The Systems of Reptiles

Comprehensive vocabulary flashcards covering the anatomical systems, sensory organs, and physiological processes of reptiles as described in the lecture notes.

Four major reptile groups

The distinct categories recognized in veterinary science consisting of Crocodiles, Snakes, Lizards, and Turtles.

Beta keratin

The stiff material in reptile scales that makes them durable and resistant to water loss.

Alpha keratin

The more pliable material in reptile scales that enables the scales to move.

Osteoderms

Body plates in the skin beneath the scales found in crocodilians and some lizards, which may fuse with the skull to form a rigid cap.

Ecdysis

The process by which lizards and snakes periodically slough or shed their skin after it stops growing.

Chromatophores

Specialized cells containing pigments that allow many reptiles to change color in response to hormones, nerves, light, or temperature.

Pheromones

Substances whose smell elicits specific behavior in others of the same species, often secreted by specialized pores or glands.

Carapace

The upper shell of a turtle, which is a living structure that fuses to the skin with over $50$ bones, primarily the ribs and vertebrae.

Plastron

The lower shell of a turtle, formed from the fusion of the clavicles, interclavicles, and abdominal ribs.

Scutes

Keratin shields that overlap the bone of the turtle shell to protect the bone seams beneath.

Tail autotomy

The capacity of a lizard to break its tail along a fracture plane of cartilage to escape a predator, followed by the regrowth of a usually weaker tail.

Velum palatinum

The soft palate in crocodilians with folds that meet the tongue, allowing the animal to breathe through its nares while the mouth is open underwater.

Tracheal lung

An extension of the vascular portion of the lung into the dorsal trachea, found in some snakes.

Epiglottic cartilage

A rigid plate in the front of the glottis that some snakes use to produce a hissing sound.

Protrusible

A term describing tongues, such as those of the chameleon, that are able to project forward out of the mouth.

Renal-portal system

A type of circulation where blood from the tail and hindlimbs goes directly through the kidneys before entering general circulation.

Parietal eye

Also known as the third eye, a skull projection in some reptiles like lizards that is connected to the pineal organ and helps sense light.

Nictitating membrane

A specialized membrane that covers the crocodilian eye when it is submerged underwater.

Spectacle

A protective eye cap formed by the embryonic fusion of the eyelids that covers the cornea in snakes.

Vomeronasal organ

Also called Jacobson’s organ, a sensory structure used to supplement the olfactory system by receiving pheromonic communication.

Metanephric kidney

The form of kidney possessed by reptiles, which lacks a loop of Henle and therefore cannot concentrate urine.

Hemipenes

Paired vascular sacs in male lizards and snakes that act as a penis during copulation and are stored inverted in the tail base.

Parthenogenesis

Reproduction without fertilization, occurring in some lizards and the blind Asian Brahminy snake.

Islets of Langerhans

Clusters of cells scattered throughout the pancreas that produce insulin and glucagon to regulate carbohydrate metabolism.