#tissue_layer__membrane  a pliable sheet of tissue that covers or lines or connects organs or cells of animals
  supertype:  animal_tissue  the tissue in the bodies of animals
  substance:  phospholipid
  subtype:  trophoblast  the membrane that forms the wall of the blastocyst in early development; aids implantation in the uterine wall; "after implantation of the blastocyst in the uterine wall the trophoblast divides into two layers, the chorion and the placenta"
  subtype:  chorioallantois__chorioallantoi__chorioallantoic_membrane__chorioallantoicmembrane  very vascular fetal membrane composed of the fused chorion and adjacent wall of the allantois
  subtype:  web.tissue_layer  membrane connecting the toes of some aquatic birds and mammals
  subtype:  Bowman's_capsule__glomerular_capsule__capsula_glomeruli__capsulaglomeruli  thin double membrane surrounding the glomerulus of a nephron
  subtype:  axolemma  outer membrane covering an axon
  subtype:  basilar_membrane__basilarmembrane  a membrane in the cochlea that supports the Organ of Corti
  subtype:  fetal_membrane__fetalmembrane  any membrane that functions for the protection or nourishment of respiration or excretion of a developing fetus
     subtype:  allantois__allantoi  vascular fetal membrane that develops from the hindgut in embryonic higher vertebrates (mammals; birds; reptiles)
     subtype:  caul__veil__embryonic_membrane__embryonicmembrane  the inner embryonic membrane of higher vertebrates (especially when covering the head at birth)
     subtype:  umbilical_cord__umbilicalcord  membranous duct connecting the fetus with the placenta
  subtype:  choroid_coat__choroidcoat__choroid  a highly vascular membrane in the eye between the retina and the sclera
  subtype:  ciliary_body__ciliarybody  the part of the tunic of the eye between the choroid coat and the iris
  subtype:  cornea  transparent anterior portion of the outer covering of the eye; it covers the lens and iris and is continuous with the sclera
     subtype:  arcus_senilis__arcussenili__arcus__arcu  an arc-shaped whitish deposit sometimes seen in the cornea
  subtype:  midriff__diaphragm  (anatomy) a muscular partition separating the abdominal and thoracic cavities; functions in respiration
  subtype:  eardrum__tympanum__tympanic_membrane__myringa  the membrane in the ear that vibrates to sound
     subtype:  perforated_eardrum  an eardrum with a hole or tear in it; can interfere with normal hearing and cause other ear problems
  subtype:  endocranium  membrane lining the inside of the skull
  subtype:  endosteum  vascular membrane that lines the inner surface of long bones
  subtype:  ependyma  thin epithelial membrane lining the ventricles of the brain and the spinal cord canal
  subtype:  fertilization_membrane__fertilizationmembrane  the membrane that forms around a fertilized ovum and prevents penetration by additional spermatozoon
  subtype:  hyaloid_membrane__hyaloidmembrane  transparent membrane that enveloping the vitreous humor of the eye and separating it from the retina
  subtype:  intima  the innermost membrane of an organ (especially the inner lining of an artery or vein or lymphatic vessel)
  subtype:  iris  muscular diaphragm that controls the size of the pupil; it forms the colored portion of the eye
  subtype:  lamella.tissue_layer  a thin membrane that is one of the calcified layers that form bones
  subtype:  lens_capsule  a tenuous mesoblastic membrane surrounding the lens
  subtype:  meninx__meninges  a membrane (one of 3) that envelops the brain and spinal cord
     subtype:  leptomeninges__leptomeninge  the two innermost layers of the meninges; cerebrospinal fluid circulates between these innermost layers
     subtype:  dura_mater__dura  the outermost (and toughest) of the 3 meninges
     subtype:  arachnoid_membrane__arachnoidmembrane__arachnoid  the middle of the 3 meninges
     subtype:  pia_mater__piamater  the highly vascular innermost of the 3 meninges
  subtype:  mucous_membrane__mucosa  mucus-secreting membrane lining all body cavities or passages that communicate with the exterior
     subtype:  conjunctiva  a transparent membrane covering the eyeball and under surface of the eyelid
        subtype:  pinguecula  a slightly elevated elastic tissue deposit in the conjunctiva that may extend to the cornea but does not cover it
        subtype:  pterygium  a thickened triangular layer of conjunctiva extending from the nasal edge of the eye to the cornea; pterygia arise from irritation of the pinguecula
     subtype:  endometrium  the mucous membrane that lines the uterus; thickens under hormonal control and (if pregnancy does not occur) is shed in menstruation; if pregnancy occurs it is shed along with the placenta at parturition
     subtype:  hymen__maidenhead__virginal_membrane  a fold of tissue that partly covers the entrance to the vagina of a virgin
        subtype:  imperforate_hymen__imperforatehymen  hymen that is completely closed so that menstrual blood cannot flow out
  subtype:  periosteum  a dense fibrous membrane covering the surface of bones (except at their extremities) and serving as an attachment for tendons and muscles; contains nerves and blood vessels that nourish the enclosed bone
  subtype:  perithelium  tissue layer around small blood vessels
  subtype:  retina  the light-sensitive membrane covering the back wall of the eyeball; it is continuous with the optic nerve
  subtype:  sarcolemma  an extensible membrane enclosing the contractile substance of a muscle fiber
  subtype:  semipermeable_membrane__semipermeablemembrane  a membrane (as a cell membrane) that allows some molecule to pass through but not others
     subtype:  cell_wall__cell_membrane__plasma_membrane  a thin membrane around the cytoplasm of a cell; controls passage of substances in and out of the cell
  subtype:  serous_membrane__serosa  a thin membrane lining the closed cavities of the body; has two layers with a space between that is filled with serous fluid
     subtype:  pleura  the thin serous membrane around the lungs and inner walls of the chest
        subtype:  parietal_pleura  pleura that lines the inner chest walls and covers the diaphragm
        subtype:  visceral_pleura  pleura that covers the lungs
     subtype:  peritoneum  a transparent membrane that lines the abdominal cavity in mammals and covers most of the viscera
        subtype:  mesentery  a double layer of peritoneum that attaches to the back wall of the abdominal cavity and supports the small intestines
           subtype:  mesocolon  mesentery that holds the lower colon the back abdominal wall
        subtype:  omentum  a fold of peritoneum supporting the viscera
           subtype:  greater_omentum__greateromentum__gastrocolic_omentum__gastrocolicomentum__caul  part of the peritoneum attached to the stomach and to the colon and covering the intestines
           subtype:  lesser_omentum  a part of the peritoneum attached to the stomach and liver and supporting the hepatic vessels
     subtype:  endocardium  the membrane that lines the cavities of the heart and forms part of the heart valves
     subtype:  pericardium  a double-layered serous membrane that surrounds the heart
     subtype:  epicardium__visceral_pericardium  the innermost of the two layers of the pericardium
     subtype:  parietal_pericardium  the tough outermost layer of the pericardium that is attached to the diaphragm and the sternum
  subtype:  synovial_membrane__synovium  a thin membrane in synovial (freely moving) joints that lines the point capsule and secretes synovial fluid
  subtype:  tunica__tunic__adventitia  an enveloping or covering membrane or layer of body tissue
     subtype:  albuginea  whitish tunic
        subtype:  sclera__sclerotic_coat__scleroticcoat  whitish fibrous membrane (albuginea) that with the cornea forms the outer covering of the eyeball
        subtype:  tunica_albuginea_testes  whitish cover of the testicle

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