L13- Pt 2

Question 1

Gas transport has 2 mechanisms for…

Answer 1

Oxygen & carbon dioxide

Question 2

Solubility of oxygen in blood

Answer 2

1. Dissolved in plasma (2%)
2. Bound to hemoglobin (HB) - 98%

Question 3

Hemoglobin (Hb) is made up of

Answer 3

Globin - protein

Heme - contains Fe (iron)

Question 4

Where does o2 and co2 bind to on hemoglobin of RBC?

Answer 4

O2 binds to Fe in heme
- co2 binds to protein (globin)

Question 5

What are the 4 protein subunits of hemoglobin?

Answer 5

• 2 alpha & 2 beta chains
• 1 heme/ chain
• 1 Fe/ heme
• 02 binding to Fe
  (4 o2/hb)

Question 6

Where does O2 load and unload of hemoglobin

Answer 6

Load = lungs

Unload = tissues

Question 7

Mechanism of o2 loading and unloading hb

Answer 7

O2 from lungs dissolves in plasma = RBC
- o2 from plasma binds to hemoglobin
- some o2 unloads from hemoglobin to tissues

Question 8

Oxyhemoglobin dissociation curve is sigmoid shaped

TRUE or FALSE

Answer 8

True

Question 9

Veins Po2 at rest is _______. Making its hemoglobin saturation ________

Answer 9

40 mmhg
Hb saturation = 75%

Question 10

Arteries Po2 at rest is _______. With hemoglobin saturation of ________

Answer 10

100mmhg

Hb saturation = 97%

Question 11

Hb saturation

Answer 11

Amount of oxygen in hemoglobin

Question 12

Significance of high Hb saturation in venous blood at rest

Answer 12

• allows for holding breath
• being able to stop breathing and still live for 4-5 minutes

Question 13

High hemoglobin (Hb) saturation in venous blood at rest indicates ….

Answer 13

There’s is an o2 reserve
- a supply of oxygen

Question 14

Significance of flat portion of curve at a high po2’s

Answer 14

• acts as an o2 reservoir
• allow us to go to altitude w/o affecting saturation

Question 15

The flat portion of the oxyhemoglobin curve at high po2 indicates

Answer 15

As po2 decreases, Hb saturation will remain high

Question 16

Significance of the steep portion of the curve at tissues po2

Answer 16

• allows for increase unloading of o2 at tissues as tissues need it
• activity level

Question 17

The steep portion of the curve at tissue pO2 indicates

Answer 17

Small change of po2 = large unloading of o2 from hemoglobin

Question 18

Bohr effect is the effect of ____ on the curve

Answer 18

Ph

Question 19

How is co2 transported in the blood (3 ways)

Answer 19

1. Dissolved in plasma
2. Bound to protein portion of hemoglobin
3. As bicarbonate ion (hco3)

Question 20

Bohr effect at rest vs during exercise

Answer 20

At rest:
- Tissue Ph = 7.4
Tissue po2 = 40mmHg
% HB saturation = 75%

During exercise:
- metabolism = acid = lower Ph
- curve shifts to right
- Tissue Po2 = 40 mmHg
% Hb saturation = 60%

Question 21

During strenuous exercise how will the oxyhemoglobin dissociation curve look like

Answer 21

• increase temp + decrease pH
  
  • shifting curve to right
  • allowing greater unloading Hb = more o2 to muscles
• Decrease in muscle Po2
  = greater unloading oh Hb = more o2 to muscles

Question 22

CO2 release from RBC (hemoglobin) to lungs

Answer 22

1. Three processes reverse allowing co2 to diffuse into alveoli and be exhaled

Question 23

What causes the bicarbonate equation to be reversed?

Answer 23

Carbonic anhydrase

Question 24

Carbonic anhydrase equation

Answer 24

CO2 + h2o ➡️ H2co3
h2co3 ➡️ Hco3+ H

Question 25

Negative feedback for oxygen
Sensor
Integrated
Effector

Answer 25

Sensor = chemoreceptors- peripheral & central
(CO2, ph, o2)

Integrator = respiratory center in medulla oblongata

Effector = diaphragm

Question 26

What are Peripheral chemoreceptors are found where and what do they sense?

Answer 26

In Carotid and aortic bodies

Sense: H+ ( as reflection of arterial Pco2)

Question 27

Central chemoreceptors monitor what

Answer 27

Ph of CSF as reflection of arterial pco2

Question 28

Central chemoreceptors are found and are stimulated by

Answer 28

In the medulla oblongata

Stimulated by: increase H+ in CSF

Question 29

Peripheral chemoreceptors are stimulated by

Answer 29

Increase H+ in blood