1.Anatomy & Physiology of Airway
-
Upload
reza-haris -
Category
Documents
-
view
232 -
download
5
description
Transcript of 1.Anatomy & Physiology of Airway
Anatomi dan Fisiologi Anatomi dan Fisiologi Jalan Nafas Jalan Nafas
The Body’s Need for The Body’s Need for OxygenOxygen
Living tissue must have oxygen to survive. Living tissue must have oxygen to survive. Brain death in humans occurs within 6 to 10 Brain death in humans occurs within 6 to 10
minutes of tissue anoxia. minutes of tissue anoxia. Rapid and safe airway control is paramount to the Rapid and safe airway control is paramount to the
successful management of critically ill and injured successful management of critically ill and injured patients. patients.
Airway AnatomyAirway Anatomy
Upper airway structures include the:Upper airway structures include the:Mouth Mouth NoseNosePharynxPharynx Oropharynx Oropharynx
The lower airway structures include the:The lower airway structures include the:LarynxLarynxTracheaTrachea BronchiBronchiBronchiolesBronchioles AlveoliAlveoliLungsLungs
..
NoseNose Nasal cavityNasal cavity PharynxPharynx LarynxLarynx TracheaTrachea BronchiBronchi BronchiolesBronchioles Respiratory bronchiolesRespiratory bronchioles Alveolar ductsAlveolar ducts AlveoliAlveoli
Conducting zone• Transport, cleanse, warm and Transport, cleanse, warm and humidify incoming air humidify incoming air • Not involved in gas exchange Not involved in gas exchange • “ “Anatomical Dead Space”Anatomical Dead Space”
Respiratory zoneFunction in gas Function in gas exchangeexchange
tongueteeth
mandible
lips
oropharyng
hard palate
soft palate
MOUTH
NOSEConcha superior
Concha medius
Concha inferior
sphenoid sinus
frontal sinus
PHARYNG:
- Nasopharyng
- Oropharyng (throat)
- Laryngopharyng
hard palate
tongue
soft palate
tonsilla palatina
epiglottis
vocal cordtrachea
concha
nasopharyng
uvula
oropharyng
laryngopharyng
UPPERLOWER
eustachian opening
frontal sinus
sphenoid sinus
LARYNG (VOICE BOX)
- separates pharyng and trachea- cartilages, membrane, ligaments- ♂ 45 mm long, Ø 35 mm- ♀ 35 mm long, Ø 25 mm
FUNCTION- Patent airway
- To act as a switching mechanism to route air and food into the proper channels- Voice production
Framework of the Larynx
thyrohyoid ligament
CRICOTHYROTOMY
- acute, life threatening upper airway obstruction- intubation not possible- conventional airway management not possible
SELLICK’S MANEUVRESELLICK’S MANEUVREUsed to prevent gastric distention Used to prevent gastric distention
TechniqueTechniqueApply slight pressure Apply slight pressure anteriorly over anteriorly over cricoid cartilagecricoid cartilageCloses off esophagusCloses off esophagus
Sellick’s Sellick’s ManueverManuever
The intrinsic muscles of the larynx attach to the Arytenoid cartilage, and allow for movement of the vocal cords.
Movements of Movements of Vocal CordsVocal Cords
Glottis & Epiglottis
glottis
epiglottis
TRACHEA
TRACHEA VIEWED FROM ABOVE
primary bronchus
secondary bronchus
tertiary bronchusbronchiole
terminalbronchiole
BRONCHIAL TREE
respiratory zone
…hair like projection called cilia line the primary bronchus to remove microbes and debris from the interior of the lungs…
Notice that the right is more vertical and fatter than the left which turns at a bit of an angle.
Respiratory bronchioles,Respiratory bronchioles,alveolar ducts, alveolar alveolar ducts, alveolar
sacssacs
Alveolar sacs Alveolar sacs look like look like clusters of clusters of grapesgrapes
The “individual The “individual grapes” are grapes” are alveolialveoli
Alveolar sacsAlveolar sacs AlveoliAlveoli
air-blood barrier
Respiratory PhysiologyRespiratory PhysiologyBreathingBreathing
Pulmonary Ventilation Pulmonary Ventilation the movement of air into and out of the movement of air into and out of the lungsthe lungs
Gas exchange occurs due to a pressure gradient (partial Gas exchange occurs due to a pressure gradient (partial pressures of gas)pressures of gas)
Two phasesTwo phases Inspiration: Breathing inInspiration: Breathing in
Active processActive process Expiration: Breathing outExpiration: Breathing out
Passive processPassive process
Inspiration isInspiration is initiated by a stimulus in the initiated by a stimulus in the respiratory center of the brain. respiratory center of the brain. The signal is transmitted to the diaphragm via the The signal is transmitted to the diaphragm via the
phrenic nerve. phrenic nerve. The impulse causes the diaphragm to contract or The impulse causes the diaphragm to contract or
flatten. flatten. This causes intrapulmonic pressure to fall below This causes intrapulmonic pressure to fall below
atmospheric pressure and air is drawn into the atmospheric pressure and air is drawn into the lungs like a vacuum. lungs like a vacuum.
