Exam 3- Chapter 16 Flashcards Preview

BIO 207- Human Physiology > Exam 3- Chapter 16 > Flashcards

Flashcards in Exam 3- Chapter 16 Deck (256)
Loading flashcards...
1
Q

What 3 things does respiration include?

A
  1. Ventilation (breathing)
  2. Gas exchange between blood and lungs and between blood and tissues
  3. Oxygen utilization by tissues to make ATP
2
Q

What is external respiration?

A

Ventilation and gas exchange in lungs

3
Q

What is internal respiration?

A

Oxygen utilization and gas exchange in tissues

4
Q

What are the two divisions of the respiratory system?

A
  1. Respiratory Zone

2. Conduction Zone

5
Q

What is the GENERAL function of the respiratory zone division of the respiratory system?

A

site of gas exchange

6
Q

What is the GENERAL function of the conduction zone division of the respiratory system?

A

gets air to the respiratory zone

7
Q

Describe the conduction route of the conduction zone (10 steps).

A
  1. Air travels down the nasal cavity
  2. Pharynx
  3. Larynx
  4. Trachea
  5. Right and left primary bronchi
  6. Secondary bronchi
  7. Tertiary bronchi —> (more branching)
  8. Terminal bronchioles
  9. Respiratory zone (respiratory bronchioles)
  10. Terminal alveolar sacs
8
Q

What are the 3 specific functions of the conduction zone division of the respiratory system?

A
  1. Transports air to the lungs
  2. Warms, humidifies, filters, and cleans the air
    (Mucus traps small particles, and cilia move it away from the lungs)
  3. Voice production in the larynx as air passes over the vocal folds
9
Q

In the conduction zone, how are small particles moved away from the lungs?

A

Mucus traps small particles, and cilia move it away from the lungs

10
Q

What are alveoli? Function?

A

Air sacs in the lungs where gas exchange occurs

11
Q

How many alveoli are there?

A

300 million of them

12
Q

How are alveoli and surface area related?

A

Provide large surface area (760 square feet) to increase diffusion rate

13
Q

What is within the central mediastinum of the thoracic cavity? What fills the rest of the thoracic cavity?

A
  1. Heart
  2. Trachea
  3. Esophagus
  4. Thymus
  • Lungs
14
Q

What lines the thoracic wall?

A

parietal pleura

15
Q

What covers the lungs?

A

visceral pleura

16
Q

The parietal and visceral pleura are normally pushed together, with a potential space between called the what?

A

intrapleural space

17
Q

Gas exchange in the lungs occurs via what?

A

diffusion

18
Q

Describe how O2 is diffused into the blood.

A

O2 concentration is higher in the lungs than in the blood, so O2 diffuses into blood.

19
Q

Describe how C02 is diffused out of the blood (into the lungs).

A

CO2 concentration in the blood is higher than in the lungs, so CO2 diffuses out of blood.

20
Q

When talking about ventilation, in what way does air move?

A

Air moves from higher to lower pressure.

21
Q

What are 3 important physical properties of the lungs?

A
  1. Compliance
  2. Elasticity
  3. Surface Tension
22
Q

Pressure differences between the two ends of the conducting zone occur due to changing what?

A

lung volumes

23
Q

What is atmospheric pressure?

A

pressure of air outside the body

24
Q

What is Intrapulmonary pressure?

A

pressure in the lungs

25
Q

What is Intrapleural pressure?

A

pressure within the intrapleural space (between parietal and visceral pleura)

26
Q

During inhalation, is intrapulmonary pressure or atmospheric pressure lower?

A

Intrapulmonary pressure is lower than atmospheric pressure

27
Q

What is pressure below that of the atmosphere called?

A

subatmospheric or negative pressure

28
Q

During exhalation, is intrapulmonary pressure or atmospheric pressure lower?

A

Intrapulmonary pressure is greater than atmospheric pressure.

29
Q

During inhalation/exhalation, how does the Intrapleural pressure relate to the intrapulmonary and atmospheric pressure?

A

Lower than intrapulmonary and atmospheric pressure in both inhalation and exhalation

30
Q

The difference between intrapulmonary and intrapleural pressure is called what?

A

transpulmonary pressure

31
Q

How does the Intrapleural pressure physically affect the lungs?

A

Keeps the lungs against the thoracic wall

32
Q

What does boyles law state?

A

States that the pressure of a gas is inversely proportional to its volume

33
Q

During inhalation, lung volume increases. What happens next?

A

An increase in lung volume during inspiration decreases intrapulmonary pressure to subatmospheric levels. Air goes in.

