Physiology Exam 3: Respiration I&ii Tiffany

Front 1

What is responsible for automatically adjusting the rate of Alveolar Ventilation almost exactly to the body's demands, and how is Arterial PCO2 and PO2 affected?

Back 1

The Nervous system is responsible, thus Arterial PCO2 and PO2 are hardly modified even with moderate to intense exercise.

Front 2

What is the Respiratory Center composed of and where is it located?

Back 2

Composed of several groups of neurons:
1. Dorsal Respirator Group
2. Ventral Respiratory Group
3. Pneumotaxic Center

Located bilaterally in the brain stem of the CNS - Medulla Oblongata and the Pons.

Front 3

Identify the part of the Respiratory Center: Responsible for inspiration or expiration depending on the nerves stimulated.

Back 3

Ventral Respiratory Group

Front 4

Identify the part of the Respiratory Center: Responsible for the rate and pattern of breathing.

Back 4

Pneumotaxic Center

Front 5

Identify the part of the Respiratory Center: Responsible for mainly inspiration.

Back 5

Dorsal Respiratory Group

Front 6

Identify the part of the Respiratory Center: Dorsally located in the Medulla Oblongata.

Back 6

Dorsal Respiratory Group

Front 7

Identify the part of the Respiratory Center: Dorsally located in the Pons.

Back 7

Pneumotaxic Center

Front 8

Identify the part of the Respiratory Center: Plays the most important role in controlling respiration.

Back 8

Dorsal Respiratory Group

Front 9

Where does the Dorsal Respiratory Group receive signals from?

Back 9

Chemoreceptors
Baroreceptors
Receptors in the Lungs

Front 10

What consists the Primary Inspiratory muscles?

Back 10

Diaphragm
External Intercostals

Front 11

What type of signal is transmitted to the primary inspiratory muscles?

How does this function?

Back 11

Ramp Signal.

Starts from 0 and continues with a steady increase for about 2 seconds, then stops for 3 seconds and starts again thus causing a steady increase in the pulmonary volume during inspiration, instead of causing respiratory gasps.

Front 12

What is the duration of Expiration determined by?

Back 12

The duration of Inspiration.

Front 13

Identify the part of the Respiratory Center: Limits the duration of Inspiration and increases the respiratory rate. Strong signals reduce the time of inspiration while weak signals increase the time of inspiration.

Back 13

Pneumotaxic Center

Front 14

Identify the part of the Respiratory Center: Mostly involved in increased levels of Ventilation.

Back 14

Ventral Respiratory Group

Front 15

What is the ultimate goal of Respiration?

Back 15

To maintain proper [H+], [O2], and [CO2] in the tissues, which is achieved by Respiratory activity.

Front 16

Out of [H+], [O2], and [CO2], which ones directly stimulate the Respiratory center causing an increase of Inspiratory and Expiratory signals?

Back 16

Increasing levels of [H+] and [CO2]

Front 17

How does [O2] act to affect the Respiratory Center?

Back 17

It does not have a direct effect but acts through the Peripheral Chemoreceptors located in the Carotid and Aortic Bodies.

Front 18

What is the total pressure of a gas directly proportional to?

Back 18

The concentration of the gas molecules.

Front 19

What is the net diffusion of a gas in one direction directly proportional to?

Back 19

The concentration gradient.

Front 20

Which three gases are included in the case of Respiratory Physiology?

Back 20

O2, CO2, N2

Front 21

True or False: The rate of diffusion of each of the gases is directly proportional to the pressure cause by this gas alone, the partial pressure.

Back 21

True

Front 22

What is air comprised of?

What is the total pressure at sea level?

Back 22

79% N2 = 600 mmHg
21% O2 = 160 mmHg

Total pressure at sea level: 760 mmHg

Front 23

Can gases that are already dissolved in H2O or Body Tissues exert pressure?

Back 23

Yes because the dissolved molecules are moving randomly and have kinetic energy.

Front 24

What two factors determine the pressure of a gas in a solution?

Which law encompasses this?

Back 24

Concentration
Solubility Coefficient

Henry's Law

Front 25

The Solubility Coefficient is measured based on what constant factor?

Back 25

Body Temperature

Front 26

True or False: The Partial Pressure of each gas tends to force molecules of that gas into solution, first in the alveolar membrane and then in the blood of the alveolar capillaries.

Back 26

True

Front 27

True or False: The rate at which molecules escape from one medium to another is directly proportional to their partial pressure in the blood.

Back 27

True

Front 28

What is the term describing the gas pressure difference between two areas?

Back 28

Pressure difference for diffusion

Front 29

What are all the reasons for why Alveolar air hasn't got the same composition as Atmospheric air?

Back 29

1. Alveolar air is only partially replaced (14%) with each breath.
2. O2 is going to the blood
3. CO2 is coming from the blood
4. Dry atmospheric air that enters the respiratory pathways is immediately humidified even before reaching the alveoli.

Front 30

Why is the slow replacement of Alveolar air important?

Back 30

It prevents sudden changes in the gases in the blood, making the respiratory control mechanisms much more stable.

Front 31

In reference to the Ventilation-Perfusion ratio normal values, list the # mmHg found for:
PO2 in:
Air
Alveoli
Venous

Back 31

PO2 in:
Air = 159 mmHg
Alveoli = 104 mmHg
Venous = 40 mmHg

Front 32

In reference to the Ventilation-Perfusion ratio normal values, list the # mmHg found for:
PCO2 in:
Air
Alveoli
Venous

Back 32

PCO2 in:
Air = 0.3 mmHg
Alveoli = 40 mmHg
Venous = 46 mmHg

Front 33

What does the Va/Q measure?

