Surgical anatomy of the internal carotid artery

Starting from the carotid trigone, a surgical approach to the parapharyngeal part of the internal carotid artery is described. The retrostyloidal part of the lateropharyngeal space is opened up from laterocaudal after resecting the posterior belly of the digastric muscle and the styloidal muscles. Vulneration of the cranial nerves (VII, IX, X) has to be prevented.     

A comparative analysis of internal cranial anatomy in the hylobatidae

Craniometric studies on the hylobatids using external metrics (Creel and Preuschoft, 1976 , 1984 ) sorted hylobatid populations into primary species groupings which are in accordance with the four currently recognized generic‐level groupings. The goal of the current study was to assess the relative orientations of the orbits, palate, and basioccipital clivus among the hylobatid genera in an effort to further clarify whether the lesser apes differ significantly in these internal cranial features and how that variation patterns across the groups. Nine angular variables quantifying orbital, palatal, and basioccipital clivus orientations were measured on lateral view radiographs of adults representing three of the four hylobatid genera: Hylobates; Nomascus; and, Symphalangus. The interspecific adult hylobatid means for the angular variables were analyzed using t‐test contrasts. The total sample was further subjected to discriminant function analysis (DFA) to test for the ability of craniofacial angular variables to distinguish the hylobatid genera from one another. The three hylobatid genera displayed significant morphological differentiation in orbital, palatal, and posterior skull base orientations. Normal, jackknifed, and cross‐validation DFA procedures correctly identified the hylobatids 50–100% of the time. The observed morphological patterns generally mapped onto the findings of earlier external craniometric hylobatid studies and suggest concordance between specific internal and external cranial features. This article is the first comprehensive study of variation in internal cranial anatomy of the Hylobatidae and includes the first published craniofacial angular data for Nomascus. Am J Phys Anthropol 143:250–265, 2010. © 2010 Wiley‐Liss, Inc.     

Comparative study of the anatomy and laminar organization in the olfactory bulb of three orders of freshwater teleosts

The anatomy and lamination of the olfactory bulb in Cyprinus carpio, Tinca tinca, Barbus bocagei (Fam. Cyprinidae, Or. Cypriniformes); Salmo gairdneri (Fam. Salmonidae, Or. Salmoniformes); and Gambusia affinis (Fam. Poeciliidae, Or. Cyprinodontiformes), all of them freshwater teleosts, are studied. These species show significative differences on the location, size, morphology, and lamination of their olfactory bulbs. The presence of a new stratum in the olfactory bulb of Salmo gairdneri and a completely different laminar organization in the olfactory bulb of Gambusia affinis are described for the first time. The anatomical and histological peculiarities of this structure in the orders studied could be the basis for different experimental approaches.     

Foliar anatomy ofPolygonum (Polygonaceae): Survey of epidermal and selected internal structures

Several anatomical characters in leaves were described, and their distribution determined, for 153 species ofPolygonum, mostly from herbarium specimens. Structures surveyed were epidermal (glandular and nonglandular trichomes, nodules, specialized parenchyma, stomatal apparatus) and internal (cavities, crystals, laticifer-like cells, nodules, subepidermal fibers). Cleared leaves were supplemented by resin-embedded sections and SEM preparations of selected species. No feature defines any taxonomic section, but some features occur only within one section. Laticifer-like cells, epidermal and internal nodules, resin cups, and unique epidermal and subepidermal cavities seem to be unknown elsewhere; other features (invaginated epidermal cells; enlarged crystal cells confined to paraveinal layer) are rare among angiosperms.     

Inferring internal anatomy from the trilobite exoskeleton: the relationship between frontal auxiliary impressions and the digestive system

