1. STUDY
This Information
Respiration
Part 1

2. Impacts, Issues Up in Smoke
Smoking immobilizes ciliated cells and kills white blood cells that defend the respiratory system; highly addictive nicotine discourages quitting

3. The Nature of Respiration
All animals must supply their cells with oxygen and rid their body of carbon dioxide
Respiration
The physiological process by which an animal exchanges oxygen and carbon dioxide with its environment

4. Interactions with Other Organ Systems

5. elimination of food residues
food, water intake
oxygen intake
elimination
of carbon dioxide
Digestive System
Respiratory System
nutrients, water,
salts
carbon dioxide
oxygen
Circulatory System
Urinary System
Figure 39.2
A dog’s breathing helps meet its cells’ need for oxygen. In dogs and other vertebrates, the respiratory system interacts with other organ systems that contribute to homeostasis.
water, solutes
elimination of food residues
rapid transport to and from all living cells
elimination of excess water, salts, wastes
Fig. 39-2b, p. 682

6. The Basis of Gas Exchange
Respiration depends on diffusion of gaseous oxygen (O2) and carbon dioxide (CO2) down their concentration gradients
Gases enter and leave the internal environment across a thin, moist layer (respiratory surface) that dissolves the gases

7. Partial Pressure Partial pressure
Of the total atmospheric pressure measured by a mercury barometer (760 mm Hg), O2 contributes 21% (160 mm Hg)
760 mm Hg
Figure 39.3
How a mercury barometer measures atmospheric pressure. That pressure makes mercury (Hg), a viscous liquid, rise or fall in a narrow tube. At sea level, it rises 760 millimeters (29.91 inches) from the tube’s base. Atmospheric pressure varies with altitude. On the top of Mount Everest, atmospheric pressure is only about one-third the pressure at sea level.
Fig. 39-3, p. 682

8. Factors Affecting Diffusion Rates
STUDY
Factors that increase diffusion of gases across a respiratory surface:
High partial pressure gradient of a gas across the respiratory surface
High surface-to-volume ratio
High ventilation rate (movement of air or water across the respiratory surface)

9. Respiratory Proteins
STUDY
Respiratory proteins contain one or more metal ions that reversibly bind to oxygen atoms
Hemoglobin: An iron-containing respiratory protein found in vertebrate red blood cells
Myoglobin: A respiratory protein found in muscles of vertebrates and some invertebrates

10. Gasping for Oxygen
Rising water temperatures, slowing streams, and organic pollutants reduce the dissolved oxygen (DO) available for aquatic species

11. Principles of Gas Exchange
Respiration is the sum of processes that move ________ from air or water in the environment to all metabolically active ________ and move __________ from those tissues to the outside
Oxygen levels are more stable in air than in water

12. Principles of Gas Exchange
Respiration is the sum of processes that move oxygen from air or water in the environment to all metabolically active tissues and move carbon dioxide from those tissues to the outside
Oxygen levels are more stable in air than in water

13. Invertebrate Respiration
STUDY
Integumentary exchange
Some invertebrates that live in aquatic or damp environments have no respiratory organs;
Gases diffuse across the skin
Gills
Filamentous respiratory organs that increase surface area for gas exchange in water
Lungs
Saclike respiratory organs with branching tubes that deliver air to a respiratory surface
Snails and slugs that spend some time on land have a lung instead of, or in addition to, gills

14. Snails with Lungs

15. Invertebrate Respiration
STUDY
Tracheal system
Insects and spiders with a hard integument have branching tracheal tubes that open to the surface through spiracles (no respiratory protein required)
Book lungs
Some spiders also have thin sheets of respiratory tissue that exchange oxygen with a respiratory pigment (hemocyanin) in blood

16. Insect Tracheal System
trachea (tube inside body)
spiracle (opening to body surface)
STUDY
Figure 39.7
Insect tracheal system. Chitin rings reinforce branching, air-filled tubes in such respiratory systems.
Insect Tracheal System
Fig. 39-7, p. 685

