山东大学：《医学生理学 Medical Physiology》课程教学资源（PPT课件讲稿，人体生理学 Human Physiology）Chapter 5 Respiratory Physiology Part 4 Oxygen and carbon dioxide transport in blood

Part 4 Oxygen and carbon. Dioxide transport in Blood

1 Part 4 Oxygen and Carbon Dioxide Transport in Blood

Basic mechanism Two forms of the gases: physical dissolution and chemical combination Most of o, and co, in the blood is transported in chemical combination Only the gas in physical dissolution express PP and diffuse to a place with low PP Dynamic balance between the two forms Physical dissolution ppt Chemical combination PP

2 Two forms of the gases: physical dissolution and chemical combination. Most of O2 and CO2 in the blood is transported in chemical combination Only the gas in physical dissolution express PP and diffuse to a place with low PP. Dynamic balance between the two forms: Physical dissolution Chemical combination PP PP Basic Mechanism

I. Transport of Oxygen

3 I. Transport of Oxygen

Oxygen Transport Method Percentage Dissolved in plasma 1.5% Combined with hemoglobin 98.5%

4 Oxygen Transport • Method Percentage • Dissolved in Plasma 1.5 % • Combined with Hemoglobin 98.5 %

Oxygen ■ Bound to hgb ■ Dissolved 5

5 Oxygen Bound to Hgb Dissolved

Hemoglobin Structure Protein made up of 4 subunits Every subunit contains a heme moiety attached a polypeptide chain CH3 CH=CH2 C=C HC-C C=CH CHrc-C C 少×y C-CH3 N-Fe CH=CH2 Heme CH2-C groups CH2 Hc=CC=CH COOH C=C CH2 CH3 CH2 (b) COoH

6 Hemoglobin Structure Protein made up of 4 subunits Every subunit contains a heme moiety attached to a polypeptide chain

Oxyhemoglobin formation An oxygen molecule reversibly attaches to the heme portion of hemoglobin The heme unit contains iron(+2)which provides the attractive force O+ hb Hbo

7 Oxyhemoglobin Formation • An oxygen molecule reversibly attaches to the heme portion of hemoglobin. • The heme unit contains iron ( +2 ) which provides the attractive force. O2 + Hb HbO2

Basic Concepts Oxygen Capacity(氧容量): The maxim eN of oxygen that will combine chemically with the hemoglobin in a unit volume of blood Normal Value: 1.34 ml of O2 per gm of Hb or 20-ml of per 100 ml of blood Oxygen Content(氧含量): how much oxygen is in the blood Oxygen Saturation(血氧饱和度):The percentage of all the available heme binding sites saturated with oxygen

8 Oxygen Capacity (氧容量）: The maximum quantity of oxygen that will combine chemically with the hemoglobin in a unit volume of blood Normal Value: 1.34 ml of O2 per gm of Hb or 20 ml of O2 per 100 ml of blood. Oxygen Content（氧含量）: how much oxygen is in the blood Oxygen Saturation （血氧饱和度）: The percentage of all the available heme binding sites saturated with oxygen Basic Concepts:

The oxygen-hemoglobin dissociation curye, (氧离曲线) 100 the curve 5o 90 relating E80 E9巴 70 Po.% saturatio percentage 60 HE saturation of 10 13.5 50 00 the Oa-carr 40 575 d30 83.5 power of 60 89 70 92 20 80 hemoglobin to 90 96.5 10 100 97.5 the Po2 60 100 P 2 (mm Hg)

9 The oxygen-hemoglobin dissociation curve: （氧离曲线） the curve relating percentage saturation of the O2 -carry power of hemoglobin to the PO2

The oxygen-hemoglobin dissociation curve A. Flattened upper portion 100 B Steep middle portion 290 E80 C. Lower portion g 70 saturation 60 (mm Hg) f Hb 13.5 s50 20 35 30 40 40 75 50 83.5 o30 60 89 芒 70 92.7 d20 80 94.5 90 96.5 10 100 97.5 20 60 80100 Po,(mm Hg)

10 The oxygen-hemoglobin dissociation curve A. Flattened upper portion B. Steep middle portion C. Lower portion