Back 33

The ventilation-perfusion ratio

Front 34

What does the Va and the Q stand for in the Va/Q ratio?

Back 34

Va = Alveolar Ventilation
Q = Blood Flow

Front 35

If Va is 0 but Q (perfusion) is normal, what is the result of the Va/Q ratio?
Does gas exchange exist?

Back 35

Va/Q = 0

No gas exchange exists.

Front 36

If Va is perfect but there is 0 Perfusion, what is the result of the Va/Q ratio?
Does gas exchange exist?

Back 36

Va/Q = Infinity

No gas exchange exists.

Front 37

If Va/Q = 0, does ventilation exist?
What are the values for PCO2 and PO2?

What are these values identical to?

Back 37

No ventilation.

PCO2 = 45 mmHg
PO2 = 40 mmHg

Same as Venous blood.

Front 38

If Va/Q = Infinity, does perfusion exist?
What are the values for PCO2 and PO2?

What are these values identical to?

Back 38

No perfusion.

PCO2 = 0 mmHg
PO2 = 159 mmHg

Same as Inspired air.

Front 39

True or False: All the blood going to the lungs goes through the Alveoli.

Back 39

False.

Around 2% of the cardiac output will go to the bronchial vessels and also some of the blood going to the alveoli goes through alveoli with abnormal Va/Q ratio.

Front 40

What is the term for the nonoxygenated blood that goes directly to the bronchial vessels, skipping the alveoli?
How does this affect its Va/Q?

Back 40

Physiologic Shunt

Decreases the Va/Q to below normal.

Front 41

What could be the result with an abnormally high Va/Q ratio?

Back 41

There is more O2 available than can be transported and the ventilation of these alveoli is said to be wasted.

Front 42

What are the two types of "wasted" ventilations?
What are they collectively known as?

Back 42

Two types:
1. When the Va/Q is high, the alveoli are said to be wasted.
2. The ventilation of the anatomical dead space areas of the respiratory pathways is said to be wasted.

Together they are known as Physiologic Dead Space.

Front 43

How much is O2 transport increased once it's bound to Hb?

Back 43

30-100x

Front 44

How much more O2 will a person require during exercise?

Back 44

20x more O2

Front 45

During exercise, when the CO2 remains in the blood capillaries, and the oxygenation suffers, what is the safety factor?

Back 45

The O2 diffusion through the pulmonary membrane maintains the blood almost saturated with O2.

Front 46

What happens when PO2 is high in the Alveoli?

Back 46

It will bind with Hb

Front 47

What happens when PO2 is low in tissues?

Back 47

It will be released from Hb

Front 48

What is the mmHg of PO2 in the Arteries?

Back 48

95 mmHg

Front 49

What is the usual O2 saturation of Arterial blood? (%)

Back 49

97%

Front 50

Shift of O2-Hb dissociation curve: Increasing acidity?

Back 50

Right

Front 51

What are all the factors that shift the O2-Hb dissociation curve to the right?

Back 51

Increasing [CO2]
Increasing blood
Increasing Temperature
Exercise
Decreasing pH (increasing acidity)
Abnormal Hemoglobin
Acute Acidosis

Front 52

What are all the factors that shift the O2-Hb dissociation curve to the left?

Back 52

Increasing pH (basicity)
Decreased [CO2]
Acute Alkalosis
Decreasing temperature
Carboxyhemoglobin
Abnormal Hemoglobin

Front 53

Explain the concept of Extracorporeal Gas Exchange.

Back 53

Once O2 diffuses from the Alveoli it is transported by the blood with Hb.
(Opposite for CO2)

Front 54

True or False: WIth exercise, more capillaries open up to diffuse.

Back 54

True.

Front 55

How fast/slow is blood oxygenated if the Va/Q ratio is high?

Back 55

Almost immediately.

Front 56

What is the cause for the blood PO2 being 95 mmHg as it leaves the ventricle?

Back 56

Due to the Pulmonary Shunt

Front 57

How much Hb/dl is found in a normal person's blood?

Back 57

15 Hb/dl

Front 58

How many # ml of O2 can each gram of Hb bind to, maximally?

Back 58

1.34ml of O2

Front 59

Hb in 100ml of blood can combine with a total of almost exactly #ml of O2? How is this expressed when Hb is 100% saturated?
Why?

Back 59

20ml of O2
Expressed as 20 volumes per cent.

Due to Hb not being pure.

Front 60

True or False: The O2-Hb dissociation curve can be expressed in terms of volume per cent of O2.

Back 60

True

Front 61

What is the total amount of O2 that will be bound with Hb in normal Arterial Blood?

Back 61

O2-Hb = 19.4 ml/dl of blood

(showing a 97% O2-Hb saturation)

Front 62

After the O2-Hb 19.4 ml/dl of Arterial blood passes through the capillaries, how low does this value drop to?

Back 62

14.4 ml/dl of capillary blood

(showing a 75% O2-Hb saturation)

Front 63

Under normal conditions, #ml of O2 is transported to the tissues by each 100ml of blood.

Back 63

5ml of O2

Front 64

True or False: Hb will maintain a constant PO2 in the tissues despite changes in the PO2 in the Alveoli.

Back 64

True