Squamates

What is the primary function of the heavily keratinized epidermis in snakes and lizards?

Prevents water loss and provides protection

What are gastropeges in snakes?

Single ventral scales important for locomotion

What are the 4 types of movement in snakes?

Lateral undulation, rectilinear movement, sidewinding, and concertina movement.

What is intromission?

The act of a male inserting his hemipenes into the female's cloaca during mating.

How often do most snakes typically shed?

2-4 times per year

What gland controls ecdysis in reptiles?

Thyroid gland

Where is the vomeronasal organ in snakes and lizards?

An olfactory organ in the rostral maxilla

How many dental arcades do snakes typically have?

Six

What type of dentition do snakes have?

Modified pleurodont

What is the function of fangs in venomous snakes?

Venom delivery

Where is the pancreas located in snakes?

On the duodenal mesenteric border

What is the primary function of the snake's colon and cloaca?

Water conservation

What type of dentition do lizards typically have?

Acrodont or pleurodont

What is the difference between acrodont and pleurodont dentition in lizards?

Acrodont teeth are fused to jaw ridges, pleurodont teeth sit in grooves

What replaces the eyelids in snakes?

A transparent scale called the spectacle or brille

What unique sensory organ do some snakes possess for detecting infrared radiation?

Pit organs

How does the pit organ work?

By sensing temperature differences between the snake's environment and its prey, allowing for accurate hunting in darkness.

How do snakes detect airborne vibrations without an external ear?

Through the quadrate bone connected to the columella

What is the parietal eye in lizards and what is it’s function?

A light-sensitive organ on the top of the head that detects changes in light and dark, helping regulate circadian rhythms and thermoregulation.

Where is the heart typically located in snakes?

In the cranial third of the coelom

What is the preferred site for venipuncture in snakes?

The ventral tail vein

How do lizards ventilate their lungs?

Primarily using intercostal muscles

What is unique about the snake's left lung?

It's often reduced or absent

How can gender be determined in snakes?

Through probing, popping, or observing sexual dimorphism

Where are the testes located in male snakes?

Dorsal in the coelom, at 65-82% of the snout-vent length

What is the function of the sexual segment in male squamates?

It enlarges during reproductive activity

How do female squamates store sperm?

In seminal receptacles in the oviducts

Where are the kidneys located in snakes?

In the dorsocaudal coelom, at 75-96% of the snout-vent length

Do snakes have a urinary bladder?

No, they lack a urinary bladder

What is the function of osteoderms in some lizard species?

Provide dermal armour

What is the function of femoral pores in some lizard species?

Scent marking and gender determination

What is the primary adaptation of marine iguanas for salt excretion?

Salt glands

How many chambers does a reptile heart have?

Three (two atria, one ventricle)

What is unique about the chameleon's tongue?

It can be twice the body length and is used for prey capture

What is the function of the dewlap in some lizard species?

Display and communication

How do geckos adhere to surfaces?

Using microscopic setae on their toe pads

What is the function of the snake's forked tongue?

Collects chemical particles for the vomeronasal organ

What is the primary function of the conus papillaris in lizard eyes?

Nourishes the retina

How do pit vipers detect their prey in the dark?

Using heat-sensitive pit organs

What is unique about the skull of snakes compared to other reptiles?

It's highly kinetic with independently movable bones

How do some lizard species change color?

By manipulating pigment-containing cells called chromatophores

What is the function of the snake's glottis being located far forward in the mouth?

Allows breathing while swallowing large prey

How do desert-dwelling lizards prevent water loss through their skin?

By having a thick, scaly epidermis

What is the function of the bifurcated penis (hemipenes) in male snakes?

Allows mating from either side of the female

How do some arboreal snakes move through trees?

Using concertina locomotion

What is the function of the prehensile tail in some lizard species?

Aids in climbing and balance

How do some squamate species regulate their body temperature?

Through behavioral thermoregulation, such as basking or seeking shade