scales have a drop-like, inclined, elongate crown, well-developed neck and small base with concave basal surface (Fig.
Metastases are typically placoid
shaped with an undulating surface and show medium to high blood flow velocity.
Figure abbreviations: ac--acrotergite; as--antecostal suture (ridge); br--transverse row of placoid
sensilla on epipharynx; c--claw; cs--campaniform sensillum; dst--distal epipharyengal sensilla; dmr--dorsomesal row of setae on lacinia; er--epipharyngeal rods; f--femur; gl--galea; l--lacinia; lp--labial palp(i); mp--mesal pair of labro--epipharyngeal setae; msr--mesal row of setae on lacinia; mxp--maxillary palp(i); p2--2nd pair of labro-epipharyngeal setae; pr--pretarsus; pls--placoid
sensilla; prst--prostheca; s--sensorium (accessory sensory papillae); sbp--subproximal epipharyngeal sensilla; st--stipes; t--tibia; tr--trochanter.
The disease is characterized by infectious etiology and overlapping clinical features in an intermediary form of acute posterior multifocal placoid
pigment epitheliopathy and serpiginous choroiditis.
Acute, posterior, multifocal, placoid
, pigment epitheliopathy and Lyme disease.
Shark skins bear thousands of rigid denticles, or placoid
scales, comprised of hard materials, such as dentin and enamel, which are high in strength and stiffness (Raschi and Tabit, 1992).
Raschi W Tabit C (1992) Functional aspects of placoid
scales: a review and update.
Secondly we assign isolated placoid
scales from synchronous levels of two stratigraphical sections (Middle Triassic) of the Iberian Chain (Spain), to these "functional" morphologies.
2002), and questionably identified from a placoid
scale from South Carolina, U.
scales in sharks are formed of dentine with dermal papillae located at their core.
Syphilitic chorioretinitis presents as a vitritis associated with bilateral, large, solitary, placoid
, pale yellow subretinal lesions with central fading and stippled retinal pigment epithelial (RPE) hyperpigmentation.
Syphilitic posterior uveitis may present as multifocal chorioretinitis, acute posterior placoid
chorioretinitis4, neuroretinitis and retinal vasculitis.