Page 18 - One Million Things: Animal Life - The Incredible Visual Guide

VERTEBRATES

Inside view of a female rabbit with
the digestive system unraveled
Fish, amphibians, reptiles, birds, and mammals are called
vertebrates because they have a vertebral column, or backbone.
This is the part of an internal skeleton that supports the skull
Neck muscles
and to which the limbs are attached. Aside from the skeleton, move and
several other body systems interact to produce a working support the
head
vertebrate. Most are described here, using the rabbit
Outer ear
as an example. flap channels
sounds into
inner part
of ear
1

Eye detects
SKIN, HAIR, AND CLAWS
light and
All vertebrates have an outer
sends signals
4
skin. In fish and reptiles the skin
to the brain
is covered by scales, in birds it is
covered by feathers, and in
RESPIRATION
Nerve carries
mammals, such as the rabbit, by
signals to and
hair or fur. Hair grows from the
from face
so it can keep its internal
skin and helps insulate the animal
During respiration, air is drawn into the lungs. Here,
temperature constant. Claws, and
5 NERVOUS SYSTEM
oxygen from the air passes into the bloodstream and
related structures such as hooves,
is carried to the animal’s cells, where it is used to
are made from the same substance
release energy from food. Waste carbon dioxide is
carried back to the lungs and breathed out.
as hair, and help mammals grip
the ground as they move.
1
The nervous system controls the rabbit’s movements
and enables it to sense its surroundings. Located
2 connects to its base. Cablelike nerves attached to the Small intestine
SKELETON of the body.
inside the skull, the brain is the control center of the
digests food
nervous system, aided by the long spinal cord that
and absorbs
The bones of the skeleton form
a flexible framework that
6 the end
products
supports the rabbit, protects its
brain and spinal cord relay signals to and from all parts
internal organs, and enables it
to move. Where two or more
DIGESTIVE SYSTEM
Appendix
bones meet they form a joint,
is a store of
and most of the skeleton’s
Food is essential for life since it supplies
food-digesting
joints are freely movable.
both energy and building materials.
bacteria
3 and intestines—that digests (breaks
The digestive system consists of a long
CIRCULATION nutrients, absorbs those nutrients
tube—including the mouth, stomach,
Blood carries oxygen, food, and
down) food into simple, useful
other essentials to all parts of
the body, and removes waste
7 URINARY SYSTEM
into the bloodstream, and then
for disposal. The heart pumps
gets rid of undigested waste.
oxygen-rich blood to the body
Two kidneys, the bladder, and the tubes that
along tubes called arteries.
connect them make up the urinary system.
Oxygen-poor blood returns to
The kidneys filter blood to remove wastes and
the heart through veins. excess water. These form urine that is stored
in the baglike bladder before being released
from the body.
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