Basic Principles of Animal Form and Function. Chapter 40 P. Biology Rick L. Knowles Liberty Senior High School. Figure 40.1. The comparative study of animals Reveals that form and function are closely correlated Natural selection can fit structure, anatomy, to function, physiology.
Rick L. Knowles
Liberty Senior High School
Could they ever exist?
(a) Single cell
(b) Two cell layers
A microscopic view of the lung reveals
that it is much more spongelike than
balloonlike. This construction provides
an expansive wet surface for gas
exchange with the environment (SEM).
The lining of the small intestine, a diges-
tive organ, is elaborated with fingerlike
projections that expand the surface area
for nutrient absorption (cross-section, SEM).
Inside a kidney is a mass of microscopic
tubules that exhange chemicals with
blood flowing through a web of tiny
vessels called capillaries (SEM).
in body cells
This photograph shows a ghost crab in arespirometer. Temperature is held constant in thechamber, with air of known O2 concentration flow-ing through. The crab’s metabolic rate is calculatedfrom the difference between the amount of O2entering and the amount of O2 leaving therespirometer. This crab is on a treadmill, runningat a constant speed as measurements are made.
(b) Similarly, the metabolic rate of a manfitted with a breathing apparatus isbeing monitored while he works outon a stationary bike.
Figure 40.8a, b
River otter (endotherm)
Body temperature (°C)
Largemouth bass (ectotherm)
Ambient (environmental) temperature (°C)
BMR for Human Males = 1, 800 kcal/day
BMR for Human Females = 1,500 kcal/day
A = 60-kg alligator
H = 60-kg human
Maximum metabolic rate
(kcal/min; log scale)
Existing intracellular ATP
ATP from glycolysis
ATP from aerobic respirationActivity and Metabolic Rate
In general, an animal’s maximum possible metabolic rate is inversely related to the duration of the activity.
Endotherm Respiration Rate is 20 X an Ectotherm, causes less endurance
Annual energy expenditure (kcal/yr)
0.025-kg female deer mouse
4-kg male Adélie penguin
from Antarctica (brooding)
60-kg female human
from temperate climate
4-kg female python
Total annual energy expenditures
Energy expenditure per unit mass
Energy expenditures per unit mass (kcal/kg•day)
Higher BMRs to generate heat require:
waves by all objects warmer than absolute
zero. Radiation can transfer heat between
objects that are not in direct contact, as when
a lizard absorbs heat radiating from the sun.
Evaporation is the removal of heat from the surface of a
liquid that is losing some of its molecules as gas.
Evaporation of water from a lizard’s moist surfaces that
are exposed to the environment has a strong cooling effect.
Conduction is the direct transfer of thermal motion (heat)
between molecules of objects in direct contact with each
other, as when a lizard sits on a hot rock.
Convection is the transfer of heat by the
movement of air or liquid past a surface,
as when a breeze contributes to heat loss
from a lizard’s dry skin, or blood moves
heat from the body core to the extremities.Modes of Heat Exchange
Arteries carrying warm blood down the
legs of a goose or the flippers of a dolphin
are in close contact with veins conveying
cool blood in the opposite direction, back
toward the trunk of the body. This
arrangement facilitates heat transfer
from arteries to veins (black
arrows) along the entire length
of the blood vessels.
Near the end of the leg or flipper, where
arterial blood has been cooled to far below
the animal’s core temperature, the artery
can still transfer heat to the even colder
blood of an adjacent vein. The venous blood
continues to absorb heat as it passes warmer
and warmer arterial blood traveling in the
In the flippers of a dolphin, each artery is
surrounded by several veins in a
countercurrent arrangement, allowing
efficient heat exchange between arterial
and venous blood.
As the venous blood approaches the
center of the body, it is almost as warm
as the body core, minimizing the heat lost
as a result of supplying blood to body parts
immersed in cold water.
(a)Bluefin tuna. Unlike most fishes, the bluefin tuna maintains
temperatures in its main swimming muscles that are much higher
than the surrounding water (colors indicate swimming muscles cut
in transverse section). These temperatures were recorded for a tuna
in 19°C water.
(b) Great white shark. Like the bluefin tuna, the great white shark
has a countercurrent heat exchanger in its swimming muscles that
reduces the loss of metabolic heat. All bony fishes and sharks lose
heat to the surrounding water when their blood passes through the
gills. However, endothermic sharks have a small dorsal aorta,
and as a result, relatively little cold blood from the gills goes directly
to the core of the body. Instead, most of the blood leaving the gills
is conveyed via large arteries just under the skin, keeping cool blood
away from the body core. As shown in the enlargement, small
arteries carrying cool blood inward from the large arteries under the
skin are paralleled by small veins carrying warm blood outward from
the inner body. This countercurrent flow retains heat in the muscles.
Figure 40.16a, b
Time from onset of warmup (min)
Additional metabolism that would be
necessary to stay active in winter
(kcal per day)