Lecture 12 Flashcards

1
Q

Oxygen Transport:
- ______% bound to hemoglobin
- _____% is gas dissolved in plasma (low solubility compared to CO2)
- arterial blood carries about ______ mL of O2 per liter, so about ___ L of O2 in our body

A
  • 98.5%
  • 1.5%
  • 200; 1
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2
Q

Hemoglobin
- Four protein (globin) portions
- each has a heme group, binds one O2 to an ____ atom
- ____________________ (____): O2 bound to hemoglobin
- ____________________ (HHb): hemoglobin with no O2
-serves as a _______ for H+

A
  • iron
  • oxyhemoglobin (HbO2)
  • Deoxyhemoglobin (HHb)
  • buffer
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3
Q

One hemoglobin can carry up to ___ O2
- _____% saturation Hb with ___ O2 molecules per Hb
- _____ % saturation Hb with ___ O2 molecules per Hb

A
  • 100%; 4
  • 50%; 2
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4
Q

Carbon Dioxide is _________ in the blood in three forms:
1. _________________ (___% of CO2)
2. ________________ (___% of CO2)
3. ________________ (___% of CO2)

A

transported
1. Gas; 5%
2. Carbonic acid; 90%
3. Carbamino compounds; 5%

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5
Q

Carbon Dioxide transportation
- Gas: dissolved in _______
- Carbonic acid: __________ –> _______–> __________
-this reaction occurs _______ in the blood plasma
-occurs _______ in RBC, catalyzed by enzyme _____________
- Carbamino compounds: CO2 + ________–> carbamino compounds (mostly _____________)

A
  • blood plasma
  • CO2+ H2O –> H2CO3–> HCO3- + H+
    -slowly
    -rapidly; carbonic anhydrase
  • plasma protein; carbaminohemoglobin (HbCO2)
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6
Q

Relative amounts of CO2 _________ from the blood to the alveolar air from these 3 reservoirs are __________ from the relative amounts transported in the blood
- while most exchanged CO2 comes from carbonic acid, it is not the full percentage present in blood; ____ % CO2
- more exchanged CO2 comes from ___________ than is present in blood; ____% CO2
- slight more gaseous CO2 is delivered to the alveoli than is present in blood; ___% CO2

A

exchange; DIFFERENT
- 70%
- carbamino compounds; 23%
- 7%

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7
Q

Blood gives up the ____________ and CO2 from the ____________ more easily than CO2 from __________________________

A

dissolved CO2 gas; carbamino compounds; bicarbonate-carbonic acid

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8
Q

Systemic Gas Exchange (in ________)
- ______ O2 from hemoglobin released into tissue
- ______ dissolved O2 gas released into tissue
- ______ CO2 + H2O into RBC, converted into H2CO3 —> HCO3- + (H+) by _____________
- ______ dissolved CO2 gas into blood
- ______ CO2+ plasma protein—> ______________
- _________ ______: uses HCO3- & Cl- ______ to put Cl- ____ and HCO3- _______ of RBC
-this helps keep concentration gradient going

A

Tissues
- 98.5%
- 1.5%
- 70%; carbonic anhydrase
- 7%
- 23%; carbamino compounds
- Chloride shift; antiport; IN; OUT

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9
Q

Alveolar Gas Exchange
- ______ O2 released into RBC to bind to HHb–> _____ + (H+)
- ______ O2 dissolved gas into plasma
- HCO3- + (H+)—> H2CO3—> CO2+H2O (70%) converted by ____________ and released into alveoli
- _____ dissolved CO2 gas into alveoli
- carbamino compounds—> CO2 + plasma protein (___%) into alveoli
- __________ __________ _______: uses HCO3- & Cl- antiport to put Cl- ______ and HCO3- _____ RBC

A
  • 98.5%; HbO2
  • 1.5%
  • carbonic anhydrase
  • 7%
  • 23%
  • Reverse Chloride shift; OUT; IN
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10
Q

hemoglobin unloads O2 to match ___________ needs of different states of activity of the tissues
FOUR factors adjust the _____ of oxygen unloading to match need:
1.
2.
3.
4.

A

metabolic; rate
1. Ambient PO2
2. Ambient pH (Bohr effect)
3. Temperature
4. Bisphophoglycerate (BPG)

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11
Q
  1. Ambient PO2
    - active tissue has ______ PO2
    - O2 is ________ from Hb
  2. Ambient pH (Bohr effect)
    - Active tissue has _____ CO2
    - _______ pH of blood
    - __________ O2 unloading
A
    • decreased
    • released
    • increased
    • lowers
    • promotes
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12
Q

Acidosis= blood pH ______ than _____
Alkalosis= blood pH ______ than _____

A

lower; 7.35
higher; 7.45

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13
Q
  1. Temperature
    - active tissue has ______ temp; _______ O2 unloading
  2. Bisphophogylcerate (BPG)
    - RBCs produce BPG which binds to ____; O2 is _________
    - ______ body temp (fever), _________, ___________, __________, and ____________ all raise BPG and _______ O2 unloading
A
    • increased; promotes

