Mammalogy lecture exam 2

what is measured as volume of oxygen consumed per unit time?

resting metabolic rate

what is measured as oxygen consumed per day?

total metabolic rate

how does metabolic rate increase?

total metabolic rate increases with size, larger animals need more food

what is oxygen consumed/per day/gram body mass, decreases with body mass, smaller mammals need more food per gram of body mass?

mass specific metabolic rate

what is the maintenance of body temperature by means of heat produced inside the body by chemical reactions?

endothermy

what maintain a relatively consistent body temperature?

homeothermy

what means the regulation of body temperature varies?

heterothermy

what means body temperature is regulated in different parts of the body?

regionally

what means temperature of body is regulated at different times?

temporally

why is body temperature maintained?

enhance chemical reactions, increases information processing, enhances neuromuscular system, allows animals to be active in almost any environment

what is the normal body temperature for eutherian “placental” mammals?

36 C to 38 C

what is the normal body temperature for monotremes and marsupials?

30 C to 33 C

what is Heat Production = Heat Loss?

thermodynamic equilibrium

what are properties which influence heat exchange (loss to environment)?

metabolic rate, moisture loss, insulation, absorption of radiation, size, shape and orientation of body, temperature difference of animal and environment

what measures the internal temperature of mammals?

hypothalamus

what means range of temperature within which the metabolic rate is minimal and does not change as ambient temperature increases or decreases?

thermal neutral zone

what means air movement?

convection

how is heat lost to the environment?

radiation, conduction, convection, evaporation

what does this graph show?

higher surface:volume equals more surface to lose heat relative to body size of mammal

what does this graph show?

larger animals consume more per day, smaller animals need to consume more per their body mass

what means races from cooler climates tend to be larger than members of same species in warmer climates, because of the energetic advantage of decreasing surface area:volume, larger mammals have less surface area per volume and benefit from reduced rates of cooling?

bergman’s rule

what reduces thermal conductance using fur or fat, and effectively reduces lower critical temperature?

insulation

what insulates by trapping a layer of air near skin, works well for terrestrial and amphibious mammals, and is not effective if water displaces layer of air?

fur

what means marine and aquatic mammals have blubber, blubber is a thick layer of adipose tissue, up to 40% of mass of ring seals, also insulation?

fat

what means appendages of endotherms in colder climates tend to be shorter than those in warmer climates?

Allen’s rule

what means arteries and veins in extremities are close together, blood from the core warms blood returning from extremities, lower temperature in extremities reduces the difference in temperature between appendage and environment, lower heat loss in environment?

countercurrent heat exchange

what is used by many small mammals to combat cold, effectively decreases surface:volume ratio?

huddling 

what means many small mammals forage in tunnels covered by leaves or snow?

foraging zones

what means move to a milder climate?

migration

what means stay in sheltered location?

reduced activity levels

what means period of inactivity characterized by a reduced metabolic rate and lowering of body temperature?

dormancy

what is generally short term, body temperature 10-22 C, common in bats and shrews?

torpor

what is profound dormancy, lasts weeks, body temperature 2-5 C?

hibernation

what is the cost of hibernation?

large mass loss

which lost the most mass in Wyoming ground squirrels?

adult and yearling males

how much of earth is desert?

35%

how much of body mass of mammals is water?

70%

what is the maintenance of proper internal salt concentrations?

osmoregulation

what are primarily responsible for osmoregulation, rid body of nitrogenous waste?

kidneys

what are the three types of nitrogenous wastes in vertebrates?

ammonia, urea, uric acid

what is very toxic, requires a lot of water to dilute and dispose of, no energy cost, and found in fish and amphibians?

ammonia

what is not as toxic, water soluble, can be concentrated more than ammonia, requires energy to produce, primary product in mammals?

urea

what is not as toxic, not very soluble in water, requires very little water to expel, energetically costly, used by birds and reptiles?

uric acid

what produce feces 2.5 times drier and rats and also assimilate 90% of digested food?

heteromyids

what produce concentrated milk?

desert mammals

what does carbohydrates + O2 = CO2 +H2O mean about animals?

use metabolic water

what are most water requirements met by in desert living mammals?

prey

what is a major mechanism employed by mammals to reduce body temperature, water absorbs a great deal of heat when it changes state, water may be scarce so this may be limited?

evaporative cooling

what is the loss of water and salts from eccrine glands (not in rodents and lagomorphs)?

sweating

what is rapid shallow breathing that increases evaporation from respiratory tract, do not lose salts, cools brain, may cause respiratory alkalosis?

panting

what is the spreading of saliva on limbs, tails, chest etc (common in rodents and lagomorphs)?

saliva spreading

what prevents water loss through respiration, inhaled air passes over moist tissue and is warmed and humidified, nasal tissues are cooled by this evaporation, during exhalation, moisture in returning warm, saturated air from lungs condenses in nasal passages, water is conserved?

respiratory heat exchange

what is an almost hairless region that allows heat loss?

thermal windows

what is a period of dormancy in response to hot or dry conditions (common in rodents and also occurs in marsupials and others)?

estivation

to avoid high temperature almost all rodents of North American deserts (except sciurids) are what?

nocturnal and fossorial

what does this graph show?

subsurface temperature in deserts

what have small daily fluctuations in body temperature, 36 C in early morning and 39 C by midafternoon?

hydrated camels

what has their daily variation in temperature triple, 34.5 C at night and 40.5 C during the day, enables them to lose heat at night when cool, does not require sweating, saves 4.5 L water a day?

dehydrated camels

what can tolerate a water loss of 30% (most other mammals die at 15%), and rehydrate quickly, concentrate urine and reabsorb water from feces, fur insulates and thermal windows allow heat loss, have numerous sweat glands?

camels

what detect radiant energy in form of light, is the primary sense in humans?

photoreceptors

what is the reflective layer in the eye that reflects light back to the retina, improves night vision, and is responsible for eye shine (nocturnal mammals)?

tapetum lucidum

what are light sensitive in the eye?

rods

what are color sensitive in the eye?

cones

which animals have more rods?

nocturnal

which animals have more cones?

diurnal

what is hearing by?

mechanoreceptors

what are the external ears that are unique to mammals called?

pinnae

what kind of sound is used by elephants and is too low for humans (< 20 Hz)?

infrasound

what kind of sound is used by bats and is too high for humans (> 20 kHz)?

ultrasound

where do bats form their sound for echolocation, notice when pulse is altered, can detect size, shape, distance, texture and movement, can discriminate echo delays as short as 70 millionths of a second, and resolve objects as small as the width of human hair?

larynx

where does the echolocation pulse originate in toothed whales, is directed by disc shaped skull and focused by fluid filled melon, and is received via lower jaw and channeled through fluid filled sinus to inner ear?

nasal sac in forehead

what type of receptors are taste and smell?

chemoreceptors

what is generally not a primary sense, important in diet selection?

taste

what is well developed in most mammals, important in locating danger, finding food and mates, communication, etc, reduced in whales and some higher primates?

olfaction

what is through mechanoreceptors, includes vibrissae, many have specialized receptors in snouts and lips, highly evolved tactile receptors in digits(especially primates), tactile systems highly developed in mammals that burrow?

touch

what are used to detect small electrical fields produced by prey, can be found in star nosed mole and platypus?

electroreceptors