1. 05.24.17 What can we do to stop the spread of measles?
I will describe how the body exchanges gases.

2. How do organisms exchange gas?

3. Parapodium (functions as gill)
Fig a
Figure Diversity in the structure of gills, external body surfaces that function in gas exchange
Parapodium (functions as gill)
(a) Marine worm

4. Gills (b) Crayfish Fig. 42-21b
Figure Diversity in the structure of gills, external body surfaces that function in gas exchange
Gills
(b) Crayfish

5. Coelom Gills Tube foot (c) Sea star Fig. 42-21c
Figure Diversity in the structure of gills, external body surfaces that function in gas exchange
Gills
Tube foot
(c) Sea star

6. Figure 42.22 The structure and function of fish gills
Fluid flow
through
gill filament
Oxygen-poor blood
Anatomy of gills
Oxygen-rich blood
Gill
arch
Lamella
Gill
arch
Gill filament
organization
Blood
vessels
Water
flow
Operculum
Water flow
between
lamellae
Blood flow through
capillaries in lamella
Figure The structure and function of fish gills
Countercurrent exchange
PO2 (mm Hg) in water
150
120 90 60 30
Gill filaments
Net diffu-
sion of O2
from water
to blood
140
110 80 50 20
PO2 (mm Hg) in blood

7. Air sacs Tracheae External opening Tracheoles Mitochondria
Fig
Air sacs
Tracheae
External
opening
Tracheoles
Mitochondria
Muscle fiber
Body
cell
Air
sac
Tracheole
Figure Tracheal systems
Trachea
Air
Body wall
2.5 µm

8. Breathe In. Pharynx Larynx Alveoli Trachea Bronchus Bronchiole
Fig
Branch of
Pulmonary vein
(oxygen-rich
blood)
Branch of
Pulmonary artery
(oxygen-poor
blood)
Terminal
bronchiole
Pharynx
Nasal
cavity
Larynx
Alveoli
Trachea
Bronchus
Figure The mammalian respiratory system
Bronchiole
Diaphragm
Heart
SEM
Colorized
SEM
50 µm
50 µm

10. Big ideas.
Work with a partner or independently to respond the the questions.
We will review these tomorrow at the beginning of the period.

12. Artery v. Vein