17. A Spider’s Book Lung air-filled space blood-filled space book lung
STUDY
air-filled space
blood-filled space
book lung
Figure 39.8
Above, a spider’s book lung. The lung contains many thin sheets of tissue, somewhat like the pages of a book. As blood moves through spaces between the “pages,” it exchanges gases with air in adjacent spaces. Left, horseshoe crab blood. Like spider blood, it contains the respiratory pigment hemocyanin, which turns blue-green when carrying oxygen.
A Spider’s Book Lung
Fig. 39-8, p. 685

18. Key Concepts Gas Exchange in Invertebrates
Gas exchange occurs across the body surface or gills of aquatic invertebrates
In large invertebrates on land, it occurs across a moist, internal respiratory surface or at fluid-filled tips of branching tubes that extend from the surface to internal tissues

19. Vertebrate Respiration
Fishes use gills to extract oxygen from water
Countercurrent flow aids exchange (blood flows through gills in opposite direction of water flow)
Amphibians exchange gases across their skin, and at respiratory surfaces of paired lungs
Larvae have external gills

20. Fish Gills (a) Location of the gill cover of a bony fish. gill cover
Figure 39.9
(b) Water is sucked into the mouth and over the gills when a fish closes its gill covers, opens its mouth, and expands its oral cavity. (c) The water moves out when the fish closes its mouth, opens its gill covers, and squeezes the water past its gills.
gill cover
Fig. 39-9a, p. 686

21. gill mouth open cover closed STUDY
Figure 39.9
(a) Location of the gill cover of a bony fish. (c) The water moves out when the fish closes its mouth, opens its gill covers, and squeezes the water past its gills.
(b) Water is sucked into the mouth and over the gills when a fish closes its gill covers, opens its mouth, and expands its oral cavity.
Fig. 39-9b, p. 686

22. mouth closed gill cover open STUDY
Figure 39.9
(a) Location of the gill cover of a bony fish. (b) Water is sucked into the mouth and over the gills when a fish closes its gill covers, opens its mouth, and expands its oral cavity.
(c) The water moves out when the fish closes its mouth, opens its gill covers, and squeezes the water past its gills.
Fig. 39-9c, p. 686

23. Countercurrent Flow gill filaments one gill arch water is sucked into
STUDY
gill filaments
one gill arch
water is sucked
into
mouth
Water exits through gill slits
Figure 39.10
Structure and function of the gills of a bony fish.
A A bony fish with its gill cover removed. Water flows in through the mouth, flows over the gills, then exits through gill slits. Each gill has bony gill arches to which the gill filaments attach.
Fig a, p. 686

24. STUDY respiratory surface gill arch gill filament
fold with a capillary
bed inside
water flow
direction of
blood flow
Figure 39.10
Structure and function of the gills of a bony fish.
oxygen-poor blood from deep in body
oxygenated blood back toward body B
Two gill arches with filaments C
Countercurrent flow of water and blood
Fig (b-c), p. 686

25. Frog Respiration STUDY A B C D
Lowering the floor of the mouth draws air inward through nostrils.
Closing nostrils and raising the floor of the mouth pushes air into lungs.
Rhythmically raising and lowering the
floor of the
mouth assists
gas exchange.
Contracting chest muscles and raising the floor of the mouth forces air out of lungs, and the frog exhales.
Figure 39.11
How a frog breathes.
Fig , p. 687

26. Vertebrate Respiration
Reptiles, birds and mammals exchange gases through paired lungs, ventilated by chest muscles
Birds have the most efficient vertebrate lungs
Air sacs allow oxygen-rich air to pass respiratory surfaces on both inhalation and exhalation

