Mammals
Mammals
• Vertebrates
(backbone), have hair,
develop specialized
teeth
backbone
Mammals
• Have various glands, including mammary glands that
produce milk
• Endothermic (warm-blooded)
• Can keep a stable temperature by using energy from food
• Hair/fur and fat also provide insulation
Mammals: Respiration
• Use lungs to breathe
• Diaphragm (at bottom
of ribs) forces air into
and out of lungs
• In lungs, oxygen
enters blood and
carbon dioxide exits
blood
Mammals: Circulation
• 4-chambered heart and
2 loops of vessels –
keeps oxygen-rich
blood completely
separate from oxygenpoor blood
• Blood also removes
waste from cells and
helps regulate body
temperature
Blue = oxygen-poor blood
Red = oxygen-rich blood
Mammals: Movement
• Movement- varies with organisms
– Walk on 2 or 4 limbs, hop, swing on vines, use
flippers
Mammals: Nervous System
• Receives and interprets
information from the
environment
• 5 senses: vision, hearing,
smell, taste, and touch
• Chemical and electrical
signals travel to the brain,
and the brain directs the
action of the body
OUCH!
Mammals: Reproduction
• Reproduce sexually through internal fertilization
• Mammals are divided into 3 subclasses based on
reproductive methods:
Mammals: Reproduction
1.
Placental mammals
(90%) – give birth to
young that have
developed inside the
mother’s uterus until the
body systems are fully
developed
–
Placenta – organ that
passes nutrients and
oxygen to baby and
removes waste from baby
through umbilical cord
Placental Mammals
Mammals: Reproduction
2. Marsupials – short period of development inside
the mother’s body, then finishes development in
a pouch
–
Ex.: opossum, kangaroo, koala
Opossum embryos in a
pouch
Mammals: Reproduction
3. Monotremes – lay eggs
– Only 3 (2 spiny anteaters and 1 duck-billed platypus)
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