Mammalogy Exam 1

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Mammal
-endothermic, regulates temp
-mammary glands
-viviparous
fossorial
underground
arboreal
tree dwelling
myrmecophagous
ant/termite eating
saltatorial
hopping
lactogenic
milk producing
viviparous
live birth
double occipital condyle
on back of skull, allows for attachment to axis. Better range of motion for head
atlas/axis complex
modified head rotation
tympanic bone
within inner ear
better hearing
Malleus, incus, stapes
3 ear ossicles
dentary bone
reduced jaw bone
nares
nostrils
respiratory turbinates
folds inside naval cavity, producing more surface area. Neutralizes temp of inhaled air
thecodont
teeth in a socket
diphyodont
two sets of teeth
monotremes
egg laying mammals
metatherians
marsupials
eutherians
placental mammals
Early therapsids
developed into cynodonts
D-S jaw joint
Dentary to squamosal joint. Identifying characteristic in mammals.
Morganucodonts exhibited it first
heterodont dentition
different kinds of teeth. Unique to mammals
Endothermy consequences
-need constant supply of energy
-require efficient food processing
-require cardio-pulmonary efficiency
cardio-pulmonary efficiency
-enucleate red blood cells
-separation of oxygenated and deoxygenated blood
-4 chambered heart
-muscular diaphragm
-thoracic ribs
-respiratory turbinates
morganucodonts
-small animals
-large nasal cavity
-developed inner ear
-very large eye sockets
-expanded dentary, D-S joint
- small articular
- no auditory bullae
-tricuspid molarity
-diphyodont
-possible vibrissae
Angiosperms
diversification coincided with mammal diversification
Phylogenetic mammal origins
synapsids
therapsids
cynodonts
prototheria (monotremes)
metatheria
eutheria
types of teeth
incisors
canines
premolars
molars
brachydont
short crown, long roots
hypsodont
long/high crown, shorter roots
bunodont
complete covering of enamel (humans)
lophodont
ridges of enamel (rodents)
selenodont
crescent shaped ridges of enamel
carnassial teeth
occlusion btw 4th upper premolar and 1st lower molar
diastema
gap btw incisors and molars
loss of teeth
posterior incisors lost first, anterior premolars lost first, posterior molars lost first
layers of skin
epidermis
dermis
hypodermis
epidermis layers
1. stratum corneum
2. stratum granulosum
3. stratum basale
stratum corneum
top layer of epidermis
contains keratin,
stratum granulosum
where keratins starts to be produced
stratum basale
where new cells are created
dermis
collageous connective tissue
connects dermis to hypodermis
cushions body from stress
nerves, follicles, and glands in this layer
hypodermis
contains adipocyte
energy storage, thermoregulation
mucous or salivary glands
in the mouth, starts digestion, lubricates food
sebaceous glands
oil glands, near hair follicles
ceruminous glands: ear wax
sudoriferous glands
sweat glands, primates have a high number of these
scent glands
modified sebacious glands
mammary glands
compound alveolar glands
unguis
hard outer material, dead cells on nails/hooves/claws
subunguis
softer inner layer of nail, live cells with blood supply, nerves
vibrissae
whiskers, recognize changes in air current and when objects get closer to face
spines
guard hair, think porcupine
bristles
guard hair, manes like lion and horses
awns
outer coat of hair, thick hair, guard hair
wool
under-fur, animals do not have guard hair
fur
soft undercoat of dogs, cats etc.