27. Bird Respiratory System
A Inhalation 1
Muscles expand chest cavity, drawing air in through nostrils. Some of the air flowing in through the trachea goes to lungs and some goes to posterior air sacs.
Bird Respiratory System
STUDY
trachea
anterior air sacs
lung B
Exhalation 1
Anterior air sacs empty. Air from posterior air sacs moves into lungs.
posterior
air sacs
Figure 39.12
Respiratory system of a bird. Large, stretchy air sacs attach to two small, inelastic lungs. Contraction and expansion of chest muscles cause air to flow into and then out of this system.
Air flows in through many air tubes inside the lung, and into posterior air sacs. The lining of the tiniest air tubes, sometimes called air capillaries, is the site of gas exchange—the respiratory surface.
It takes more than one breath for air to flow through the system, but air flows continuously through the lungs and over the respiratory surface. This unique ventilating system supports the high metabolic rates that birds require for flight and other energy-demanding activities.
Right, this scanning electron micrograph of lung tissue shows the tubes through which air flows to and from air sacs. Gas exchange takes place across the lining of these tubes.
C Inhalation 2
Air in lungs moves to anterior air sacs and is replaced by newly inhaled air.
D Exhalation 2
Air in anterior air sacs moves out of the body and air from posterior sacs flows into the lungs.
Fig , p. 687

28. Figure 39.12
Respiratory system of a bird. Large, stretchy air sacs attach to two small, inelastic lungs. Contraction and expansion of chest muscles cause air to flow into and then out of this system.
Air flows in through many air tubes inside the lung, and into posterior air sacs. The lining of the tiniest air tubes, sometimes called air capillaries, is the site of gas exchange—the respiratory surface.
It takes more than one breath for air to flow through the system, but air flows continuously through the lungs and over the respiratory surface. This unique ventilating system supports the high metabolic rates that birds require for flight and other energy-demanding activities.
Right, this scanning electron micrograph of lung tissue shows the tubes through which air flows to and from air sacs. Gas exchange takes place across the lining of these tubes.
Fig (inset), p. 687

29. Human Respiratory System
STUDY
The human respiratory system functions in gas exchange, sense of smell, voice production, body defenses, acid-base balance, and temperature regulation

30. Airways
STUDY
Air enters through nose or mouth, flows through the pharynx (throat) and the larynx (voice box)
Vocal cords change the size of the glottis
The epiglottis protects the trachea, which branches into two bronchi, one to each lung
Cilia and mucus-secreting cells clean airways

31. Larynx: Vocal Cords and Glottis
glottis closed
glottis open
vocal cords
glottis (closed)
epiglottis
tongue’s base
Figure 39.14
Human vocal cords, inside the larynx. Contraction of skeletal muscle in these cords changes the width of the glottis, the gap between them. The glottis closes tightly when you swallow. It is open during quiet breathing. It narrows when you speak, so that air flow causes the cords to vibrate.
STUDY
Larynx: Vocal Cords and Glottis
Fig , p. 689

32. From Airways to Alveoli
STUDY
Inside each lung, bronchi branch into bronchioles that deliver air to alveoli
Alveoli are small sacs, one cell thick, where gases are exchanged with pulmonary capillaries

33. Muscles and Respiration
STUDY
Muscle movements change the volume of the thoracic cavity during breathing
Diaphragm
A broad sheet of smooth muscle below the lungs
Separates the thoracic and abdominal cavities
Intercostal muscles
Skeletal muscles between the ribs

34. Functions of the Respiratory System
Nasal Cavity
Chamber in which air is moistened, warmed, and filtered, and in which sounds resonate
Oral Cavity (Mouth) Supplemental airway
when breathing is
labored
Pharynx (Throat)
Airway connecting nasal cavity and mouth with larynx; enhances sounds; also connects with esophagus
Pleural Membrane
Epiglottis
Double-layer membrane with a fluid-filled space between layers; keeps lungs airtight and helps them stick to chest wall during breathing
Closes off larynx during swallowing
Larynx (Voice Box)
Airway where sound is produced;
closed off during swallowing
Trachea (Windpipe)
Airway connecting larynx with two bronchi that lead into the lungs
Intercostal Muscles
At rib cage, skeletal muscles with roles in breathing. There are
two sets of intercostal muscles (external and internal)
Lung (One of a Pair)
Lobed, elastic organ of breathing; enhances gas exchange between internal environment and outside air
Figure 39.13
(a) Components of the human respiratory system and their functions. The diaphragm and other muscles, as well as certain bones of the axial skeleton, have secondary roles in respiration. (b, c) Location of alveoli relative to the bronchioles and the lung (pulmonary) capillaries.
Bronchial Tree
Increasingly branched airways starting with two bronchi and ending at air sacs (alveoli) of lung tissue
Diaphragm
Muscle sheet between the chest cavity and abdominal cavity with roles in breathing
STUDY
Fig a, p. 688