Lerosey‐Aubril, R., Hegna, T.A. & Olive, S. 2011: Inferring internal anatomy from the trilobite exoskeleton: the relationship between frontal auxiliary impressions and the digestive system. Lethaia, Vol. 44, pp. 166–184. The digestive system of trilobites is rarely preserved. As a result, many aspects of its organization remain unknown. Fortunately, the exoskeleton sometimes preserves evidence of soft‐tissue attachment sites that can be used to infer internal anatomy. Among them are the frontal auxiliary impressions (FAIs), probable soft‐tissue insertion sites located on the fronto‐median glabellar lobe of some trilobites. FAIs are herein described in the Carboniferous trilobite Phillipsia belgica Osmólska 1970 – representing the only known example of such structures in the Proetida and their youngest occurrence. A taphonomic scenario is proposed to explain their variable preservation. Although particularly common in the Phacopina, FAIs or FAI‐like structures are also found in several orders that differ greatly. Comparisons with modern analogues suggest that FAIs might represent attachment sites for extrinsic muscles associated with a differentiated crop within the foregut. A review of purported remains of the trilobite digestive system indicates that it usually consisted of a tube‐like tract flanked by a variable number of metamerically paired diverticulae. Its anterior portion is not particularly individualized, except in a few specimens that might hint at the presence of a crop. This differentiation of a crop might have constituted a secondarily evolution of the foregut in trilobites, occurring independently in different clades. Accompanied by a strengthening of associated extrinsic muscles, this modification of the foregut might explain the presence of more conspicuous muscle insertion sites on the glabella. Study of FAIs might therefore provide new data on the anatomy of the foregut in trilobites and evidence of diverse feeding habits. □Arthropoda, digestive system, ecology, muscle scars, Proetida, Trilobita.     

Anatomy of the serotonergic nervous system of an entoproct creeping-type larva and its phylogenetic implications

Abstract. Although the internal phyletic relationships of Spiralia (and Lophotrochozoa) remain unresolved, recent progress has been made due to molecular phylogenetic analyses as well as developmental studies of crucial taxa such as Mollusca, Sipuncula, or Annelida. Despite this progress, the phylogenetic position of a number of phyla, such as Entoprocta, remains problematic, mainly due to their unique morphology, their aberrant mode of development, and their exclusion in most large-scale phylogenetic analyses. In order to extend the morphological dataset of this enigmatic taxon, we herein describe the anatomy of the serotonergic nervous system of the creeping-type larva of Loxosomella murmanica . The apical organ is very complex and comprises six to eight centrally positioned flask cells and eight bipolar peripheral cells. In addition, a prototroch nerve ring, an anterior nerve loop, a paired buccal nerve, and an oral nerve ring are found. Moreover, the larva of L. murmanica has one pair of pedal and one pair of lateral longitudinal nerve cords and thus expresses a tetraneurous condition. Several paired serotonergic perikarya, which form contact with the pedal nerve cords but not with the lateral ones, are found along the anterior–posterior axis. The combination of a complex larval serotonergic apical organ and (adult) tetraneury, comprising one pair of ventral and one pair of more dorsally situated lateral longitudinal nerve cords without ganglia, has so far only been reported for basal molluscs and may be diagnostic for a mollusc–entoproct clade. In addition, the larva of Loxosomella expresses a mosaic of certain neural features that are also found in other larval or adult Spiralia, e.g., a prototroch nerve ring, an anterior nerve loop, and a buccal nervous system.     

Clinical anatomy of the blood spaces and blood vessels surrounding the siphon of the internal carotid artery

The anterior blood space of the cavernous sinus is situated anterolateral to the carotid siphon in 70%, anterior to it in 15%, and lateral to it in 15%. Its height, depth, and mediolateral breadth were measured. The mean distance between the carotid siphon and the skin at the supraorbital foramen was measured with 63 (52.4-71.4) mm. The drainage of the orbital veins was studied and described as well as the area of origin and first course of the ophthalmic artery and its clinical importance.     

The internal cranial anatomy of the Plesiosauria (Reptilia, Sauropterygia): evidence for a functional secondary palate

In the late 19th Century, the choanae (or internal nares) of the Plesiosauria were identified as a pair of palatal openings located rostral to the external nares, implying a rostrally directed respiratory duct and air path inside the rostrum. Despite obvious functional shortcomings, this idea was firmly established in the scientific literature by the first decade of the 20th Century. The functional consequences of this morphology were only re-examined by the end of the 20th Century, leading to the conclusion that the choanae were not involved in respiration but instead in underwater olfaction, the animals supposedly breathing with the mouth agape. Re-evaluation of the palatal and internal cranial anatomy of the Plesiosauria reveals that the traditional identification of the choanae as a pair of fenestrae situated rostral to the external nares appears erroneous. These openings more likely represent the bony apertures of ducts that lead to internal salt glands situated inside the maxillary rostrum. The 'real' functional choanae (or caudal interpterygoid vacuities), are situated at the caudal end of the bony palate between the sub-temporal fossae, as was suggested in the mid-19th Century. The existence of a functional secondary palate in the Plesiosauria is therefore strongly supported, and the anatomical, physiological, and evolutionary implications of such a structure are discussed.