Metazoa 2

coelom

a fluid-filled cavity that separates the ectoderm from the endoderm

foot

large mass of muscle at base of organism, chief locomotor structure of molluscs

visceral mass

the region where most internal organs are contained including the external gill

mantle

specialized epidermis that includes envelopes all visceral mass and secretes shells

gills

respiratory structures formed by the mantle

radula

tongue-like organ with chitinous ornamentation

chromatophores

special pigment cells that contain pigments in the skin

iridophores, leucophores

reflect light and can make blue, green, and white

metamerism

series of body structures that are similar internally and externally such as segments (true segmentation)

teloblastic growth

the segments behind the head arise sequentially from a growth region anterior to the pygidium (tail)

clitellum

a reproductive structure that generates mucus to aid sperm transfer and also produces a "cocoon," within which fertilization occurs

setae

Chitinous bristles that are anchored in the epidermis and provide traction

chitin

forms a protective armor outside the epidermis

renette cells

the excretory cells unique to nematodes

molting

physiological process that all anthropods periodically go through

ecdysis

follows the molting process, the actual shedding of the exoskeleton

tagmata

discrete body regions/segments with different functions

hemocoel

bloody cavity

chelicerae

modified first pair of appendages that often serve as specialized clawlike or fanglike mouthparts

pedipalps

second pair of appendages that may also be used for general sensing the environment as well as the manipulation of food

pheromones

external chemical signals

water vascular system

consists of a central ring canal and radial canals that extend along each arm

tube feet

\-Extensions of an echinoderm's water vascular system that stick out from the body \n -function as tactile and ambulatory structures

ampullae

controls individual tube feet

notochord

a flexible, rod-shaped mesodermal structure that is found in the embryonic stage of all chordates and in the adult stage of some chordate species \n -becomes intervertebrate discs in vertebrates

dorsal hollow nerve cord

\-derived from ectoderm that rolls into a hollow tube during development \n -lost in urochordates

pharyngeal gill slits

\-openings in the pharynx (the region just posterior to the mouth) that extend to the outside environment \n -used for filter feeding in aquatic chordates \n -only present in embryonic stage of tetrapods

post-anal tail

a posterior elongation of the body, extending beyond the anus

vertebrae

a series of separate, irregularly shaped bones joined together to form a backbone

gnathostomes

animals that possess jaws

tetrapods

four-footed animals

ganglia

mass of neurons in a centralized nervous system

hydrostatic skeleton

fluid within the coelom provide support for muscles to move against

protostomes

blastopore develops into the mouth

Deuterostomes

blastopore develops into the anus

jointed appendages

muscles are attached to jointed cuticle of the arthropods, make movement possible

spiracles

pores on the body of an insect that allow for gas exchange

aquatic crustacean gas exchange organs

gills

eusocial

organism population in which the role of each organism is specialized and not all of the organisms will reproduce

pentaradial symmetry

radial symmetry in multiples of 5

Echinodermata larvae symmetry

bilateral

endoskeleton

internal skeleton for protection and support made from calcium carbonate

water vascular system

A system of fluid-filled tubes in an echinoderm's body. \n -Extends down each arm, ending in tubed feet that have tactile and movement functions