L13- Pt 2 Flashcards

1
Q

Gas transport has 2 mechanisms for…

A

Oxygen & carbon dioxide

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2
Q

Solubility of oxygen in blood

A
  1. Dissolved in plasma (2%)
  2. Bound to hemoglobin (HB) - 98%
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3
Q

Hemoglobin (Hb) is made up of

A

Globin - protein

Heme - contains Fe (iron)

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4
Q

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

A

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

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5
Q

What are the 4 protein subunits of hemoglobin?

A
  • 2 alpha & 2 beta chains
  • 1 heme/ chain
  • 1 Fe/ heme
  • 02 binding to Fe
    (4 o2/hb)
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6
Q

Where does O2 load and unload of hemoglobin

A

Load = lungs

Unload = tissues

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7
Q

Mechanism of o2 loading and unloading hb

A

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

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8
Q

Oxyhemoglobin dissociation curve is sigmoid shaped

TRUE or FALSE

A

True

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9
Q

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

A

40 mmhg
Hb saturation = 75%

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10
Q

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

A

100mmhg

Hb saturation = 97%

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11
Q

Hb saturation

A

Amount of oxygen in hemoglobin

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12
Q

Significance of high Hb saturation in venous blood at rest

A
  • allows for holding breath
  • being able to stop breathing and still live for 4-5 minutes
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13
Q

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

A

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

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14
Q

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

A
  • acts as an o2 reservoir
  • allow us to go to altitude w/o affecting saturation
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15
Q

The flat portion of the oxyhemoglobin curve at high po2 indicates

A

As po2 decreases, Hb saturation will remain high

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16
Q

Significance of the steep portion of the curve at tissues po2

A
  • allows for increase unloading of o2 at tissues as tissues need it
  • activity level
17
Q

The steep portion of the curve at tissue pO2 indicates

A

Small change of po2 = large unloading of o2 from hemoglobin

18
Q

Bohr effect is the effect of ____ on the curve

19
Q

How is co2 transported in the blood (3 ways)

A
  1. Dissolved in plasma
  2. Bound to protein portion of hemoglobin
  3. As bicarbonate ion (hco3)
20
Q

Bohr effect at rest vs during exercise

A

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%

21
Q

During strenuous exercise how will the oxyhemoglobin dissociation curve look like

A
  • 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
22
Q

CO2 release from RBC (hemoglobin) to lungs

A
  1. Three processes reverse allowing co2 to diffuse into alveoli and be exhaled
23
Q

What causes the bicarbonate equation to be reversed?

A

Carbonic anhydrase

24
Q

Carbonic anhydrase equation

A

CO2 + h2o ➡️ H2co3
h2co3 ➡️ Hco3+ H

25
Negative feedback for oxygen Sensor Integrated Effector
Sensor = chemoreceptors- peripheral & central (CO2, ph, o2) Integrator = respiratory center in medulla oblongata Effector = diaphragm
26
What are Peripheral chemoreceptors are found where and what do they sense?
In Carotid and aortic bodies Sense: H+ ( as reflection of arterial Pco2)
27
Central chemoreceptors monitor what
Ph of CSF as reflection of arterial pco2
28
Central chemoreceptors are found and are stimulated by
In the medulla oblongata Stimulated by: increase H+ in CSF
29
Peripheral chemoreceptors are stimulated by
Increase H+ in blood