1. Respiration
Chapter 34

2. Atmospheric Pressure
Pressure exerted by the weight of the air on objects on Earth’s surface
At sea level = 760 mm Hg
Oxygen is 21% of air

3. Fick’s Law
Describes the rate at which a substance (such as oxygen) will diffuse across a membrane (such as a respiratory surface)
Rate is proportional to the pressure gradient across the membrane and to the surface area of the membrane

4. Surface-to-Volume Ratio
As animal size increases, surface-to-volume ratio decreases
Respiratory surfaces tend to be
large and thin
moist
Small, flattened animals can use the body surface as their respiratory surface
Larger animals have special structures to increase respiratory surface
gills or lungs
tracheal tubes

5. Invertebrate Respiration
Examples of respiratory surfaces

6. Fish Gills
Bony fish respiration

7. Countercurrent Flow
Blood flow runs in the opposite direction of water flow over the filaments
This enhances movement of oxygen from water to blood
respiratory surface
direction of water flow
direction of blood flow
oxygenated blood back toward body
oxygen-poor blood from deep in body

8. Vertebrate Lungs
Originated in some fishes as outpouching from gut wall
Allow gas exchange in oxygen-poor aquatic habitats and on land
salamander
reptile

9. Avian Respiration
Lungs are inelastic and connect to a series of air sacs
Air is drawn continually though each lung
air
sacs
air
sacs
lung
air
sacs

10. Avian Respiration
Bird respiration

11. Human Respiratory System

12. Respiration
The two systems that supply oxygen and eliminate carbon dioxide are the
Cardiovascular System
Respiratory System
Failure of either of the two systems:
disrupts homeostasis
promotes cell death
from oxygen starvation and waste product overflow

13. Respiration 5 activities of the respiratory process: Ventilation
air moving from atmosphere into our lungs
External respiration
moving O2 and CO2 to and from our alveoli and pulmonary vessels
Transport of gases
how O2 and CO2 are carried in the blood
Internal respiration
moving of O2 and CO2 in and out of the tissues of the body
Cellular respiration
how tissues use O2 to produce ATP

14. Organs Nose – Openings – internal nares
Nasal cavity divided by the nasal septum
Functions of the Nose
Interior structures warm, moisten and filters air
Receives olfactory stimuli
Provides a resonating chamber for speech sounds

15. Air Passage Air passes through nasal convolutions
Mucous membrane lines the cavity and shelves
traps particles
More surface area for
warming (from capillary beds)
filtering
moistening air

16. Pharynx Composed of skeletal muscle lined with mucous membrane
Passageway for air and food
Resonating chamber for speech sounds

17. Larynx Voice Box connects pharynx with trachea Thyroid
forms front wall (triangular)
Adam’s apple
Epiglottis – (epi-above; glottis-tongue)
leaf shaped covered by epithelium on top of larynx
“leaf” free – trap door

18. Trachea Wall is lined with mucous membrane and supported by cartilage
Pseudo stratified ciliated columnar epithelium makes up the inside of the trachea
Ciliated columnar cells
cilia
Goblet cells
mucous

19. Lungs Pleural membrane
double layer that encloses and protects each lung
Parietal pleura membrane
outer layer is attached to the wall of the thoracic cavity and diaphragm
Visceral pleura
covers the lungs themselves
Pleural cavity
space between the two membranes
contains fluid to reduce friction 19

20. Bronchi The trachea divides into a right and left primary bronchus
The right is more vertical, shorter and wider than left
more objects lodge here
Structured like the trachea
Incomplete rings of cartilage
Lined with pseudo stratified ciliated epithelium

21. Secondary Bronchi One leads to each lobe of the lungs
Right lung=3 lobes
Left lung= 2 lobes
Secondary bronchi break down to tertiary bronchi bronchioles terminal bronchioles

22. Alveolus Alveolus cup-shaped projection lined with epithelium
Alveolar sacs
two or more alveoli that share a common opening
Gas exchange takes place here at the alveoli
Arteriole and venule surround alveolus to form a capillary network
Lungs contain 300 million alveoli
large surface area

25. Oxygen Transport
Most oxygen is carried bound to hemoglobin in red blood cells
Hemoglobin has a great affinity for oxygen when it is at high partial pressure
in pulmonary capillaries
Lower affinity for oxygen in tissues, where partial pressure is low

26. alpha globin
alpha globin
heme
beta globin
beta globin
a) Hemoglobin
b) Myoglobin

27. Globin and hemoglobin structure
Oxygen Transport
Globin and hemoglobin structure

28. Bicarbonate Formation
H2CO3
carbonic acid
CO2 + H2O
HCO3–
bicarbonate
+ H+
3 ways CO2 transported:
some is dissolved in the plasma 7%
some binds to hemoglobin
23%
most carbon dioxide is transported as bicarbonate
70%

29. Animation: CO2 Tissues to Blood
Right click slide / Select play

30. CO2 produced during cellular respiration lowers blood pH and decreases the affinity of hemoglobin for O2
Bohr shift
Hemoglobin also assists in preventing harmful changes in blood pH and plays a minor role in CO2 transport 30

