Glossary of Terms

The glossary contains definitions for developmental concepts and anatomical terms that were coined or adapted for Schmidtea mediterranea. These terms were deposited into Uberon composite-metazoan ontology, a multi-species anatomy ontology. Our goal is to provide users with a controlled vocabulary and relationships among terms for describing planarian anatomical features. Our current list of defined terms is not comprehensive, and will be expanded upon in the future to include additional structures, tissue and cell types.​

 

termdefinition
Stage 3-5 embryo hemisphere centered around the pole opposite to the temporary embryonic pharynx.
    aboral hemisphere is aplanarian tissue
    aboral hemisphere is aSchmidtea mediterranea developmental term
The single, central gut branch of the triclad gut anterior to the definitive pharynx.
    anterior primary gut branch is aplanarian tissue
    anterior primary gut branch containsgastrodermis
    anterior primary gut branch containsgoblet cell
    anterior primary gut branch containsintestinal phagocyte
    anterior primary gut branch containssecondary gut branch
    anterior primary gut branch containstertiary gut branch
A thin sheet of proteoglycans and glycoproteins, especially laminin, secreted by cells as an extracellular matrix.
    basal lamina is aplanarian tissue
Undifferentiated, zygote-derived cleavage progeny that give rise to temporary embryonic tissues during Stage 2, continue dividing asynchronously in the embryonic wall, and ultimately give rise to neoblasts and adult lineage progenitors beginning in Stage 5.
    blastomere is aembryonic tissue
    blastomere is aplanarian tissue
    blastomere develops fromzygote
Post-mitotic, mesenchymally located epidermal progenitors downstream of the zeta neoblasts.
    Category 2 cell is aplanarian tissue
Post-mitotic, mesenchymally located epidermal progenitors downstream of the Category 2 cells.
    Category 3 cell is aplanarian tissue
Post-mitotic, mesenchymally and epidermally located progenitors downstream of the Category 3 cells.
    Category 4 cell is aplanarian tissue
Post-mitotic, ciliated epidermal cells.
    Category 5 cell is aplanarian tissue
The central nervous system is the core nervous system that serves an integrating and coordinating function. In vertebrates it consists of the neural tube derivatives: the brain and spinal cord. In invertebrates it includes central ganglia plus nerve cord.
    central nervous system is aplanarian tissue
The planarian brain, consisting of two bilaterally symmetric lobes occupying a ventral position in the head.
    cephalic ganglia is aplanarian tissue
An epithelial cell that has a cillia.
    ciliated epithelial cell is aplanarian tissue
Body wall muscle fibers arrayed around the dorsoventral axis. Upon regeneration, these are thought to be produced de novo in the blastema.
    circular muscle fiber is aplanarian tissue
Pluripotent piwi-1+ stem cells that self-renew, form expanding colonies and produce differentiating daughters that contribute to multiple organ systems. cNeoblasts are predicted to be broadly distributed across the anteroposterior axis of the adult worm.
    clonogenic neoblast is aplanarian tissue
Non-ciliated tubules associated with the distal tubules, which cross the basement membrane and terminate in the dorsal epidermis.
    collecting duct is aplanarian tissue
A single cell layer of post-mitotic epithelial cells containing ciliated and non-ciliated cell types.
    definitive epidermis is adefinitive tissue
    definitive epidermis is aplanarian tissue
    definitive epidermis develops fromCategory 2 cell
    definitive epidermis develops fromCategory 3 cell
    definitive epidermis develops fromCategory 4 cell
    definitive epidermis develops fromepidermal progenitor
    definitive epidermis develops fromzeta neoblast
    definitive epidermis containsCategory 4 cell
    definitive epidermis containsCategory 5 cell
    definitive epidermis containsciliated epithelial cell
    definitive epidermis containsdorsal epidermis
    definitive epidermis containsdorsal stripe
    definitive epidermis containsrhabdite
    definitive epidermis containsventral epidermis
The planarian triclad gut contains a central anterior gut branch connected to two posterior gut branches arranged around the definitive pharynx. Secondary gut branches extend laterally from the primary gut branches, while tertiary gut branches extend from the secondary branches. Food and waste enter and exit the definitive gut through the defintive pharynx.
