Anterior

• Head

ventral

• Belly

Spicule

• Hard structure in sponges, used for defense/structure

Choanocyte

• Flagellum, most interior cell of sponge

Amoebocyte

• Forms spicule 

Osculum

• Main opening of sponge

Morula

• Solid mass that forms after cleavage 

Radial cleavage

• up/down, deuterostomes

Spiral cleavage

• spiral/blackberry, protostomes 

Cleavage

• Early cell divisions of an embryo

Diploblastic

• Endoderm and ectoderm

Triploblastic

• Endoderm, ectoderm, and mesoderm

Protostomes

• Mouth

Deuterostomes

• Anus

Blastula

• Hollow ball of cells

Mesoderm

• Muscles

Ectoderm

• Skin

Endoderm

• gut

Gastrulation

• Hollow embryo invaginates, forms the archenteron and blastopore

archenteron

• Cavity inside gastrula

Blastopore

• Opening to archenteron

Cephalization

• Concentration of sensory organs/nerve tissues at the anterior end

Acoelomate

• Lacks a fluid-filled body cavity

Pseudocoelomate

• Body cavity is a fluid-filled space in which internal organs are suspended, lacking mesoderm

Coelomate

• Body cavity is a coelom that develops within the mesoderm

Hydrostatic skeleton

• Muscles contract, push fluid, able to move

Nerve nets

• Diffuse nervous systems

Hydra

• Sessile polyp phase

Medusa

• Motile jellyfish phase

Nematocyst

• Fluid filled capsule that holds cnidocyte

Cnidocyte

• Stinging cell

Corona 

• Sweeps food into mouth

Mastax

• Grounds food up

Lophophore 

• Tentacles around the mouth used for food collection and gas exchange

Trochophore

• Beating a band of cilia to move