Biol2420 - Respiratory System #2

Front 1

What is the total pressure produced by the atmosphere a sum of and how can it be calculated?

Back 1

The total pressure produced by the atmosphere is the sum of the pressures produced by each of its gases
It can be calculated as partial pressures

Hint 1

Pg. 255

Front 2

What is the name of the principle that states, the total pressure of the atmosphere (or any gas mixture) is equal to the sum of the pressures that each gas in the mixture would exert independently?

Back 2

Dalton’s Law

Hint 2

Pg. 255

Front 3

If only a dry atmosphere is being considered (that is water vapor pressure will not be a factor) what would the total atmospheric pressure equal?

Back 3

The total atmospheric pressure would equal PN2 + PO2 + PCO2

Hint 3

Pg. 255

Front 4

Nitrogen composes 78% of the atmosphere, what is its calculated partial pressure at sea level?

Back 4

0.78 x 760mmHg = 593

Hint 4

Pg. 255

Front 5

Oxygen composes 21% of the air, what is its calculated partial pressure at sea level?

Back 5

0.21 x 760mmHg = 159

Hint 5

Pg. 255

Front 6

Carbon Dioxide composes 0.04 of the air, what is its calculated partial pressure at sea level?

Back 6

0.0004 x 760 = 0.3

Hint 6

Pg. 255

Front 7

True or False. Partial pressure of each gas decreases with altitude.

Back 7

True. The total atmospheric pressure decreases with altitude, the partial pressure of each gas correspondingly decreases.

Hint 7

Pg. 255

Front 8

What are the factors that affect Henry’s Law?

Back 8

Henry’s law equals the amount of a gas that can dissolve in water.
Henry’s law depends on:
The temperature of the water
The solubility of the gas in water
The partial pressure of the gas in the air above the water

Hint 8

Pg. 256

Front 9

True or False. More of a gas can dissolve in hot water.

Back 9

False. Gas can dissolve more in colder water.

Hint 9

Pg. 256

Front 10

Why is the amount of oxygen (or carbon dioxide) dissolved in the blood determined by partial pressures in the air within the alveoli?

Back 10

Because the solubility of oxygen (or carbon dioxide) is a physical constant, and blood temperature is maintained relatively constant. Therefore the amount of oxygen (or carbon dioxide) dissolved in the blood is determined by their partial pressures in the air within the alveoli.

Hint 10

Pg. 256

Front 11

Measurements of which partial pressures are performed in hospitals to assess the effectiveness of pulmonary gas exchange?

Back 11

PO2 and PCO2

Hint 11

Pg. 256

Front 12

What conditions may cause blood gases to be abnormal?

Back 12

Disorders of the lungs
or
Pulmonary circulation
or
By depressed breathing under anesthesia

Hint 12

Pg. 257

Front 13

What action maintains the homeostasis of blood PO2 and PCO2?

Back 13

Breathing

Hint 13

Pg. 257

Front 14

What is the name of the sensors involved in the negative feedback control of breathing and that also monitor the blood gasses in arterial blood?

Back 14

Chemoreceptors

Hint 14

Pg. 257

Front 15

How many types of sensors involved in the negative feedback control of breathing and that also monitor the blood gasses in arterial blood and what are the names of the different types?

Back 15

2

Peripheral Chemoreceptors
and
Central Chemoreceptors

Hint 15

Pg. 257

Front 16

Where are the Peripheral Chemoreceptors located?

Back 16

They are in the Aortic Bodies (which are located around the aortic arch)
and
In the Carotid Bodies (which are located in each common carotid artery near its branch forming the internal and external carotids)

Hint 16

Pg. 257

Front 17

Where are the Central Chemoreceptors located?

Back 17

They are located in the medulla oblongata

Hint 17

Pg. 257

Front 18

How do the Peripheral Chemoreceptors send sensory information and where is it sent to?

Back 18

The peripheral chemoreceptors send sensory information via 2 cranial nerves:

The Glossopharyngeal Nerve or (Cranial Nerve IX)
and
The Vagus Nerve or (Cranial Nerve X)

The sensory information is sent to the Rhythmicity Center of the Medulla Oblongata

Hint 18

Pg. 257

Front 19

What is the function of the Rhythmicity Center?

