SISTEM RESPIRASI

Assistants of PhysiologyPhysiology Department

Medical Faculty, Hasanuddin University

Menyediakan oksigen bagi seluruh jaringan tubuh dan membuang karbon dioksida ke atmosfir.

Menghasilkan energi

Tujuan Pernapasan

Ventilasi paru, yaitu masuk keluarnya udara dari Atmosfir ke alveoli paru

Difusi pertukaran oksigen dan karbondioksida antara darah dan alveoli

Transpor 02 dan CO2 dalam darah dan cairan tubuh ke dan dari sel

Perfusi pertukaran oksigen dan karbondioksida antara darah dan sel-sel tubuh

Pengaturan ventilasi dan hal-hal lain pernapasan

Respiration

Eksternal

Internal

1. Inspiration Ventilation Diffusion Perfusion

2. Expiration

Zona KonduksiZona Respiratoris

Jalur Udara Pernafasan

Hukum gas (Boyle’s Law)

P1V1 = P2V2 Pergerakan udara terjadi akibat perbedaan

tekanan gas antara atmosfir dan paru (alveoli)

Perbedaan tekanan terjadi akibat perubahan ukuran rongga toraks kontraksi dan relaksasi otot-otot pernapasan

Mekanisme Ventilasi Paru

Otot-otot Pernafasan

Inspirasi 1. Diaphragm

2. External intercostal muscles 3. Accessory muscles

- M. sternocleidomastoideus- M. serratus anterior- M. pectoralis minor- M. scalenius

Otot-otot Pernafasan

Expirasi 1. M. Rectus abdominis 2. M. Obliqus abdominis ext et int

3. M. Tranversus abdominis4. Internal intercostal muscles

Otot-otot Pernafasan

Difusi dalam hal ini adalah proses berpindahnya gas O2 dari alveoli ke kapiler paru, dan berpindahnya CO2 dari kapiler paru ke alveoli.

Menurut hukum Fick, kecepatan suatu gas melewati membran adalah sesuai rumus :  Vgas = A.D. (P1 - P2) T

Difusi

Transport O2 dan CO2O2 diangkut oleh darah dalam bentuk :

TerlarutTerikat dengan Hb

Pada keadaan normal 97% O2 diangkut dari paru ke jaringan dalam bentuk terikat dengan Hb (Haemoglobin; HbO2 saturation = 97 % dalam darah arteri).

Sisanya diangkut dalam bentuk terlarut dalam plasma dan sel.

Transport CO2 dalam darah dalam bentuk :Terlarut (7 - 10 %) Ion bikarbonat (HCO3) dlm sel RBC (60 - 70 %)Berikatan dengan Hb (HbCO2) (23 - 30 %) (Carbamino Compound)

Transpor CO2

Regulasi Sistem RespirasiTiga Komponen utama :

SensorKontrol sentralEfektor (otot-otot pernafasan)

1. Sensor - Central Chemoreceptor

CO2 darah dgn cepat melewati sawar darah otak ke CSF H2O + CO2 ----- H2CO3 ---- H+ + HCO3-

Konsentrasi H+ yg tinggi memacu ventilasi- Peripheral Chemoreceptor

O2 dan ion hidrogen- Pulmonary Receptor- Reseptor non kimiawi--- baroreseptor

Regulasi Sistem Respirasi

Regulasi Sistem Respirasi2. Central Controller

- Brain Stem a. Medullary Respiratory center b. Apneustic center c. Pneumotaxic center (menghentikan inspirasi)- Cortex- Limbic system and hypothalamus

3. Effector : Respiratory muscles

Assistants of PhysiologyPhysiology Department

Medical Faculty, Hasanuddin University

SPIROMETRY

PULMONARY VOLUMESVT (Tidal Volume) = 500 mlIRV (Inspiratory Reserve Volume) = 3100 mlERV (Expiratory Reserve Volume) = 1200 mlRV (Residual Volume) = 1200 ml

PULMONARY CAPACITIES IC (Inspiratory Capacity) = 3600 ml VC (Vital Capacity) = 4800 ml FRC (Functional Residual Capacity )= 2400 ml TLC (Total Lung Capacity) = 6000 ml

Spirographic

identifying the presence of abnormal lung function;

determining the nature of abnormal lung function;

grading the extent of functional impairment;

monitoring the onset and progression of dysfunction; and

evaluating the response to interventions.

Indications for spirometry

Obstructive Disorders: Disorders is characterized by obstruction of normal airflow due to airway narrowing and includes :

AsthmaCOPDBronchiektasisCystic FibrosisTumors ( inside or outside the

airways )The mechanism causing the airway narrowing

differ, including obstruction by mucus plug, airway compression and smooth constriction.

Restrictive Disorders : Disorders is characterized by stiffer lungs which cannot expand to normal volumes.A large number of disorders can be classifed as restrictive, including :

Pulmonary FibrosisSarcoidosis

SilicosisAsbestosis

Normal LungA normal flow-volume loop:

A normal volume-time loop:

Obstructive Lung Disease

Volume-time curve in obstructive lung disease:

FEV1 low, FET higher

Flow-volume in obstructive lung disease:

is concave, FEF25-75 too low, FVC normal

Restrictive Lung Disease

Flow-volume in restrictive lung disease:shape normal, FVC low

Volume-time curve in restrictive lung disease: FEV1 too low, FET normal

Mixed Lung Disease

Volume-time curve in mixed lung disease:

FVC, FEV1 and FEF25-75 too low

Obstructive Restrictive Mixed

FEV1

FVC N or

FEV1/FVC ratio N

TLC N or

VC N or

RV N or N or

RV/TLC ratio N or

Pattern of lung function

SpirographicNORMAL : FEV = 80 %

FVCOBSTRUCTIVE : FEV1 < 80 %

FVCRESTRICTIVE : FEV1 > 80 %

FVCFEV = FORCED EXPIRATORY VOLUMEFVC = FORCED VITAL CAPACITY