34
Q

During inhalation does the lung volume increase or decrease?

A

Increase

35
Q

During exhalation does the lung volume increase or decrease?

A

Decrease

36
Q

During exhalation , lung volume decreases. What happens next?

A

A decrease in lung volume during exhalation increases intrapulmonary pressure above atmospheric levels. Air goes out.

37
Q

Can lungs expand when stretched? What is this referred to?

A

Yes. Lung compliance.

38
Q

What is lung compliance defined as?

A

Defined as the change in lung volume per change in transpulmonary pressure (ΔV/ΔP)

39
Q

What disease decreases lung compliance and how?

A

Reduced by infiltration of connective tissue proteins in pulmonary fibrosis

40
Q

Summarize what lung elasticity is.

A

Lungs return to initial size after being stretched.

41
Q

Do lungs have a low or high amount of elastin fiber?

A

Lungs have lots of elastin fibers.

42
Q

The lungs are always under elastic tension because?

A

Because the lungs are stuck to the thoracic wall, they are always under elastic tension

43
Q

Surface tension allows the lungs to resist what?

A

distension

44
Q

What is surface tension exerted by?

A

Exerted by fluid secreted in the alveoli

45
Q

Surface tension raises the pressure of the alveolar air as it acts to ____ __ ____.

A

collapse the alveolus

46
Q

What does the law of laplace state?

A

Pressure is directly proportional to surface tension and inversely proportional to radius of alveolus.

47
Q

Would smaller or larger alveoli be at greater risk of collapse without surfactant?

A

Small alveoli would be at greater risk of collapse without surfactant

48
Q

What is surfactant secreted by?

A

type II alveolar cells

49
Q

What is surfactant composed of?

A

Consists of hydrophobic protein and phospholipids

50
Q

What is the function of surfactant?

A
  1. Reduces surface tension between water molecules

2. Prevents collapse

51
Q

Is surfactant more concentrated in smaller or larger alveoli?

A

More concentrated in smaller alveoli

52
Q

When does production of surfactant begin?

A

Production begins late in fetal life

53
Q

Since production of surfactant begins in fetal life, what are premature babies at risk of?

A

premature babies may be born with a high risk for alveolar collapse called respiratory distress syndrome (RDS)

54
Q

What is respiratory distress syndrome (RDS)

A

premature babies may be born with a high risk for alveolar collapse due to insufficient concentrations of surfactant called respiratory distress syndrome (RDS)

55
Q

What is another name for breathing?

A

pulmonary ventilation

56
Q

What are the two types of breathing/pulmonary ventilation and describe what they do.

A
  1. Inspiration: breathe in

2. Expiration: breathe out

57
Q

How is breathing/pulmonary ventilation accomplished?

A

Accomplished by changing thoracic cavity/ lung volume

58
Q

During inspiration, how does the volume of the thoracic cavity (and lungs) increase when the diaphragm contracts (flattens)?

A

Volume of thoracic cavity (and lungs) increases vertically when diaphragm contracts (flattens)

59
Q

During inspiration, how does the volume of the thoracic cavity (and lungs) increase when parasternal and external intercostals raise the ribs?

A

Volume of thoracic cavity (and lungs) increases horizontally when parasternal and external intercostals raise the ribs

60
Q

During expiration, how does the volume of the thoracic cavity (and lungs) decrease when the diaphragm relaxes (dome)?

A

Volume of thoracic cavity (and lungs) decreases vertically when the diaphragm relaxes (dome)

61
Q

During expiration, how does the volume of the thoracic cavity (and lungs) decrease when internal intercostals lower the ribs in forced expiration?

A

Volume of thoracic cavity (and lungs) decreases horizontally when internal intercostals lower the ribs in forced expiration

62
Q

What is an example of a Pulmonary Function Test?

A

Spirometry

63
Q

How is a spirometry conducted?

A

Subject breathes into and out of a device that records volume and frequency of air movement on a spirogram.

64
Q

What type of graph does a spirometry produce?

A

spirogram

65
Q

What is a spirometry measuring?

A

Measures lung volumes and capacities

66
Q

What can a spirometry diagnose?

A

Can diagnose restrictive and disruptive lung disorders

67
Q

Lung Capacity Measurements:

What is vital capacity?

A

maximum amount of air that can be forcefully exhaled after a maximum inhalation

68
Q

Lung Capacity Measurements:

What is total lung capacity?

A

amount of gas in the lungs after a maximum inspiration

69
Q

Lung Capacity Measurements:

What is inspiratory capacity?