35. alveolar sac (sectioned) bronchiole
alveolar duct
Figure 39.13
(a) Components of the human respiratory system and their functions. The diaphragm and other muscles, as well as certain bones of the axial skeleton, have secondary roles in respiration. (b, c) Location of alveoli relative to the bronchioles and the lung (pulmonary) capillaries.
alveoli
STUDY
Fig b, p. 688

36. alveolar sac pulmonary capillary STUDY Figure 39.13
(a) Components of the human respiratory system and their functions. The diaphragm and other muscles, as well as certain bones of the axial skeleton, have secondary roles in respiration. (b, c) Location of alveoli relative to the bronchioles and the lung (pulmonary) capillaries.
pulmonary capillary
Fig c, p. 688

37. Cyclic Reversals in Air Pressure Gradients
STUDY
Respiratory cycle
One inhalation and one exhalation
Inhalation is always active
Contraction of diaphragm and external intercostal muscles increases volume of thoracic cavity
Air pressure in alveoli drops below atmospheric pressure; air moves inward

38. Cyclic Reversals in Air Pressure Gradients
STUDY
Exhalation is usually passive
As muscles relax, the thoracic cavity shrinks
Air pressure in the alveoli rises above atmospheric pressure, air moves out
Exhalation may be active
Contraction of abdominal muscles forces air out

39. The Thoracic Cavity and the Respiratory Cycle

40. Inward flow of air
Figure 39.15
Changes in the size of the thoracic cavity during a single respiratory cycle. The x-ray images reveal how inhalation and expiration change the lung volume.
A Inhalation. Diaphragm contracts, moves down. External intercostal muscles contract, lift rib cage upward and outward. Lung volume expands.
Fig a, p. 690

41. Outward flow of air
Figure 39.15
Changes in the size of the thoracic cavity during a single respiratory cycle. The x-ray images reveal how inhalation and expiration change the lung volume.
B Exhalation. Diaphragm, external intercostal muscles return to resting positions. Rib cage moves down. Lungs recoil passively.
Fig b, p. 690

42. Supplemental: First Aid for Choking
Heimlich maneuver
Upward-directed force on the diaphragm forces air out of lungs to dislodge an obstruction

43. Respiratory Volumes
Air in lungs is partially replaced with each breath
Lungs are never emptied of air (residual volume)
Vital capacity
Maximum volume of air the lungs can exchange
Tidal volume
Volume of air that moves in and out during a normal respiratory cycle

44. Respiratory Volumes

45. Control of Breathing
Neurons in the medulla oblongata of the brain stem are the control center for respiration
Rhythmic signals from the brain cause muscle contractions that cause air to flow into the lungs
Chemoreceptors in the medulla, carotid arteries, and aorta wall detect chemical changes in blood, and adjust breathing patterns

46. Respiratory Responses
CO2 concentration
and acidity rise in the
blood and cerebrospinal fluid.
STIMULUS
Chemoreceptors in wall of carotid arteries and aorta
Respiratory Responses
Respiratory center in brain stem
RESPONSE
CO2 concentration and acidity decline
in the blood and cerebrospinal fluid.
Tidal volume and rate of breathing change.
Figure 39.18
Respiratory response to increased activity levels. An increase in activity raises the CO2 output. It also makes the blood and cerebrospinal fluid more acidic. Chemoreceptors in blood vessels and the medulla sense the changes and signal the brain’s respiratory center, also in the brain stem. In response, the respiratory center signals the diaphragm and intercostal muscles. The signals call for alterations in the rate and depth of breathing. Excess CO2 is expelled, which causes the level of this gas and acidity to decline. Chemoreceptors sense the decline and signal the respiratory center, so breathing is adjusted accordingly.
Diaphragm, Intercostal muscles
Stepped Art
Fig , p. 691