    definitive gut is adefinitive tissue
    definitive gut is aplanarian tissue
    definitive gut develops fromgamma neoblast
    definitive gut develops fromneoblast
    definitive gut containsanterior primary gut branch
    definitive gut containsesophagus
    definitive gut containsgastrodermis
    definitive gut containsgoblet cell
    definitive gut containsintestinal phagocyte
    definitive gut containsposterior primary gut branch
    definitive gut containssecondary gut branch
    definitive gut containstertiary gut branch
A plicate and protrusible organ that is the sole point of entry and exit for the Triclad gut. It contains epithelial, muscular, secretory and neuronal cell types.
    definitive pharynx is adefinitive tissue
    definitive pharynx is aplanarian tissue
    definitive pharynx develops fromdefinitive pharynx progenitor cell
    definitive pharynx develops fromneoblast
    definitive pharynx containsepithelial cell
    definitive pharynx containsmuscle organ
    definitive pharynx containsneuron
    definitive pharynx containssecretory cell
foxA1+ neoblasts and their post-mitotic, differentiating daughters required for maintenance and regeneration of the definitive pharynx.
    definitive pharynx progenitor cell is aplanarian tissue
Adult tissues built during organogenesis that are present in juveniles at birth.
    definitive tissue is aplanarian tissue
Body wall muscle fibers arrayed diagonally along the anteroposterior axis.
    diagonal muscle fiber is aplanarian tissue
Anatomical system that has as its parts the organs devoted to the ingestion, digestion, and assimilation of food and the discharge of residual wastes.
    digestive system is adefinitive tissue
    digestive system is aplanarian tissue
    digestive system containsanterior primary gut branch
    digestive system containsdefinitive gut
    digestive system containsdefinitive pharynx
    digestive system containsesophagus
    digestive system containsgoblet cell
    digestive system containsgut cavity
    digestive system containsintestinal phagocyte
    digestive system containsmouth
    digestive system containspharyngeal pouch
    digestive system containsposterior primary gut branch
    digestive system containssecondary gut branch
    digestive system containstemporary embryonic pharynx
    digestive system containstertiary gut branch
Any of the organs or elements that are part of the digestive system. Examples: tongue, esophagus, spleen, crop, lunge feeding organ, tooth elements.
    digestive system element is aplanarian tissue
    digestive system element containsanterior primary gut branch
    digestive system element containsdefinitive pharynx
    digestive system element containsesophagus
    digestive system element containsgoblet cell
    digestive system element containsgut cavity
    digestive system element containsintestinal phagocyte
    digestive system element containsmouth
    digestive system element containspharyngeal pouch
    digestive system element containsposterior primary gut branch
    digestive system element containssecondary gut branch
    digestive system element containstemporary embryonic pharynx
    digestive system element containstertiary gut branch
Embryonic development producing juvenile animals with body plans and feeding behavior similar to adults. Juveniles grow and mature into adults without undergoing metamorphosis.
    direct development is aSchmidtea mediterranea developmental term
A derived form of early embryonic cleavage present in ectolecithal embryos. Blastomeres divide asynchronously within a yolk syncytium, and division progeny do not remain in direct contact with one another.
    dispersed cleavage is aSchmidtea mediterranea developmental term
Sinusoidal, non-ciliated tubules connected to proximal tubules within the parenchyma. Tubules are formed via intercellular junctions between two epithelial cells.
    distal tubule is aplanarian tissue
Single cell layer of dorsal, post-mitotic, epithelial cells containing the dorsal stripe.
    dorsal epidermis is aplanarian tissue
    dorsal epidermis containsciliated epithelial cell
    dorsal epidermis containsdorsal stripe
Dorsal ciliated epithelial cells along the midline.
