Chapter 26- Chordata (Reptiles)

Amniotic Egg

eggs with 4 extraembryonic membranes

Amnion

encloses embryo in fluid, cushions and provides aqueous medium for growth

Allantois

stores metabolic waste

Chorion

surrounds contents of egg, highly vascularized

Yolk Sac

nutrient storage

Rib Ventilation

fill lungs by expanding the thoracic cavity using costal (rib) muscles or pulling the liver posterior

Keratin

makes up the skin

Chromatophores

pigment cells

Dessication

drying out

Scutes

sections of the shell

Osteoderms

raised, bony plates located in dermis beneath scales (crocodiles and alligators)

Ammonia

toxic waste in urine

Uric Acid

less toxic excretory waste

Salt Glands

excrete excess salt, in head region

Jacobson’s Organ

2 pits in roof of mouth lined with olfactory epithelium in snakes

Carapace

dorsal shell

Plastron

ventral shell

Diaphragm

major muscle of respiration

Pits

in pit vipers, have nerve endings to sense warm-bodied heat

Ectotherms

environment determines temperature

Parietal Eye

light sensitive organ on the top of head

Amniotes Characteristics

Amniotic eggs, Rib Ventillation, Thicker/More waterproof skin

Layers of an Amniotic egg

Amnion, Allantois, Chorion, Yolk

Variety in Amniote skin and what skin is made of

Crocodilian: scales remain through whole life

Lizards/Snakes: keratinized epidermis replaces old epidermis

Turtles: scutes

Crocs/Lizards: osteoderms

How is reptile respiration different from amphibians

reptile lungs have more surface area, respiration in cloaca or pharynx also occurs, and cutaneous respiration in sea snakes/turtles

how is reptile skin specifically used

protects from physical trauma and lipids prevent water loss

adaptions in reptile jaws

efficient for crushing/gripping prey, larger jaw muscles, muscular and mobile tongue to move food in mouth, snakes have loosely attached jaws and skull bones for large prey

circulatory system seen in reptiles vs amphibians

Reptiles: right atrium receives deoxygenated blood, left receives oxygenated, blood doesnt mix as much as amphibians but pressure sensitive valve allows some mix

Amphibians: deoxygenated blood from body returns to heart, mixed with oxygenated blood from lungs

how have Reptiles adapted to conserve water

excrete nitrogen waste as uric acid, which is less toxic than ammonia or urea so it requires less water for dilution

unique adaptions in reptile nervous system

small brain with a larger cerebrum, they can learn simple tasks

Testudines

turtles and tortoises

Squamata

Lizards and Snakes. Auria means lizards. Diverse group

Serpentes

Snakes

Sphenodonta

2 species in New Zealand, so rare from non-native species, slow growth and slow reproduction

Crocodilia

Alligators and Caimans, Crocodiles, Gharials. order of semiaquatic, predatory reptiles

Pulmonary Circulation

deoxygenated blood from heart to lungs, returns oxygenated blood to heart

Systemic Circulation

oxygenated blood from heart to muscles/body organs and brings deoxygenated blood back to heart

Renal Circulation

blood going to the kidneys

Hepatic Circulation

blood going to the liver

Coronary Circulation

blood circulation supplying the heart

Internal Nares

allow closed mouth breath

Glottis

opening to respiratory system

Gullet

opening to digestive system from mouth

Stomach

starts breakdown of food

Pyloric Sphincter

muscle at end of stomach that controls passage of food

Small Intestine

does most of digestion, absorbs almost all nutrients

Duodenum

upper portion of small intestine closest to stomach

Ileum

part of small intestine

Liver

produces bile and filters toxins

Pancreas

makes insulin

Large Intestine

or colon, where undigested waste passes through to the cloaca

Gall Bladder

green, in liver, stores bile

Aveoli

air sacs in lungs to increase surface area

Testes

make sperm

Vas Deferens

Transports sperm to the cloaca

Kidney

Filter uric acid from blood and dilute it to urine