Back 19

It is the neural center that controls automatic breathing

Hint 19

Pg. 257

Front 20

What 2 conditions of the blood stimulate chemoreceptors?

Back 20

The pH
and
The PCO2

Hint 20

Pg. 257

Front 21

What is it called when the CO2 exhaled by the lungs is less than the rate at which it is produced by tissue cells and enters the venous blood?

Back 21

Hypoventilation
or
Inadequate Ventilation

Hint 21

Pg. 257

Front 22

How does Hypoventilation affect the arterial PCO2?

Back 22

It causes a rise in the arterial PCO2

Hint 22

Pg. 257

Front 23

What is it called when CO2 is being eliminated by ventilation at a greater rate than it enters the blood from the metabolizing tissues?

Back 23

Hyperventilation
or
Excessive Ventilation

Hint 23

Pg. 257

Front 24

How does Hyperventilation affect the arterial PCO2?

Back 24

It causes a decrease in arterial PCO2

Hint 24

Pg. 257

Front 25

How is the rate and depth of breathing measured?

Back 25

It is measured by the Total Minute Volume
The Total Minute Volume = (The Tidal Volume) x (The number of breaths per Minute)

Hint 25

Pg. 257

Front 26

What does it mean when a high Total Minute Volume lowers the arterial PCO2?

Back 26

The person is Hyperventilating

Hint 26

Pg. 257

Front 27

What does it mean when a low Total Minute Volume raises the arterial PCO2?

Back 27

The person in Hypoventilating

Hint 27

Pg. 257

Front 28

What condition of the arterial blood changes as the arterial PCO2 changes?

Back 28

The arterial Blood pH

Hint 28

Pg. 258

Front 29

Why does the arterial blood pH change as the arterial PCO2 changes?

Back 29

Because the arterial PCO2 is a measure of the concentration of CO2 dissolved in the plasma.
And CO2 combines with water to form Carbonic Acid (H2CO3)

Hint 29

Pg. 258

Front 30

What is formed in the following equation?
CO2 + H2O ---> _____

Back 30

H2CO3 (Carbonic Acid)

Hint 30

Pg. 258

Front 31

What happens once Carbonic Acid (H2CO3) has been formed?

Back 31

It ionizes (dissociates) to produce two ions:
H+ (a proton)
and
HCO3- (which is the bicarbonate ion)

Hint 31

Pg. 258

Front 32

Complete the following equation.
H2CO3 ---> ___ + HCO3-

Back 32

H+

Hint 32

Pg. 258

Front 33

The __ is inversely related to the H+ concentration. As the H+ concentration increases, the pH _______.
As the H+ concentration decreases the pH ______.

Back 33

pH
Decreases
Increases

Hint 33

Pg. 258

Front 34

What does Hypoventilation cause in regards to H+ concentration and pH?

Back 34

It causes a rise in the arterial PCO2, which produces an increased H+ concentration and a decrease in the arterial pH.

Hint 34

Pg. 258

Front 35

What does Hyperventilation cause in regards to H+ concentration and pH?

Back 35

It causes a decrease in arterial PCO2, which produces a decreased H+ concentration and an increase in the arterial pH.

Hint 35

Pg. 258

Front 36

How is breathing primarily regulated?

Back 36

Breathing is primarily regulated by the CO2 dissolved in the plasma.

Hint 36

Pg. 258

Front 37

What action do the Peripheral Chemoreceptors cause when they are stimulated by a fall in blood pH due to a rise in blood CO2 concentrations?

Back 37

An immediate increase in breathing

Hint 37

Pg. 258

Front 38

True or False. The Central Chemoreceptors are stimulated by H+ from the blood crossing the blood-brain barrier.

Back 38

False. H+ from the blood can’t cross the blood-brain barrier to stimulate the central chemoreceptors.

Hint 38

Pg. 258

Front 39

True or False. The Central Chemoreceptors neurons in the medulla oblongata are different neurons from those in the rhythmicity center of the medulla oblongata.

Back 39

True

Hint 39

Pg. 258

Front 40

How are the Central Chemoreceptors in the brain stimulated?