A

amount of gas that can be inspired after a normal expiration

70
Q

Lung Capacity Measurements:

What is functional residual capacity?

A

amount of gas left in lungs after a normal expiration

71
Q

Lung Capacity Measurements:

What is tidal volume?

A

amount of air expired or inspired in quiet breathing

72
Q

Lung Capacity Measurements:

What is expiratory reserve volume?

A

amount of air that can be forced out after tidal volume

73
Q

Lung Capacity Measurements:

What is inspiratory reserve volume?

A

amount of air that can be forced in after tidal volume

74
Q

Lung Capacity Measurements:

What is residual volume?

A

amount of air left in lungs after maximum expiration

75
Q

In a restrictive lung disorder, describe the:

  1. Lung tissue
  2. Vital capacity
  3. Forced Expiration
A
  1. Lung tissue is damaged
  2. Vital capacity is reduced
  3. Forced expiration is normal
76
Q

In a obstructive lung disorder, describe the:

  1. Lung tissue
  2. Vital capacity
  3. Forced Expiration
A
  1. Lung tissue is normal
  2. Vital capacity is normal
  3. Forced expiration is reduced
77
Q

What are 2 examples of a restrictive lung disorder?

A
  1. Pulmonary Fibrosis

2. Emphysema

78
Q

What is an example of an obstructive lung disorder?

A

Asthma

79
Q

How are obstructive lung disorders usually diagnosed?

A

by doing forced expiratory volume tests (FEV test)

80
Q

What are the symptoms of asthma?

A

dyspnea (shortness of breath) and wheezing

81
Q

What is dyspnea?

A

shortness of breath

82
Q

What are 3 things asthma is caused by?

A

Caused by inflammation, mucus secretion, and constriction of bronchioles

83
Q

What is another name for asthma?

A

airway hyperresponsiveness

84
Q

What is allergic asthma triggered by?

A
  1. Allergens stimulating T lymphocytes to secrete cytokines and recruit eosinophils and mast cells, which contribute to inflammation
  2. Cold or Dry Air
85
Q

Is allergic asthma reversible?

A

YES

86
Q

What is allergic asthma reversible with? (give an example)

A

bronchodilator (albuterol)

87
Q

What symptoms are characterized by Chronic Obstructive Pulmonary Disease (COPD)?

A
  1. Chronic inflammation
  2. excessive mucus production
  3. narrowing of the airways
  4. Alveolar destruction
88
Q

What two other diseases are included with COPD?

A

emphysema and chronic obstructive bronchiolitis

89
Q

In an FEV test, a patient with COPD would show what?

A

Accelerated decline in FEV

90
Q

Inflammation from COPD is due to/involved what?

A
  1. Macrophages
  2. Neutrophils
  3. Cytotoxic T cells
91
Q

With COPD, what can smoking trigger?

A

Excessive mucus production and inflammation

92
Q

Is COPD common to people who do or do not smoke?

A

Most people with COPD smoke

93
Q

Is there a cure for COPD?

A

NO

94
Q

What is the 5th leading cause of death?

A

COPD

95
Q

In addition to the excessive mucus production and inflammation that smoking triggers in COPD, what else does it trigger?

A

Smoking also promotes the infiltration of obstructing fibrous tissue and muscle in the airways and remodeling of blood vessels in the lungs, leading to pulmonary hypertension

96
Q

What is emphysema?

A

Destruction of alveoli

97
Q

How does emphysema affect surface area for gas exchange?

A

Reduces surface area for gas exchange

98
Q

How does the destruction of alveoli in emphysema physically affect the bronchioles during expiration?

A

With fewer alveoli to put pressure on bronchioles, they collapse during expiration.

99
Q

What is the most common cause of emphysema? What does this cause trigger?

A

Smoking is the most common cause. It triggers inflammation and destruction of alveoli by immune cells

100
Q

What is pulmonary fibrosis?

A

accumulation of fibrous tissues in the lungs when alveoli are damaged.

101
Q

What may pulmonary fibrosis be due to?

A

inhalation of small particles

102
Q

What is an example of pulmonary fibrosis?

A

black lung in miners

103
Q

What does dalton’s law state?

A

The total pressure of a gas mixture is equal to the sum of the pressures of each gas in it.

104
Q

What is partial pressure?

A

the pressure of an individual gas

105
Q

How can partial pressure be measured?

A

can be measured by multiplying the % of that gas by the total pressure

106
Q

In the alveoli does the percentage of oxygen increase or decrease during gas exchange? CO2? How does this affect the partial pressure of each?

A

In the alveoli, the percentage of oxygen decreases and CO2 increases, changing the partial pressure of each.

