Herpetology Exam 2

Front 1

What are the 3 ways herps can gain water? What are the 3 ways herps can lose water?

Back 1

Gain:

1) Liquid water

2) preformed water (from prey)

3) metabolic water (produced as a side effect of ATP production)

Loss:

1) evaporation

2) urine/feces

3) salt glands

Front 2

What is rain-harvesting behavior?

Back 2

In reptiles, described positioning the body in a certain way so that water can flow down the hydrophobic scales into the reptile's mouth. Ex: water flows through the scale-hinge joints of turtles.

Front 3

What's the difference between freshwater amphibians and saltwater amphibians as far as urine and water balance mechanisms go?

Back 3

1) Freshwater amphibians struggle to keep excess water OUT of the body, so they produce dilute urine.

2) Marine amphibians struggle to keep water IN the body, so they allow solutes to accumulate in the body and decrease the water loss gradient.

Front 4

What is a Pelvic Patch and how does it work?

Back 4

Pelvic patch= patch of skin on terrestrial amphibians which is specialized for water absorption.

-Low water levels increases # of aquaporins in pelvic patch, leading to increased water absorption via diffusion into the body.

Front 5

Pelvic patches are under ___________ control.

Back 5

Hormonal. (Specifically, AVT/arginine vasotocin, similar to our ADH hormone)

Front 6

True or false: the stratum corneum of amphibians has less keratin in it than reptiles.

Back 6

TRUE, so they're less water-proof

Front 7

What are the glands that amphibians can have that allows them to stay moist and prevent water loss?

Back 7

1) mucous glands

2) lipid glands (less common)

Front 8

In some amphibians, what is "cocooning"?

Back 8

Making/shedding layers of skin and mucous that builds up over time that seals off the skin.

Front 9

True or false: as far as respiratory water loss goes, there aren't really any physiological adaptations to help amphibians and reptiles. However, there are behavioral adaptations.

Back 9

TRUE (example: moving into the shade)

Front 10

What are the 3 ways that vertebrates have evolved to get rid of nitrogenous waste?

What's the efficiency/characteristics of each method?

Back 10

1) Ammonia production.

-gets rid of 1N, highly water-soluble, highly toxic

2) Urea production.

-gets rid of 2N, highly soluble, nontoxic, harder to produce.

3) Uric acid production

-gets rid of 4N, harder to produce. Insoluble in water (good for animals who need to retain water)

Front 11

As far as getting rid of nitrogenous waste goes, what kinds of animals produce:

1) Ammonia?

2) Urea?

3) Uric Acid?

Back 11

1) Ammonia = produced by aquatic animals.

2) urea = produced by mammals, turtles, some terrestrial amphibians.

3) Uric acid = found in birds, (desert) reptiles (that white stuff in poop)

Front 12

What kinds of reptiles tend to have salt glands?

Back 12

Marine reptiles (sea turtles, saltwater crocs, sea snakes, marine iguanas)

Front 13

What are 2 examples of behavioral adaptations that frogs do during the rainy versus dry season to conserve water?

Back 13

dry season: frogs ball up to decrease amount of water lost

wet season: frogs go out at night when it rains and sit in such a way that only the toes touch the surface water.

Front 14

True or false: reptiles can do long-term water balance, but it's more difficult for amphibians.

Back 14

TRUE

Front 15

What are 2 examples of reptilian long-term water balance?

Back 15

1) Allowing solute concentrations to build up until it rains, then they get rid of it.

2) Tortoises can go for months without drinking and months without urinating.

Front 16

How do sea snakes drink water?

Back 16

Freshwater accumulates on top of the salt water and the snakes drink this.

Front 17

What's the difference between an ectotherm and an endotherm?

Back 17

Ectotherm = gains heat from environment.

Endotherm = generates internal heat.

Front 18

What factors can affect the radiation absorbed by an animal's surface? (4 examples)

Back 18

1) intensity of radiation

2) surface area of animal

3) view factor (proportion of surface area getting direct exposure)

4) absorptivity of animal's surface)

Front 19

Infrared radiation flows down a gradient; so, if the animal is warmer than the environment, it loses heat and vice-versa.

What are 3 factors that can affect infrared radiation?

Back 19

1) temp difference

2) area exposed

3) infrared emissivity

Front 20

As far as Infrared Emissivity goes, what's the difference in dorsal versus ventral scales on reptiles (in general)?

Back 20

-dorsal scales = matte, good at absorbing/emitting infrared radiation.

-Ventral scales = shiny, smooth, poor at absorbing/emitting IR radiation.

Front 21

What are 3 factors can affect the heat gained/lost by an animal from Convection (air/water movement)?

Back 21

1) temperature difference

2) surface area

3) convective coefficient

Front 22

What is Heliothermy?

What's an example of one reptile that practices this?

Back 22

the behavior of some reptiles of getting heat from the sun.

Ex: Texas horned lizard: gradually pulls body out of sand in the morning to expose body to sun so it can get to the activity range of temperature. Midday, it takes on too much heat so it changes behavior to lose heat (panting, cloacal cooling, burrowing).

Front 23

What are the 3 kinds of orientations heliotherms can do to change their exposure to the sun?

