Unit 4 - Reptile A&P And Clinical Techniques

Question 1

Where are tuataras only found?

Answer 1

on islands off coast of new zealand

Question 1

What are the 4 orders of class reptilia

Answer 1

1 crocodylia (alligators and crocs
2. squamata (snakes and lizards
3. chelonian (turtles and turtoises)
4. rhyncocephalia (tuataras)

Question 2

What are the 3 orders of class amphibian?

Answer 2

1. gymnophiona (caecilians) worm/snake like amphibian
2. Anura (frogs and toads)
3. Caudata (salamanders and newts

Question 3

What is unique about reptiles and amphibians metabolism

Answer 3

they are ectothermic or cold blooded
ectothermic animals are unable to generate lg amounts of body heat internally - body temp depends on enviro temp
some lg reptiles can markedly raise body temp by muscular contractions
Ex. leatherback sea turtle swimming, pyhons (shiver when incubating egs)

Question 4

How do reptiles and amphibians thermoregulate?

Answer 4

herptiles - mainyl regulate body temp via behaviour
sun bathing, changing skin color, coiling or uncoiling
less important if in hot enviro

Question 5

What is ectothermy?

Answer 5

related to energy conservation
animal metabolism depends on body temp
allows many herptiles to survive on very small amount of food
depends on access to temps within the preferred optimal temp zone (POTS)

Question 6

What is POTZ?

Answer 6

range of temperature in which the animal can perform all necessary metabolic functions
critical that an ill patient’s environment is at POTS as well as when administering meds
if not, can lead to a no response to treatment, lack of healing, overdose or even death
Preferred optimal temperature zone

Question 7

What do we need to keep in mind about reptile integument

Answer 7

limited subcutaneous space so it is difficult to administer subq injections

Question 8

What is unique about the dermis of reptiles?

Answer 8

dense connective tissue
blood and lympth vessels, nerves and chromatophores (Pigment-containing cells)
chromatophores allow some lizards to change skin color and pattern
osteoderms; bony plates within dermis of some lizards and crocodilians

Question 9

What is uniqe about the epidermis of reptiles?

Answer 9

scales and scutes of reptiles are formed by epidermal folds in most reptiles. vary in size and shape.
epidermis is keratinized

Question 10

What are some other epidermal structures that could be present on a reptile?

Answer 10

crests, tubercles, spines and dewlaps, keels, horns and barbles

Question 11

How is an epidermal plate numbered?

Answer 11

Starting from the head/cervical scute, the outside ring is the marginals. 2nd ring is the pleural scutes and the big scutes along the back is the vertebral scutes.

Question 12

What is ecdysis?

Answer 12

shedding of skin
occurs w/ growth and in response to skin injury
shed in pieces or in one large piece
shed skin: exuvia
controlled by the thyroid gland
cells replicate new epidermis
enzyme containing lymph secreted btw old and new epidermal layers
skin colors dulls; spectacle opacifies
lymph - resorbed prior to ecdysis
mechanical rubbing on objects aids shedding

Question 13

What does dysecdysis mean?

Answer 13

abnormal shedding
usually rom poor husbandry - low humidity, no objects in enviro to rub against, malnutrition and dehydration
can also be due to skin wounds, illness, dermatitis and parasites
fix by correcting problem and a 2 hour warm water bath
if not corrected can lead to dyspnea, dermatitis, future shed issues and loss of toes or tail tips

Question 14

What is unique about the amphibian integumen?

Answer 14

extremely permeable - absorbs water directly from enviro, has drink patches or areas of inc permeability on ventral surfaces
epidermis - single or few layers of keratinized cells - aquatic amphibians - no keratinized cells
Dermis - chromatophores and glands that prod secretions which help protect the amphibian’s skin
Toxic secretions - prod by some glands within dermis and epidermis as defense mechanisms
Dermis - little subq space in salamanders and caecilians (anurans: looser attachments of dermis(more Sq space)
amphibians regularly shed outer layers of epidermis and usually eat the exuvia

Question 15

How might we monitor a reptiles nervous system under anesthetic?

Answer 15

tongue withdrawal, jaw, pedal and tail reflexes are all present
When monitoring depth of anesthesia in reptiles other than snakes, can use corneal and palpebral reflexes
In snakes, tongue withdrawal reflex will be maintained at the surgical plane of anesthesia

Question 16

What is unique about reptile vision?

Answer 16

iris made up of skeletal muscle under voluntary control - Pupilary light reflex not seen, lower lid usually more mobile than upper
Some species of lizards have thin, transparent lower lids to allow for a degree of vision even when lids are closed
nictitans: well developed, mobile in many reptiles

Question 17

Which reptiles don’t have a true eyelid? What do they have instead?

