The Cold-Blooded Vertebrates

Chapter 13BBody Systems in

Vertebrates

Circulatory System

• All vertebrates have blood

• Blood circulates due to pumping action of heart

Circulatory System

• Blood:–Brings food to cells–Transports oxygen and

carbon dioxide–Other substances taken

to and from cells

Circulatory System

• Oxygenated blood has abundant oxygen

• Deoxygenated blood has given most of its oxygen to body cells and has taken on carbon dioxide

Circulatory System

• Vertebrate hearts contain chambers

• Blood is pumped in one direction only–Arteries–Veins

Circulatory System

• Fish have two-chambered hearts

• Most reptiles and adult amphibians have three-chambered hearts

Circulatory System

• Birds and mammals have four-chambered hearts–Two chambers pump

oxygenated blood–Two chambers pump

deoxygenated blood

Evidence of Design

• Irreducible complexity–Heart–Gills (or lungs) for gas

exchange–Blood–Muscles, nerves, and

hormones

Evidence of Design

• Irreducible complexity–Blood vessels–Respiratory system–How could the cells

survive before everything else developed?

Respiratory System

• Supplies body with oxygen• Carries away carbon

dioxide waste• Gills are used by

vertebrates living in water–Some invertebrates, too

Respiratory System

• Gills–Capillaries–Exchange of carbon dioxide

in blood for oxygen in water–Deoxygenated blood

becomes oxygenated blood

Counter current flow

Respiratory System

• Lungs–Air chambers–Capillaries–Deoxygenated blood

becomes oxygenated blood–Breathing–Diaphragm

Nervous System

• Central nervous system (CNS)–Brain–Spinal cord

Nervous System

• Peripheral nervous system (PNS)–Nerves• Cranial nerves• Spinal nerves

–Sensory receptors–Sensory organs

Nervous System

• PNS receives stimuli• PNS carries impulses

from CNS to various muscles and organs

• Reactions are controlled in the CNS

Digestive System

• Mouth –Some mechanical and

chemical digestion in certain animals

• Esophagus• Stomach–Some chemical digestion, but

mostly mechanical digestion

Digestive System

• Small intestine–Digestive enzymes for

chemical digestion–Site of diffusion for digested

nutrients–Helped by accessory organs

Digestive System (Accessory Organs)

• Liver–Bile–Gallbladder

• Pancreas

Digestive System

• Large intestine–Water absorption

• Anus

Digestive System

• Groups based on the food they eat:–Herbivores–Carnivores–Omnivores

Excretory System

• Kidneys• Ureter• Urinary bladder

The Cold-Blooded Vertebrates

Chapter 13CFish

Fish

• Ectothermic• Live in water

Fish Anatomy

• Propulsion–Swim bladder

• Closed circulatory system–Two-chambered heart–Blood vessels

Fish Anatomy

• Scales• Lateral line• Most fish reproduce by

spawning–A few give birth to live fish

Fish Groups

• Jawless fish–No jaws, scales, or paired

fins–Lampreys and hagfish

Fish Groups

• Cartilaginous fish–Endoskeleton is made of

cartilage–Have jaws, scales, and paired

fins–Sharks, skates, rays

Fish Groups

• Bony fish–Largest group–Endoskeleton is made of

bone–Have jaws and paired fins

The Cold-Blooded Vertebrates

Chapter 13DAmphibians

Amphibians

Ectothermic vertebrates that

usually live in water when young but can

live on land when adults

Development

• Amphibians are the only vertebrates that undergo metamorphosis

• Young have gills; adults have lungs

Development

• Two-chambered heart to three-chambered heart

• Growth of limbs

Amphibian Groups

• Those with tails in adulthood

• Those without tails in adulthood

Tailless Amphibians

• Frogs and toads• Resorb tails during

metamorphosis• Hibernation• Estivation

Tailless Amphibians

• Salamanders–Many found in

Appalachian region of southeastern US–Usually small

The Cold-Blooded Vertebrates

Chapter 13EReptiles

Reptiles

• Breathe air with lungs• Do not experience

metamorphosis• Dry, scaly skin• Three-chambered heart• Most lay eggs

Reptile Groups

• Snakes and lizards• Alligators and crocodiles• Turtles• Tuataras

Snakes and Lizards

• Molting• Snakes do not hear or see

well• Snakes are carnivores• Snakes can swallow prey

Snakes and Lizards

• Snakes can be found in almost any environment

• Lizards are usually found in warm/hot, dry places

Crocodiles and Alligators

• Usually in tropical or subtropical climates

• Usually found in fresh water

• Only two species in the United States

Turtles

• Sea turtles• Tortoises• Terrapins• Two hard, bony shells