FINAL EXAM MAMMALS Flashcards
1
Q
Largest and smallest mammal
A
- largest blue whale
- smallest bumblebee bat, 2nd is etruscan shrew
2
Q
characteristics of mammals
A
- hair
- skin glands
- mammary glands
- three middle ear ossicles
- four chambered heart
- endothermic/homeothermic
- heterodont
- one bone in lower jaw
- double chondyle connecting skull to vertebrae
3
Q
describe mammal hair
A
- anatomy:
follicle: hair growth
papilla: bottom of follicle, stem cells (living cells), capillaries
matrix: cell division and elongation, melanin production
keratogenous zone: kerotin production, cell death
medulla: inner cells
cortex: find melanin and keratin
cuticle: flat cells, lipids, scales, species specific
4
Q
3 major types of mammal hair
A
- guard hairs: long, visible, protection, coloration, communication, infrared receptors
- underhair: dense, insulator, short
- vibrisae: tactile whiskers, nocturnal, feed in dark places
5
Q
3 types of mammal skin glands
A
- eccrine (sweat) glands: not attached to hair follicle, thermoregulation, waste elimination (excess salt, waste, urea)
- sebaceous glands (oil): empty into follicle, lubricating hair and skin
- scent glands: empty at follicle opening, face, legs, anus
6
Q
describe mammal mammary glands
A
- functional MAINLY in female… monotremes: functional in both
- milk ridges: where they grow
- secretory cells form spheres called alveolus
- alveolus form clusters called lobules, empty into milk ducts
- milk ducts empty into mammae (teats, nipples)
- mammae in pairs (even)
7
Q
describe the three middle ear ossciles of mamamals
A
- additional “two” have identical development as reptile jaw bones
8
Q
describe heterodont dentition
A
- incisors: 0-6 per jaw
- canines: 0-2 per jaw… carnivores
- pre molars: 0-8 per jaw
- molars: usually 6 per jaw for chewing
9
Q
characteristics of subclass monotremata
A
- duck billed platypus: venomous spine
- echidnas
- cloaca: common opening for digestive/urine/repro….
- oviparous
- no complex mammae (no teat/nipple), young get milk by licking hair from mom or dad
10
Q
describe subclass marsupalia characteristics
A
- forked reproductive structures (2 uterus, 2 vagina
- young born live in very premature state, crawl into marsupium, where mammae are located (teat)
11
Q
families of marsupalia
A
- didelphidae : oppossums
- dasyduridae: carnivorous marcupials
- macropodidae: kangaroo, wallabies, pademelons
12
Q
characteristics of didelphidae
A
- oppossum
- central america
- 50 teeth
- resistant to pit viper venom… clotting
13
Q
characteristics of dasyuridae
A
- mice, rats, cats, tasmanian devil
- devil facial tumor disease: causes tumor on face/head
- first observed in people in 1996
- 95% population decline by 2020
- transmissible cancer… fighting by biting
- DFTD 1… DFTD 2… tumor in tongue
- thylacine… tasmanian wolf… extinct 1936
14
Q
characteristics of macropodidae
A
- kangaroo, wallabies, pademelons (small)
15
Q
characteristics of eutheria?
A
- placental mammals: provide nutrients
- zona intima (overlapping capillary networks)
- no pouch
- advanced young
