Anatomy of the buccal fat pad and its clinical significance

Interest in the anatomy of the buccal fat pad was aroused by two clinical cases where the fat pad was involved by pathology. In one, there was an extensive lipoma of the buccal fat pad which had been unsuccessfully operated on on two previous occasions. The reason for the lack of success was incomplete removal of the fat pad. In the second case, there was an arteriovenous malformation involving the fat pad which necessitated complete removal. Fresh cadaver dissections were carried out to accurately determine the anatomy. Particular attention was paid to the temporal extension, since this area is frequently disregarded.     

The anatomy and clinical applications of the buccal fat pad

The buccal fat pad is an anatomically complex structure that has great importance in facial contour. In properly selected individuals, judicious harvesting of buccal fat can produce dramatic changes in facial appearance by reducing the fullness of the cheek and highlighting the malar eminences. Using fresh cadaver dissection, the anatomy of the buccal fat pad is delineated and its relationship to the masticatory space, facial nerve, and parotid duct is defined. An intraoral approach for buccal fat harvesting is described based on these anatomic findings. Clinical experience manipulating the buccal fat pad for aesthetic modification of facial contour is illustrated.     

Structural characteristics and functional significance of the buccal fat pad (corpus adiposum buccae)

Corpus adiposum buccae (c.a.b.) was studied on 42 human subjects (fetuses and adults) using microdissection under magnifying glass after injection of the great vessels of the head with plastics, transparency technique of Spalteholtz and current histological methods. In fetuses, c.a.b. appeared as a well-developed mass located between Buccinator and inferior border of the Masseter. In adults, it emanated three prolongations among which the anteriorly directed molar prolongation was more conspicuous in edentulous old people. Externally, it was covered by a fine conjunctival wrap, which sent septa dividing the buccal fat pad in a series of minute fibroadipous compartments. C.a.b. contained a rich vascular network deriving from the branches of the facial and maxillary arteries. In this vascular net a more developed artery emanated branches to the prolongations of the c.a.b. The veins were tributaries of the pterygoid venous plexus. Beside the vessels, c.a.b. contained also lymphatics and myelinated nerves. The authors postulated that c.a.b. assumed the following functions: a) It filled up the masseter-zygomaticus-buccinator space forming an amortizing and a slipping platform for the masticatory muscles in action; b) in the baby, it resisted to the negative pressure which acted into the buccal cavity during sucking; c) its rich venous net, provided with valve-like structures, may be implicated in the exo-endocranial blood flow by means of the pterygoid plexus.     

Anatomical adaptations of shrews

The family Soricidae is reviewed with special regard to anatomical structures related to habitat and life-style. Some 266 species in 20 genera are classified into six feeding and foraging categories: terrestrial, semifossorial, scansorial, semiaquatic, psammophilic and anthropophilic. Examples of corresponding anatomical adaptations are given as well as notes on adaptive radiation and convergent evolution.     

斜方肌皮瓣的解剖学研究及临床应用

目的：通过对斜方肌、菱形肌的解剖学研究,了解其血供特点,为临床应用该肌皮瓣提供解剖学依据。方法：界成年男尸30具、60侧,观察和测量斜方肌、菱形肌的血供来源、经行及分支分布。临床应用该组织瓣5例。结果：斜方肌接受双重血供,其上3／5至2／3接受颈横动脉血供,下2／5至1／3和菱形肌主要接受肩胛背动脉血供。用低位斜方肌和菱形肌皮瓣修复头颈、颌面部组织缺损5例,均获满意效果。结论：斜方肌、菱形肌的血供可靠,血管分支分布较恒定,血管蒂长,是修复颅枕部、项部、侧颅底、颅颌颈组织缺损理想的肌皮瓣。     

Wood structure of Aegiceras corniculatum and its ecological adaptations to salinities

We describe the wood structure of Aegiceras corniculatum and its differences under various soil salinities. This species had diffuse-porous wood with poorly defined growth rings. Vessels which had single perforations occurred abundantly and in multiples and were storeyed. Intervascular pits between contiguous vessels were alternate bordered ones while half-bordered pit-pairs existed between both vessel-ray and vessel-parenchyma. Homogenous xylem rays were multiseriate and uniseriate. Fiber-tracheids with bordered pits often had thinner walls. Xylem parenchyma cells were scant and distributed diffusely and paratracheally. Differences in the structural and quantitative characters of vessels, xylem rays and fiber-tracheids under diverse soil salinities are described. This revised version was published online in August 2006 with corrections to the Cover Date.     

