Jess Ackerman Maddy Smith Class Mammalia Jess Ackerman Maddy Smith

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

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

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.

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

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

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

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

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

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

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

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.)

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

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