Turtle Dissection

Scientists believe other land vertebrates evolved from BONY LOBE-FINNED fish

TURTLE LATIN meaning KINGDOM _____________ PHYLUM ____________________________ SUBPHYLUM ___________________________ CLASS _______________________________ ORDER _____________________________ ANIMALIA CHORDATA VERTEBRATA “backbone” REPTILIA “to creep or crawl” CHELONIA “tortoise”

INTEGUMENT THICK, DRY, SCALY SKIN Contains KERATIN (protein) LIPIDS & PROTEINS make it water tight

ADVANTAGES over thin, moist Amphibian skin 1.WATER TIGHT - Keeps them from drying out on land 2.TOUGH PROTECTION – - prevents injury, keeps out germs, - prevents wear & tear on skin when crawling around on land

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SHELL IS LIVING PART OF BODY Expanded ribs form shell Can regenerate damaged scutes Growth rings tell age

Limbs at right angles to body

Location of Pelvic and Pectoral girdles allow turtle to pull limbs into shell

Nictitating membrane Tympanic membrane External nares Only reptiles with NO TEETH

Claws on feet

VENT

WHAT SEX IS IT? FEMALES: MALES: Short tail Longer tail Vent closer Vent farther from body

MALE PLASTRON slightly CONCAVE to fit on top of female CURVE OF PLASTRON FEMALE PLASTRON slightly CONVEX to make more room for eggs

INTERNAL FERTILIZATION Increases chances of sperm and egg meeting Image from: Penis deposits sperm inside female’s body

GLOTTIS – respiratory opening

PHARYNX GULLET GLOTTIS INTERNAL NARES

Ectothermic Body heat comes from surrounding environment Slow metabolism/low activity in cold places “cold-blooded” EX: All invertebrates, fish, amphibians, reptiles

ECTOTHERMIC ADVANTAGES: Slow metabolism means you can survive on 1/10 the food as a same size endotherm DISADVANTAGES: Can’t to live in extremely cold places (NO reptiles in Arctic) Can’t keep up max activity level for long

Endothermic “warm-blooded” Create own body heat FAST metabolism allows for: high activity for extended time ability to live in variety of environments EX: Birds, Mammals

PELVIC & PECTORAL GIRDLES inside ribs PERICARDIAL MEMBRANE Covers & protects heart

EXCRETORY URINARY BLADDER

Image from: Vent

LIVER Makes BILE Stores GLYCOGEN Stores VITAMINS Processes TOXINS including nitrogen waste for kidneys

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GALL BLADDER Stores BILE

STOMACH Add ACID; Start DIGESTION; Grind & mash food

MESENTERY

PANCREAS In mesentery near first loop of small intestine Makes TRYPSIN, INSULIN, GLUCAGON

SMALL INTESTINE Duodenum Ileum LARGE INTESTINE (Also called COLON)

CLOACA

SPLEEN Make, store, recycle RBC’s

TURTLE HEART 3 CHAMBERS 2 atria; 1 ventricle Sinus Venosus & Conus Arteriosus are smaller PARTIAL SEPTUM: begins to divide ventricle into two sides Image from: BIODIDAC

FISH

Sinus venosus RIGHT Atrium Ventricle Conus arteriosus      Lungs Body organs LEFT Atrium          FROG/TURTLE CIRCULATION

REPTILES Can bypass lungs to save energy Holding breath underwater Hibernating When want to warm up quickly

ENDOCRINE Glands that make hormones that control other body organs THYROID: located above heart Makes hormones that control heart rate, blood pressure; cell development and growth PANCREAS controls blood sugar levels

TRACHEA & ESOPHAGUS

BRONCHI

LUNGS HAVE ALVEOLI FROG LUNGTURTLE LUNG Increase surface area for more gas exchange Images modified from:

REPRODUCTIVE MALEFEMALE Images modified from: Vent

OVARY- make eggs OVIDUCT- add shells transport to cloaca

Image from: BIODIDAC EPIDIDYMIS –sperm mature here; add tails TESTES – make sperm

INTERNAL FERTILIZATION Increases chances of sperm and egg meeting Image from:

DIRECT DEVELOPMENT Image from:

SEX is determined by TEMPERATURE of NEST Image from:

Types of Reproduction

Ways offspring enter world OVIPARITY- Reproductive tract encloses egg in a protective shell Eggs deposited outside body to hatch Nourishment comes from egg EX: Most reptiles,birds & a few mammals (monotremes)

VIVIPARITY- No shell around egg Eggs retained in body Nourished by mother through placenta Offspring are born alive Ex: Mammals & some reptiles Ways offspring enter world

OVOVIVIPARITY- Egg surrounded by protective shell but kept in body until just before hatching or can hatch inside female Nourishment comes from egg not mother Ex: Some reptiles (snakes) Ways offspring enter world

OVI PARITY OVOVIVI PARITY VIVI PARITY SHELL? NO SHELL? Embryo grows? Food comes From? Seen in? SHELL OUTSIDE EGG Birds, Reptiles, Few mammals NO SHELL INSIDE MOTHER Mammals, few reptiles SHELL INSIDE EGG Reptiles

AMNIOTIC EGG

NERVOUS COMPLEX BRAIN DORSAL SPINAL CORD (Spine is fused to shell)

TURTLE BRAIN BIGGER CEREBRUM than same sized amphibian Image modified from:

WHAT’S IN REPTILES? Internal fertilization- (Penis) increases chances of sperm finding egg allows addition of protective shell Amniotic eggs- can lay eggs on land now; better protection for embryos Partial septum- better separation on high/low oxygen blood

WHAT’S IN REPTILES? Other kinds of reproduction- (OVOVIVIPARITY; VIVIPARITY) increases chances for offspring survival Control over Pulmonary circulation can shift blood away from lungs to body when needed Dry, scaly skin better able to live on land

WHAT’S IN REPTILES? Nitrogen waste = uric acid AMMONIA UREA URIC ACID Least toxic form; Needs least water to dilute conserves water Bigger cerebrum- “smarter”; more complex behaviors

WHAT’S IN REPTILES? LUNGS have ALVEOLI increases surface area for more gas exchange Sex depends on temperature of eggs- can change sex based on population needs