Download Circulation and Gas Exchange

Circulation and Gas Exchange
The Respiratory System
GETS oxygen for the body
 GETS RID of carbon dioxide
Characteristics/Requirements of ALL Gas
Exchange Mechanisms:
 MOIST membranes
 Close spacing of gas and blood for easy
diffusion
 High surface area-to-volume ratio
 An animal’s respiratory surfaces must
be large enough to provide oxygen and
expel carbon dioxide for the entire body


Countercurrent Exchange- blood &
water flow in opposite directions
Tracheae



The respiratory
system used by
insects
Tracheae are air
tubes that branch
throughout the
insect body
The finest branches
of the tracheae
extend to the
surface of nearly
every cell, where gas
is exchanged by
diffusion
Human Respiratory System
Open vs. Closed Circulatory Systems

In open circulatory systems,
hemolymph bathes the internal
organs directly


Insects, arthropods, mollusks
In closed circulatory systems, blood
is confined to vessels


Blood exchanges materials with the ISF
bathing the cells
Earthworms, squids, octopuses,
vertebrates
Open vs. Closed Circulatory Systems

Vertebrate circulatory systems
AMPHIBIANS
REPTILES (EXCEPT BIRDS)
MAMMALS AND BIRDS
Lung and skin capillaries
Lung capillaries
Lung capillaries
FISHES
Gill capillaries
Artery
Pulmocutaneous
circuit
Gill
circulation
Right
systemic
aorta
Pulmonary
circuit
Heart:
ventricle (V)
A
A
Atrium (A)
V
V
Right
Vein
Systemic
circulation
Systemic capillaries
A
Left
Right
A Left
Systemic
V aorta
Left
A
V
Right
A
V
Left
Systemic
circuit
Systemic
circuit
Systemic capillaries
Pulmonary
circuit
Systemic capillaries
Systemic capillaries
Double Pump



Right side pumps to the lungs and
back to left atrium (PULMONARY
CIRCUIT)
Left side pumps to the entire body
and returns blood to right atrium
(SYSTEMIC CIRCUIT)
Oxygenated & deoxygenated blood
never mix!

The mammalian cardiovascular system
7
Capillaries of
head and
forelimbs
Anterior
vena cava
Pulmonary
artery
Aorta
Pulmonary
artery
9
6
Capillaries
of right lung
Capillaries
of left lung
2
4
3
Pulmonary
vein
5
1
Right atrium
3
11
Left atrium
Pulmonary
vein
10
Left ventricle
Right ventricle
Aorta
Posterior
vena cava
8
Figure 42.5
Capillaries of
abdominal organs
and hind limbs