107
Q

What does the partial pressure of oxygen change with?

A

Altitude and location

108
Q

What does the blood gas measurement measure?

A

Only measures oxygen dissolved in the blood plasma. It will NOT measure oxygen in red blood cells

109
Q

Does the blood gas measurement provide a good measurement of lung function?

A

It does provide a good measurement of lung function

110
Q

If partial pressure oxygen in blood is more than _____ below that of lungs, gas exchange is impaired.

A

5 mmHg

111
Q

The rate of blood flow through the lungs is equal to what?

A

that through the systemic circuit (5.5 L/minute cardiac output)

112
Q

What is the pressure difference between the left atrium, and the pulmonary artery?

A

only 10 mmHg.

113
Q

For pulmonary circulation, must vascular resistance be very low or very high?

A

Very low

114
Q

For pulmonary circulation vascular resistance must be very low. Why? What does this reduce the possibility of?

A
  1. Low pressure/low resistance pathway

2. Reduces possibility of pulmonary edema

115
Q

Pulmonary arterioles constrict when alveolar partial pressure O2 is___ , and dilate when partial pressure O2 is ___.

A
  1. Low

2. High

116
Q

Blood flow to alveoli is _____ when they are full of oxygen and _____ when not.

A
  1. increased

2. decreased

117
Q

The constriction/dilation of of the pulmonary arterioles are opposite of that of the what?

A

systemic arterioles

118
Q

Systemic arterioles constrict when partial pressure O2 in tissues is ____, and dilate when the partial pressure O2 in tissues is _____.

A
  1. High

2. Low

119
Q
  • Pulmonary arterioles constrict when alveolar partial pressure O2 is low, and dilate when partial pressure O2 is high.
    BY CONTRAST
  • Systemic arterioles constrict when partial pressure O2 in tissues is high, and dilate when the partial pressure O2 in tissues is low.

What does this ensure?

A

This ensures that only tissues that need oxygen are sent blood.

120
Q

Ventilation/Perfusion Ratios:

The response of pulmonary arterioles to low oxygen levels makes sure that ___________ matches _________.

A
  • ventilation (O2 into lungs)

- perfusion (blood flow)

121
Q

What is an example of a group of people that experience disorders caused by high partial pressure of gases?

A

deep-sea divers

122
Q

What are 3 disorders that deep-sea divers experience due to high partial pressure of gases?

A
  1. Oxygen Toxicity
  2. Nitrogen Narcosis
  3. Decompression sickness
123
Q

Disorders Caused by High Partial Pressure of Gases (Deep Sea Divers):
What is oxygen toxicity? Why is this true?

A
  1. 100% oxygen is dangerous at 2.5 atmospheres.

2. Due to oxidation of enzymes

124
Q

Disorders Caused by High Partial Pressure of Gases (Deep Sea Divers):
How does nitrogen narcosis occur? What does it result in?

A
  1. Occurs if nitrogen is inhaled under pressure

2. Results in dizziness and drowsiness

125
Q

Disorders Caused by High Partial Pressure of Gases (Deep Sea Divers):
How is decompression sickness caused?

A

When a diver comes to the surface too fast, nitrogen bubbles can form in the blood and block small vessels.

126
Q

Besides deep sea diving, what is another scenario in which decompression sickness can be initiated?

A

Can also happen if an airplane suddenly loses pressure

127
Q

Where is the rhythmicity center located?

A

Medulla Oblongata

128
Q

How many types of neurons are located within the rhythmicity center?

A

four types of neurons identified for different stages of breathing

129
Q

What are the two main groups of the rhythmicity center?

A
  1. Dorsal respiratory group

2. Ventral respiratory group

130
Q

What is the dorsal respiratory group made up of? What nerve does it stimulate?

A
  1. Made up of inspiratory neurons

2. Phrenic nerve

131
Q

What is the ventral respiratory group made up of? What types of neurons does it stimulate?

A
  1. Made up of inspiratory neurons

2. stimulate spinal respiratory neurons and expiratory neurons that INHIBIT the phrenic nerve

132
Q

What structure influences the medulla activity?

A

Pons

133
Q

What are the two divisions of the pons involved in respiration?

A
  1. Apneustic center

2. Pneumotaxic center

134
Q

What does the apneustic center of the pons do?

A

Promotes inspiration

135
Q

What does the pneumotaxic center of the pons do?

A

Inhibits inspiration

136
Q

Automatic control of breathing is influenced by feedback from ______.

A

chemoreceptors

137
Q

Chemoreceptors involved in respiration monitor what 4 things?

