1. Jess Ackerman Maddy Smith
Class Mammalia
Jess Ackerman
Maddy Smith

2. Phylum name: Chordates
Subphylum: vertebrata
Class: mammalia
Common Name: mammals

3. General Characteristics
Hair (insulation and protection)
Sweat glands
Mammary glands (produce milk for young)
Differentiation of teeth (incisors, canines, premolars, molars)
3 middle ear bones (malleus, incus, stapes)
Jaw (composed of dentary and squamosal) Endotherms (constant body temperature)
Complex nervous system
Bilateral Symmetry

4. Various Body Systems System Type Mammals System Muscular-Skeletal
A mammal has an inner skeleton. It has developed muscles and generally have four limbs attached.
Digestion
A mammal has a developed digestive tract with mouth, teeth, stomach, intestines. Herbivores eat plants, carnivores eat meat and omnivores eat both.
Nervous
A mammal has a highly developed brain, nerves and sensory organs such as eyes, nose, mouth, ears and touch.
Circulation
A mammal has a four chambered heart, blood vessels and blood within their system.
Respiration
A mammal has lungs and breathes in oxygen and gives off carbon dioxide.
Reproduction
A mammal reproduces sexually with the female being fertilized by the male internally. Mammals have live birth and care for their young for quite a time after birth.
Excretion
A mammal gas kidneys and is covered with skin. The skin has hair. Mammals are warm blooded.
Symmetry
A mammal has bilateral symmetry.
Coloration
A mammal can be various shades of brown, black, tan, white.

5. Anatomy: Skeletal System
Internal skeletal system
Seven cervical vertebrae (normally)
Four limbs (usually); limbs adapted for:
climbing
swimming
flying
running/walking

6. Anatomy: Respiratory System and Gas Exchange
Take in oxygen, expel carbon dioxide
Lungs:
Spongy texture
Epithelium (larger surface area)
Muscular Diaphragm:
Drives breathing
Divides thorax from abdominal cavity
Air enters through oral and nasal cavities
Flows through larynx, trachea, and bronchi
Air is sucked into or expelled out of lungs
Moves down pressure gradiant
Aka “bellows lungs”
Red blood cells serve as oxygen transports
Four chambered heart pumps blood throughout body

7. Anatomy: Integumentary System
Three layers: epidermis, dermis, hypodermis
Epidermis:
Ten to thirty cells thick
Provides waterproof layer
Outermost cells constantly lost
Bottommost cells constantly dividing
Dermis:
Fifteen to forty times thicker than epidermis
Components include bony structures and blood vessels
Hypodermis:
Made of adipose tissue
Stores lipids
Provides cushioning and insulation
Hair

8. Anatomy: Nutrition and Digestion
Keeping high constant body temperature is energy expensive
Need nutritious and plentiful diet
Different species adapted to dietary requirements in a variety of ways
Carnivores (including insectivores)
Herbivores (granivores, folivores, fruivores, nectivores, etc.)
Size of animal is a factor in diet type
Small: high-energy requirements
Large: can tolerate slower collection process or slower digestive process
Developed digestive tract
Mouth, teeth, esophagus, stomach, intestines

9. Response to Stimuli Eyes Ears Nervous System
Respond to light, movement, etc.
Ears
Responsible for hearing and balance
Nervous System
Complex brain (neocortex)
System of nerves throughout the body

10. Anatomy: Reproductive System
Most are vivipary (live young)
Metatheria
Eutheria—placental mammals
Marsupials—undeveloped young kept in pouch
A few lay eggs
Holotheria (monotremes)
Mammary glands
Specialized to produce milk
Newborns’ primary source of nutrition

11. Classes: 3 subclasses Holotheria (monotremes, egg laying mammals)
Metatheria (marsupials, pouch mammals)
Eutheria (placental mammals)

12. Holotheria Ex: duck billed platypus, spiny ant eaters
Reproduction: females lay eggs, or carry in pouches
Feeding practices: varied (ant eaters use sticky tongue, platypus eats freshwater invertebrates, etc.)

13. Metatheria Ex: kangaroos and opossums
Reproduction: young are born in undeveloped stage, complete development in pouch
Feeding practices: varied

14. Eutheria Ex: humans, lions, etc.
Reproduction: young remain in mothers until development is complete
Feeding practices: varied