velli
baby animal fur
hair morphology
-medulla
-cortex: where the color is
- cuticle
-follicles
-errector pilli
pheomelanin
produces yellows and reds
eumelanin
produces browns and blacks
albanism
lacking production of melanin
melanism
greater than average production of melanin
countershading
dark on top, light on bottom
ex. great white
cryptic coloration
same color as surroundings
disruptive coloration
breaks up outline of body
ex. leopard, zebra, tiger
molt/shedding
replacement of definitive hair
-post juvenile molt: shed villi
-annual molt: shed winter coat
-seasonal molt: molts to blend with habitat
bovine horn
true horns, keratinized sheath
pronghorn
keratinized sheath that is shed and regrown every year
hair horns
aglutinized hair, not shed
rhino
antlers
dermal bone attached to frontal bone, shed and regrown every year, coated in velvet
baleen
whales have this instead of teeth, allows for filter feeding
type of modified hair
ischial callosites
hardened skin on ischium
tori
callouses on carnivore feet
ambulatory
walking
cursorial
running
plantigrade
tarsals, metatarsals, and phalanges on ground
digitigrade
only phalanges on ground
unguligrade
stand on tips of digits or nails
scansorial
climbing
volant
flying
glissant
gliding
ricochetal
bipedal hopping
saltatorial adaptations
-long back legs
-large back limb muscles
-reduced # of digits
-elastic ligaments in hind legs
-long tail for balance
cursorial adaptations
-elongated distal limb bones
-loss/reduction of clavicle
-increased spinal flexibility
scansorial adaptations
-friction pads
-claws
-prehensile organs
-suction cups
-expanded ribs
-elongated thoracic region
-reduced lumbar region
-some have long arms (gibbons)
swimming animals
-must overcome
-pressure/form drag
-fictional drap
-spindle-shape optimized form
semi-aquatic adaptations
-long sleek bodies
-swim using limbs
-webbed digits
fully aquatic adaptations
-modified limbs
-front flipper or rudders
-hind vestigial or flippers
axial skeleton in whales
-reduced cervical vertebrae
-fusion of atlas and axis
-more robust vertebrae
-cartilagenous flukes
gliding adaptations
-patagium
flying adaptations
-elongated phalanges and metacarpals
-must generate lift
-relies on laminar flow
-cambar: curve of the wing
-must overcome thrust
-keeled sternum: more muscular attachments
insectivory
eating insects
-adapted dentition
-short alimentary canal
-often modified digits
carnivory
meat eating
-strong jaws, skull, and teeth
-sharp incisors and canines
-carnassial teeth
-enhanced jaw adductor muscles
-short alimentary canal
-no caecum
sanguinivory
blood eating
-groove in lip
-anticoagulant in saliva
-sharp incisors
-short alimentary canal
herbivory
plant eating
-reduced or absent canines
-diastema
-broad molars
-long intestines
-foregut fermentation of hindgut fermentation
foregut fermentation
ruminants
-4 stomach compartment
1.rumen
2. reticulum
3. omasum
4. abomasum
-more efficient, microorganisms are digested, they are high in protein
-detoxify alkaloids
hindgut fermentation
-horses, tapirs, rhinos, lagomorphs, rodents
-very long caecum
-one chamber stomach
-no regurg.
-do not digest microorganisms
-can process large quatities
gnawing herbivores
-do not ruminate
-simple stomach, large caecum, long large intestine
coprophagy
feces eating
-allows animals to digest undigested materials
granivory
grain eating
folivory
leaf eating
frugivory
fruit eating
nectivory
nectar eating
gumivory
gum (tree sap) eating
mycophagy
fungus eating
omnivory
-versatile dentition
-short digestive system, short caecum
-diverse num. of species
binocular vision
-eyes in front of face
-allows them to judge distance and depth
-primates and predators
peripheral vision
-larger range of vision
-prey animals
-can see movement on all sides
night shine
tapetum lucidum reflects light back on retina in nocturnal animals
ultra sonic
animals that can hear above the human range
subsonic
animals that can hear below the human range
human hearing range
20 hZ to 20.000 hZ
olfaction
allows for communication and territorial marking
5 general tastes
sweet
salty
bitter
sour
unami
taste
allows animals to determine nutritional value of food
mammalian nervous system adaptations
mammals have expanded cerebrum and cerebellum, improved memory and problem solving
hypothalamus
-master gland
-part of forebrain
-controls action of pituitary gland
pituitary gland
at base of brain, attached to hypothalamus
-2 parts
- adenohypophysis
- neurohypophysis
adenohypophysis (anterior)
-growth hormone
-gonad hormones
neurohypophysis (posterior)
antidiuretics and oxytocin
adrenal gland
-on top of kidneys
-2 parts
-adrenal cortex
-adrenal medulla
adrenal cortex
mediates steroids and K ions
-aldosterone
-cortisol
-gonadocorticoids
adrenal medulla
fight or flight
-epinephrine
-norepinephrine
thyroid
regulates metabolism
-thyroxine
-triiodothyronine
-calcitonin
parathyroid
located on the thyroid
-parathyroid hormone: absorbs bones, raises blood Ca
pancreas
-glucagon
-insulin
circadian
-pattern over 24 hours
diurnal
active during the day
nocturnal
active during the night
crepuscular
active near sunset and sunrise
biological rhythms
main driver is photoperiod
circannual
patterns over a year
-regulates seasonal changes, hibernation, breeding seasons
ultradian
patterns within periods less than 24 hours
-often observed in rodents
heat gain
-solar radiation
-infrared heat
-produced heat
heat loss
-infrared
-convectional heat loss
-evaporative heat loss
homeotherm
constant body temp, regulation of temp
(endotherms)
poikilotherm
variation of body temp under environmental conditions (ectotherms)
