S: (n) zona pellucida (thick membrane around the mammalian ovum; can be penetrated by one sperm in the fertilization process; usually remains around the fertilized egg until it is implanted in the wall of the uterus)
S: (n) gill arch, branchial arch, gill bar (one of the bony or cartilaginous arches on each side of the pharynx that support the gills of fishes and aquatic amphibians)
S: (n) peristome (region around the mouth in various invertebrates)
S: (n) bulb (a rounded dilation or expansion in a canal or vessel or organ)
S: (n) carina (any of various keel-shaped structures or ridges such as that on the breastbone of a bird or that formed by the fused petals of a pea blossom)
S: (n) cingulum ((anatomy) an encircling structure (as the ridge around the base of a tooth))
S: (n) concha ((anatomy) a structure that resembles a shell in shape)
S: (n) filament, filum (a threadlike structure (as a chainlike series of cells))
S: (n) germ (a small apparently simple structure (as a fertilized egg) from which new tissue can develop into a complete organism)
S: (n) infundibulum (any of various funnel-shaped parts of the body (but especially the hypophyseal stalk))
S: (n) interstice (a small structural space between tissues or parts of an organ) "the interstices of a network"
S: (n) landmark (an anatomical structure used as a point of origin in locating other anatomical structures (as in surgery) or as point from which measurements can be taken)
S: (n) limbus (a border or edge of any of various body parts distinguished by color or structure)
S: (n) rib (a riblike supporting or strengthening part of an animal or plant)
S: (n) blade (a broad flat body part (as of the shoulder or tongue))
S: (n) radicle ((anatomy) a small structure resembling a rootlet (such as a fibril of a nerve))
S: (n) plexus, rete (a network of intersecting blood vessels or intersecting nerves or intersecting lymph vessels)
S: (n) passage, passageway (a path or channel or duct through or along which something may pass) "the nasal passages"
S: (n) fundus ((anatomy) the base of a hollow organ or that part of the organ farthest from its opening) "the uterine fundus"; "the fundus of the stomach"
S: (n) funiculus (any of several body structure resembling a cord)
S: (n) head (that part of a skeletal muscle that is away from the bone that it moves)
S: (n) membranous labyrinth (the sensory structures of the inner ear including the labyrinthine receptors and the cochlea; contained within the bony labyrinth)
S: (n) cytoskeleton (a microscopic network of actin filaments and microtubules in the cytoplasm of many living cells that gives the cell shape and coherence)
S: (n) centromere, kinetochore (a specialized condensed region of each chromosome that appears during mitosis where the chromatids are held together to form an X shape) "the centromere is difficult to sequence"
S: (n) aster (star-shaped structure formed in the cytoplasm of a cell having fibers like rays that surround the centrosome during mitosis)
S: (n) costa (a riblike part of a plant or animal (such as a middle rib of a leaf or a thickened vein of an insect wing))
S: (n) head (the rounded end of a bone that fits into a rounded cavity in another bone to form a joint) "the head of the humerus"
S: (n) bridge (the hard ridge that forms the upper part of the nose) "her glasses left marks on the bridge of her nose"
S: (n) rotator cuff (a supporting structure of the shoulder consisting of the muscles and tendons that attach the arm to the shoulder joint and enable the arm to move)
S: (n) cornu ((anatomy) any structure that resembles a horn in shape)
S: (n) corona ((anatomy) any structure that resembles a crown in shape)
S: (n) receptor (a cellular structure that is postulated to exist in order to mediate between a chemical agent that acts on nervous tissue and the physiological response)
S: (n) zone, zona ((anatomy) any encircling or beltlike structure)
Verb
S: (v) zone, district (regulate housing in; of certain areas of towns)
S: (v) partition, zone (separate or apportion into sections) "partition a room off"