Answer 17

snakes, some lizards
clear, fused scale or spectacle
caecilians eyes - covered w/ skin

Question 18

How is the vision of reptiles?

Answer 18

poorly developed extraocular muscles
except chameleons; eyes move freely and independently of one another

Question 19

What is the tear film

Answer 19

btw cornea and spectacle in sub-spectacular space where tears drain into mouth thru nasolacrimal duct system

Question 20

Does chelonians have nasolacrimal ducts?

Answer 20

no, tears spill over lid margins

Question 21

What is unique about amphibian eyes compared to the rest

Answer 21

often protrube ventrally into oral cavity when animal swallowing

Question 22

What are ossicles? What about the lens? How do they accomodate

Answer 22

scleral bone spresent in most reptiles - except snakes and crocodilians
lens: more fluid in reptiles than mammals (more rigid in snakes)
Chelonians - lens is squeezed thru the pupil
Snakes - lens moves back and forth due to pressure changes within the aqueous and vitreous humors
parietal (rudimentary) eye in some reptiles

Question 23

What is hypovitaminosis A?

Answer 23

common dz for turtle/tortoises
usually from deficient diet
treated w/ vit A (injectable or dietary supplements) - also need to treat and 2nd bact infections

Question 24

What are some possible signs of hypovitaminosis A?

Answer 24

swollen eyelids, loss of appetite and weight, raw skin w/ 2nd bact infections, nasal discharge (runny nose) abnormal development of the eyes in embryos

Question 25

How do snakes hear?

Answer 25

Columella articulates w/ quadrate bone allows snakes to be very sensitive to ground vibrations transmitted thru the mandibles snakes also able to hear aerial sounds

Question 26

What are aural abscesses in reptiles?

Answer 26

middle ear infections common in chelonians can be 2nd to hypovitaminosis A

Question 27

Where does the location of hear lie for chelonians, most lizards, crocs and some lizards, and snakes

Answer 27

Chelonians - on midline just caudal to thoracic girdle, ventral to lungs Most lizards - within thoracic girdle Crocodilians and some lizards - farther back into the coelomic cavity snakes - usually @ junction of the first and 2nd 3rd of the body length - fairly mobile within coelomic cavity

Question 28

What is different about reptiles and amphibians hearts than mammals?

Answer 28

3-chambered heart w/ two atria and one ventricle crocodilians have 4 chambered heart, but not like the mammalian or avian heart no mixing of oxygenated and deoxygenated blood

Question 29

How do we get a HR with reptiles?

Answer 29

difficult to auscultate. May be able to see movement thru skin rate depends on species, size, temp, activity lvl and metabolic fun Lizards - vasovagal reflex induces drop in HR, BP and catatonic state - triggered by applying gentle pressure to both eyeballs tru closed lids lizard recovered w/ cessation of pressure or mild stimulation

Question 30

How do reptiles breath?

Answer 30

reptiles can survive living long periods w/o breathing resp driven by O lvls in blood lizards tend to experience severe resp depression while under anesthetics, so important to admin positive pressure entilation (two to four respo per minutes)

Question 31

What should we know about the glottis of reptiles and amphibians?

Answer 31

most amphbs and reptiles - rostral portion of oral cavity glottis very mobile in snakes; protrudes from mouth to allow respiration during ingestion of prey Paired arytenoid cartilages: border glottal opening; open turning respiration The visible glottis makes it easy to pass ET tube and to avoid trachea when passing a stomach tube for force feeding

Question 32

What is a glottal keel?

Answer 32

present in some snakes - increase volume of vocalizations and makes intubation difficult

Question 33

Can reptiles and amphibians makes vocalizations?

Answer 33

only possible are hissing, grunting, bellowing frogs and toads - vocal sacs arise from trachea no vocal cords

Question 34

How do reptiles breath?

Answer 34

no true diaphragms action of intercostal muscles and parts of axial musculature used for respiration do not restrain too tightly

Question 35

How do amphibians breath?

Answer 35

simple saclike lungs some salamanders have no lungs - cutaneous respiration Pulmonary ventilation results from pumping of buccal cavity and pharynx - gas exchange can also occur across MM of buccal cavity, pharynx and cloaca Gills may also be present, particularly in young amphibians

Question 36

Are reptiles, snakes, crocodiles and adult amphibs carnivorous, omnivorous or herbivorous

Answer 36

reptiles can be carnivorous, omni or herb snakes/crocos/adult amphibs strict carnivores some diets are very specialized

Question 37

What is the oral cavity of snakes and lizards like?