The ribs elevate and expand, the alveoli inflate, The ribs elevate and expand, the alveoli inflate, and oxygen and carbon dioxide diffuse across the and oxygen and carbon dioxide diffuse across the membrane.membrane.
Respiratory pressures are always described relative Respiratory pressures are always described relative to atmospheric pressureto atmospheric pressure
Boyle’s Law:Boyle’s Law: Volume of gas is inversely proportional to Volume of gas is inversely proportional to
pressure (if temperature constant)pressure (if temperature constant)
Volume= Volume= Constant Constant PressurePressure So, when the volume of the container increases So, when the volume of the container increases
(expansion of the lungs), the pressure decreases(expansion of the lungs), the pressure decreases
Pressure in Thoracic Pressure in Thoracic CavityCavity
As the size of As the size of closed container closed container decreases, decreases, pressure inside pressure inside is increaseis increase
Same number Same number of molecules of molecules striking a striking a smaller smaller surface areasurface area
Boyle’s Law
Atmospheric Pressure (PAtmospheric Pressure (Patmatm)) - pressure exerted by - pressure exerted by the air surrounding the body. At sea level its the air surrounding the body. At sea level its equal to 760mmHg. equal to 760mmHg.
Intrapulmonary Pressure (PIntrapulmonary Pressure (Palvalv)) - pressure exerted by - pressure exerted by the air within the alveoli. It rises and falls during the air within the alveoli. It rises and falls during inspiration and expiration, but it always inspiration and expiration, but it always equalizes with atmospheric pressure. equalizes with atmospheric pressure.
Intrapleural Pressure (PIntrapleural Pressure (Pipip)) - pressure within the - pressure within the pleural cavity. It is always lower than both pleural cavity. It is always lower than both atmospheric pressure and intrapulmonary atmospheric pressure and intrapulmonary pressure.pressure.
Pressure in Thoracic Pressure in Thoracic CavityCavity
pleura parietalis
pleura visceralis (attach to the lung)
pleural cavity
alveoli
PPatm
PPalvalv
Pip
• PPatm 760 mmHg• PPalv alv rises and falls during inspiration and expiration, but it always equalizes with atmospheric pressure• Pip < Patm or Palv
It is elastic and has a It is elastic and has a tendency to recoil tendency to recoil
Ribs want to expandRibs want to expand outward outward
Lungs want to collapseLungs want to collapse
Since the pressure in the plural space is lower Since the pressure in the plural space is lower than in the alveoli, the alveoli do not collapse.than in the alveoli, the alveoli do not collapse.
Lung Tissue
Alveolar pressure falls below atmospheric Alveolar pressure falls below atmospheric pressure.pressure.
Contraction of the diaphragm and external Contraction of the diaphragm and external intercostal muscles increases the size of the intercostal muscles increases the size of the thorax (thereby decreasing the intra-pleural thorax (thereby decreasing the intra-pleural pressure) and the lungs expand.pressure) and the lungs expand.
