Download Respiration - Del Mar College

Respiration
Chapter 39 Part 1
Impacts, Issues
Up in Smoke
 Smoking immobilizes ciliated cells and kills white
blood cells that defend the respiratory system;
highly addictive nicotine discourages quitting
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
Interactions with Other Organ Systems
Fig. 39-2b, p. 682
food, water intake
oxygen intake
Digestive
System
Respiratory
System
nutrients,
water,
salts
oxygen
elimination
of carbon
dioxide
carbon
dioxide
Circulatory
System
Urinary
System
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
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
Fig. 39-3, p. 682
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
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)
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
39.2 Gasping for Oxygen
 Rising water temperatures, slowing streams, and
organic pollutants reduce the dissolved oxygen
(DO) available for aquatic species
39.1-39.2 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
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
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
Snails with Lungs
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
Insect Tracheal System
trachea (tube
inside body)
spiracle (opening
to body surface)
Fig. 39-7, p. 685
A Spider’s Book Lung
air-filled space
blood-filled space
book lung
Fig. 39-8, p. 685
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
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
Fish Gills
gill cover
Fig. 39-9a, p. 686
Fig. 39-9b, p. 686
mouth
open
gill
cover
closed
Fig. 39-9b, p. 686
Fig. 39-9c, p. 686
mouth
closed
gill
cover
open
Fig. 39-9c, p. 686
Countercurrent Flow
gill filaments
one gill arch
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. 39-10a, p. 686
gill arch
respiratory surface
gill
filament
fold with a
capillary
bed inside
water
flow
direction of
blood flow
oxygen-poor blood
oxygenated blood from deep in body
back toward body
B Two gill arches with
filaments
C Countercurrent flow
of water and blood
Fig. 39-10 (b-c), p. 686
Animation: Bony fish respiration
Frog Respiration
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. 39-11, p. 687
Animation: Frog respiration
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
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.
B Exhalation 1
Anterior air sacs
empty. Air from
posterior air sacs
moves into lungs.
trachea
anterior
air sacs
lung
posterior
air sacs
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. 39-12, p. 687
Fig. 39-12 (inset), p. 687
Animation: Bird respiration
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
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
Larynx: Vocal Cords and Glottis
glottis
closed
vocal cords
glottis
open
glottis (closed)
epiglottis
tongue’s base
Fig. 39-14, p. 689
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
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
Functions of the Respiratory System
Fig. 39-13a, p. 688
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. 39-13a, p. 688
Fig. 39-13b, p. 688
bronchiole
alveolar sac
(sectioned)
alveolar duct
alveoli
Fig. 39-13b, p. 688
Fig. 39-13c, p. 688
alveolar
sac
pulmonary
capillary
Fig. 39-13c, p. 688
Animation: Human respiratory system
Animation: Examples of respiratory
surfaces
Animation: Vertebrate lungs