transport - DM SEMINAR FEBRUARY 27, 2004 OXYGEN - CARBON...

Info iconThis preview shows pages 1–13. Sign up to view the full content.

View Full Document Right Arrow Icon
DM SEMINAR FEBRUARY 27, 2004 OXYGEN - CARBON DIOXIDE TRANSPORT NAVNEET SINGH DEPARTMENT OF PULMONARY AND CRITICAL CARE MEDICINE PGIMER CHANDIGARH
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
HEADINGS INTRODUCTION OXYGEN TRANSPORT FROM LUNGS TO CELLS OXYGEN DELIVERY DURING EXERCISE OXYGEN DELIVERY DURING CRITICAL ILLNESS CARBON DIOXIDE TRANSPORT
Background image of page 2
INTRODUCTION TO PHYSIOLOGY OF OXYGEN TRANSPORT Substrate used by cells in max qty Key factor for aerobic metabolism and cell integrity No storage system in tissues - req for continuous supply Tissue hypoxia anaerobic metabolism Cascade for transport from environmental air to mitochondria
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
OXYGEN TRANSPORT - CONVECTIVE AND DIFFUSIVE Convective - bulk movement Active energy dependant process Tracheobronchial tree and circulation Diffusive - passive movement down concentration gradient Alveolo-capillary membrane and capillary-tissue transport
Background image of page 4
REQUIREMENTS FOR OXYGEN TRANSPORT SYSTEM Energy efficient (avoid unnecessary cardiorespiratory work) Match O2 supply with demand Efficient transportation of oxygen (‘minimal wastage/ transmission losses’)
Background image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
ROLE OF HEMOGLOBIN Increases oxygen transport capacity by 30-100 fold Increases CO2 transport capacity 15- 20 fold
Background image of page 6
KEY STEPS IN OXYGEN CASCADE Uptake in the lungs Carrying capacity of blood Delivery from lungs to tissue capillaries Delivery from capillary blood to interstitium Delivery from interstitium to individual cells Cellular use of oxygen
Background image of page 7

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
OXYGEN UPTAKE IN LUNGS DETERMINANTS OF PaO2 Inspired O2 concentration & barometric pressure Alveolar ventilation O2 diffusion from alveoli to pul capillaries
Background image of page 8
DIFFUSION FROM ALVEOLI TO PULMONARY CAPILLARIES PAO2 – Driving Pressure for O2 Diffusion Into Pul Capillary Bed and Main Determinant of PaO2 normally PAO2-PaO2 reflects overall efficiency of O2 uptake from alveoli to arterial blood Capillary blood fully oxygenated before traversing 1/3 distance of alveolo-capillary interface Inadequate oxygenation due to reduced pul capillary time occurs only with very high C.O. or severe desaturation of mixed pul arterial blood
Background image of page 9

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
OXYGEN CARRYING CAPACITY OF BLOOD 97-98% Carried in Combination With Hb (2-3% Dissolved in Plasma) O2 CONTENT = 1.31 x Hb x Sat + 0.0031 x PO2 1gm Hb Binds 1.31 Though Expected 1.39 Due to Presence of Iron in non-heme form O2 content in 100 ml blood (in normal adult with Hb 15 gm/dl) ~ 20 ml (19.4 ml as OxyHb + 0.3 ml in plasma)
Background image of page 10
Shift of Curve to Right Release of O2 to Tissues & Improves O2 availability provided PaO2 > 60 mm Hg FACTORS AFFECTING O2-Hb DISSOCIATION CURVE PCO2 TEMPERATURE 2,3 – DIPHOSPHOGLYCERATE PRESENCE/PERCENTAGE OF FETAL Hb pH
Background image of page 11

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
2200 In pH from 7.4 to 7.2 causes shift of curve to right by 15% 2200 In pH by similar value causes shift of curve to left by similar magnitude 2200 Temp affinity of O2 to Hb and hence
Background image of page 12
Image of page 13
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 45

transport - DM SEMINAR FEBRUARY 27, 2004 OXYGEN - CARBON...

This preview shows document pages 1 - 13. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online