Euryhaline adaptations in the fat sleeper, Dormitator maculatus

Salinity tolerances and plasma osmotic concentrations were determined in the fat sleeper, Dormitator maculatus , a common species in estuarine and coastal fresh waters along the Atlantic and Caribbean coasts of North, Central and South America. Analyses followed sequential laboratory acclimations to a series of ambient salinities at a constant temperature of 20 ± 1° C and photoperiod of 12L: 12D. These fish tolerated a range of ambient salinities from fresh water through a salinity of 75‰. Plasma osmotic concentrations were regulated at an essentially constant level in the salinity range from fresh water through a salinity of 50‰, beyond which plasma concentrations trended upward with increased ambient salinity. We conclude that D. maculatus , while truly euryhaline, docs not show the extreme euryhalme capabilities of several teleost fishes that are 'full-time' estuarine inhabitants.     

Brown adipose tissue in the parametrial fat pad of the mouse

Cold acclimation has been shown to produce a substantial increase in the number of brown adipocytes in the parametrial fat pad of female BALB/c mice-a site normally thought to consist of typical white adipocytes. The brown adipocytes have been identified not only on the basis of their morphology using light and electron microscopy, but also on the basis of the content of the mitochondrial 'uncoupling protein' (Mr = 32000) which is characteristic of the proton conductance pathway of brown adipose tissue.     

Anatomical adaptations of Astragalus gombiformis Pomel. under drought stress

The present study was designed to study the effect of drought on root, stem and leaf anatomy of Astragalus gombiformis Pomel. Several root, stem and leaf anatomical parameters (cross section diameter, cortex, root cortical cells, pith, leaf lamina and mesophyll thickness) were reduced under moderate to severe water deficit (20–30 days of withheld irrigation). The stele/cross section root ratio increased under moderate water deficit. The root’s and stems vascular systems showed reduced xylem vessel diameter and increased wall thickness under water deficit. In addition, the root xylem vessel density was increased in these drought conditions while it was unchanged in the stems. The stomata density was increased under prolonged drought conditions whereas the stomata size was untouched. The leaf vascular system showed reduced xylem and phloem tissue thickness in the main vein under moderate to severe water deficit. However, in the lamina the vascular tissue and the distance between vascular bundle were unaffected. Our findings suggest a complex network of anatomical adaptations such as a reduced vessel size with increased wall thickness, lesser cortical and mesophyll parenchyma formation and increased stomata density. These proprieties are required for the maintenance of water potential and energy storage under water stress which can improve the resistance of A. gombiformis to survive in arid areas.     

Metabolism and structure of triacylglycerols in rat epididymal fat pad adipocytes determined by 13C nuclear magnetic resonance

Carbon-13 nuclear magnetic resonance (NMR) methods have been applied to a study of the structure and metabolism of the triacylglycerols from rat epididymal fat pad adipocytes. Complete NMR signal assignments are provided for adipocytes, the extracted triacylglycerols, and methyl esters of the derived fatty acids. 13C NMR yielded rapid, nondestructive, quantitative analysis of the amounts of unsaturation of the fatty acyl chains; in cells from rats given ad libitum access to a standard laboratory diet the predominant fatty acids were found to be palmitate (29.9%), oleate (27.9%), and linoleate (34.1%). These results agreed with gas chromatographic separation of the derived methyl esters of the extracted lipids. Lipid dynamics were examined in situ and showed a substantial restriction of motion of glyceride-glycerol as compared with free glycerol; the nuclear magnetic spin-lattice relaxation times for free glycerol of 2.52 +/- 0.12 (C1,3) and 4.37 +/- 0.21 (C2) s decreased to 0.15 +/- 0.009 and 0.21 +/- 0.013 s, respectively, upon esterification. Segmental motion of the chains, monitored by relaxation time measurements, increased progressively from the alpha-carbon (nT1 = 0.70 s) to the methyl ends of the chains (nT1 = 9.63). The incorporation of C-13-labeled substrates ([1-13C]glucose and [3-13C]lactate) into the glycerol moiety of triacylglycerols was monitored in real time, in the presence of insulin. Lactate (10 mM) inhibited the incorporation of glucose (5.5 mM) into glyceride-glycerol. Lipolysis at the natural abundance level of 13C was measured in the presence of 10 microM isoproterenol. Simultaneous lipogenesis and lipolysis were found to occur in situ and were measured with the aid of [1-13C]glucose and isoproterenol; the labeling pattern of medium glycerol versus extracted triacylglycerols was significantly different from that found using natural abundance glucose. Our results indicate that 13C NMR is a useful new method for the real-time monitoring of lipid structure and metabolism in vivo.