endotherm
maintenance of relatively constant body temp by produced heat
ectotherm
determination of body temp comes from sources primarily outside body
Baso metabolic rate (BMR)
metabolic rate when at rest
thermo neutral zone
temp of outside environment that doesnt require chance in metabolism in order for organism to maintain body tmep
zone of metabolic regulation
outside temp is above/below TNZ, metabolism must be adjusted to maintain body temp
lower lethal temp
ambient temp is too low for body to be able to maintain constant temp
lower critical temp
ambient temp where an organism must get out of bmr
thermogenesis
production of heat
piloerection
erection of hairs, gives a thicker layer of insulation
huddling in groups
decreases surface area exposed to environment
close thermal window
smaller loss of heat
increase body size
Bergmans Rule
lower surface area to body mass ratio
fat
white adipose fat and brown fat can produce heat
regional heterothermy
some areas of the body have different temps than the core temp of organism
countercurrent heat exchange
heat transferred btw cappillaries/veins and arteries that are next to each othe so that cold blood is not going to main organs; cold blood goes to extremities
kidney water conservation
bowmans capsule extracts H2O from blood
loop of henle regulates salt, water and toxins entering kidney
water economy in hot environments
-very efficient kidneys
-thick, viscous urine
-very dry feces
-eat food with more water content
evaporative cooling
sweating to cool surface temp of body
panting
saliva spreading
cool brains
rete mirabile: network of blood vessels behind nasal cavity that cools blood before going to brain
insulation
thicker hair, traps heat
longer appendages
Allen's rule
more surface area allows for more heat dissipation
estivation
lower metabolic rate
nocturnal/fossorial animals
able to avoid high temps
dioecious
2 sexes to reproduce
mammals are dioecious
testis
sperm produced here
path of sperm
testis
epididymus
ductus (vas) deferens
urethra
penis
scrotum
where testes are housed, external scrotum allows for cooler testes
testes location
varies among species
-abdominal: monotremes, anteaters, armadillos
seasonally descended
scrotum descends depending on the season and temperature during the season
permanently descended
scrotum permanently outside body
leydig cells
cells in testes that produce sperm
semen
only 75% sperm, seminal fluids added along the way
baculum (os penis)
bone in penis in some mammal species
female reproductive system primary functions
-produce egg
-receive sperm
-gestation and nurishment
-raise young
female reproductive system main structures
-pari of ovaries
-oviducts (fallopian tubes)
-uterus
-cervix
-vagina
ovaries and ova
1 - 2 million follicles, each produce an egg
ovulation
release of an egg, egg than moves into the fallopian tube
ectopic pregnancy
egg implants in fallopian tubes
fertilized ovum
-fertilization occurs in fallopian tubes
-will implant in uterus
-ruptured follicle will become corpus luteum -- produces progesterone
uterus
-where fertilized egg implants
-expands with growing embryo
monotreme uterus
-has a cloaca
-urogenital sinus
-eggs develop in tubes
didelphous uterus
-in many marsupials
-2 lateral canals (males have bifurcated penis)
-urogenital sinus
duplex uterus
-2 uteri, 2 cervix
-lagomorphs and rodents
bipartite uterus
-2 uteri, 1 cervix
bicornuate uterus
-Y shaped uterine horns
simplex uterus
-no uterine horns
-primates
-1 uterus, 1 cervix
placenta
-connects to umbilical cord, provides nutrients and waste exchange
-connects to mothers system
-anchors fetus to uterine wall
-produces hormones that regulate organs
choriovitelline placenta
-in marsupials
-lack villi, weak connection to uterine wall
-enlarged yolk sac
-inefficient
-produced underdeveloped young
-short gestation period
chorioallantoic placenta
-villi enhance nutrient exchange, strong connection
-small yolk sac
-produces developed young
-eutherians
estrus
receptive period before and after ovulation
spontaneous ovulation
environmental factors affect hormone change, usually polyestrous mammals
induced ovulation
breeding behavior induces ovulation, better chance of fertilization
gestation
period between fertilization and parturition
delayed fertilization
ex. hibernating bats
-delay happens after copulation
-sperm is stored until female is ovulating
delayed development
reduced growth rate of embryo following implantation
-delay happens after implantation
delayed implantation
postponement of embedding of blastocyst in uterine lining
-delay happens after fertilization and before implantation
embryonic diapause
-doesn't always happen
-animals read environmental and body conditions to determine if they are sufficient enough to allow for fetus growth
-same sequence as delayed implantation
lactation
phase of growth and what kind of animal dictate constituents of milk, number of teats indicates average number of young
teats
monotremes are the only mammals that lack teats, instead they secret milk onto their hair and young lick it off
Allen's Rule
Longer appendages allows for more heat dissipation in hotter environments
Bergman's rule
Increased body size means a smaller surface area to mass ratio, allows for less heat loss in colder environments
eccrine glands
pass through cell membrane
holocrine glands
entire celll
apocrine glands
cell ruptures
functions of vertebrate integument
-physical protection
-hydroregulation
-temperature regulation
-synthesis
-communication
-sensory reception
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