Intra-pleural (thoracic) pressure is always 4 Intra-pleural (thoracic) pressure is always 4 mmHg less than the atmospheric pressure just mmHg less than the atmospheric pressure just before inhalation (756 mm Hg)before inhalation (756 mm Hg)
Inspiration
Expansion of the lungs decreased alveolar Expansion of the lungs decreased alveolar pressure to 758 mm Hgpressure to 758 mm Hg
Atmospheric pressure is 760 mm HgAtmospheric pressure is 760 mm Hg Air flows into the lungs because of this Air flows into the lungs because of this
pressure gradientpressure gradient Inspiration causes intra-pleural pressure to Inspiration causes intra-pleural pressure to
decrease to 754 mm Hgdecrease to 754 mm Hg
Inspiration
Air is forced out Air is forced out of the lungs as of the lungs as the muscles the muscles relax reducing relax reducing the volume of the volume of the chest cavity the chest cavity and increasing and increasing the pressurethe pressure
EXPIRATION
Occurs when alveolar pressure is higher than Occurs when alveolar pressure is higher than atmospheric pressureatmospheric pressure
762 mm Hg762 mm Hg Elastic recoil of the chest wall and lungs (main Elastic recoil of the chest wall and lungs (main
force) force) and the relaxation of the diaphragm and the relaxation of the diaphragm increases intra-pleural and alveolar pressure and increases intra-pleural and alveolar pressure and decreases lung volumedecreases lung volume
Air moves outAir moves out Quiet breathing does not take any effort (no Quiet breathing does not take any effort (no
muscles are being contracted)muscles are being contracted)
EXPIRATION
3 Major Factors3 Major Factors Alveolar surface tensionAlveolar surface tension ComplianceCompliance Airway resistanceAirway resistance
Pulmonary VentilationPulmonary Ventilation
Surface tension causes the alveoli to Surface tension causes the alveoli to assume the smallest diameterassume the smallest diameter Major component of lung elastic recoilMajor component of lung elastic recoil
Surfactant is a phospholipid produced by Surfactant is a phospholipid produced by Type II cells in alveolar wallsType II cells in alveolar walls Alters surface tension below the surface Alters surface tension below the surface
tension of pure watertension of pure water Prevents alveolar collapse following expirationPrevents alveolar collapse following expiration If surface tension is too high, alveoli collapse If surface tension is too high, alveoli collapse
and great effort is needed to reopen themand great effort is needed to reopen them
Alveolar surface tensionAlveolar surface tension
ComplianceComplianceRatio of volume changes caused by pressure changes Ratio of volume changes caused by pressure changes V/V/PP
• Lung ComplianceLung Compliance• Thoracic wall ComplianceThoracic wall Compliance
Low compliance To get desired volume there must be higher pressureTo get desired volume there must be higher pressure
High compliance Low pressure will give high tidal volume Low pressure will give high tidal volume
stiff Elastis
LOW COMPLIANCE
HIGH COMPLIANCE
BALLOON
COMPLIANCE COMPLIANCE (COMPL)(COMPL)
P-V P-V LOOPLOOP
15
30
250
500
0
P
Vol
500
500
250
250
15
30
15
30
LOW COMPLIANCE
HIGH COMPLIANC
ENORMAL
PEEP 5INSPIRATION
EKSPIRATION
Spontaneus breathing
The walls of the respiratory passageways have The walls of the respiratory passageways have resistance to the normal flow of air into the resistance to the normal flow of air into the lungslungs
The smaller the diameter, the greater the The smaller the diameter, the greater the resistanceresistance
Any condition that obstructs the air passageway Any condition that obstructs the air passageway increases resistance, and more pressure is need increases resistance, and more pressure is need to force air throughto force air through AsthmaAsthma Inflammation due to infectionInflammation due to infection EmphysemaEmphysema
ResistanceResistance
FLOW = PRESSURE
RESISTANCE
BRONCHOCONSTRICTION: HISTAMIN
OBSTRUCTION: MUCUS / SECRET
AIRWAY RESISTANCE (RAW)
FLOW = PRESSURE
RESISTANCE
BRONCHOSPASM TUMOUR / SECRET
TOO SMALL ETT
COLLAPSE/ATELECTASIS
AIRWAY RESISTANCE (RAW)
Partial PressurePartial Pressure Dalton’s LawDalton’s Law: each gas in a mixture of : each gas in a mixture of
gases exerts its own pressure as if all gases exerts its own pressure as if all other gases were not presentother gases were not present Air 78% nitrogen, 21% oxygen, 1% other Air 78% nitrogen, 21% oxygen, 1% other
(CO(CO22)) Partial pressure of a gas is the pressure Partial pressure of a gas is the pressure
of an individual gas in a mixture.of an individual gas in a mixture. PO2 21% X 760 = 159.6 mm HgPO2 21% X 760 = 159.6 mm Hg Total pressure is adding all the partial Total pressure is adding all the partial
pressurespressures
Exchange of OExchange of O22 and CO and CO22
OO22 and CO and CO22 Diffuse from areas of higher Diffuse from areas of higher partial pressures to areas of lower partial partial pressures to areas of lower partial pressurepressure
Results in exchange of OResults in exchange of O22 and CO and CO2 2 in the in the alveolialveoli Alveoli: PAlveoli: PAAOO22=105 =105 mm Hg, mm Hg, PCO2=40PCO2=40 mm Hgmm Hg Capillaries: PCapillaries: PvvOO22=40 =40 mm Hg, mm Hg, PPVVCOCO2 2 =45 =45 mm Hgmm Hg Pulmonary veinPulmonary vein::PPAAOO22=100 PCO2=40=100 PCO2=40 mm Hgmm Hg
O2 and CO2 Diffuse from areas of higher partial pressures to areas of lower partial pressure
Exchange of O2 and Exchange of O2 and CO2CO2
RELATIONSHIP BETWEEN VENTILATION (V) AND PERFUSION (Q)
Normal V/Q = 1
V/Q > 1
alveolar dead spaceV/Q < 1
shunt
TERIMA KASIH