Answer 37

deeply forked tongues function as particle delivery system for vomeronasal organ allow for detection of particle gradients

Question 38

What does the oral cavity of chameleons, turtles and tortoises like?

Answer 38

Chameleons: specialized projectile tongues designed for capturing prey from a long distance - sticky end to stick prey w/ turtles/tortoises - typically thick, fleshy, relatively immobile tongues

Question 39

What does the crododilian oral cavity look like?

Answer 39

imobile tongue attached to intermadibular space muscular flaps from base of tongue and dorsal pharynx allow for opening of mouth while submerged without ingesting or inhaling water

Question 40

Which reptiles has venom glands?

Answer 40

some snakes, lizards - modified salivary gland

Question 41

What is the dentition like of turtle and tortoises?

Answer 41

no teeth, tomia (keratinized beaks), other reptiles - teeth

Question 42

What is the dentition of snakes like?

Answer 42

snakes have 6 rows of teeth, two mandiblar, two max and two on palatine/pterygoid bones snakes w/o venomous fangs called aglyphous snakes

Question 43

What are snakes w/o venemous fangs called?

Answer 43

aglyphous snakes

Question 44

What is the dentition like of amphibs?

Answer 44

most have teeth caecilians and salamanders - both max and mand teeth, palatal teeth in some max dentition present in some anuran species odontoid process - cutting plates on rostral mand of some frogs

Question 45

What is the esophagus of reptiles?

Answer 45

thin and distensible - usually reflects type of prey amphib eso very short and wide, especially in anurans

Question 46

What does the stomach of reptiles look like?

Answer 46

variable size and shape snakes - highly distensible crocs - thick muscle compared to avian gizzard

Question 47

What does the stomach of amphibian's look like?

Answer 47

capable of prolapsing stomach thru mouth used for emptying stomach if they ingest something undesirable gastric prolapse is terminal in dying animals can be seen with some methods of anesthesia

Question 48

Can reptiles and amphibians have foreign bodies

Answer 48

100%

Question 49

Which has a longer intestinal tract? herbs vs carni's?

Answer 49

Herbirvores Snakes have relatively straight int tract

Question 50

Where does hindgut fermentation for digstion occur in reptiles?

Answer 50

in the colon, large and complex in herbivores

Question 51

Where does the site of hindgut fermentation in herbivorous lizards and chelonians occur?

Answer 51

cecae

Question 52

How does the liver in reptiles look like?

Answer 52

large and bi-lobed

Question 53

What is the cloaca?

Answer 53

outflow of GI and urogenital tract three chambers - coprodeum, urodeum and proctodeum

Question 54

What do we need to avoid when injecting into the caudal half of reptiles?

Answer 54

the renal portal system arising from veins of pelvic limbs and tail

Question 55

What is unique about amphibian kidney?

Answer 55

excrete ammonia as a nitrogenous waste product; others excrete urea, some excrete uric acid no ability to concentrate urine urinary bladders and cloacal anatomy similar to reptiles

Question 56

What does the male reptile repro system look like?

Answer 56

males have internal testes loc in dorsal coelomic cavity ductus deferens leads from testes to dorsal wall of the urodeum they possess a copulatory organ such as phallus or paired hemipenes Most also have a sexual portion to the renal tubules - develops in response to high lvls of circulating sex hormones and provides secretions that contribute to the seminal fluid

Question 57

What are the copulatory organs of croc's and chelonians?

Answer 57

Phallus of erectile tissue rising from floor of cloaca

Question 58

What are the copulatory organs of snakes and lizards?

Answer 58

paired hemipenes everted from the tail base thru the vent

Question 59

What does the female repro system look like?

Answer 59

paired ovaries in dorsal coelomic cavity paired oviducts lead to cloaca and end at genital papilae in dorsal wall of the urodeum

Question 60

What is the reptile repro cycle?

Answer 60

In viviparous species, fetuses are retained and nourished in uterine portion of oviduct Oviposition - many reptiles dig nests to lay eggs ◦Without suitable nesting material, female may experience dystocia Chelonians and lizard species may excavate deep holes to deposit eggs

Question 61

What happens after oviposition or parturition, reptiles not involved with care of eggs or offspring

Answer 61

Exceptions - crocodilians protect their nests and young for a period of time following hatching ◦ Pythons and cobras - protect their nests until hatching

Question 62

What is egg incubation

Answer 62

Development and hatching requires proper temperature, humidity, and gas composition of nest Incubation time and temperature varies Reptile eggs should not be rotated during incubation

Question 63

How is sex determined?