47. Gas Exchange and Transport
Gases diffuse between a pulmonary capillary and an alveolus at the respiratory membrane
Alveolar epithelium
Capillary endothelium
Fused basement membranes
O2 and CO2 each follow their partial pressure gradient across the membrane

48. The Respiratory Membrane
red blood cell inside pulmonary capillary
alveolar epithelium
pore for
air flow between adjoining alveoli
capillary endothelium
fused basement membranes of both epithelial tissues
a Surface view of capillaries associated with alveoli
air space inside alveolus
b Cutaway view of one of the alveoli and adjacent pulmonary capillaries
Figure 39.19
Zooming in on the respiratory membrane in human lungs.
c Three components of the respiratory membrane
Fig , p. 692

49. Oxygen Transport
In alveoli, partial pressure of O2 is high; oxygen binds with hemoglobin in red blood cells to form oxyhemoglobin (HbO2)
In metabolically active tissues, partial pressure of O2 is low; HbO2 releases oxygen
Myoglobin, found in some muscle tissues, is similar to hemoglobin but holds O2 more tightly

50. Hemoglobin alpha globin alpha globin beta globin beta globin
Structure of hemoglobin, the oxygen-transporting protein of red blood cells. It consists of four globin chains, each associated with an iron-containing heme group, color-coded red.
Figure 39.20
(a) (b) Myoglobin, an oxygen-storing protein in muscle cells. Its single chain associates with a heme group. Compared to hemoglobin, myoglobin has a higher affinity for oxygen, so it helps speed the transfer of oxygen from blood to muscle cells.
beta globin
Hemoglobin
beta globin
Fig a, p. 693

51. Myoglobin
Figure 39.20
(a) Structure of hemoglobin, the oxygen-transporting protein of red blood cells. It consists of four globin chains, each associated with an iron-containing heme group, color-coded red. (b)
Myoglobin, an oxygen-storing protein in muscle cells. Its single chain associates with a heme group. Compared to hemoglobin, myoglobin has a higher affinity for oxygen, so it helps speed the transfer of oxygen from blood to muscle cells.
heme
Fig b, p. 693

52. Carbon Dioxide Transport
Carbon dioxide is transported from metabolically active tissues to the lungs in three forms
10% dissolved in plasma
30% carbaminohemoglobin (HbCO2)
60% bicarbonate (HCO3-)
Carbonic anhydrase in red blood cells catalyzes the formation of bicarbonate
CO2 + H2O → H2CO3 → HCO3- + H+

53. Partial Pressures for Oxygen and Carbon Dioxide
DRY
INHALED AIR
160
0.03
MOIST
EXHALED AIR
120 27
Partial Pressures for Oxygen and Carbon Dioxide
104 40
alveolar sacs
pulmonary arteries 40 45
pulmonary veins
100 40
Partial pressures (in mm Hg) for oxygen (pink boxes) and carbon dioxide (blue boxes) in the atmosphere, blood, and tissues.
Figure It Out: What is the partial pressure of oxygen in arteries that carry blood to systemic capillary beds?
Answer: 100 mm Hg
start of
systemic
veins 40 45
start of
systemic
capillaries
100 40
Figure 39.21
Partial pressures (in mm Hg) for oxygen (pink boxes) and carbon dioxide (blue boxes) in the atmosphere, blood, and tissues.
Figure It Out: What is the partial pressure of oxygen in arteries that carry blood to systemic capillary beds?
Answer: 100 mm Hg
cells of body tissues
less than 40
more than 45
Stepped Art
Fig , p. 693