    dorsal stripe is aplanarian tissue
    dorsal stripe containsciliated epithelial cell
Turbellarian (freshwater flatworm) embryos that undergo a modified form of cleavage due to separation of oocyte and yolk. Yolk is not contained within oocytes, and is produced by somatic vitellogenic gland cells.
    ectolecithal embryo is aplanarian tissue
    ectolecithal embryo is aSchmidtea mediterranea developmental term
The first few specialized divisions of an activated animal egg.
    embryonic cleavage is aSchmidtea mediterranea developmental term
    embryonic digestive system is aplanarian tissue
    embryonic digestive system containsembryonic gut cell
    embryonic digestive system containsgut cavity
    embryonic digestive system containsprimitive gut cell
    embryonic digestive system containstemporary embryonic pharynx
Dispersed, phagocytic gut cells that appear during Stage 4 and ultimately generate a honeycomb-like lattice surrounding the central gut cavity in Stage 5 embryos. Early embryonic gut cell specific transcripts are expressed from Stage 4-6, and are downregulated during Stage 7.
    embryonic gut cell is aembryonic tissue
    embryonic gut cell is aplanarian tissue
A portion of tissue that is part of an embryo.
    embryonic tissue is aplanarian tissue
    embryonic tissue containsblastomere
The parenchymal space between the gut cavity and the primitive ectoderm containing undifferentiated blastomeres in Stage 3-5 embryos.
    embryonic wall is aplanarian tissue
    embryonic wall is aSchmidtea mediterranea developmental term
    embryonic wall containsblastomere
    embryonic wall containsyolk cell
Visceral muscle surrounding the definitive gut.
    enteric muscle is aplanarian tissue
Mitotically active zeta neoblasts and their post-mitotic descendants which undergo progressive differentiation and outward directed movement through the mesenchyme prior to incorporation into the epidermis, where terminal differentiation occurs.
    epidermal progenitor is aplanarian tissue
    epidermal progenitor containsCategory 2 cell
    epidermal progenitor containsCategory 3 cell
    epidermal progenitor containsCategory 4 cell
    epidermal progenitor containszeta neoblast
A cell that is usually found in a two-dimensional sheet with a free surface. The cell has a cytoskeleton that allows for tight cell to cell contact and for cell polarity where apical part is directed towards the lumen and the basal part to the basal lamina.
    epithelial cell is aplanarian tissue
Attachment between the triclad gut and the proximal end of the definitive pharynx; also known as the pharynx implanation zone.
    esophagus is aplanarian tissue
A multicellular anatomical structure that is associated with an embryo and derived from the zygote from which it develops, but which does not contribute to the embryo proper or to structures that are part of the same organism after embryogenesis.
    extraembryonic structure is aplanarian tissue
    extraembryonic structure is aSchmidtea mediterranea developmental term
An organ that detects light.
    eye is adefinitive tissue
    eye is aplanarian tissue
    eye develops fromneoblast
    eye develops fromtrail cell
    eye containsoptic cup
    eye containsphotoreceptor neuron
    eye containspigment cup
    eye containstrail cell
A cell specialized to detect and transduce light.
    eye photoreceptor cell is aplanarian tissue
Terminal structure of protonephridia unit; consists of flame cells.
    flame bulb is aplanarian tissue
Terminal structure of the protonephridia unit, capping the proximal tubules. Flame cells are defined by the filtration weir, which consists of closely apposed strands of cytoplasm surrounding a central cilia bundle, and by numerous microvilli between weir and cilia. Positive for acetyated tubulin.
    flame cell is aplanarian tissue
An abundant neoblast subclass, exhibiting enriched expression of gata456a, hnf4, prox-1 and nkx2.2, implicated in maintenance and regeneration of the definitive gut.