Back 40

The Central Chemoreceptor neurons are stimulated by a fall in the pH of their surrounding brain interstitial fluid, which is a result of CO2 diffusing across the blood-brain barrier.

Hint 40

Pg. 258

Front 41

True or False. The Aortic and Carotid Bodies are directly stimulated by both a decrease in the blood pH, and by an increase in CO2.

Back 41

False. The Aortic and Carotid Bodies are directly stimulated by a decrease in the blood pH, and not by an increase in CO2

Hint 41

Pg. 258

Front 42

What other substances besides H+ ions can stimulate the Peripheral Chemoreceptors to cause breathing to be stimulated?

Back 42

Any acids in the blood such as Lactic Acid or Ketone Bodies, can also lower blood pH.

Hint 42

Pg. 258

Front 43

How is breathing normally regulated?

Back 43

Breathing is normally regulated by the changes in pH that result from changes in CO2, so that homeostasis of the arterial PCO2 is maintained.

Hint 43

Pg. 258

Front 44

Which Chemoreceptors produce an immediate increase in breathing?

Back 44

Peripheral Chemoreceptors

Hint 44

Pg. 258

Front 45

Which Chemoreceptors are responsible for 70% to 80% of the increased ventilation that occurs when the high arterial PCO2 is sustained?

Back 45

Central Chemoreceptors

Hint 45

Pg. 258

Front 46

What process stimulates a newborn baby to take its first breath?

Back 46

When the umbilical cord is clamped and cut, the build up of CO2 and the accompanying fall in pH (caused by increased H+) stimulates the central chemoreceptors in the medulla oblongata, and the newborn takes its first breath.

Hint 46

Pg. 258-259

Front 47

What muscle do babies use to breathe when they are first born?

Back 47

The Diaphragm

Hint 47

Pg. 259

Front 48

True or False. Babies for the first 2 months of life are primarily nose breathers.

Back 48

True

Hint 48

Pg. 259

Front 49

True or False. A low arterial PO2 cannot stimulate breathing.

Back 49

False. A low arterial PO2 can also stimulate breathing. However, the concentration of O2 in the plasma (measured by the arterial PO2) has little effect on breathing at sea level or moderate altitudes.

Hint 49

Pg. 259

Front 50

Why can you hold your breath longer if you Hyperventilate?

Back 50

An enhanced ability to hold your breath after Hyperventilating is due to lowering of arterial PCO2.

Hint 50

Pg. 259

Front 51

How and why does Shallow Water Blackout occur?

Back 51

When a swimmer Hyperventilates at the side of the pool, the hyperventilation blows off CO2, which abnormally reduces the amount of free hydrogen ion (H+) in the blood, causing the pH to rise. The swimmer has now reduced the main stimulus for breathing. When the swimmer goes underwater and swims vigorously, reduction of available oxygen levels in the blood occur. A the Oxygen levels decrease, insufficient Oxygen for aerobic metabolism results, thereby reducing the levels of ATP in the brain which results in unconsciousness.

Hint 51

Pg. 259

Front 52

Which specific Peripheral Chemoreceptor is sensitive to arterial PO2?

Back 52

The Carotid Bodies

Hint 52

Pg. 259

Front 53

What effect does a rise in the arterial PO2 have on the chemoreceptor sensitivity to PCO2?

Back 53

A rise in the arterial PO2 decreases the chemoreceptor sensitivity to PCO2.

Hint 53

Pg. 259

Front 54

What effect does a decrease in the arterial PO2 have on the chemoreceptor sensitivity to PCO2?

Back 54

A decrease in the arterial PO2 increases the chemoreceptor sensitivity to PCO2.

Hint 54

Pg. 259

Front 55

Why if you go up to moderate altitudes does an increase in PCO2 have a greater effect on breathing?

Back 55

Because of the lower PO2 at these heights.

Hint 55

Pg. 259

Front 56

What is breathing in response to lowered arterial PO2 known as?

Back 56

Hypoxic Drive

Hint 56

Pg. 259

Front 57

What have experiments suggested that the arterial PO2 would have to fall below for breathing to be directly stimulated by the lowered O2 levels?