Back 23

1) Neutral orientation (animal is flat)

2) positive orientation (animal angles back toward the sun to increase heat gained)

3) negative orientation (animal angle back away from the sun to minimize heat gain)

Front 24

What happens during the process of thermoregulatory changes in color?

Back 24

The distribution of melanin in melanophores is altered.

-clumping the melanin into capsules = animal is lighter.

-dispersing the melanin = animal is darker.

Front 25

What is cloacal cooling?

Back 25

A type of LE (heat lost/gained by condensation/evaporation) used by some lizards.

Front 26

How do some toads get around the problem of losing heat thru evaporation while basking?

Back 26

1) Toad clumps!

2) They stay near running water but sit on a really hot rock

Front 27

What is Thigmothermy?

What's an example of a reptile that practices it?

Back 27

Practice of primarily getting heat through conduction.

-Ex: some embryos will change position in the egg shell depending on the heat source location

Front 28

What is kleptothermy?

Give an example of a reptile that does this?

Back 28

Kleptothermy = "stealing" heat from endotherms.

-Ex: sea kraits hang out in birds nests

Front 29

What is the Preoptic nucleus?

Back 29

Part of the midrbain that deals with temperature. Triggers behavioral changes to modulate body temperature in heliotherms and thigmotherms.

Front 30

What is an example of a physiological mechanism of thermoregulation in marine iguanas?

Back 30

Changing the distribution of heat through vasoconstriction and vasodilation in the body.

Front 31

What is an example of a physiological mechanism of thermoregulation in leatherback turtles?

Back 31

They generate heat through the constant digestion of jellyfish.

Front 32

What is an example of a physiological mechanism of thermoregulation in snakes?

Back 32

snakes like pythons can do muscular thermogenesis (they contract the muscles to generate heat). This works because they're relatively big.

Front 33

What are the 2 basic sites/categories of gas exchange?

Back 33

1) pulmonary (lungs)

2) non-pulmonary

-skin

-gills

-pharynx

-cloaca

Front 34

What must a site in the body have in order to perform any kind of gas exchange?

Back 34

You need a vascularized area (lots of blood vessels)

Front 35

What is the method of gas exchange of choice for the plethodontids (lungless salamanders)?

Back 35

Buccopharyngeal gas exchange

(also cutaneous, to some degree)

Front 36

What are 4 examples of cutaneous gas exchange in amphibians?

Back 36

1) hellbender

2) lake Titicaca frog

3) African hairy frog (develop filaments during the breeding season)

4)Newts (develop filaments during breeding season)

Front 37

What are gills made up of?

Back 37

thin, vascularized sheets of tissue

Front 38

What kinds of gas exchange do softshell turtles use?

Back 38

Buccopharyngeal and cloacal gas exchange

Front 39

What are cloacal bursae?

What kinds of reptiles have it?

Back 39

Pouches in the cloaca of pleurodira (side-necked) turtles that are lined with papillae to perform gas exchange.

Front 40

What kind of ventilation (positive or negative) do amphibians use?

Back 40

Positive-pressure ventilation

Front 41

describe the 3 steps of positive pressure ventilation?

Back 41

First, it's important to know that the buccal cavity and lungs are separated by a glottis.

1) Expand buccal cavity by dropping floor of mouth (air in)

2) Glottis opens --> elastic recoil (deoxygenated air in lungs forced out and mixes with oxygenated air from mouth)

3) Nostrils close and frog forces oxygenated air into the lungs.

Front 42

What is negative-pressure ventilation?

Back 42

Creates a vacuum inside lungs to suck air into them.

Front 43

What are the 2 steps (in general) for negative-pressure lung ventilation?

Back 43

1) Inspiration: intercostals expand thoracic cavity and lungs to suck in air like a bellows.

2) Intercostals relax, leading to elastic recoil which forces air out.

Front 44

Why do lizards have a problem with locomotion and breathing at the same time?

Back 44

The same intercostal muscles used for ventilation are also used for locomotion.

Front 45

How do varanids (monitors) get around the problem of locomotion while breathing?

Back 45

They fill up the gular cavity with air and swallow it into the lungs while moving.

Front 46

Why do pregnant viviparous species tend to have low activity levels?

Back 46

Because their lungs are being pressed upon, so they can't get as much gas exchanged.

Front 47

The single lung that's used in snakes is split into 2 divisions. What are they and what do they do?

Back 47

1) Vascular lung (gas exchange happens here)

2) Saccular lung: stays inflated and acts as a bellows to ventilate the vascular lung.

Front 48

How does ventilation/gas exchange happen in crocadylians?

Back 48

1) Lungs are connected to the liver via diaphragm.

2) Diaphragm pulls on liver --> pulls lungs --> inflation.

3) elastic recoil deflates lungs

Front 49

What about turtles' bodies pose a unique challenge to ventilation and gas exchange compared to other reptiles?

Back 49

Unlike other reptiles, turtles can't change the shape of the thorax.

Front 50

How does ventilation happen in turtles?

Back 50

Inguinal and transversus abdominis muscles are attached to the posterior limiting membrane and pull it down, pulling the lung down and expanding it.

Axial and shoulder muscles pull the posterior limiting membrane back to where it was, allowing exhalation.

Front 51

CO2 and O2 molecules can get through calcified eggs, but H2O can't.

What membrane allows gas exchange in reptilian eggs?

Back 51

The Chorioallantoic membrane.