Mammology Test 1

What are the soft anatomy characteristics of mammals

Lactogenic, Viviparous, Pelage, Sudoriferous and sebaceous glands, endothermic, four-chambered heart with active left aorta, anucleate erythrocytes, muscular diaphragm, facial muscles, expanded cerebrum and carabellum

What is the medulla in hair

inner most layer, may be absent in lighter hair

what is the cortex in hair

the strength, moisture, color, texture

what is the cuticle of hair

outermost, hard/shingle- like, overlaping cells

hard anatomy characteristics 

double occipital condyle, atlas/axis complex, tympanic bone present, 3 ear ossicles, jaw bones to dentaries, secondary palate, respiratory turbinates

what did the malleus form from

articular

what did incus form from

the quadrate

what did the stapes form from 

ancestral 

dental characteristics 

lack placental teeth, diphyodont, thecodont, heterodont, multicuspate 

diphyodont

two sets of teeth/ deciduous

thecodont

teeth deeply set in bony sockets in jaw

epiphysis

end of long bone that initially grows seperately from shaft

Fossil aging

relative, radiometric (carbon)

Synsapsida

1 cranial fenestra ~ 320 mya

Therapsid

~270 mya, enlarged temporal fenestra, partial evolving secondary palate, 

cynodonts

~ 250 mya, responsible for adaptive radiation post dinosaurs, complete secondary palate, enlargement of dentary,

What is Q-A to D-S

Quadrate and Articular to Dentary and Squamosal

suite of characteristics

when mammals turn into mammals based off of hard and soft anatomy

key characteristic

Q-A to D-S jaw joint

Suite of Characteristics 

D-S, Heterodont, Posture, well developed inner ear, occlusal surface on teeth, c1 c2 vertebrae, 2 occipital condyles, regionalized vertebrae and thoracic ribs

How did mammals survive extinction of dinosaus

endotherms, dentition, masseter, secondary palate, anucleates

Procumbent incisors 

teeth stick out from skull

insectavore adaptations

dentiton, short alimentary canal, lack cecum, close nostrils and ears, corse fur or scaley, long snouth, front claws, venemous saliva, , tactile organs on face or modified digits,

carnivore adaptations 

strang jaws/skulls/teeth, carnassial teeth, sharp incisors/canines, enhanced jaw adductor, no cecum, short GI,

carnassial teeth

4th upper pre-molar , and first lower molar

vampire bat adaptation

straw teeth, sanguiniverous, anticoagulant

herbivory adaptation

canines reduced/absent, broad molars, long intestine, no sellulose enzymes, rumination, cecum,

suborder ruminantia

cattle, bison, sheep, goats

ruminants oddballs

artiodacyls, kangaroos, colobus monkeys

masticate

saliva initiates digestion

hindgut

cecum, no regurgitation

foregut pros

more efficient (microorganism help), Protein from microorganisms, detoxify alkaloids

hindgut fermentation pros 

good internal storage, microorganisms not digested, more generalist 

rumination allows

leave and chew cud

hindgut fermentation cons

toxic chem into bloodsteram, less effecient cellulose digestion,

gnawing animals

large incisers, diastema, cecum and colon, simple stomach

convergent evolution

2 things evolving to be similar

integument

skin

epidermis

3 leyers( stratum corneum (alpha- keratin) , granulosum, basale

dermis

collagenous connective, cushion, nerves, glands, folliculs, bleed and bruise 

hypodermis

adipocytes, energy reserve, thermoregulation

glands

mucosal - mouth nose 

sebaceous (oil) - hair follicles 

Ceruminous - ear ear wax

sudoriferous - sweat 

specialized regions of stratium corneum

calluses, claws, hair, hooves

Vibrissae

face whiskers

guard hairs

large hair on atleast one part of the outside (spine bristle and awn)

