1. How does a feathery fringe help this animal survive?
Figure 42.1 How does a feathery fringe help this animal survive?

2. Internal transport in gastrovascular cavities
Circular
canal
Mouth
Pharynx
Mouth
Radial canal
5 cm
2 mm
Figure 42.2 Internal transport in gastrovascular cavities
(a) The moon jelly Aurelia, a cnidarian
(b)
The planarian Dugesia, a
flatworm

3. Open and closed circulatory systems
Heart
Heart
Blood
Hemolymph in
sinuses
surrounding organs
Interstitial
fluid
Small branch vessels
In each organ
Pores
Dorsal vessel
(main heart)
Figure 42.3 Open and closed circulatory systems
Tubular heart
Auxiliary hearts
Ventral vessels
(a) An open circulatory system
(b) A closed circulatory system

4. Single circulation in fishes
Gill capillaries
Artery
Gill
circulation
Ventricle
Heart
Atrium
Figure 42.4 Single circulation in fishes
Systemic
circulation
Vein
Systemic capillaries

5. Double circulation in vertebrates
Mammals and
Birds
Amphibians
Reptiles
Lung and skin capillaries
Lung capillaries
Lung capillaries
Right
systemic
aorta
Pulmocutaneous
circuit
Pulmonary
circuit
Pulmonary
circuit
Atrium (A)
Atrium (A) A A A A
Ventricle (V) V V
Left
systemic
aorta V V
Right
Left
Right
Left
Right
Left
Systemic
circuit
Systemic
circuit
Figure 42.5 Double circulation in vertebrates
Systemic capillaries
Systemic capillaries
Systemic capillaries

6. mammalian cardiovascular system
Superior vena cava
Returns deoxygenated blood from
body to heart RA
Capillaries of head and
Forelimbs - EXCHANGE 7
Pulmonary artery
Pulmonary artery
Carries deoxygenated blood to lungs
Capillaries
of right Lung
GAS EXCHANGE
Aorta 9
Capillaries
of left Lung
GAS EXCHANGE 3 2 3 4 11
Pulmonary vein
Carries oxygenated blood
to heart: LA
Pulmonary vein 5 1
Right Atrium
RA - Receives deoxygenated blood
from body
Left Atrium - LA
Receives oxygenated blood
from lungs 10
Figure 42.6 The mammalian cardiovascular system: an overview
Right Ventricle
RV - Pumps blood to lungs
Left Ventricle - LV
Pumps oxygenated blood to body
Inferior vena cava
Returns deoxygenated blood from
body to heart RA
Aorta = main artery to body
for Systemic Circulation
mammalian cardiovascular system
Capillaries of
abdominal organs and hind limbs
EXCHANGE with body cells 8

7. Mammalian Heart Pulmonary artery - to lungs Aorta - systemic
circulation
Right Atrium RA
Receives
Deoxygented
Blood from
body
Pulmonary veins -
from lungs to heart
Left Atrium LA
Receives oxgenated
blood from lungs
Semilunar
valve
Semilunar
valve
Figure 42.7 The mammalian heart: a closer look
Atrioventricular
valve
Atrioventricular
valve
Right Ventricle RV
Pumps to lungs for
gas exchange
Left Ventricle LV
Pumps oxygenated
blood to body via aorta

8. Cardiac cycle 2 Atrial systole; ventricular diastole Semilunar valves
closed
0.1 sec
Semilunar
valves
open AV
valves
open
0.4 sec
0.3 sec
Figure 42.8 The cardiac cycle 1
Atrial and
ventricular
diastole
AV valves
closed 3
Ventricular systole;
atrial diastole

9. Control of heart rhythm1
Pacemaker
generates wave of
signals to contract. 2
Signals are
delayed at
AV node. 3
Signals pass
to heart apex. 4
Signals spread
throughout
ventricles. AV
node
SA node
(pacemaker)
Bundle
branches
Purkinje Fibers:
ventricles contract
Figure 42.9 The control of heart rhythm
Heart
apex
ECG

10. Structure of blood vessels
Artery
Vein
SEM
100 µm
Valve
Basal lamina
Endothelium
Endothelium
Smooth
muscle
Smooth
muscle
Connective
tissue
Connective
tissue
Capillary
Artery
Vein
Figure The structure of blood vessels
Arteriole
Venule
15 µm
Red blood cell
Capillary LM

11. The interrelationship of cross-sectional area of blood vessels, blood flow velocity, and blood pressure.
5,000
4,000
Area (cm2)
3,000
2,000
1,000 50 40
Velocity
(cm/sec) 30 20 10
Figure The interrelationship of cross-sectional area of blood vessels, blood flow velocity, and blood pressure
120
Systolic
pressure
100
Pressure
(mm Hg) 80 60
Diastolic
pressure 40 20
Aorta
Veins
Arteries
Arterioles
Venules
Capillaries
Venae cavae