31. O2 saturation of hemoglobin (%)
100
pH 7.4 80
pH 7.2
Hemoglobin
retains less
O2 at lower pH
(higher CO2
concentration 60
O2 saturation of hemoglobin (%) 40 20
Figure 34.25b Dissociation curves for hemoglobin at 37°C (part 2: variable pH) 20 40 60 80
100
PO2 (mm Hg)
(b) pH and hemoglobin dissociation 31

32. Partial Pressure Gradients

33. Partial Pressure Gradients
3 pressures involved in pulmonary ventilation
Atmospheric pressure
air outside the body
Intrapulmonary pressure
pressure within alveoli of the lungs
Intraplueral pressure
pressure within the pleural cavity
space between visceral and parietal pleural membrane

34. Breathing Moves air into and out of lungs
Occurs in a cyclic pattern called the respiratory cycle
One respiratory cycle consists of inhalation and exhalation
12 – 20 adults
15 – 30 children
25 – 50 infants

35. Inhalation Diaphragm flattens External intercostal muscles contract
Volume of thoracic cavity increases
Lungs expand
Air flows down pressure gradient into lungs

36. Normal Passive Exhalation
Muscles of inhalation relax
Thoracic cavity recoils
Lung volume decreases
Air flows down pressure gradient and out of lungs

37. Rib cage expands as rib muscles contract. Rib cage gets smaller as
relax.
Air
inhaled.
Air
exhaled.
Lung
Diaphragm
Figure Negative pressure breathing
Inhalation:
Diaphragm contracts
(moves down). 1
Exhalation:
Diaphragm relaxes
(moves up). 2 37

38. Active Exhalation
Muscles in the abdomen and the internal intercostal muscles contract
This decreases thoracic cavity volume more than passive exhalation
A greater volume of air must flow out to equalize intrapulmonary pressure with atmospheric pressure

39. 4 Respiratory Volumes Tidal volume (500 mL) normal quiet breathing
Inspiratory reserve volume (3100 mL)
forced inhalation
Expiratory reserve volume (1200 mL)
forced exhalation
Residual volume (1200 mL)
air left in lungs after expiratory volume

40. Control of Breathing Medulla oblongata sets main rhythm
Magnitude (depth) of breathing depends on concentration of oxygen and H+
Brain detects H+
increases breathing
Carotid bodies and aortic bodies detect drop in oxygen, increase breathing

41. Homeostasis: Blood pH of about 7.4 Stimulus: Rising level of CO2
in tissues lowers
blood pH.
Figure Homeostatic control of breathing (step 1) 41

42. Homeostasis: Blood pH of about 7.4 Stimulus: Rising level of CO2
in tissues lowers
blood pH.
Carotid
arteries
Figure Homeostatic control of breathing (step 2)
Sensor/control
center:
Aorta
Cerebro-
spinal
fluid
Medulla
oblongata 42

43. Homeostasis: Blood pH of about 7.4 Stimulus: Rising level of CO2
in tissues lowers
blood pH.
Response:
Signals from
medulla to rib
muscles and
diaphragm
increase rate
and depth of
ventilation.
Carotid
arteries
Figure Homeostatic control of breathing (step 3)
Sensor/control
center:
Aorta
Cerebro-
spinal
fluid
Medulla
oblongata 43

44. Homeostasis: Blood pH of about 7.4 CO2 level decreases. Stimulus:
Rising level of CO2
in tissues lowers
blood pH.
Response:
Signals from
medulla to rib
muscles and
diaphragm
increase rate
and depth of
ventilation.
Carotid
arteries
Figure Homeostatic control of breathing (step 4)
Sensor/control
center:
Aorta
Cerebro-
spinal
fluid
Medulla
oblongata 44

45. Humans at High Altitude
Permanent residents of high areas have
More vascularized lungs
Larger ventricles in heart
More mitochondria in muscle
Acclimatization
Changes in rate of breathing, heart output
Kidney secretes erythropoitein; red cell production increases

46. hemoglobin of llamas
hemoglobin of humans
hemoglobin of other mammals (combined range)

47. Carbon Monoxide (CO) Colorless, odorless gas
Competes with oxygen for binding sites in hemoglobin
Binding capacity is at least 200 times greater than oxygen’s
Exposure impairs oxygen delivery

48. The Bends Pressure increases with depth
Increases N2 dissolved in blood
Can bubble out if diver ascends too fast
Pain in joints, impaired vision, paralysis

49. Heimlich Maneuver
Heimlich maneuver

50. Emphysema An irreversible breakdown in alveolar walls
Lungs become inelastic
May be caused by a genetic defect
Most often caused by smoking

51. Bronchitis
Irritation of the ciliated epithelium that lines the bronchiole walls
Air pollutants, smoking, or allergies can be the cause
Excess mucus causes coughing, can harbor bacteria
Chronic bronchitis scars and constricts airways

52. Impacts, Issues Video
Up In Smoke

53. Impacts, Issues-Up In Smoke
Filmy gunk from pathogens promotes:
asthma attacks
bronchitis
colds
Nicotine:
constricts blood vessels
raises blood pressure
makes blood stickier and clots more likely
Costs of smoking:
clogged arteries
heart attacks
strokes
lung cancer