Reptiles

  • 4 categories

    • Order chelonia

      • turtles, torts

    • order Squamata

      • lizards and snakes

    • Order sohenodontia

      • tuataras

    • crocodilia

      • crocodiles, charial, caimans, alligators

  • Chelonians

    • Understand true turtles are marine turtles

    • box turtles: fresh water turban

    Integument

    • Epidermis: made of keratin

      • thick layers: scales, ornamental structure

      • thin: present at joints

    • dermis: mostly connective tissue

    • ecdysis: shedding skin (scales)

      • Snakes: one piece if in healthy condition

      • lizards, chelonians, crocodilians: multiple pieces

    • Snakes:

      • Scutes: ventral scales

      • spectacle: scale covering cornea

      • rattle: unshed skin

      • few skin glands: 2 scents glands

    • lizards

      • parietal eye does not form images

        • third eye

      • chromatophores

        • allows them to change colors

    • chelonians

      • Carapace: dorsal shell

      • plastron: ventral shell

      • scutes: superficial keratin layer: each is named

Musculoskeletal

  • Single occipital condyle

  • lizards

    • tail autotomy

  • chelonians

    • carapace: derived from ribs, vertebrae, skin

    • Plastron: derived from clavicles, abdominal ribs, skin

    • Bridge: bony connections

  • Snakes

    • Vestigial pelvic appendages

    • jaw disarticulation

    • Very prominent right Palatino vein

      • all of right vascular system

Cardiovasc

  • Heart:

    • three chambers - 2 atria, 1 ventricle

    • atrial septum complete

    • ventricles communicate- functional separation

    • bilateral aortic arches

    • crocodilians have 4 chambers

  • Position

    • lizards and chelonians: cranial in thorax

    • snakes: mobile, but approx ¼ distance from nose to vent

  • ventral abdominal vein

  • renal portal system

    • venous return from himblimbs and tail may go directly to kidneys

    • not wekk understood

    • err on the side of caution

      • may effect drug kineticswell

      • admin. injectbaale meds cranial to kidneys

Gastrointestinal

  • venom gland: derived from salivatory gland

  • forked tongue: transfer chemical stimuli to vomeronasal organs in the roof of mouth

    • teeth: squamates and crocodilians: replaced throughout life

      • chelonians: beak, NO teeth

  • Gallbladder present

  • urinary bladder:

    • chelonian and many lizards

    • water storage

      • resorption of water, changes in lizards

      • urinalysis may not accurately indicate renal failure

Reproduction

  • Male

    • squamates: paired hemipenes

    • chelonians and crocodilians: single penis-like organ

    • no function in urination

  • Female

    • oviparous: egg-laying

    • viviparous: live-bearing

  • squamates

    • femoral pores: larger in males

    • probe hemipenes: snakes

  • chelonians:

    • males: cloacal opening farther from shell

    • males: longer tail

    • Concave plastron: tortoises, box turtles

    • red iris: male eastern box turtles

    • aquatic males: long front claws

  • Iguanas

    • males will be larger, more defined head, and more orange in color

penile prolapse

  • causes:

    • urolith, FB, infection, overengorgment