Back 57

Experiments suggest that the arterial PO2 would have to fall below 70 mmHg for breathing to be directly stimulated by the lowered O2.

Hint 57

Pg. 259

Front 58

Approximately what percent of oxyhemoglobin is contained in the systemic arterial blood?

Back 58

The systemic arterial blood contains about 97% oxyhemoglobin

Hint 58

Pg. 259

Front 59

About how much of the oxyhemoglobin’s oxygen is unloaded to the tissues for cell respiration?

Back 59

About one-fifth of its oxygen

Hint 59

Pg. 259

Front 60

What does the extent of the unloading of oxygen to the tissues for cell respiration depend on?

Back 60

It depends on:
The pH of the tissue
and
The temperature of the tissue.

Hint 60

Pg. 259

Front 61

How is Carbon Dioxide primarily transported in the blood?

Back 61

It is primarily transported as Bicarbonate in the plasma.

Hint 61

Pg. 259

Front 62

What does each hemoglobin molecule consist of?

Back 62

Each hemoglobin molecule consists of four polypeptide chains (2 alpha and 2 beta chains produced by different genes), which are bound to four iron-containing disc-shaped organic pigment molecules called “Hemes”.

Hint 62

Pg. 260

Front 63

What requirements must be met in order for blood to have a normal content of oxygen?

Back 63

1. Breathing must be normal, producing a normal arterial PO2
2. The red blood cell count must be in the normal range
3. There must be a normal concentration of hemoglobin
4. The hemoglobin must be in a normal from (not in the abnormal carboxyhemoglobin form)

Hint 63

Pg. 260

Front 64

What is the approximate amount of oxygen carried by arterial blood under normal conditions?

Back 64

It is approximately 20 ml O2 per 100 ml of blood

Hint 64

Pg. 260

Front 65

How many heme group are there per hemoglobin and how many Oxygen molecules can each hemoglobin molecule bind to?

Back 65

There are four heme groups per hemoglobin
Each hemoglobin molecule can bond to four molecules of oxygen.

Hint 65

Pg. 260

Front 66

What was the name designation of Hemoglobin prior to the bonding of Oxygen molecules?

Back 66

Deoxyhemoglobin

Hint 66

Pg. 260

Front 67

What are the binding and release of oxygen known as respectively?

Back 67

The binding and release of oxygen are known as the “Loading” and “Unloading” reactions.

Hint 67

Pg. 260

Front 68

Where does the loading reaction occur?

Back 68

In the Lungs

Hint 68

Pg. 260

Front 69

Where does the unloading reaction occur?

Back 69

In the tissue capillaries

Hint 69

Pg. 260

Front 70

What is it called when 97% of the hemoglobin is loaded with oxygen?

Back 70

Percent Oxyhemoglobin
or
Oxyhemoglobin Percent Saturation

Hint 70

Pg. 260

Front 71

What is another name for increased depth of breathing required to meet demand?

Back 71

Hyperpnea

Hint 71

Pg. 261

Front 72

What happens to the PO2 of the exercising muscles during exercise?

Back 72

The PO2 of the exercising muscles decreases

Hint 72

Pg. 261

Front 73

Exercising muscles produce ____ and ____, which forms carbonic acid.

Back 73

Lactic Acid
Carbon Dioxide (CO2)

Hint 73

Pg. 261

Front 74

What is it called when some of the H+ binds to hemoglobin causing hemoglobin to serve as a buffer and which results in its bond strength with oxygen becoming weaker?

Back 74

The Bohr Effect

Hint 74

Pg. 261

Front 75

What condition(s) slightly reduces hemoglobin’s affinity for oxygen, and also the ability of hemoglobin to load with oxygen in the lungs?

Back 75

A decrease in pH or (an increase in H+ concentration)
and
An increase in temperature

Hint 75

Pg. 261-262

Front 76

What would happen in regards to loading and unloading reaction if the blood pH were to increase?

Back 76

Hemoglobin would load with slightly more oxygen in the lungs, but would unload less as it travels through the systemic capillaries.

Hint 76

Pg. 261

Front 77

Why is oxygen unloading increased in exercising muscles?