A
  1. pH of fluids in the brain
  2. pH of the blood
  3. PCO2 of the blood
  4. PO2 of the blood
138
Q

Where are the central chemoreceptors located?

A

Medulla

139
Q

Where are the peripheral chemoreceptors located?

A

Carotid and aorta arteries

140
Q

When ventilation is inadequate, CO2 levels ___ and pH ____.

A
  1. Rise

2. Falls

141
Q

carbon dioxide + water = ________

A

carbonic acid

142
Q

In hyperventilation, CO2 levels ___ and pH ____.

A
  1. Falls

2. Rises

143
Q

Why do oxygen levels not change as rapidly?

A

because of oxygen reserves in hemoglobin

144
Q

Why are O2 levels not a good index for control of breathing?

A

Because oxygen levels do not change as rapidly because of oxygen reserves in hemoglobin

145
Q

Ventilation is controlled to maintain _____ levels of CO2 in the blood. Oxygen levels _____ ___.

A
  1. constant

2. naturally follow

146
Q

When increased CO2 in the fluids of the brain decrease pH, this is sensed by chemoreceptors in the medulla, and ventilation is _____.

A

increased

147
Q

What do chemoreceptors in the medulla (central chemoreceptors) respond to?

A

increased CO2 in the fluids of the brain which decrease pH

148
Q

When increased CO2 in the fluids of the brain decrease pH, this is sensed by chemoreceptors in the medulla, and ventilation is increased. This takes longer, but is responsible for how much % of increased ventilation?

A

70-80%

149
Q

What do peripheral chemoreceptors in the aorta, and carotid bodies respond to?

A

rise in H+ due to increased CO2 levels

150
Q

Which respond quicker, central or peripheral chemoreceptors.

A

Peripheral chemoreceptors respond much quicker, but are not responsible for as much of the increased ventilation of the lungs.

151
Q

How does the pressure of O2 in row blood effect ventilation?

A

Indirectly affects ventilation by affecting chemoreceptor sensitivity to PCO2 (Low blood O2 makes the carotid bodies more sensitive to CO2)

152
Q

Pulmonary Receptors and Ventilation: What are Unmyelinated C fibers affected by? What do they produce, when a person breathes pepper spray?

A
  1. Capsaicin

2. Produce rapid shallow breathing when a person breathes in pepper spray

153
Q

Pulmonary Receptors and Ventilation: What are two receptors that stimulate coughing?

A
  1. Irritant Receptors

2. Rapidly Adapting Receptors

154
Q

Pulmonary Receptors and Ventilation: Where are irritant receptors located? What do they respond to? What is the response?

A
  1. In the wall of the larynx
  2. Respond to smoke, particulates, etc.
  3. Coughing
155
Q

Pulmonary Receptors and Ventilation: Where are rapidly adapting receptors located? What do they respond to? What is the response?

A
  1. In the Lungs
  2. Respond to excess fluid
  3. Coughing
156
Q

Pulmonary Receptors and Ventilation: What is the Hering-Breuer reflex stimulated by? What does it inhibit? What is it’s purpose?

A
  1. Stimulated by pulmonary stretch receptors
  2. Inhibits respiratory centers as inhalation proceeds
  3. Makes sure you do not inhale too deeply
157
Q

Most of the oxygen in blood is bound to what?

A

Hemoglobin

158
Q

What is the structure of hemoglobin?

A

4 polypeptide globins and 4 iron-containing hemes

159
Q

How many molecules of O2 can each hemoglobin carry?

A

Each hemoglobin can carry 4 molecules O2

160
Q

How many hemoglobin per RBC?

A

248 million hemoglobin/RBC

161
Q

Wha are the 3 different forms of hemoglobin?

A
  1. Oxyhemoglobin/reduced hemoglobin
  2. Methemoglobin
  3. Carboxyhemoglobin
162
Q

Oxyhemoglobin/reduced hemoglobin:

How is the iron structured? Can it bind with O2?

A
  1. Iron is in reduced form (Fe2+)

2. YES

163
Q

Methemoglobin hemoglobin:

How is the iron structured? Can it bind with O2? Is this normal? What can cause this?

A
  1. Oxidized iron (Fe3+)
  2. NO
  3. NO
  4. Some drugs can cause this
164
Q

Carboxyhemoglobin:

What is hemoglobin bound to?

A

Hemoglobin is bound with carbon monoxide

165
Q

% Oxyhemoglobin Saturation= what?

A

% oxyhemoglobin to total hemoglobin

166
Q

What does % Oxyhemoglobin Saturation measure?