nape as it relates to hair

direction of hair

3 types of under fur / under hair

wool, fur, velli (soft hair to keep the babt warm

pheomelanin

reddish/ yellow pigment

eumelanin

black and brown pigment

countershading

dark dorsal, light ventral 

cryptic coloration

Camouflage

disruptive coloration

stripes/spots (disorienting)

molt

post juvenile molt, annual, seasonal,

True horn

boney core, made of keratin, doesnt fall off

hair horns

clumps of keratin, no fall off

pronghorn

boney core, sheath of keratin, but shed sheath

antler

boney projection, falls off, velvet, grows from frontal bone,

the functions of vertebrate integument

water, secretions/microorganisms, abrasion, pigmentation, temperature regulation, respiratory gases absorption, sensory, communication, 

saltatorial

jumping

cursorial

run

glissant

gliding

scansorial

climbing

bipedal hopping, ricochetal

side to side hopping

saltatorial adaptations

long hindlimbs, large hing limp muscluature, stiffening of spine, elastic ligaments, long tail

cursorial adaptations 

distal limb bones longer, feet get longer, reduction/loss of clavicle, increased spinal flexion, increased amount of joints

scansorial

larger ribcage, clavicle, friction pads, prehensile organs, reduced lumbar

brachiation

swinging

fossorial adaptations

short, strong limbs, reduced eyes, fusiform, lack external ears, improved smell, more vibrissae, long incisors

swimming adaptation 

fully aquatic, flippers or rudders (front) , vestigial or flippers (rear), fusion of c1 and c2, robust vertebrae, long body, webbing (semi aquatic) 

patagium 

air foil, protection, insulations, neonates 

europatagium

patagium on tail

lift

laminar flow, camber (curve of wing), angle of attack, leading flap edge (streamlined) 

heat gain =

heatloss - Tb 

how do you gain heat as a mammal

1. solar radiation 

2. infrared/from environment 

3. metabolism 

how do you lose heat

1. infrared/ heat

2. convetional heat loss 

3. evaporative (panting, licking, sweating) 

2 states of thermoregulation classification

1. homeotherm

2. poikilotherm 

2 mechanisms of thermoregulation classification

1. endotherm 

2. ectotherm 

lower critical temperature

when you must find other ways to stay warm (shiver, metabolic)

lower lethal temp

hypothermic

4 individual behavioral responses to cold

1. piloerection 

2. movement 

3. thermal window close

4. movement 

3 species physiological evolutionary responses to cold 

1. increase body size (bergmann’s) 

2. increase subcutaneous fat 

3. molt (grow thick dense underfur)

loop of henle (active transport)

salt and water regulation

water economy

effective kidneys, concentrated urine and feces, diet

rete mirabile

wonderful net for counter current heat exchange around brain 

temp regulation in hot environments

1. evaporative cooling 

2. cool brains

3. estivation

4. avoid high temp

5. body size

6. decrease metabolic rate

7. appendages (Allens)

ultrasonic and infrasonic

above 20 k and below 20 k htz

endocrine glands

cells that secrete their products directly into bloodstream

hypothalamus

master gland, forebrain, controls pituitary

pituitary gland

base of brain

2 structurally lobes of pituitary

adenohypophysis and neurohypophysis

adenohypophysis (anterior)

1. growth hormones

2. prolactin

3. thyroid stimulating

4. adrenocorticotropic 

5. follicule 

6. luteinizing hormone 

7. melanocyte 

neurohypophysis via infundibulum 

1. antidiuretic 

2. oxytocin 

2 parts of adrenal gland

cortex and medulla

thyroid gland distributes

T3 and T4

Parathyroid

4 glands on posterior - controls calcium

pancrease

exocrine and endocrine, glucagon and insulin

islets of langerhans (in pancreas)

alpha cells- glucagon

beta cells- insulin 

diurnal

active during day

crepuscular

dawn and dusk

circannual rhythms

1. coat

2. hibernation

3. reproduction