54. The Carbon Monoxide Threat
Carbon monoxide (CO)
A colorless, odorless gas that can fill up O2 binding sites on hemoglobin, block O2 transport, and cause carbon monoxide poisoning
Carbon monoxide poisoning often results when fuel-burning appliance are poorly ventilated
Symptoms include nausea, headache, confusion, dizziness, and weakness

55. Key Concepts Gas Exchange in Vertebrates
Gills or paired lungs are gas exchange organs in most vertebrates
The efficiency of gas exchange is improved by mechanisms that cause blood and water to flow in opposite directions at gills, and by muscle contractions that move air into and out of lungs

56. Respiratory Diseases and Disorders
Interrupted breathing
Brain-stem damage, sleep apnea, SIDS
Potentially deadly infections
Tuberculosis, pneumonia
Chronic bronchitis and emphysema
Damage to ciliated lining of bronchioles and walls of alveoli; tobacco smoke is the main risk factor

57. Cigarette Smoke and Ciliated Epithelium
Figure 39.22
(a) Cigarette smoke about to enter bronchi that lead to the lungs. Smoke irritates ciliated and mucus-secreting cells that line the airways (b) and can exacerbate bronchitis.
Fig a, p. 694

58. free surface of a mucus- secreting cell
of a cluster of ciliated cells
Figure 39.22
(a) Cigarette smoke about to enter bronchi that lead to the lungs. Smoke irritates ciliated and mucus-secreting cells that line the airways (b) and can exacerbate bronchitis.
Fig b, p. 694

59. Risks Associated With Smoking and Emphysema
(a) From the American Cancer Society, a list of major risks incurred by smoking and the benefits of quitting. (b) Appearance of normal lung tissue in humans. (c) Appearance of lung tissues from someone who was affected by emphysema.

60. Key Concepts Respiratory Problems
Respiration can be disrupted by damage to respiratory centers in the brain, physical obstructions, infectious disease, and inhalation of pollutants, including cigarette smoke

61. High Climbers and Deep Divers
Altitude sickness
Hypoxia can result when people who live at low altitudes move suddenly to high altitudes
People who grow up at high altitudes have more alveoli and blood vessels in their lungs
Acclimatization to altitude includes adjustments in cardiac output, rate and volume of breathing
Hypoxia stimulates erythropoietin secretion

62. Adaptation to High Altitude
Llamas that live at high altitudes have special hemoglobin that binds oxygen more efficiently

63. Deep-Sea Divers
Water pressure increases with depth; human divers using compressed air risk nitrogen narcosis (disrupts neuron signaling)
Returning too quickly to the surface from a deep dive can release dangerous nitrogen bubbles into the blood stream (‘the bends”)
Without tanks, trained humans can dive to 210 meters; sperm whales can dive 2,200 meters

64. Adaptations for Deep Diving
Leatherback turtles dive up to one hour
Move air to cartilage-reinforced airways
Flexible shell for compression
Four ways diving animals conserve oxygen
Deep breathing before diving
High red-cell count, large amounts of myoglobin
Slowed heart rate and metabolism
Conservation of energy

65. Deep Divers

66. Key Concepts Gas Exchange in Extreme Environments
At high altitudes, the human body makes short-term and long-term adjustments to thinner air
Built-in respiratory mechanisms and specialized behaviors allow sea turtles and diving marine mammals to stay under water, at great depths, for long periods

67. Video Supplements

68. Animation: Bird respiration

69. Animation: Human respiratory system

70. Animation: Examples of respiratory surfaces

71. Animation: Vertebrate lungs

72. Animation: Bony fish respiration

73. Animation: Frog respiration

74. Animation: Respiratory cycle

75. Animation: Heimlich maneuver

76. Animation: Changes in lung volume and pressure

77. Animation: Partial pressure gradients

78. Animation: Bicarbonate buffer system

79. Animation: Globin and hemoglobin structure

80. Animation: Pressure-gradient changes during respiration

81. Animation: Structure of an alveolus

82. Animation: Vocal cords

83. ABC video: Blood test for lung cancer

84. Video: Up in smoke