Download The Mammalian Body - Walker Elementary

Section 35.1
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Hair – all mammals have hair, even
whales (a few whiskers on snout)
Filament composed of dead cells
filled with keratin
Functions: insulation, camouflage,
warning, sensory, defense
Teeth – usually only 2 sets: milk teeth and
permanent teeth
 Functions: killing, chewing, protection, tools
 Types: incisors – biting & cutting; canines –
stabbing & holding, premolars and molars –
crushing & chewing
 Specialization – teeth are designed for the
food the mammal eats
Body temperature
 Endotherms – high metabolism generates
body heat; allows for:
 activity at any time of day or night
 mammals to live in more habitats than
reptiles or amphibians
 sustained activity such as running or flying
Respiratory system
 Alveoli air sacs which provide a large internal
surface area which provides for exchange of
O2 and CO2
Heart & circulatory system
 Double-loop circulation
 4 chambered heart with completely divided
septum
 No mixing of high O2 and low O2 blood
Parental care
 Mammary glands – modified sweat glands
which produce milk for young
 Rich in protein, carbohydrates (lactose), fat,
water, minerals and immunity
 Weaning – mother stops nursing young
 Young mammals spend a long time with
mothers compared to other animals, even after
weaning