title: Ultrastructure and distribution of epidermal sensory receptors in the beak of the echidna, Tachyglossus aculeatus.
abstract: Within the rostral one centimetre of the Echidna beak, three specialised receptors were found: a mucous sensory gland, a rod-like structure, and an innervated epidermal pit. The mucous sensory gland consists of a dermal mucous gland and a modified epidermal portion. Bulbous nerve terminals, similar to those reported for the Platypus, were found within the modified epidermal portion of the mucous gland. The rod-like structure contains four types of nerve terminals: Merkel cells, Paciniform corpuscles, and a central and a peripheral vesicle chain receptor. Apart from minor differences, the rod-like structure is similar to that previously reported for the Platypus. Preliminary results are presented for a third structure: an innervated epidermal pit. Topographical and ultrastructural analyses are used in the context of functional interpretation.
authors: Department of Physiology and Pharmacology, Anatomical Sciences University of Queensland, St Lucia, Australia.
authors: P R
authors: PR
authors: Manger
authors: R L
authors: RL
authors: Hughes
mesh_terms: D000818:Animals; D001369:Axons / Q000648:ultrastructure; D001502:Beak / Q000294:innervation*; D004817:Epidermis / Q000294:innervation; D005088:Exocrine Glands / Q000033:anatomy & histology; D015603:Keratinocytes / Q000648:ultrastructure; D008465:Mechanoreceptors / Q000033:anatomy & histology*; D009093:Mucus / Q000378:metabolism; D009413:Nerve Fibers, Myelinated / Q000648:ultrastructure; D011984:Sensory Receptor Cells / Q000033:anatomy & histology*; D012867:Skin / Q000294:innervation*; D004442:Tachyglossidae / Q000033:anatomy & histology*; D014276:Trigeminal Nerve / Q000033:anatomy & histology*