12. Question: How do endothelial cells control vasoconstriction?
RESULTS
Ser
Leu
Endothelin
Ser
Met
Cys
Ser
Cys
—NH3+
Asp
Lys
Glu
Cys
Val
Tyr
Phe
Cys
His
Leu
Asp
Ile
Ile
Trp
—COO–
Cys
Trp
Figure How do endothelial cells control vasoconstriction?
Parent polypeptide 53 73 1
203
Endothelin

13. Measurement of blood pressure: sphygmomanometer
Blood pressure reading: 120/70
Pressure in cuff
greater than
120 mm Hg
Pressure in cuff
drops below
120 mm Hg
Pressure in
cuff below
70 mm Hg
Rubber
cuff
inflated
with air
120
120 70
Figure Measurement of blood pressure
Artery
closed
Sounds
audible in
stethoscope
Sounds
stop

14. Blood flow in veins Valve (closed) Direction of blood flow
in vein (toward heart)
Valve (open)
Skeletal muscle
Figure Blood flow in veins
Valve (closed)

15. Blood flow in capillary beds
Precapillary sphincters
Thoroughfare
channel
Capillaries
Arteriole
Venule
(a) Sphincters relaxed
Figure Blood flow in capillary beds
Arteriole
Venule
(b) Sphincters contracted

16. Fluid exchange between capillaries and the interstitial fluid
Body tissue
INTERSTITIAL FLUID
Capillary
Net fluid
movement out
Net fluid
movement in
Direction of
blood flow
Blood pressure = hydrostatic pressure
Figure Fluid exchange between capillaries and the interstitial fluid
Inward flow
Pressure
Outward flow
Osmotic pressure
Arterial end of capillary
Venous end

17. Composition of mammalian blood
Plasma 55%
Constituent
Major functions
Cellular elements 45%
Cell type
Number
per µL (mm3) of blood
Functions
Water
Solvent for
carrying other
substances
Erythrocytes
(red blood cells)
5–6 million
Transport oxygen
and help transport
carbon dioxide
Ions (blood electrolytes)
Sodium
Potassium
Calcium
Magnesium
Chloride
Bicarbonate
Osmotic balance,
pH buffering, and
regulation of
membrane
permeability
Separated
blood
elements
Leukocytes
(white blood cells)
5,000–10,000
Defense and
immunity
Plasma proteins
Albumin
Osmotic balance
pH buffering
Lymphocyte
Basophil
Fibrinogen
Figure The composition of mammalian blood
For the Discovery Video Blood, go to Animation and Video Files.
For the Cell Biology Video Leukocyte Adhesion and Rolling, go to Animation and Video Files.
Clotting
Immunoglobulins
(antibodies)
Defense
Eosinophil
Neutrophil
Monocyte
Substances transported by blood
Nutrients (such as glucose, fatty acids, vitamins)
Waste products of metabolism
Respiratory gases (O2 and CO2)
Hormones
Platelets
250,000–
400,000
Blood clotting

18. Blood clotting Platelet plug Fibrin clot Platelet releases chemicals
Red blood cell
Collagen fibers
Platelet plug
Fibrin clot
Platelet releases chemicals
that make nearby platelets sticky
Clotting factors from:
Platelets
Damaged cells
Plasma (factors include calcium, vitamin K)
Figure Blood clotting
Prothrombin
Thrombin
Fibrinogen
Fibrin
5 µm

19. Differentiation of Blood Cells
Stem cells
in bone marrow
Lymphoid
stem cells
Myeloid
stem cells
Lymphocytes
B cells
T cells
Figure Differentiation of blood cells
Erythrocytes
Neutrophils
Platelets
Eosinophils
Monocytes
Basophils

20. Atherosclerosis Plaque Connective tissue Smooth muscle Endothelium
Figure Atherosclerosis
(a) Normal artery
50 µm
(b) Partly clogged artery
250 µm

21. Gills are outfoldings of the body that create a large surface area for gas exchange
Coelom
Gills
Figure Diversity in the structure of gills, external body surfaces that function in gas exchange
Gills
Tube foot
Parapodium (functions as gill)
(a) Marine worm
(b) Crayfish
(c) Sea star

22. 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
Countercurrent exchange
Figure The structure and function of fish gills
PO2 (mm Hg) in water
150
120 90 60 30
Gill filaments
Net diffusion
of O2from
water to
blood
140
110 80 50 20
PO2 (mm Hg) in blood

23. Tracheal systems Tracheae = air tubes Air sac Trachea Air sacs
External opening:
spiracles
Tracheoles
Mitochondria
Muscle fiber
Body
cell
Air
sac
Tracheole
Figure Tracheal systems
Trachea
Air external openings
spiracles
Body wall
2.5 µm

