Download Form and Function 2 Single Loop Double Loop

Form and Function 2
Today’s topics:
•  Life in Land vs. Water
The circulatory system
allows multicellular
organisms to exchange
heat, water, nutrients,
with their environment.
External environment
CO2 O
Food
2
Mouth
Animal
body
Respiratory
system
Nutrients
Cells
Heart
–  Physical Constraints affect
the design of animals
•  Circulatory and
Respiratory Systems!
Circulatory
system
–  Gas exchange
–  Open and closed
circulatory systems
–  Osmosis (again)
Interstitial
fluid
Digestive
system
Excretory
system
•  Energy budgets
Anus
Unabsorbed
Metabolic waste products
matter (feces) (nitrogenous waste)
7 April 2014
Fig. 42-28
Fig. 42-3
Alveolus
PCO2 = 40 mm Hg
PO2 = 100 mm Hg
Heart
PO2 = 40
PCO2 = 46
PO2 = 100
Heart
PCO2 = 40
Blood
Hemolymph
Circulatory
system
PO2 = 40
Circulatory
system
PO2 = 100
PCO2 = 46
Pores
Oxygen
Single
Loop
Tubular heart
PCO2 " 46 mm Hg
Heart
Gill
circulation
Ventral vessels
Closed circulatory system
Double
Loop
Superior
vena cava
Capillaries of
head and
forelimbs
7
Pulmonary
artery
Pulmonary
artery
Capillaries
of right lung
Aorta
9
3
Ventricle
Capillaries
of left lung
3
2
4
11
Atrium
Vein
Open circulatory system
Auxiliary hearts
Carbon dioxide
Gill capillaries
Artery
Dorsal vessel
(main heart)
PCO2 = 40
Body tissue
PO2 ! 40 mm Hg
Small branch vessels
In each organ
Interstitial
fluid
Pulmonary
vein
Systemic
circulation
Right atrium
1
Pulmonary
vein
5
Left atrium
10
Right ventricle
Left ventricle
Inferior
vena cava
Systemic capillaries
Aorta
8
Capillaries of
abdominal organs
and hind limbs
1
Fig. 42-UN4
Diffusion always moves down a
concentration gradient.
Diffusion of gasses depends on their partial pressure.
•  Atmospheric pressure = 760 mm Hg at sea level.
•  Air is 21% O2
•  Therefore the Partial Pressure of O2 = 0.21*760 = 160 mm Hg
At top of Mt. Everest, atmospheric
pressure is only 250.
Therefore PO2 = ______
How does your body respond to low O2
concentration at high altitude?
Respiration in Aquatic Species
Use gills
instead of
lungs
Fig. 42-22
In water
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
•  Solubility of O2 is only .003%
–  Fish have to process more water than air
breathers to get the same O2
•  Temperature
Operculum
Water flow
between
lamellae
Blood flow through
capillaries in lamella
–  Cold water can hold more dissolved gas. For fish,
warm water is the same as high elevation for us.
Countercurrent exchange
PO (mm Hg) in water
2
150 120 90 60 30
Gill filaments
Net diffusion of O2
from water
to blood
140 110 80 50 20
PO (mm Hg) in blood
2
•  Water surface area, turbulence, salinity, etc.
–  Shallow, fast moving bodies of water hold more
oxygen
2
Fig. 42-22
Fluid flow
through
gill filament
Oxygen-poor blood
Anatomy of gills
Gills use counter current flow, also!
Oxygen-rich blood
Gill
arch
Lamella
Gill
arch
Same current
Counter current
Gill filament
organization
Blood
vessels
Water
flow
Operculum
Water flow
between
lamellae
Blood flow through
capillaries in lamella
Countercurrent exchange
PO (mm Hg) in water
2
150 120 90 60 30
Gill filaments
Net diffusion of O2
from water
to blood
140 110 80 50 20
PO (mm Hg) in blood
2
Exchange surfaces and water balance
Diffusion stops when
concentrations are
equal
Diffusion continues along
the whole length because
it does not reach
equilibrium
Approx. Human Water Budget!
Water intake
water intake in form of fluids
water intake in form of semi-solid
and solid foods
water from oxidation
Total daily water intake
We lose about a
cup of water a day
just by breathing
(and we lose a
similar amount
through our skin)
1000-1500 ml
700 ml
300 ml
2000-2500 ml
Water output
water loss in urine
water loss through skin
water loss through lungs
water loss in stools
Total daily output
1000-1500 ml
500 ml
400 ml
100 ml
2000-2500 ml
Source: http://www.iv-partner.com/index.cfm?BEFDDE916A254231BF46392979BA89EA
Positive
pressure
Osmosis (again)
Blood pressure causes fluid to leak
out of capillaries
Body tissue
INTERSTITIAL FLUID
ψ = ψS+ ψP
Capillary
Water potential =
solute potential
+ pressure potential
Net fluid
movement out
Net fluid
movement in
H 2O
What will happen if the
pressure stops?
Direction of flow
Osmosis brings (most)
fluid back in
3
Fig. 43-7!
Fig. 44-4b
Interstitial fluid
Uptake of water and
some ions in food
Osmotic water
gain through gills
and other parts
of body surface
Uptake
of salt ions
by gills
Blood
capillary
Tissue
cells
Lymphatic
vessels
Lymphatic
vessel
We have a second
circulatory system,
the lymphatic
system.
Excretion of large
amounts of water in
dilute urine from kidneys
Osmoregulation in a freshwater fish
Gain of water and
salt ions from food
Excretion
of salt ions
from gills
Osmotic water
loss through gills
and other parts
of body surface
Basal Metabolic
Rate scales with
Body size
103
Elephant
BMR (L O2/hr) (Iog scale)
Fig. 44-4a
Horse
102
Human
Sheep
10
Cat
Dog
1
10–1
Rat
Ground squirrel
Shrew
Mouse
Harvest mouse
10–2
10–3
10–2
10
10–1
1
102
Body mass (kg) (log scale)
103
(a) Relationship of BMR to body size
8
Gain of water
and salt ions from
drinking seawater
Excretion of salt ions and
small amounts of water in
scanty urine from kidneys
BMR (L O2/hr) (per kg)
7
Shrew
6
5
4
3
Harvest mouse
Mouse
Sheep
Rat Cat
Human Elephant
Dog
Horse
Ground squirrel
0
10–3 10–2
102
103
10–1
1
10
Body mass (kg) (log scale)
2
1
Osmoregulation in a saltwater fish
(b) Relationship of BMR per kilogram of body mass to body size
Figure 40.20
Energy Budgets
4