A

Measured to assess how well lungs have oxygenated the blood

167
Q

What is the normal % Oxyhemoglobin Saturation?

A

97%

168
Q

What is % Oxyhemoglobin Saturation measured with?

A

Measured with a pulse oximeter or blood– gas machine

169
Q

Oxygen-carrying capacity of blood is measured by its what?

A

hemoglobin concentration

170
Q

What is anemia?

A

below-normal hemoglobin levels

171
Q

What is polycythemia? What may it occur from?

A

above-normal hemoglobin levels; may occur due to high altitudes

172
Q

_______ made in the kidneys stimulates hemoglobin/RBC production when O2 levels are low.

A

Erythropoietin

173
Q

What is loading?

A

when hemoglobin binds to oxygen in the lungs

174
Q

What is unloading?

A

when oxyhemoglobin drops off oxygen in the tissues

175
Q

What chemical equation represents loading and unloading?

A

deoxyhemoglobin + O2 oxyhemoglobin

176
Q

The direction of the loading/unloading reaction depends on what?

A

depends on PO2 of the environment and affinity for O2

177
Q

Does high PO2 favor loading or unloading?

A

loading

178
Q

Systemic arteries have a PO2 of what?

A

100 mmHg

179
Q

Oxygen Unloading: Systemic arteries have a PO2 of 100 mmHg. This makes enough oxygen bind to get what % oxyhemoglobin?

A

This makes enough oxygen bind to get 97% oxyhemoglobin (20 ml O2/100 ml blood)

180
Q

Systemic veins have a PO2 of what?

A

40 mmHg

181
Q

Oxygen Unloading: Systemic veins have a PO2 of 40 mmHg. This makes enough oxygen bind to get what % oxyhemoglobin

A

75% (15.5 ml O2/100 ml blood)

182
Q

What % of oxygen is unloaded in tissues?

A

22% oxygen is unloaded in tissues

183
Q

Oxygen Dissociation Curve: Oxygen remaining in veins serves as a what?

A

oxygen reserve

184
Q

Is oxygen unloading during exercise greater or smaller?

A

greater

185
Q

What is the % of oxygen unloaded in tissues:

  1. At rest
  2. Light exercise
  3. Heavy exercise
A
  1. 22% at rest
  2. 39% light exercise
  3. 80% heavy exercise
186
Q

How does pH and Temperature effect Oxygen Transport?

A

pH and temperature change the affinity of hemoglobin for O2.

187
Q

pH and temperature change the affinity of hemoglobin for O2. What does this ensure?

A

This ensures that muscles get more O2 when exercising

188
Q

Affinity _____ at lower pH and ___ at higher pH

A
  1. decreases

2. increases

189
Q

Affinity decreases at lower pH and increases at higher pH = ___ ___

A

Bohr effect

190
Q

More unloading occurs at ____ pH.

A

lower

191
Q

Increased metabolism = ____ CO2 = ___ pH

A
  1. more

2. lower

192
Q

Hemoglobin affinity for O2 is decreased at _____ temperatures. What does this further enhance?

A
  1. Increased

2. This further enhances the amount of O2 unloaded to muscles during exercise.

193
Q

Effect of 2,3-DPG on Oxygen Transport: RBCs obtain energy from the anaerobic metabolism of ____.

A

Glucose

194
Q

Effect of 2,3-DPG on Oxygen Transport: RBCs obtain energy from the anaerobic metabolism of glucose. During this process what is made? What is this inhibited by?

A
  1. 2,3 diphosphoglyceric acid (2,3-DPG) is made

2. Inhibited by oxyhemoglobin

195
Q

When is 2,3-DPG produced? What does this increase?

A

2,3-DPG is produced if a person is anemic or at high altitude. This increases oxygen unloading.

196
Q

Can adult hemoglobin (hemoglobin A) bind to 2,3-DPG? Fetal hemoglobin (hemoglobin F)?

A

Adult hemoglobin (hemoglobin A) can bind to 2,3-DPG, but fetal hemoglobin (hemoglobin F) cannot

197
Q

Since fetal hemoglobin (hemoglobin F) cannot cannot bind to 2,3-DPG what does this mean?

A

Fetal hemoglobin therefore has a higher affinity for O2 than the mother, so oxygen is transferred to the fetus

198
Q

What are two types of inherited hemoglobin defects?

A
  1. Sickle-cell anemia

2. Thalassemia

199
Q

Sickle-cell anemia is found in what % of african americans?

A

found in 8−11% of African Americans

200
Q

The affected person with sickle-cell anemia has hemoglobin __ with a ____ amino acid difference.