    gamma neoblast is aplanarian tissue
The single cell layer columnar epithelial lining of the intestine. The gastrodermis is surrounded by a basal lamina and enteric muscle.
    gastrodermis is aplanarian tissue
    gastrodermis containsgoblet cell
    gastrodermis containsintestinal phagocyte
Secretory cells that release digestive enzymes into the lumen of the intestine.
    goblet cell is aplanarian tissue
lumen of digestive tract
    gut cavity is aplanarian tissue
Inner most body wall muscle fibers arrayed along the anteroposterior axis. These fibers are thicker than the outer longitudinal muscle fibers. The pattern of these muscles differs along the dorsoventral axis, with the dorsal arrangement converging at the central zone of the anterior pole. The ventral arrangement is more parallel or may diverge slightly as it approaches the ventral pole.
    inner longitudinal muscle fiber is aplanarian tissue
Absorptive digestive cells that engulf food particles for intracellular digestion.
    intestinal phagocyte is aplanarian tissue
Body wall muscle fibers arrayed along the anteroposterior axis. Upon regeneration, these muscles are thought to be established from truncated pre-existing fibers.
    longitudinal muscle fiber is aplanarian tissue
    longitudinal muscle fiber containsinner longitudinal muscle fiber
    longitudinal muscle fiber containsouter longitudinal muscle fiber
The sole point of entry and exit for the Triclad planarian flatworm gut. The mouth is connected to the pharyngeal pouch to allow for exit and re-entry of the definitive pharynx on the ventral side of the animal. The mouth contains several cell types, including epithelial cells, muscle, and secretory cells.
    mouth is aplanarian tissue
    mouth containsepithelial cell
    mouth containsmuscle cell
    mouth containssecretory cell
A mature contractile cell, commonly known as a myocyte. This cell has as part of its cytoplasm myofibrils organized in various patterns.
    muscle cell is aplanarian tissue
Organ consisting of a tissue made up of various elongated cells that are specialized to contract and thus to produce movement and mechanical work[GO].
    muscle organ is adefinitive tissue
    muscle organ is aplanarian tissue
    muscle organ develops frommuscle progenitor
    muscle organ develops fromneoblast
    muscle organ containscircular muscle fiber
    muscle organ containsdiagonal muscle fiber
    muscle organ containsenteric muscle
    muscle organ containsinner longitudinal muscle fiber
    muscle organ containslongitudinal muscle fiber
    muscle organ containsmusculature of body wall
    muscle organ containsouter longitudinal muscle fiber
    muscle organ containsparenchymal musculature
    muscle organ containspharyngeal muscle
myoD+ neoblasts and their post-mitotic, differentiating daughters implicated in the maintenance and regeneration of muscles.
    muscle progenitor is aplanarian tissue
Any collection of muscles that is part of a body wall.
    musculature of body wall is aplanarian tissue
    musculature of body wall containscircular muscle fiber
    musculature of body wall containsdiagonal muscle fiber
    musculature of body wall containsinner longitudinal muscle fiber
    musculature of body wall containslongitudinal muscle fiber
    musculature of body wall containsouter longitudinal muscle fiber
A heterogeneous population of pluripotent, somatic adult stem cells and lineage primed progenitors that are required for maintenance and regeneration of all cell types in planaria, including the germline.
    neoblast is adefinitive tissue
    neoblast is aplanarian tissue
    neoblast develops fromblastomere
    neoblast containsclonogenic neoblast
    neoblast containsgamma neoblast
    neoblast containssigma neoblast
    neoblast containszeta neoblast
The nervous system is an organ system containing predominantly neuron and glial cells. In bilaterally symmetrical organism, it is arranged in a network of tree-like structures connected to a central body. The main functions of the nervous system are to regulate and control body functions, and to receive sensory input, process this information, and generate behavior [CUMBO].