Back 77

Exercising muscles are warmed by their faster metabolism.
Therefore both pH and temperature effects are operating to increase the unloading of oxygen as blood travels in the capillaries through these muscles.

Hint 77

Pg. 262

Front 78

How is Carbon Dioxide carried by the blood?

Back 78

Carbon Dioxide is carried by the blood in 3 forms:
1. Dissolved CO2 in the plasma
2. Carbaminohemoglobin
3. Bicarbonate ion (HCO3-) in the plasma

Hint 78

Pg. 262

Front 79

Which specific form of blood Carbon Dioxide transportation produces the PCO2 measurement and about 10% of the total carbon dioxide in the blood?

Back 79

CO2 dissolved in the plasma

Hint 79

Pg. 262

Front 80

Which specific form of blood carbon dioxide transportation accounts for about 20% of the total carbon dioxide in the blood?

Back 80

Carbaminohemoglobin (carbon dioxide bound to an amino acid in hemoglobin)

Hint 80

Pg. 262

Front 81

What is it called when Carbon Monoxide binds to the iron in heme groups?

Back 81

Carboxyhemoglobin

Hint 81

Pg. 262

Front 82

Which specific form of blood carbon dioxide transportation accounts for about 70% of the total carbon dioxide in the blood?

Back 82

Bicarbonate ion (HCO3-)

Hint 82

Pg. 262

Front 83

Why can Carbon Dioxide combine with water to form Carbonic Acid (H2CO3) to a much greater extent in the red blood cells as compared to in the plasma?

Back 83

Because the red blood cells contain Carbonic Anhydrase (an enzyme which catalyzes this reaction)

Hint 83

Pg. 262

Front 84

What is established as the HCO3- diffuses out of red blood cells into the plasma?

Back 84

An electrical gradient is established for chloride ions (Cl-) to diffuse into the red blood cells.

Hint 84

Pg. 262

Front 85

What is the exchange of Cl- for HCO3- in the plasma called?

Back 85

It is called the Chloride Shift

Hint 85

Pg. 262

Front 86

Can the form that accounts for how the majority of carbon dioxide is transported in blood be exhaled?

Back 86

No

Hint 86

Pg. 263

Front 87

What must happen so the carbon dioxide being transported as Bicarbonate ion can be exhaled?

Back 87

It must be converted back into carbon dioxide and water. The HCO3- in the plasma must re-enter the red blood cells, as Cl- moves out of the red blood cells in a “Reverse Chloride Shift”. The HCO3- then combines with H+ to form H2CO3. Then carbonic anhydrase catalyzes the reverse reaction were H2CO3 is converted into CO2 and H2O, so that the CO2 can be exhaled.

Hint 87

Pg. 263

Front 88

Which 2 structures maintain the arterial blood pH within an extremely narrow range?

Back 88

The Lungs
and
The Kidneys

Hint 88

Pg. 263

Front 89

What structure assumes the responsibly for the maintenance of normal amounts of free bicarbonate?

Back 89

The maintenance of normal amounts of free bicarbonate is the responsibility of the kidneys

Hint 89

Pg. 263

Front 90

What is the value for normal arterial blood pH?

Back 90

Normal arterial blood has a pH of 7.40
Within a range of about 7.35-7.45

Hint 90

Pg. 263

Front 91

What is the homeostasis of blood pH called?

Back 91

The Acid-Base Balance

Hint 91

Pg. 263

Front 92

What 2 components make up the Acid-Base Balance and what regulates these 2 components?

Back 92

The Respiratory Component (regulated by the lungs)
The Metabolic Component (regulated by the free bicarbonate in the blood, which is in turn maintained by the kidneys)

Hint 92

Pg. 263

Front 93

What structure is responsible for the homeostasis of Carbonic Acid?

Back 93

The Lungs

Hint 93

Pg. 263

Front 94

What is the regulation of acid-base balance by the lungs and breathing known as?

Back 94

It is known as the “Respiratory Component” of Acid-Base Balance

Hint 94

Pg. 263

Front 95

What is the name of the condition that is produced from a decrease in arterial pH due hypoventilation?

Back 95

Respiratory Acidosis

Hint 95

Pg. 263

Front 96

True or False. In Respiratory Acidosis the arterial blood pH is acidic.