24. Mammalian Respiratory System
Branch of
pulmonary
vein
(oxygen-rich
blood)
Branch of
pulmonary
artery
(oxygen-poor
blood)
Terminal
bronchiole
Nasal
cavity
Pharynx
Larynx
Alveoli
(Esophagus)
Left
lung
Trachea
Right lung
Figure The mammalian respiratory system
Bronchus
Bronchiole
Diaphragm
Heart
SEM
Colorized
SEM
50 µm
50 µm

25. Negative pressure breathing: H --> L
Rib cage
expands as
rib muscles
contract
Rib cage gets
smaller as
rib muscles
relax
Air
inhaled
Air
exhaled
Lung
Figure Negative pressure breathing
Diaphragm
INHALATION
Diaphragm contracts
(moves down)
Volume increases
Pressure decreases
Air rushes in
EXHALATION
Diaphragm relaxes
(moves up)
Volume decreases
Pressure increases
Air rushes out

26. The Avian Respiratory System
Air
Air
Anterior
air sacs
Trachea
Posterior
air sacs
Lungs
Lungs
Air tubes
(parabronchi)
in lung
Figure The avian respiratory system
1 mm
INHALATION
Air sacs fill
EXHALATION
Air sacs empty;
Lungs Fill

27. Automatic control of breathing
Cerebrospinal
fluid
Pons
Breathing
control
centers
Medulla
oblongata
Carotid arteries
Figure Automatic control of breathing
Aorta
Diaphragm
Rib muscles

28. Loading and unloading of respiratory gases
Alveolus
Alveolus
PO2 = 100 mm Hg
PCO2 = 40 mm Hg
PO2 = 40
PO2 = 100
PCO2 = 46
PCO2 = 40
Circulatory
system
Circulatory
system
PO2 = 40
Figure Loading and unloading of respiratory gases
PO2 = 100
PCO2 = 46
PCO2 = 40
PO2 ≤ 40 mm Hg
PCO2 ≥ 46 mm Hg
Body tissue
Body tissue
(a) Oxygen
(b) Carbon dioxide

29.  Chains
Iron
Heme
 Chains
Hemoglobin

30. Dissociation curves for hemoglobin at 37ºC
100
O2 unloaded
to tissues
at rest 80
O2 unloaded
to tissues
during exercise 60
O2 saturation of hemoglobin (%) 40 20 20 40 60 80
100
Tissues during
exercise
Tissues
at rest
Lungs
PO2 (mm Hg)
(a) PO2 and hemoglobin dissociation at pH 7.4
100
pH 7.4 80
pH 7.2
Figure Dissociation curves for hemoglobin at 37ºC
Hemoglobin
retains less
O2 at lower pH
(higher CO2
concentration) 60
O2 saturation of hemoglobin (%) 40 20 20 40 60 80
100
PO2 (mm Hg)
(b) pH and hemoglobin dissociation

31. Carbon dioxide transport in the blood
Body tissue
CO2 produced
CO2 transport
from tissues
Interstitial fluid
CO2
Plasma
within capillary
CO2
Capillary
wall
CO2
H2O
Red
blood
cell
Hemoglobin
picks up
CO2 and H+
H2CO3 Hb
Carbonic acid
HCO3–
Bicarbonate + H+
HCO3–
To lungs
CO2 transport
to lungs
HCO3–
HCO3– + H+
Figure Carbon dioxide transport in the blood
Hemoglobin
releases
CO2 and H+
H2CO3 Hb
H2O
CO2
CO2
CO2
CO2
Alveolar space in lung

32. Review Inhaled air Exhaled air Lungs - Alveolar Air Spaces
GAS EXCHANGE
Alveolar
epithelial cells
CO2 O2
CO2 O2
Pulmonary arteries
Alveolar
capillaries of
lung
Pulmonary veins
Systemic veins
Systemic arteries
Heart
Systemic
capillaries
CO2 O2
CO2 O2
Body tissue - GAS EXCHANGE

33. You should now be able to:
Compare and contrast open and closed circulatory systems.
Compare and contrast the circulatory systems of fish, amphibians, reptiles, and mammals or birds.
Distinguish between pulmonary and systemic circuits and explain the function of each.
Trace the path of a red blood cell through the human heart, pulmonary circuit, and systemic circuit.

34. Define cardiac cycle and explain the role of the sinoatrial node.
Relate the structures of capillaries, arteries, and veins to their function.
Define blood pressure and cardiac output and describe two factors that influence each.
Explain how osmotic pressure and hydrostatic pressure regulate the exchange of fluid and solutes across the capillary walls.

35. Describe the role played by the lymphatic system in relation to the circulatory system.
Describe the function of erythrocytes, leukocytes, platelets, fibrin.
Distinguish between a heart attack and stroke.
Discuss the advantages and disadvantages of water and of air as respiratory media.

36. For humans, describe the exchange of gases in the lungs and in tissues.
Draw and explain the hemoglobin-oxygen dissociation curve.