Reptiles

Question 1

What is the cause of most reptile diseases in the UK?

Answer 1

Poor nutrition and husbandry e.g. Think lizard with calcium problems in bones

Question 2

What does stress do?

Answer 2

Reduces immune response and predisposes to infection

Question 3

Describe the taxonomy of reptiles.

Kingdom? Phylum? Class? And various orders?

Answer 3

Animalia
Chordata
Reptilia
Chelonia, Squamata, crocodilia, rhynocephalia

Question 4

What do you need to keep crocodilia spp as pets

Answer 4

A dangerous/wild animal licence

Question 5

What is the only reptile belonging to the group rhynocephalia

Answer 5

Tuatara

These are endemic of nz. They have a pronounced third eye involved in circadian and seasonal cycles

Question 6

Which is the largest order?

What animals are in this order?

Answer 6

Squamata

Snakes. Lizards and worm lizards

Question 7

Reptiles are ectothermic (rely on external sources of heat). They have a slower metabolism. They utilise mainly aerobic respiration but can switch to anaerobic if extra energy is needed. What’s the consequence of this?

Answer 7

Build up of lactate. Little ok as dealt with by buffering system but too much leads to lactic acidosis

Question 8

What 4 things does metabolism depend on?

Answer 8

Diet and feeding behaviour
Size
Body temperature
Species

Question 9

Describe thermoregulation in reptiles

Answer 9

Thermoregulation is controlled by the hypothalamus, specifically the pre optic nucleus.
Blood passes from the heart to the hypothalamus via the internal carotids.
Appropriate behavioural mechanisms can then be undertaken.
Heliothermy= direct solar radiation
Thigmothermy= contact with warm object

Question 10

What other things are altered for thermoregulation?

Answer 10

Heart rate
Vasodilation/constriction
Lungs bypassed by shunt to reduce heat loss by evaporation
Behavioural means- position, shape, burrowing, pigmentation

Question 11

What are UVA and UVB important for?

Answer 11

A- stimulates reproductive behaviour in lizards

B- important for calcium metabolism

Question 12

What factors triggers hibernation?

Answer 12

Temp
Size/weight
Photoperiod
Reproductive cycle
Food availability

Question 13

Why is hibernation important?

Answer 13

Triggering reproduction activity

Maintaining normal thyroid activity

Question 14

Describe the process of hibernation?

Answer 14

Withhold food for 2 weeks before to ensure nothing in gut that will ferment, reduce temperature, check and weigh regularly. Hibernate from November through to march. When waking up, bathe in water water to encourage drinking and expulsion of faeces.

Question 15

Give some facts about the skeletal system of reptiles

Answer 15

Not Haversian canal system
Bone healing slow
When dealing with fractures must correct nutritional deficiencies
Chelonions and snakes have modifications to their axial and appendicular skeletons
Chelonions, snakes and crocodiles never stop growing- growth plates never shut
Lizards growth plates do shut, but later on

Question 16

What happens when plasma ca levels are unsufficient to support neuromuscular activity?

Answer 16

PTH mobilises calcium from the bones
This is why you see lizards with metabolic bone disease
On X-rays bones appear clear rather than white

Question 17

Name the three skull types, how do they differ? What species have each?

Answer 17

Anapsid = no temporal fenestrate = Chelonia

Synapsid = 1 subtemporal fenestrae

Diapsid= supra and subtemporal fenestrae= snakes, lizards, crocs, tuatara

Question 18

How would you describe a snakes skull?

Answer 18

Kinetic

Has moveable joints between upper and lower jaw

Question 19

What does ecdysis mean?

Answer 19

Skin shedding

Question 20

Name the layers of the skin compared to normal

Answer 20

3 layers opposed to 5: stratum corneum, intermediate layer, stratum germinativum, stratum basale

5: cats love gravy so bad= corneum, lucidium, granulosum, spinosum, stratum basale

Question 21

What controls ecdysis?

Answer 21

The thyroid

Question 22

What does dysecdysis mean?

What is the usual cause?

Name 2 things ecdysis requires

Answer 22

Failure to shed

Husbandry

Humidity and shedding surface

Question 23

What tube would you use to take reptiles blood?

When doing a smear, you’d use edta- why would you not use this with reptikes?

Answer 23

Lithium heparin

EDTA can lyse RBCs

Question 24

How many chambers are there in the reptile heart?

Except which? Which is this similar to?

Answer 24

3

Crocodiles have 4= same as mammals and birds

Question 25

There are 2 Atria and 1 ventricle, but the ventricle is split into 3 by muscular ridges, name the parts

Answer 25

Cavae arteriosum, pulmonae and venosum | Think veins, arteries and lungs

Question 26

What two things keep mixing of oxygenated and deoxygenated blood in this ventricle to a minimum?

Answer 26

Timing of contractions Division of chambers

Question 27

What happens when reptiles breath hold?

Answer 27

Pressure in lungs increases Therefore blood bypasses the lungs and passes into aortic arch This has implications during anaesthetics

Question 28

Which veins drain the hindlimbs?

Answer 28

External Iliac veins

Question 29

The external iliac veins drain into the _________, this goes directly into the ________. What 2 things need to be considered because of this?

Answer 29

Renal portal vein Kidney Drugs injected can't be nephrotoxic and may be flushed out before they have even had a chance to take effect

Question 30

Most reptiles have an easy to visualise larynx and paired lungs- except which? Which lung is Vestigal?

Answer 30

Snakes Left is Vestigal!