A
  1. S

2. Single

201
Q

Sickle-cell anemia: Deoxygenated hemoglobin S polymerizes into what? What does this hinder?

A
  1. long fibers, creating a sickle-shaped RBC

2. This hinders flexibility and the ability to pass through small vessels

202
Q

What race is Thalassemia mainly found in?

A

found mainly in people of Mediterranean heritage

203
Q

What is going wrong with thalassemia?

A

Production of either alpha or beta chains is defective.

204
Q

What are the symptoms of thalassemia?

A

Symptoms are similar to sickle-cell anemia

205
Q

Both inherited hemoglobin defects (sickle-celll anemia, and thalassemia) carry resistance to what?

A

malaria

206
Q

What is myoglobin?

A

Red pigment found in skeletal and cardiac muscles

207
Q

What is myoglobin similar to?

A

Similar to hemoglobin

208
Q

What is different about myoglobin and hemoglobin?

A

Has 1 heme (vs 4 in hemoglobin) so can only carry 1 oxygen molecule

209
Q

What is myoglobins affinity to oxygen? When is oxygen released?

A

Higher affinity to oxygen; oxygen is only released when PO2 is very low

210
Q

What is the function of myoglobin?

A

Stores oxygen and serves as go-between in transferring oxygen from blood to mitochondria

211
Q

What are the 3 forms in which CO2 is carried in the blood?

A
  1. Dissolved in plasma
  2. As carbaminohemoglobin attached to an amino acid in hemoglobin
  3. As bicarbonate ions
212
Q

What is Carbonic Anhydrase?

A

Enzyme that combines water with CO2 to form carbonic acid at high PCO2

213
Q

Where do the actions of carbonic anhydrase occur?

A

Occurs within RBCs in the capillaries of systemic circulation

214
Q

What must the PCO2 be in order for carbonic anhydrase to work?

A

High PCO2

215
Q

What is the chemical equation for the effects of carbonic anhydrase?

A

H2O + CO2———> H2CO3

216
Q

How is bicarbonate and H+ formed?

A

Increases in carbonic acid favor dissociation into bicarbonate and hydrogen ions

217
Q

What is the chemical equation for the formation of bicarbonate and H+?

A

H2CO3———> H+ + HCO3−

218
Q

What is a chloride shift?

A
  • H+ in RBCs attach to hemoglobin and attract Cl−.

- The exchange of bicarbonate out of and Cl− into RBCs is called the chloride shift

219
Q

H+ in RBCs attach to hemoglobin and attract Cl−. The exchange of bicarbonate out of and Cl− into RBCs is called the what?

A

chloride shift

220
Q

Describe the Bohr Effect.

A
  • Bonding of H+ to hemoglobin lowers the affinity for O2 and helps with unloading
  • This allows more H+ to bind, which helps the blood carry more carbon dioxide
221
Q

Reverse Chloride Shift:

  • In pulmonary capillaries, increased PO2 favors the production of _____.
  • This makes H+ dissociate from hemoglobin and recombine with bicarbonate to form ____ ___.
A
  1. oxyhemoglobin

2. carbonic acid

222
Q

What is the chemical equation for a reverse chloride shift?

A

H+ + HCO3− ———> H2CO3

223
Q

In low PCO2 what happens with a reverse chloride shift? What is the chemical equation for that? What is the result?

A
  1. In low PCO2, carbonic anhydrase converts carbonic acid back into CO2 + H2O
  2. H2CO3 ———-> CO2 + H2O
  3. CO2 is exhaled
224
Q

How is the acid-base balance maintained?

A

Maintained within a constant range by the actions of the lungs and kidneys

225
Q

Acid-Base Balance: what is the range that the pH is maintained at?

A

pH ranges from 7.35 to 7.45.

226
Q

Why is carbonic acid considered a volatile acid?

A

Because it can be converted into a gas and exhaled

227
Q

What are examples of nonvolatile acids?

A

lactic, fatty, ketones

228
Q

What are nonvolatile acids buffered by?

A

bicarbonate

229
Q

Bicarbonate as a buffer: can bicarbonate always/continuously buffer? How do the kidneys help this situation?

A
  1. Buffering cannot continue forever because bicarbonate will run out.
  2. Kidneys help by releasing H+ in the urine
230
Q

Acidosis: When does this occur?

A

when blood pH falls below 7.35

231
Q

What are two types of acidosis?

A
  1. Respiratory acidosis

2. Metabolic acidosis

232
Q

What does respiratory acidosis result from?

A

hypoventilation

233
Q

What does metabolic acidosis result from?