    nervous system is adefinitive tissue
    nervous system is aplanarian tissue
    nervous system develops fromneoblast
    nervous system develops fromneural progenitor
    nervous system containscentral nervous system
    nervous system containscephalic ganglia
    nervous system containsneural progenitor
    nervous system containsperipheral nervous system
    nervous system containsventral nerve cord
Neoblasts and their differentiating daughters implicated in maintenance and regeneration of different tissues in the nervous system.
    neural progenitor is aplanarian tissue
The basic cellular unit of nervous tissue. Each neuron consists of a body, an axon, and dendrites. Their purpose is to receive, conduct, and transmit impulses in the nervous system.
    neuron is aplanarian tissue
A female germ cell that has entered meiosis.
    oocyte is aplanarian tissue
A portion of the eye containing pigment cells and dendritic projections from photoreceptor neurons.
    optic cup is aplanarian tissue
Stage 3-5 embryo hemisphere centered around the temporary embryonic pharynx.
    oral hemisphere is aplanarian tissue
    oral hemisphere is aSchmidtea mediterranea developmental term
A stage at which the ectoderm, endoderm, and mesoderm develop into the internal organs of the organism.
    organogenesis is aSchmidtea mediterranea developmental term
Outer most body wall muscle fibers arrayed along the anteroposterior axis. These fibers are thinner than the inner longitudinal muscle fibers.
    outer longitudinal muscle fiber is aplanarian tissue
Dorsal-ventral muscle fibers present through the mesenchyme.
    parenchymal musculature is aplanarian tissue
A major division of the nervous system that contains nerves which connect the central nervous system (CNS) with sensory organs, other organs, muscles, blood vessels and glands.
    peripheral nervous system is aplanarian tissue
A muscle that acts on the pharynx[WP, vetted].
    pharyngeal muscle is aplanarian tissue
An epithelial structure housing the definitive pharynx, connected to the esophagus and mouth.
    pharyngeal pouch is aplanarian tissue
foxA1+ neoblasts and their post-mitotic, differentiating daughters required for maintenance and regeneration of the definitive pharynx.
Bipolar photoreceptor neurons with dendritic projections into the optic cup and axons that innervate the underlying brain.
    photoreceptor neuron is aeye photoreceptor cell
    photoreceptor neuron is aplanarian tissue
Non-neuronal, pigmented cells arrayed along the proximal side of the optic cup.
Non-neuronal, pigmented cells arrayed along the proximal side of the optic cup.
    pigment cup is aplanarian tissue
A tissue found in planarians.
The primary gut branches of the triclad gut lateral and posterior to the pharynx and pharyngeal pouch.
    posterior primary gut branch is aplanarian tissue
    posterior primary gut branch containsgastrodermis
    posterior primary gut branch containsgoblet cell
    posterior primary gut branch containsintestinal phagocyte
    posterior primary gut branch containssecondary gut branch
    posterior primary gut branch containstertiary gut branch
A single cell layer of extraembryonic, post-mitotic ectodermal cells bounding the embryo. The primitive ectoderm forms during Stage 2 and is thought to degenerate as the definitive epidermis forms during Stages 5-7.
    primitive ectoderm is aplanarian tissue
    primitive ectoderm is atemporary embryonic tissue
    primitive ectoderm develops fromblastomere
    primitive ectoderm containsciliated epithelial cell
Four large phagocytic cells associated with the temporary embryonic pharynx.
    primitive gut cell is aplanarian tissue
    primitive gut cell is atemporary embryonic tissue
    primitive gut cell develops fromblastomere
Excretory organs consisting of flame cells, proximal tubules, and distal tubules connected to a mesenchymal collecting duct.
    protonephridia is adefinitive tissue
    protonephridia is aplanarian tissue
    protonephridia develops fromneoblast
    protonephridia develops fromprotonephridial progenitor
    protonephridia containscollecting duct
    protonephridia containsdistal tubule
    protonephridia containsflame cell
    protonephridia containsprotonephridial progenitor
    protonephridia containsproximal tubule
Neoblasts and post-mitotic, differentiating daughters coexpressing POU2-3, six1/2-2, Sal1, Eya and Osr, required for maintenance and regeneration of protonephridial cell types.
