S: (n) membrane, tissue layer (a pliable sheet of tissue that covers or lines or connects the organs or cells of animals or plants)
S: (n) 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"
S: (n) fetal membrane (any membrane that functions for the protection or nourishment or respiration or excretion of a developing fetus)
S: (n) choroid, choroid coat (a highly vascular membrane in the eye between the retina and the sclera; a dark pigmentation minimizes the scattering of light inside the eye)
S: (n) ciliary body (the part of the tunic of the eye between the choroid coat and the iris) "the ciliary body produces aqueous humor"
S: (n) cornea (the transparent dome-shaped anterior portion of the outer covering of the eye; it covers the iris and pupil and is continuous with the sclera)
S: (n) diaphragm, midriff ((anatomy) a muscular partition separating the abdominal and thoracic cavities; functions in respiration)
S: (n) endosteum (vascular membrane that lines the inner surface of long bones)
S: (n) ependyma (thin epithelial membrane lining the ventricles of the brain and the spinal cord canal)
S: (n) fertilization membrane (the membrane that forms around a fertilized ovum and prevents penetration by additional spermatozoon)
S: (n) hyaloid membrane, hyaloid (the transparent membrane enveloping the vitreous humor of the eye and separating it from the retina)
S: (n) intima (the innermost membrane of an organ (especially the inner lining of an artery or vein or lymphatic vessel))
S: (n) iris (muscular diaphragm that controls the size of the pupil which in turn controls the amount of light that enters the eye; it forms the colored portion of the eye)
S: (n) lamella (a thin membrane that is one of the calcified layers that form bones)
S: (n) meninx, meninges (a membrane (one of 3) that envelops the brain and spinal cord)
S: (n) mucous membrane, mucosa (mucus-secreting membrane lining all body cavities or passages that communicate with the exterior)
S: (n) 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)
S: (n) retina (the innermost light-sensitive membrane covering the back wall of the eyeball; it is continuous with the optic nerve)
S: (n) sarcolemma (an extensible membrane enclosing the contractile substance of a muscle fiber)
S: (n) semipermeable membrane (a membrane (as a cell membrane) that allows some molecules to pass through but not others)
S: (n) 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)
S: (n) synovial membrane, synovium (a thin membrane in synovial (freely moving) joints that lines the joint capsule and secretes synovial fluid)
S: (n) kettle, kettledrum, tympanum, tympani, timpani (a large hemispherical brass or copper percussion instrument with a drumhead that can be tuned by adjusting the tension on it)