BJU Biology Chapter 17: The Ectothermic Vertebrates

dorsal notochord

tough, flexible rod in chordates

ectotherm

an animal whose body temperature varies with the temperature of its surroundings

endotherm

an organism that is internally warmed by a heat-generating metabolic process

axial skeleton

skull, vertebral column, rib cage

appendicular skeleton

bones of the shoulder, pelvis, and limbs

vein

blood vessel carrying blood towards the heart

artery

blood vessel carrying blood away from the heart

capillary

smallest blood vessel

kidney

filters waste from the blood

herbivore

a consumer that eats only plants

carnivore

a consumer that eats only animals

omnivore

a consumer that eats both plants and animals

esophagus

tube connecting the mouth to the stomach

pancreas

produces juices that aid in digestion

liver

produces bile

bile

a digestive juice secreted by the liver and stored in the gallbladder; breaks down fats

gall bladder

stores bile

stomach

a muscular and elastic sac that serves mainly to store food, break it up mechanically, and begin chemical digestion of proteins and fat

small intestine

the part of the digestive system in which most chemical digestion and absorption of food molecules takes place

large intestine

absorbs water and forms feces

villi

fingerlike extensions of the intestinal mucosa that increase the surface area for absorption

anus

terminal end or opening of the digestive tract to the outside of the body

internal fertilization

process in which eggs are fertilized inside the female's body

external fertilization

process in which eggs are fertilized outside the female's body

oviparous

egg laying

viviparous

live birth

ovoviviparous

producing living young from eggs that hatch within the body

reflex

a simple, automatic response to a sensory stimulus

instinct

a complex behavior that is rigidly patterned throughout a species and is not learned

conditioned behavior

learned

intelligent behavior

an action marked by thought, analysis, communication, or the use of tools or symbols

Class Osteichthyes

bony fish

swim bladder

an air-filled sac near the spinal column in many fishes that helps maintain buoyancy

scale rings

allow us to tell the age of many fish

chromatophores

pigment cells that color an organism

countershading

dark on top, light on bottom

operculum

a protective flap that covers the gills of fish

number of chambers in a fish heart

2

atrium

upper chamber of the heart; receives blood

ventricle

lower chamber of the heart; pumps blood forward

lateral line

a faint line visible on both sides of a fish's body that runs the length of the body and marks the location of sense organs that detect vibrations in water

spawning

process by which male and female fishes release their gametes near each other in the water

milt

sperm-containing fluid released by a male fish

Class Agnatha

jawless fish; lampreys and hagfish

Class Chondrichthyes

cartilaginous fish; sharks, skates, rays

Class Amphibia

metamorphosis; frogs, toads, salamanders, caecilians

number of chambers in an amphibian heart

3

hibernation

a state of greatly reduced body activity that occurs during the winter

estivation

a state of greatly reduced body activity that occurs during the summer

nictitating membrane

a thin, transparent, eyelid-like membrane

tympanic membrane

eardrum

eustachian tubes

narrow tubes that lead from the ear chamber to the mouth

glottis

mouth of windpipe

mesentery

structure that suspends the small intestine and other organs from the body wall

trachea

windpipe

keratin

protein in reptile scales

amniotic egg

a shelled, water-retaining egg that enables reptiles, birds, and egg-laying mammals to complete their life cycles on dry land

yolk

the yellow part of an egg; food for the embryo

number of chambers in a reptile heart

3 or 4

Jacobson's organs

saclike, odor-sensing structure on the roof of a snake's mouth

neurotoxin

a chemical that disrupts the nervous systems of animals

hemotoxin

a type of venom that affects blood cells and vessels

quadrate bone

loosely attaches the skull of a snake to the lower jaw on each side

carapace

turtle's upper shell

plastron

turtle's lower shell