    protonephridial progenitor is aplanarian tissue
Stage 2 embryo undergoing the process of sphere formation.
    protosphere is aplanarian tissue
    protosphere is aSchmidtea mediterranea developmental term
Ciliated epithelial cells form tubules, generating coiled, branching units terminating in flame bulbs. Tubules are formed via intercellular junctions between two epithelial cells. Proximal tubules are connected to non-ciliated distal tubules within the parenchyma.
    proximal tubule is aplanarian tissue
The renal system in an anatomical system that maintains fluid balance and contributes to electrolyte balance, acid/base balance, and disposal of nitrogenous waste products.
    Renal system is adefinitive tissue
    Renal system is aplanarian tissue
    Renal system develops fromneoblast
    Renal system develops fromprotonephridial progenitor
    Renal system containscollecting duct
    Renal system containsdistal tubule
    Renal system containsflame bulb
    Renal system containsflame cell
    Renal system containsprotonephridia
    Renal system containsprotonephridial progenitor
    Renal system containsproximal tubule
Straight or curved rod-like structures within the epidermal cells, oriented with long axis at right angles to the epidermal surface, that are discharged into mucous secretions.
    rhabdite is aplanarian tissue
A developmental stage that is specific to the planarian Schmidtea mediterranea
    Schmidtea mediterranea developmental stage is aSchmidtea mediterranea developmental term
    Schmidtea mediterranea developmental stage containsStage 1
    Schmidtea mediterranea developmental stage containsStage 2
    Schmidtea mediterranea developmental stage containsStage 3
    Schmidtea mediterranea developmental stage containsStage 4
    Schmidtea mediterranea developmental stage containsStage 5
    Schmidtea mediterranea developmental stage containsStage 6
    Schmidtea mediterranea developmental stage containsStage 7
A term used to describe a developmental process during Schmidtea mediterranea embryogenesis.
    Schmidtea mediterranea developmental term containsaboral hemisphere
    Schmidtea mediterranea developmental term containsdirect development
    Schmidtea mediterranea developmental term containsdispersed cleavage
    Schmidtea mediterranea developmental term containsectolecithal embryo
    Schmidtea mediterranea developmental term containsembryonic cleavage
    Schmidtea mediterranea developmental term containsembryonic wall
    Schmidtea mediterranea developmental term containsextraembryonic structure
    Schmidtea mediterranea developmental term containsoral hemisphere
    Schmidtea mediterranea developmental term containsorganogenesis
    Schmidtea mediterranea developmental term containsprotosphere
    Schmidtea mediterranea developmental term containsSchmidtea mediterranea developmental stage
    Schmidtea mediterranea developmental term containssphere formation
    Schmidtea mediterranea developmental term containstissue morphogenesis
Gut branches, originating from and connected to the primary gut branches, that extend laterally towards the body edge.
    secondary gut branch is aplanarian tissue
A cell that specializes in controlled release of one or more substances.
    secretory cell is aplanarian tissue
A heterogeneous subpopulation of neoblasts with enriched expression of SoxP-1 and SoxP-2 thought to contain both pluripotent stem cells and tissue-specific progenitors.
    sigma neoblast is aplanarian tissue
A mature male germ cell that develops from a spermatid.
    sperm is aplanarian tissue
Generation of a multilayered spherical embryo comprised of temporary extraembryonic tissues and undifferentiated blastomeres.
    sphere formation is aSchmidtea mediterranea developmental term
D0-D2. Zygote and dispersed blastomere cleavage in a yolk syncytium.
    Stage 1 is aSchmidtea mediterranea developmental stage
D2-D3. Sphere formation. A fraction of the blastomeres differentiate into temporary embryonic tissues that provide form and function to the embryo. Undifferentiated blastomeres remain in the embryonic wall.