A

excessive production of acids, loss of bicarbonate (diarrhea)

234
Q

What is alkalosis?

A

when blood pH rises above 7.45

235
Q

What are two types of alkalosis?

A
  1. Respiratory alkalosis

2. Metabolic alkalosis

236
Q

What does respiratory alkalosis result from?

A

hyperventilation

237
Q

What does metabolic acidosis alkalosis from?

A

inadequate production of acids or overproduction of bicarbonates, loss of digestive acids from vomiting

238
Q

What is the respiratory component of blood pH measured by?

A

Respiratory component of blood pH measured by plasma CO2

239
Q

What is the metabolic component of blood pH measured by?

A

Metabolic component measured by bicarbonate

240
Q

What control the respiratory component of acid-base balance?

A

Ventilation controls the respiratory component of acid-base balance

241
Q

How does Hypoventilation effect the acid-base balance? What occurs?

A

1.

  • Ventilation is insufficient to “blow off” CO2
  • PCO2 is high
  • carbonic acid is high
    2. Respiratory acidosis occurs
242
Q

How does Hyperventilation effect the acid-base balance? What occurs?

A

1.

  • Rate of ventilation is faster than CO2 production.
  • Less carbonic acid forms
  • PCO2 is low
    2. Respiratory alkalosis occurs
243
Q

What can compensate for the metabolic component of acid-base balance?

A

Ventilation can compensate for the metabolic component.

244
Q

Ventilation can compensate for the metabolic component.:

  1. A person with metabolic acidosis will ______.
  2. A person with metabolic alkalosis will ______.
A
  1. hyperventilate

2. hypoventilate

245
Q

Hyperpnea

A

Occurs when exercise produces deeper, faster breathing to match oxygen utilization and CO2 production

246
Q

What control hyperpnea?

A

Neurogenic and humoral mechanisms control this.

247
Q

Lactate Threshold: Ventilation does not deliver enough O2 at the beginning of exercise. What two things happen next. If heavy exercise continues what will be used again?

A
  1. Anaerobic respiration occurs at this time.
  2. After a few minutes, muscles receive enough oxygen.
  3. If heavy exercise continues, lactic acid fermentation will be used again
248
Q

Define lactate threshold.

A

The lactate threshold is the maximum rate of oxygen consumption attained before lactic acid levels rise

249
Q

Lactate threshold occurs when how much % of the maximum oxygen uptake is reached? What is this due to?

A
  1. Occurs when 50−70% maximum oxygen uptake is reached
  2. Due to aerobic limitations of the muscles, not the cardiovascular system
  3. Endurance exercise training increases mitochondria and Krebs cycle enzymes in the muscles
250
Q

What increases mitochondria and Krebs cycle enzymes in the muscles?

A

Endurance exercise training

251
Q

Why must adjustments in high altitude be made?

A

Adjustments must be made to compensate for lower atmospheric PO2

252
Q

In high altitude, what adjustments must be made to compensate for lower atmospheric PO2?

A
  1. Changes in ventilation
  2. Hemoglobin affinity for oxygen
  3. Total hemoglobin concentration
253
Q

What is the function of the Hypoxic ventilatory response?

A

Decreases in PO2 stimulate the carotid bodies to increase ventilation.

254
Q

Hypoxic ventilatory response:
1. Hyperventilation does what to PCO2, and what does this cause?

  1. What do the kidneys do to compensate?
  2. Chronically apoxic people produce what in the lungs? What is this/What does it do?
A
  1. Hyperventilation lowers PCO2, causing respiratory alkalosis
  2. Kidneys increase urinary excretion of bicarbonate to compensate
  3. Chronically apoxic people produce NO in the lungs, a vasodilator that increases blood flow.
255
Q

Affinity of Hemoglobin for Oxygen: Oxygen affinity decreases. How does this affect the proportion of oxygen unloaded? What does this occur due to? At extremely high altitudes, what will override this, and what will that cause?

A
  1. Oxygen affinity decreases, so a higher proportion of oxygen is unloaded.
  2. Occurs due to increased production of 2,3-DPG
  3. At extreme high altitudes, effects of alkalosis will override this, and affinity for oxygen will increase.
256
Q

Increased Hemoglobin Production:
1. Kidney cells sense decreased PO2 and produce what?

  1. What does this stimulate
  2. What can increased RBC’s lead to.. which produces what?
A
  1. Erythropoietin
  2. This stimulates bone marrow to produce more hemoglobin and RBCs.
  3. Increased RBCs can lead to polycythemia, which can produce pulmonary hypertension