Respiration. Chapter 39 Part 1

Transcription

1 Respiration Chapter 39 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 39.1 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 Fig. 39-2b, p. 682

6 food, water intake oxygen intake Digestive System Respiratory System elimination of carbon dioxide nutrients, water, salts oxygen carbon dioxide Circulatory System water, solutes Urinary System elimination of food residues rapid transport to and from all living cells elimination of excess water, salts, wastes Fig. 39-2b, p. 682

7 Partial Pressure Partial pressure Of the total atmospheric pressure measured by a mercury barometer (760 mm Hg), O 2 contributes 21% (160 mm Hg)

8 760 mm Hg Fig. 39-3, p. 682

9 The Basis of Gas Exchange Respiration depends on diffusion of gaseous oxygen (O 2 ) and carbon dioxide (CO 2 ) down their concentration gradients Gases enter and leave the internal environment across a thin, moist layer (respiratory surface) that dissolves the gases

10 Factors Affecting Diffusion Rates 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)

11 Respiratory Proteins 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

12 39.2 Gasping for Oxygen Rising water temperatures, slowing streams, and organic pollutants reduce the dissolved oxygen (DO) available for aquatic species

13 Key Concepts 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

14 39.3 Invertebrate Respiration 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

15 Invertebrate Respiration 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

16 Snails with Lungs

17 Invertebrate Respiration 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

18 Insect Tracheal System

19 trachea (tube inside body) spiracle (opening to body surface) Fig. 39-7, p. 685

20 A Spider s Book Lung

21 air-filled space blood-filled space book lung Fig. 39-8, p. 685

22 39.3 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

23 39.4 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

24 Fish Gills

25 gill cover Fig. 39-9a, p. 686

26 Fig. 39-9b, p. 686

27 mouth open gill cover closed Fig. 39-9b, p. 686

28 Fig. 39-9c, p. 686

29 mouth closed gill cover open Fig. 39-9c, p. 686

30 Countercurrent Flow

31 one gill arch gill filaments water is sucked into mouth Water exits through gill slits 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

32 gill arch gill filament respiratory surface fold with a capillary bed inside water flow direction of blood flow oxygenated blood back toward body oxygen-poor blood from deep in body B Two gill arches with filaments C Countercurrent flow of water and blood Fig (b-c), p. 686

33 Animation: Bony fish respiration

34 Frog Respiration

35 A Lowering the floor of the mouth draws air inward through nostrils. B Closing nostrils and raising the floor of the mouth pushes air into lungs. C Rhythmically raising and lowering the floor of the mouth assists gas exchange. D Contracting chest muscles and raising the floor of the mouth forces air out of lungs, and the frog exhales. Fig , p. 687

36 Animation: Frog respiration

37 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

38 Bird Respiratory System

39 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. B Exhalation 1 Anterior air sacs empty. Air from posterior air sacs moves into lungs. posterior air sacs trachea anterior air sacs lung 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

40 Fig (inset), p. 687

41 Animation: Bird respiration

42 39.5 Human Respiratory System The human respiratory system functions in gas exchange, sense of smell, voice production, body defenses, acid-base balance, and temperature regulation

43 Airways 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

44 Larynx: Vocal Cords and Glottis

45 glottis closed vocal cords glottis open glottis (closed) epiglottis tongue s base Fig , p. 689

46 From Airways to Alveoli 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

47 Muscles and Respiration 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

48 Functions of the Respiratory System

49 Fig a, p. 688

50 Oral Cavity (Mouth) Supplemental airway when breathing is labored Pleural Membrane Double-layer membrane with a fluid-filled space between layers; keeps lungs airtight and helps them stick to chest wall during breathing Intercostal Muscles At rib cage, skeletal muscles with roles in breathing. There are two sets of intercostal muscles (external and internal) Diaphragm Muscle sheet between the chest cavity and abdominal cavity with roles in breathing Nasal Cavity Chamber in which air is moistened, warmed, and filtered, and in which sounds resonate Pharynx (Throat) Airway connecting nasal cavity and mouth with larynx; enhances sounds; also connects with esophagus Epiglottis 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 Lung (One of a Pair) Lobed, elastic organ of breathing; enhances gas exchange between internal environment and outside air Bronchial Tree Increasingly branched airways starting with two bronchi and ending at air sacs (alveoli) of lung tissue Fig a, p. 688

51 Fig b, p. 688

52 bronchiole alveolar sac (sectioned) alveolar duct alveoli Fig b, p. 688

53 Fig c, p. 688

54 alveolar sac pulmonary capillary Fig c, p. 688

55 Animation: Human respiratory system

56 Animation: Examples of respiratory surfaces

57 Animation: Vertebrate lungs