    Stage 2 is aSchmidtea mediterranea developmental stage
D2-D4. Dispersed blastomere cleavage in the embryonic wall of nascent spheres. Yolk ingestion into the gut cavity.
    Stage 3 is aSchmidtea mediterranea developmental stage
D3-D5. Dispersed blastomere cleavage in the embryonic wall. Yolk ingestion into the gut cavity. Early embryonic gut formation.
    Stage 4 is aSchmidtea mediterranea developmental stage
D5-D7. Organogenesis onset. Downregulation of early embryo enriched transcripts and birth of adult lineages in blastomere population. Early embryonic gut formation continues. Yolk ingestion into the gut cavity.
    Stage 5 is aSchmidtea mediterranea developmental stage
D7-D9. Organogenesis and morphogenesis. Definitive organ formation. Temporary embryonic cell types degenerate. Embryo elongation.
    Stage 6 is aSchmidtea mediterranea developmental stage
D9-D11. Organogenesis and organ maturation continues. Onset of gliding motility.
    Stage 7 is aSchmidtea mediterranea developmental stage
D13-D15. Organogenesis and organ maturation continues. Hatching.
    Stage 8 is aSchmidtea mediterranea developmental stage
Yolk surrounding blastomeres undergoing dispersed cleavage during Stages 1 and 2.
    syncytial yolk is aplanarian tissue
An innervated, muscular pump that ingests yolk cells into the gut cavity. The temporary embryonic pharynx is an extraembryonic tissue that forms during Stage 2, functions during Stages 3-5, and degenerates during Stages 6-7.
    temporary embryonic pharynx is aplanarian tissue
    temporary embryonic pharynx is atemporary embryonic tissue
    temporary embryonic pharynx develops fromblastomere
    temporary embryonic pharynx containsepithelial cell
    temporary embryonic pharynx containsmuscle organ
    temporary embryonic pharynx containsneuron
Extra-embryonic tissues that provide form and function to planarian embryos, including the primitive ectoderm, temporary embryonic pharynx and primitive gut. These tissues differentiate from blastomeres during sphere formation, and are thought to degenerate as definitive organogenesis and morphogenesis ensue.
    temporary embryonic tissue is aplanarian tissue
    temporary embryonic tissue develops fromblastomere
    temporary embryonic tissue containsprimitive ectoderm
    temporary embryonic tissue containsprimitive gut cell
    temporary embryonic tissue containstemporary embryonic pharynx
Gut branches originating from and connected to the secondary gut branches.
    tertiary gut branch is aplanarian tissue
The process in which the anatomical structures of a tissue are generated and organized.
    tissue morphogenesis is aSchmidtea mediterranea developmental term
Ovo+ neoblasts and post-mitotic eye progenitors that simultaneously migrate and differentiate into photoreceptor neurons and non-neuronal pigment cup cells comprising the optic cup.
    trail cell is aplanarian tissue
Single cell layer of ventral, post-mitotic, heavily ciliated epithelial cells
    ventral epidermis is aplanarian tissue
The pair of closely united ventral longitudinal nerves with their segmental ganglia that is characteristic of many elongate invertebrates (as earthworms)[BTO]. A large process bundle that runs along the vental mid-line extending from the ventral region of the nerve ring[WB]. The ventral cord is one of the distinguishing traits of the central nervous system of all arthropods (such as insects, crustaceans and arachnids) as well as many other invertebrates, such as the annelid worms[GO].
    ventral nerve cord is aplanarian tissue
An extraembryonic cell , produced by somatic vitellogenic glands in adult hermaphrodites, that provides nutrition to the developing embryo.
    yolk cell is aplanarian tissue
An abundant neoblast subclass consisting of p53+, zfp1+ progenitors required for maintenance and regeneration of epidermal cell type(s).
    zeta neoblast is aplanarian tissue
Diploid cell produced by the fusion of sperm cell nucleus and egg cell.
    zygote is aplanarian tissue