4.
- Hb; unloaded
- increased; thyroxine; growth hormone; testosterone; epinephrine; PROMOTE

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14
Q

Percentage saturation of Hb at normal systemic capillaries: ____%

A

78%

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15
Q

Oxyhemoglobin dissociation curve:
Left Shift:
- _______ O2 unloading to tissue
- _______ H+ (_____ pH)
- _______ PCO2
- _______ 2,3-BPG
- _______ temperature

Right Shift:
- ______ O2 unloading to tissue
- _______ H+ (_____ pH–> Acid)
- _______PCO2
- _____ 2,3-BPG
- ______ temperature
- ____________
- _________ altitude

A

Left shift:
- decrease
- decrease (increase)
- decrease
- decrease
- decrease

Right shift:
- increase
- increase (decrease)
- increase
- increase
- increase
- exercise
- high

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16
Q

Blood Gases and the Respiratory Rhythm:
Rate and depth of breathing adjust to maintain arterial blood levels of:
- pH _____ to ______
- PCO2 ___ mmHg
- PO2 ____ mmHg

Brainstem respiratory centers receive input from ______ and ______ _____________ that monitor composition of ______ and _______

  • most POTENT stimulus for breathing is _____, followed by ______, and least significant is _______
A
  • 7.35; 7.45
  • 40
  • 95

central; peripheral; chemoreceptors; CSF; blood

  • pH; CO2; O2
17
Q

Pulmonary ventilation adjusted to maintain pH of the _____
- ________ chemoreceptors in medulla produce about ___% of the change in respiration induced by pH shift
-CO2 crosses _________ and reacts with water in ____ to produce _______ ______
-the ____ from _________ strongly stimulates ________ chemoreceptors, since CSF does not contain much protein buffer
- Hydrogen ions also stimulate ____________________- which produce, _____% of the respiratory response to pH changes

A

Brain
- central; 75%
-BBB; CSF; carbonic acid
-H+ carbonic acid; central
- peripheral chemoreceptors; 25%

18
Q

____________: PCO2 less than 37 mmHg
- most common cause of ____________

___________: PCO2 greater than 43 mmHg
- most common cause of ____________

A

hypocapnia
- alkalosis

hypercapnia
- acidosis

19
Q
  • __________ can be a corrective homeostatic response to _________ (gets rids of CO2)
  • ___________ can be a corrective homeostatic response to _________ (not exhaling as much, retaining CO2)
A
  • hyperventilation; acidosis
  • hypoventilation; alkalosis
20
Q

PO2 usually has little effect on respiration at low elevations except with ________ ______________
- only if arterial PO2 < ____ mmHg (_____ bodies sense this)
-stimulates _______ breathing
- Hypoxic drive
-respiration driven ________ by low PO2 than by CO2 or pH
-can occur in: _________, ____________ or at ________ elevations after several days

A

chronic hypoxemia
- 60 (carotid)
-heavy
- MORE
-emphysema; pneumonia; high

21
Q

Respiration and Exercise:
Causes of increase respiration during exercise
- when the brain sends motor commands to the muscles, it also sends this information to the __________ _______
-they increase pulmonary ventilation in _________ of the needs of the exercising muscles
- Exercise stimulates ____________ of muscles and joints, they transmit excitatory signals to brainstem ___________ _______
-increase breathing because they are informed that muscles are moving- prior to body’s demand/need for more O2
-increase in pulmonary ventilation keeps blood gas values at their normal levels in spite of the elevated____ consumption and _____ generation by the muscles

A
  • respiratory centers
    -anticipation
  • proprioceptors; respiratory centers
  • O2; CO2
22
Q

____________: deficiency of oxygen or the inability to USE oxygen
- a consequence of respiratory diseases

____________ ___________: state of low arterial PO2
- usually due to inadequate pulmonary ____ _________
- many possible causes:
-oxygen deficiency at high elevations; ________ ventilation: drowning, aspiration of a foreign body, respiratory arrest, degenerative lung diseases

A

Hypoxia

hypoxemia hypoxia
- gas exchange
- impaired

23
Q
  • ___________: inadequate circulation of blood
    -congestive ______ failure
  • _____________: due to inability of the blood to carry adequate oxygen
  • _____________: metabolic poisons (for example, cyanide) prevents O2 use in tissue
  • Hypoxia is often marked by __________ (blueness of skin)
A
  • ischemic hypoxia
    -heart
  • anemic hypoxia
  • histotoxic hypoxia
  • cyanosis
24
Q

Oxygen imbalances: too much
- Although safe to breathe ____% oxygen at 1 atm for a few hours, ________ _________ develops when pure O2 breathed at _____ atm or greater
-generates _____ ______ and ________
-destroys ____________
-damages ____________ ______
-leads to seizures, coma, death

A
  • 100%; oxygen toxicity; 2.5
    -free radicals; H2O2 (hydrogen peroxide)
    -enzymes
    -nervous tissue