Back 96

False. In Respiratory Acidosis the arterial blood pH is acidotic, but not acidic.

Hint 96

Pg. 264

Front 97

What is the name of the condition that is produced from an increase in arterial pH due hyperventilation?

Back 97

Respiratory Alkalosis
This occurs when the arterial pH becomes greater than 7.45

Hint 97

Pg. 264

Front 98

What does it mean to be a Volatile Acid (ex: Carbonic Acid)?

Back 98

It means that it can become gaseous and be eliminated in the exhaled breath.

Hint 98

Pg. 264

Front 99

Why can Hyperventilation cause a complication such as tetanic contractions?

Back 99

Because, the elevated blood pH causes an increased portion of the free calcium ions (Ca2+) to bind to plasma albumin. This reduction in free calcium causes nerve cell membranes to become highly excitable and will start to send out spontaneous and unnecessary nerve impulses to skeletal muscles.

Hint 99

Pg. 264

Front 100

What is the condition of tetanic contractions produced by hyperventilation called?

Back 100

Hypocalcemic Tetany

Hint 100

Pg. 264

Front 101

What specific substance buffers the nonvolatile acids?

Back 101

Bicarbonate

Hint 101

Pg. 264

Front 102

What are some other nonvolatile acids besides Carbonic Acid?

Back 102

Lactic Acid
Fatty Acids
Ketone Bodies

Hint 102

Pg. 264

Front 103

What is the condition called if the amount free bicarbonate is disappear because of acceptance of free H+, resulting in nonvolatile acid releasing unbuffered H+ thus lowering the arterial pH below 7.35?

Back 103

This condition is called Metabolic Acidosis

Hint 103

Pg. 264

Front 104

True or False. Metabolic Acidosis does not normally occur.

Back 104

True. Metabolic acidosis does not normally occur, and would thereby indicate a pathological condition.

Hint 104

Pg. 264

Front 105

What 2 conditions could cause Metabolic Acidosis?

Back 105

1. Uncontrolled Type 1 Diabetes Mellitus (due to the overproduction of acidic ketone bodies)
2. Excessive diarrhea (due to loss of bicarbonate from pancreatic juice that would otherwise be absorbed into the blood.

Hint 105

pg. 265

Front 106

What is the name of the condition that occurs when there is an increased ratio of HCO3- to H+ that produces an arterial pH greater than 7.45?

Back 106

Metabolic Alkalosis

Hint 106

pg. 265

Front 107

What 2 things could cause Metabolic Alkalosis?

Back 107

1. Taking too much exogenous bicarbonate (as in antacids)
2. Excessive Vomiting (The most common cause)

Hint 107

pg. 265

Front 108

What 2 conditions constitute the Metabolic Component of the Acid-Base Balance?

Back 108

Metabolic Acidosis
and
Metabolic Alkalosis

Hint 108

pg. 265

Front 109

What structure is responsible for maintaining the homeostasis of the Metabolic Component of the Acid-Base Balance?

Back 109

The Kidneys

Hint 109

pg. 265

Front 110

True or False. At high mountain altitudes the amount of oxygen available for diffusion into the pulmonary capillaries is less.

Back 110

True

Hint 110

pg. 265

Front 111

What is the name of the condition that can occur quite readily to many persons above 3,000 meters (approximately 9,800 feet)?

Back 111

Mountain Sickness
or
Altitude Sickness

Hint 111

Pg. 265

Front 112

What are some of the symptoms someone with Mountain Sickness would have?

Back 112

Headache
Shortness of Breath
Rapid Heart Rate
Nausea
Fatigue and Weakness
Impaired Mental Function
In a small percentage of persons, Cerebral Edema (brain swelling) and Pulmonary Edema (collection of fluid in the lungs) may also occur.

Hint 112

Pg. 265

Front 113

What are some of the respiratory adaptations of the Natives who live in high mountains?

Back 113

1. Development of enlarged “Barrel Chests” to increase alveolar ventilation
2. Increased amounts of Red Blood Cells and Hemoglobin
3. Development of many new capillaries to increase gas diffusion in the tissues

Hint 113

Pg. 265