| posterior layer of rectus abdominis sheath | The portion of the sheath of the rectus abdominis muscle that lies posterior to the muscle covering only its upper two-thirds; it is formed by contributions from the aponeuroses of the internal oblique and transversus abdominis muscles; its free inferior margin forms the arcuate line; it is deficient below this, the posterior aspect of the muscle being covered only by transversalis fascia and peritoneum. Synonym: lamina posterior vaginae musculi recti abdominis. (05 Mar 2000) |
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| posterior limiting layer of cornea | A transparent homogeneous acellular layer between the substantia propria and the endothelial layer of the cornea; considered to be a highly developed basement membrane. Synonym: lamina limitans posterior corneae, membrana vitrea, Descemet's membrane, Duddell's membrane, entocornea, hyaloid membrane, lamina elastica posterior, limiting layers of cornea, membrana hyaloidea, posterior elastic layer, tunica vitrea, vitreous membrane. (05 Mar 2000) |
| cutaneous layer of tympanic membrane | The thin layer of skin on the external surface of the tympanic membrane. Synonym: cutaneous layer of tympanic membrane. (05 Mar 2000) |
| half-value layer | <radiobiology> The thickness of a specified material (usually a specific absorber), which attenuates a beam of radiation so that the exposure rate or absorbed dose rate at a specified point is reduced by half. (20 Sep 2002) |
| pretracheal layer | The layer of fascia investing the infrahyoid muscles and contributing to the formation of the carotid sheath. Synonym: lamina pretrachealis, middle cervical fascia, Porter's fascia, pretracheal layer. (05 Mar 2000) |
| prevertebral layer | The part of the cervical fascia which covers the bodies of the cervical vertebrae and the muscles attaching to them and to the anterior parts of their transverse processes. Synonym: lamina prevertebralis, prevertebral layer. (05 Mar 2000) |
| prickle cell layer | The layer of polyhedral cells in the epidermis; shrinkage artifacts and adhesion of these cells at their desmosomal junctions gives a spiny or prickly appearance. Synonym: prickle cell layer, spinous layer. (05 Mar 2000) |
| Henle's fibre layer | The layer of inner cone fibres in the central area of the retina. (05 Mar 2000) |
| Henle's layer | The outer layer cells of the inner root sheath of the hair follicle. (05 Mar 2000) |
| Henle's nervous layer | The layers of the retina from the outer plexiform to the nerve fibre layer inclusive. Synonym: Henle's nervous layer. (05 Mar 2000) |
| Sattler's elastic layer | The middle layer of the choroid. (05 Mar 2000) |
| scrape-off layer | <radiobiology> Outer layer of a plasma which is affected (scraped off) by a divertor or limiter. That is, the outer layer of a magnetically confined plasma (ca. 2 cm thick) where the field lines penetrate a material surface (limiter or divertor plate) rather than close upon themselves. This region defines the outer limit of the plasma because any plasma crossing into the SOL is rapidly lost since transport along the field is much faster than that across the field. That is, particles follow these field lines into the material surface and are lost from the plasma. (09 Oct 1997) |
| horny layer of epidermis | The outer layer of the epidermis, consisting of several layers of flat keratinised non-nucleated cells. Synonym: corneal layer of epidermis, horny layer of epidermis. (05 Mar 2000) |
| horny layer of nail | The outer, horny layer of the nail. Synonym: cornified layer of nail, horny layer of nail. (05 Mar 2000) |
| Purkinje's layer | The layer of Purkinje cells between the molecular and granular layers of the cerebellar cortex. Synonym: stratum neuronorum piriformium, ganglionic layer of cerebellar cortex, layer of piriform neurons, Purkinje's layer, stratum gangliosum cerebelli. (05 Mar 2000) |