Lecture 24 Reptiles

reptiles

Raptiles evolved from _______-like ancestors

amphibian

Amniotic eggs did what for reproduction

Allowed reproduction without needing water, enabling reptiles to colonize diverse environments

Skin for reptiles

Waterproof, scaly skin to reduce water loss and protect from harsh environments

Lungs in reptiles

Are more efficient for air breathing

What is the Amniotic egg

-Protective membranes & porous shell around embryo

-Shell may be hard or leathery & waterproof

-Egg is fertilized internally, before shell is formed

Ectothermic

Body temperature controlled by the environment

Skin characteristics

Dry, watertight skin covered by scales to prevent desiccation (water loss)

Integumentary system

Is heavily keratinized with little subcutaneous space and has many ______ and some have bony plates called _______

chromatophores, osteoderms

What are scales?

-Keratinized skin that provides protection and prevents water loss

-many different types of scales

-can be used for identification

Ribs

typically short in the neck and long in the trunk

turtles-

snakes-

crocodiles-

Turtles – fused to carapace

Snakes – long and curved

Crocodiles – Gastralia are NOT ribs

what do some boids like pythons and boa contrictors have?

pelvic remnants with bony components of their skeletal system

Muscle systems:

tetrapod reptiles are similar to_____

mammals

Muscle systems:

Snakes, how is the muscle system different than other animals

Much longer and more numerous than in many other animals

epaxial/ hypaxial muscles are more important

Nervous system

Most _____ and legless ____ are missing CN ___

snakes, legless lizards, XI

What is Jacobson’s organ:

critical for detecting scents, odors, and chemical information from the reptile’s environment.

Reptiles flick tongue to capture chemical signals within the environment

Respiration:

What do reptiles breath with since they lack a diaphragm

Breathing happens completely by the intercostal muscles

Lack a true partition between the pleural and peritoneal cavities,

Turtles cant move intercostal muscles due to their shell so how do they breath

Use flank muscles to breath

label turtle respiratory system

Turtles: Enternal respiratory system

Cloaca tissue allows for what?

gas exchange

Digestive track of turtle:

similar to mammals until the end (cloaca)

Some reptiles have converted salivary glands into ______ glands

poison

label turlte

Reptile repro

most are asexual, but most are?

sexual

egglayers

cloacal transfer

Copulatory organ

Hemipenes in snakes and lizards

-can protrude

Turtles and crocs have a penis as a thickening on floor of cloaca.

In male snakes, hemipenes become engorged with lymph fluid rather than whole blood as in mammals

female repro

Hearing

specialized in subterranean life

Lack of many _______ error components

Highly sensitice to ______ frequency

Snakes and turtles are more sensitive to ____ based sound waves than ______ based

external

lower

earth, aerial

label color regions

Supercilaries

Temporals

Post labials

ear opening

supralabials

infralabials

What chambers are present in a three chambered heart

two atriums

one ventricle

alligators have pseudo 4 chambered heart

valve that can be closed and split the ventricle

sinus venosus

Large thin-walled and bilobed chamber on the dorsal side of the heart covering both the auricles

found in the fetus of mammals, but gets absorbed into the right atrium.

formed by fusion of several veins

gather venous blood from different parts of the body

Pacemaker shift

mixed oxygenated blood

Combined ventricle allows for mixing of oxygenated blood from lung and less oxygenated blood from the body

Which is reptile/ amphibian heart and which is mammal heart

Thermoregulation

lack the ability to control their own temperature

hypothalmus processes thermal information

controlled by behavioral changes

blood shunting

controlling temp

can alter blood flow to increase or decrease heat in body

da fuq