Answer 63

Determined by genotype or temperature at which eggs are incubated Sex chromosomes: ◦Females are heterozygous (ZW) and males are homozygous (ZZ)

Question 64

How is sex determined in reptiles?

Answer 64

Some species do not have sex chromosomes ◦ Higher incubation temperatures produce males in crocodilians and lizards ◦ Opposite occurs in chelonians ◦ Temperature range within the nest allows for production of a mixed clutch of hatchlings

Question 65

What are secondary sex characteristics of snakes

Answer 65

Snakes - no real sexual dimorphism In some species, pelvic spurs can be larger in males ◦ Pelvic spurs: remnants of pelvic limbs; provide tactile stimulation to female

Question 66

What are some secondary sex characteristics of chelonians and lizards?

Answer 66

Male chelonians may have concave plastron and more distally located vent ◦ Allows closer apposition of the cloacas when the male mounts the female Some lizards show obvious dimorphism ◦ Example: the male Jackson’s chameleon has three well-developed horns on its face

Question 67

How is sexual dimorphism in amphib repro?

Answer 67

Sexual dimorphism in some species ◦ Poison dart frog males have enlarged toe pads ◦ Large tympanic membranes in some male anurans ◦ Prominent cloacal glands in male salamanders

Question 68

What does amphib repro look like?

Answer 68

Paired gonads in dorsocaudal coelomic cavity Most caecilians (serpentine amphibians) are viviparous Most anurans and salamanders are oviparous amplexus spermatophores

Question 69

What is amplexus?

Answer 69

Amplexus - Male frogs and toads fertilize eggs as they are laid while grasping the female

Question 70

What are spermatophores?

Answer 70

Spermatophores - packets of sperm deposited onto substrate by male salamanders ◦ Picked up by the female salamander’s cloaca ◦ Spermatotheca - pocket in cloaca of female salamanders where sperm can be stored

Question 71

Once eggs are born, what is their life cycle?

Answer 71

eggs usually deposited in or near water some parental care of eggs and/or young in anurans and most salamanders larval anurans (tadpoles) have completely aquatic lives prior to metamorphosis tadpole metamorphosis - usually complete within 90 days - stimulated by thyroid hormones

Question 72

What is unique about snake skulls?

Answer 72

extremely mobile Mandibular symphysis is connected by ligaments that allow jaws to move independently of each other

Question 73

What is tail autonomy?

Answer 73

defensive mechanism - some lizards and salamanders. discarded tail usually continues to wiggle and distract predator species capable of tail autonomy have fracture planes along which tail breaks that have little to no blood loss lost tail can regenerate,regenerative tail still and cartilaginous

Question 74

What is metabolic bone disease in reptiles and amphibs

Answer 74

Caused by an imbalance of calcium, phosphorous and Vitamin D3  Proper diet, temperature and lighting will prevent MBD  Symptoms include swollen mandible, curvature of the tail and possibly the spine and decreased bone density on radiographs.

Question 75

How do we control snakes?

Answer 75

control the head  Grasp just behind the head, then support the rest of the body with your other hand/arm; or allow body to rest on the same arm so one hand is free  Must support at least 2 points

Question 76

How do we control lizards?

Answer 76

depends on the type of lizard  Support the body and give something for feet to rest on  Iguanas – very large tails that can thrash (wear long sleeves); may bite; very fast  Geckos – may lose their tail if handled roughly (avoid handling tail if possible)  Always warn owners of this possibility prior to handling/blood collection

Question 77

How do we restrain chelonians?

Answer 77

support the shell May bite  Can use a block in front of face to keep their heads retracted into shell (ie. Tongue depressor)

Question 78

What are ways to take blood from a snake?

Answer 78

cardiocentesis (only is anesthitized) tail vein

Question 79

How are blood collected from a lizrds?

Answer 79

tail vein

Question 80

How is blood collected in a chelonians?

Answer 80

jug + subcarapacial sinus

Question 81

How do we take rads with reptiles?

Answer 81

Goal is similar views as for mammals for most reptiles  At least one lateral and a VD/DV  Often easier said than done  Sometimes, you have to get creative  Very helpful to have a mobile X-ray tube  Can use dental x-ray for very small reptiles (tiny lizards, pediatrics, etc.)  Often, anesthesia (or at very least sedation) may be required

Question 82

How do we take rads of snakes?

Answer 82

Can manually hold the section you want to X-ray  “Snake in a box” can give a nice whole-body DV view