 200% of resting volume
Can store blood in the lungs so that the LV doesn’t run dry as it pumps out to the systemic circulation
Inspired air O2/CO2 concentrations
PO2 150 mm Hg
PCO2 0 mm Hg
RBC/alveolar O2/CO2 concentrations
PO2 = 100 mm Hg PCO2 = 40 mm Hg
Deoxygenated blood O2/CO2 concentrations
PO2 = 40 mm Hg PCO2 = 46 mm Hg
Lung Zone 1
alveolar flow > pulmonary artery pressure > pulmonary vein pressure
very negligible blood flow through this area of the lung; can ventilate it all day long, but it’s not doing any gas exchange
Lung Zone 2
pulmonary artery pressure > alveolar pressure > pulmonary vein pressure
might get intermittent flow/exchange through zone 2 with changes in systolic/diastolic pressure during inhalation/exhalation; not a lot of flow/exchange going on here
Lung Zone 3
pulmonary artery pressure > pulmonary vein pressure > alveolar pressure
maximizes both blood flow and gas exchange because you have uninterrupted alveolar interfaces
Blood vessels are more distended at the ___ of the lung
Base
___ resistance to flow in the base of the lung
Decreased
___ (higher/lower) blood flow at the base of the lung
Higher
Higher ___ pressures in apex of lung than capillary pressures
Higher alveolar pressures; causes decreased perfusion in apex of lung
What are 3 ways to expand zone 1?
- Decreased pulmonary artery pressure (i.e.: shock, hypovolemia)
- Increased alveolar pressure (i.e.: PEEP)
- Occlusion of blood vessels (i.e.: pulmonary embolism)
What are 2 ways to reduce zone 1?
- Increased pulmonary artery pressure (i.e.: infusion of fluid or blood)
- Reduced hydrostatic effect (i.e.: change patient position; standing to supine)
V/Q ratio is ___ in the upper lung
High
Because you have ventilation, but no perfusion
V/Q ratio is ___ in the lower lung
Low
Because you have good ventilation & perfusion in the bases of the lungs
What are 4 things that cause vasoconstriction of the pulmonary vasculature?
- Reduced PaO2
- Increased PCO2
- Thromboxane A2
- Histamine
What are 3 things that cause vasodilation of the pulmonary vasculature?
- Increased PaO2
- Prostacyclin
- Nitric oxide
High CO2 =
Vasoconstriction
Why we hyperventilate neurosurgery patients…because low CO2 = vasodilation
Thromboxane A2 is a ___
Potent vasoconstrictor
Thromboxane A2 is produced during…
Produced during acute lung tissue damage by
macrophage, leukocytes, and endothelial cells
Effect localized to injured region because half-time of thromboxane inactivation is only seconds
Body’s way of protecting itself when the lung is injured
Prostacyclin is a ___
Potent vasodilator
Prostacyclin inhibits ___
Platelet activation
Nitric oxide is a ___
Epithelial vasodilator
Nitric oxide has a ___ effect
Strictly localized effect (only works where it is produced)
Nitric oxide is produced from ___
L-arginine
How does nitric oxide cause vasodilation?
Nitric oxide activates guanylyl cyclase, which produces cyclic GMP…cyclic GMP causes smooth muscle relaxation
Nitric oxide is delivered via ___
Inhalation technique