Question 31

The functional unit in mammals is called the alveoli- what's the functional unit in reptiles called? Describe the lung itself

Answer 31

Faveoli Lung is a simple sac structure with a reticular pattern of ridges which increases surface area for gas exchange (Ridges to inc SA cf to alveoli)

Question 32

Name 3 other things that the respiration system aids with except respiration

Answer 32

Vocalisation Display (think jurassaic park) Buoyancy

Question 33

Name the 3 phases of respiration

Answer 33

Expiration, inhalation and rest phase (can last long periods)

Question 34

What is the controlling factor for respiration?

Answer 34

Temperature With increased temperature, oxygen demand increases and pulmonary resistance reduces

Question 35

What things help with prehension? What glands are found in the oral cavity? Which species have no teeth?

Answer 35

Tongue, jaw etc. Mucus secreting to help snakes swallow whole, some glands are modified into venom glands Chelonions

Question 36

The structure of the reptile tooth is the same as mammals e.g. Cementum/enamel etc. How is it different thought?

Answer 36

No periodontal ligament

Question 37

Name and explain the three tooth types

Answer 37

Acrodont= water dragon/chameleons= attached to surface, easily damaged Pleurodont= attached to medial aspect of bone,lateral eroded away= snakes etc. Thecodont= crocodiles only. Like mammal tooth but no periodontal ligament

Question 38

What's the process called by which teeth are replaced throughout life

Answer 38

Polyphydonty

Question 39

The egg tooth is used for rupturing the leathery egg and rupturing membranes, what's it called in chelonions and crocodiles compared to snakes and lizards?

Answer 39

Egg caruncle Modified Maxillary tooth

Question 40

Chelonions don't have teeth, how do they eat?

Answer 40

Hard keratinous beak

Question 41

Name 3 things that effects rate of digestion

Answer 41

Temp (stops if drops below 7degrees) Diet (herbivore diet takes longer to digest) Health status (decreased rate if poorly)

Question 42

Do reptiles have a gall bladder?

Answer 42

Yes

Question 43

What does the reptiles GI tract end in? Name the parts

Answer 43

Cloaca Copradeum, urodeum, proctodeum (remember cup, faeces, urine/repro, common)

Question 44

What's the end product of protein catabolism?

Answer 44

Uric acid

Question 45

Where do you find the kidneys?

Answer 45

Caudal coelomic cavity

Question 46

Name 3 things reptile kidneys don't have that mammals do

Answer 46

Renal pelvis Renal pyramids Loop of Henle (They have the tubules- nothing else!!!)

Question 47

Do reptiles have a bladder?

Answer 47

No!!! Except chelonions!!!! They do!

Question 48

Name some ways reptiles conserve water

Answer 48

Not much by kidneys but instead use: Cloaca reflux Reduced GFR Renal portal system

Question 49

Eggs are water proof but what do they allow?

Answer 49

Some gas exchange

Question 50

Females can have babies ages later when kept alone. This is because sperm can be stored for long periods of time. Is fertilisation external or internal?

Answer 50

Internal

Question 51

In oviparous species, what's the benefit of the yolk?

Answer 51

Nutrient for neonates

Question 52

What does viviparous mean?

Answer 52

Eggs hatch internally

Question 53

During development, which 2 things determine the sex of the reptile?

Answer 53

Sex chromosomes and temperature

Question 54

Deprive where you would find the testes?

Answer 54

Internally The right one is near the vena cava The left one is near the adrenal gland These increase in size during the breeding season

Question 55

How do penis' differ in reptiles?

Answer 55

Lizards and snakes have paired extracloacal hemipenes which are everted during mating Chelonia have a single phallus, this develops from the proctodeum (last part) and everts during mating (Remember double: snakes & lizards)

Question 56

What's a common problem with reptile penises?

Answer 56

Prolapse

Question 57

Like birds, reptiles have many follicles on their ovaries. Name the parts of the oviduct

Answer 57

``` Infundibulum Uterine tube Isthmus Uterus Vagina ```

Question 58

Name the three phases of the repro cycles

Answer 58

Quiescent Vitelline Gravid

Question 59

It's important to realise that sperm is _________

Answer 59

Stored for years

Question 60

Describe the snakes eye

Answer 60

Fused transparent eyelids called spectacle. | Light is detected through the eye and the pineal gland is involved

Question 61

How the the eye of a snake differ to a mammal?

Answer 61

The iris is skeletal muscle rather than smooth muscle

Question 62

How do snakes detect pheromones? | What other species has this?

Answer 62

Vomeronasal organ | Horses

Question 63

How do snakes feel?

Answer 63

They have receptors on their tongue and oral epithelium

Question 64

Which reptile has external eyes? | What do the others have?

Answer 64

Crocodiles The others have a short eustatian tube and an outer margin tympanic membrane

Question 65

Describe travel of vibrations in the ear

Answer 65

Down short Eustachian tube to tympanic membrane Vibrates the membrane Which vibrates the 1 Middle ear bone called the collumella To the quadrate bone of the skull

Question 66

What does the third eye look like?

Answer 66

Not an eye, it's a modified scale, located on the top of the head between the two lateral eyes

Question 67

Chelonia have 2 neck shapes, name them, and how do they differs?

Answer 67

Pleurodira= side neck= 3 bends= can't draw head into shell Cryptodira= 2 bends= head can go into shell

Question 68

Are Chelonia heliothermic or thigmothermic

Answer 68

Heliothermic They bask in the sun

Question 69

Name the three muscles which give lizards a very strong jaw

Answer 69

Depressor mandible Pterygoideus External adductor muscle