Lab material Flashcards
What are the three characteristics of the phylum Chordata?
- hollow dorsal nerve tube
- gill pouches in early embryonic development
- notochord in early embryonic development
What is the characteristic of the subphylum Vertebrata?
Bony skeleton enclosing brain and spinal chord
What is the official defining characteristic of mammals?
Lower jaw is composed of a single pair of bones - dentaries, and is connected directly to the cranium - specifically the articulation between the dentary and squamosal bones
- also by presence of three bones in the middle ear - articular and quadrate bones become malleus and incus
Soft tissue characteristics common to mammals?
- hair at some stage in life
- mammary glands that produce milk in females
- muscular diaphragm in abdominal cavities
- ## ennucleate erythrocytes - no nuclei in red blood cells
Heirarchy of taxonomic classification?
Kingdom
Phylum
Class
Order
Family
Genus
Species
What are the seven faunal regions?
Neotropical - south + central america
Nearctic - North america
Palearctic - Europe + north asia + north africa
Holarctic - north russia + alaska - usually nearctic + palearctic
Ethiopian - Central + south africa
Oriental - south asia
Australian - Australia
What is Wallaces Line?
Faunal boundary between south asia and australia
What are the two main components of the mammalian skull?
Cranium and mandible
Three layers of skin
Epidermis - only living cells in the deepest layers
Dermis - connective tissue, muscles, nerves, sensory structures
Hypodermis - fat layer
Two kinds of scales
True dermal bone - formed in dermal layer of integument
Epidermal scales - modified stratum corneum cells that create flattened epidermal plates
5 important parts of hair anatomy
Medulla - central core
Cortex - bulk of the hair
Cuticle - outer layer composed of cuticular scales
Pigment granules - melanin
Erector pilli muscle - keeps hair standing up
Two kinds of hair growth
Angora - continuous growth and not shed
Definitive - grows to a defined length and is shed periodically
3 types of hair
Vibrissae - long stiff hairs as tactile receptors - whiskers
Guard hairs - spines, bristles and awns
Underhairs - wool (angora), fur (definitive) and velli (definitive / downy)
3 classes of hair colour
Eumelanin - dark colours
Pheomelanin - red / light colours
Agouti - more than one colour on a single hair
6 functions of hair coloring
Concealment - cryptic coloration, disruptive coloration, countershading
Communication - warning coloration, reverse countershading, flag
Special cases of hair coloring
Albinism - lack of all external pigment
Leucism - partial loss of pigmentation
Melanism - unusally dark pigmentation due to disposition of large amount of melanin
Piebald - patches of white on body
Two types of hairless mammals
All mammals have hair at some stage in life (defining characteristic)
- Naked mole rat - has whiskers but no true fur coat
- Marine mammals - hair is greatly reduced in sirenians and cetaceans
4 Integumentary glands
Sweat glands - unique to mammals, two types - sudoriferous - empty into hair follicles, and eccrine - empty onto surface of skin (for cooling and tactile reasons)
Sebaceous glands - secrete fatty substance to prevent brittle hair and water proof the coat]
Scent glands - can be sebaceous or sudoriferous, for defense, marking territory and social
Mammary glands - derived from integumentary glands and secrete milk
What two orders have horns?
Aritodactyla and perissodactyla
What are the 5 major types of horns?
True horns
Pronghorns
Antlers
Giraffe horns
Rhinoceros horns
What are true horns
Found in bovidae
- inner bony core extension of frontals - sheathed in a keratinized epidermis - found in males and females
- grow throughout life with no shedding
- in pairs except for 4 horned antelope
What are pronghorns
- antilocarpa americana
- shed sheath annually
- form prongs from new sheath
- females have no prongs
What are antlers?
Cervidae (except 1)
- males onlly
- forms from a pedicel - permanent extension of frontal bone that connects to deciduous antlers via a burr
- growing antler fed by velvet
- consists of main beam and tines, shed after mating
What are giraffe horns?
Permanent bony processes arising from suture between parietals and frontals
- ossified from ossicones and then fuse to skull
- NOT projections of frontal bones
- permanently covered by skin and air
What are rhinoceros horns?
Only extant non artiodactyls with horns
- hardened epithelial cells formed from dermal papillae - not fused to the bone
- skin-bearing horn situated over fused nasal bones
3 other keratinized structures
Claws - encase the most distal phalanx
Nails - modified claw that only covers dorsal surface of distal phalanx, less protection but more dexterity
Hooves - contacts ground in ungulates
Baleen - replaces teeth in whales , grows continuously
Two types of postcranial skeleton?
Axial skeleton - skull spine and ribcage
Appendicular skeleton - everything else, limbs, pectoral and pelvic girdles
6 main bones in the limbs
Humerus
Radius
Ulna
Carpals
Metacarpals
Phalanges
4 parts of a claw?
Unguis - dorsal plate, curves and encloses the subunguis
Subunguis - ventral plate
Dermis - live tissue
Bone (phalanges)
Nail anatomy differences
Nail covers only the dorsal surface
Unguis is broad and flattened
Subunguis is reduced to small remnant under tip of nail
Will have a finger pad of sorts
Functions in precision manipulation and tactile perception
Hoof anatomy differences
Unguis curves almost completely around end of digit
Subunguis is completely enclosed
Pad behind hoof is called a frog
Two main and sub types of locomotion
Cursorial - Running
- digitigrade - on one or more toes
- unguligrade - hooves
Ambulatory - walking
- plantigrade - soles of hands and feet
- graviportal - heavy bodied on pads like elephants
4 types of terrestrial locomotion
Cursorial
- digitigrade - metacarpals do not touch surface, limbs can move in several planes
- unguligrade - phalanges are elevated and hooves contact surface - bones are fused and reduced in number, restricted to lateral movement only
Saltatorial - leaping movement generated by hindlimbs, can be jumping or ricocheting
Graviportal - digits radiate out to form a series of arches with thick cushioning pad
What is fossorial locomotion?
Underground
What is natatorial locomotion?
Semiaquatic
larger zygomatic arch in what?
IN carnivores for muscle attachement
