Respiration Carrying Oxygen Carrying CO2 Controlling Breathing .Be able to describe how O2 is carried in the blood. Be able to explain blood saturation. Be able to describe the various ways CO2 is carried in the blood. Be able to describe the key factors that influence breathing. Be able to describe the anatomical features necessary to control breathing. Marieb 22

Oxygen Transport Dissolved 1.5% Hemoglobin 98.5%

Hemoglobin Oxyhemoglobin Deoxyhemoglobin/ Reduced hemoglobin O2 binds heme CO2 binds globin

Partially vs Fully Saturated Hemoglobin Affinity increases as O2 added

Hemoglobin Sheds O2 at Tissue Capillary Tissue

Gas Transport is very efficient at Sea Level 760 mmHg 523 mmHg 225 mmHg

Carbon Dioxide Transport Dissolved: 10% On globin: 20% Bicarbonate ions: 70%

CO2 Binds to Hemoglobin Binds to globin Deoxygenated hemoglobin more able to pick up CO2

Bicarbonate Transport of CO2 Carbonic anhydrase H2CO3 H+ and HCO3- Chloride Shift

Bicarbonate Release of CO2 Chloride Shift H+ and HCO3- Carbonic anhydrase H2CO3 CO2

Minute Ventilation

Controlling Breathing Movement

PCO2 (By measuring H+) Medulla Blood  CSF Carbonic Acid Acidic CSF 37-43mmHg

Aortic Arch and the Carotid Sinus

PO2 Carotid Receptors PO2 less than 60 mmHg

Baroreceptors Detect Pressure Aortic Reflex Carotid Sinus Reflex

Control of Breathing DRG Information from receptors VRG “Pacemaker” for respiration

Control of Breathing: VRG Inspiratory cells Expiratory cells Phrenic nerve

Short Term Neuronal Controls Cardiac Inhibitory Center + Cardiac Excitatory Center Vasomotor Center Cardiovascular Center