Anatomy, variations

Stomach, variations in form. From laboratory specimens. The author is deeply indebted to Dr. Barry J. Anson of Northwestern University, who has kindly allowed him to reproduce illustrative material from his valuable Atlas of Human Anatomy (W. B. Saunders Co., Philadelphia, Pa., 1951). This illustration is on page 287. 

Pelvic colon. Variation in form and position. Diagrammatic. Major types (I to IX) are illustrated, together with varieties (A to C, etc.) within the more inclusive categories. The percentage occurrence of each type and subtype is recorded, as determined from an examination of 210 specimens. From Barry J. Anson, Atlas of Human Anatomy, p. 349. 

Liver, variations in form. Laboratory specimens. Anterior views. From Barry J. Anson, Atlas of Human Anatomy, p. 288. 

Accompanying the variations in heart anatomy are variations in function as well. In a series of 182 normal young men8 it was found that the heart rates ranged from 45 to 105 beats per minute. The pumping capacities of normal hearts vary from 3.16 to 10.81 liters of blood per minute.9... 

Branches of the aortic arch. Variation in the pattern of origin, a and b, Common pattern c and d, left common carotid artery from the innominate (long and short stem) e, separate origin of a thyreoidea ima artery / independent origin of a left vertebral. From Barry J. Anson, Atlas of Human Anatomy, p. 197. 

Blood itself, from the standpoint of anatomy, shows wide variations in its make-up. We are now speaking of course, in terms of microscopic anatomy, since macroscopically blood has no structure. 

Since we are digressing somewhat from biochemical consideration it may be well to remind ourselves that the basic anatomy, including the musculature, is not the same in men and women for this reason a woman cannot throw a ball as a man can, nor can women run in competition with men. However, as swimmers women show up very well, in contrast to their lack of ability to throw well or run fast Within the sexes, however, there are variations in anatomy so that... 

We will merely call attention here to the tremendous inter-individual human variability which exists in the anatomy of the endocrine glands. This variability is foreshadowed by the data already given with respect to rabbits and pigeons (pp. 2021). Since a separate chapter is devoted to these glands and their functioning, specific anatomical information with respect to the specific glands will be presented there. It is possible that these anatomical variations are more important from the standpoint of health and well-being than any we have so far discussed. 

Both hypo- and hyperparathyroidism have been observed in human beings, and, if the principle of genetic gradients (p. 13) is valid, various intermediate levels of hormone activity will be found in the general population. Although the data on the subject, with the exception of that concerning anatomy, are not definitive, there would seem to be little doubt as to the existence of several-fold variation in the parathyroid activities of "normal" individuals. 

In Table 15 is given pertinent information with respect to the anatomical variations in human pituitary glads.26,27,28 Detailed comparative study of the patterns of individual glands has not been attempted, but there is nothing in the available data to preclude the existence of wide inter-individual differences with respect to the detailed anatomy and the machinery for the production of each specific hormone. 

It seems inevitable in view of our discussion on variations of anatomy and of heart outputs that normal individuals should have circulatory peculiarities. An extreme case of what may be a circulatory peculiarity has been called to my attention. This individual continually has a problem of cold feet he uses a heating pad under his working desk, carries one around with him and on social occasions sits near an electric outlet, plugs it in, and attempts to be comfortable. It seems likely that this individual suffers because of unrecognized... 

Much of the inter-species variation in pharmacokinetic properties can be explained as a consequence of body size (allometry). Consequently it is possible to scale pharmacokinetic parameters to the organism s individual anatomy, biochemistry and/or physiology in such a manner that differences between species are nuUified. Several excellent reviews on allometric scaling are available in the literature [2-7]. Allometric relationships can be described by an equation of the general form ... 

Differences in the physiology and anatomy of the udder, the level of milk production, and the stage of lactation may sometimes be the cause of residue violations in milk. Failure to observe the proper withdrawal period after prophylactic and therapeutic use for mastitis might be simply due to some variation from the established milk-out rates (66). 

FIGURE 19-1 Biochemical anatomy of a mitochondrion. The convolutions (cristae) of the inner membrane provide a very large surface area. The inner membrane of a single liver mitochondrion may have more than 10,000 sets of electron-transfer systems (respiratory chains) and ATP synthase molecules, distributed over the membrane surface. Heart mitochondria, which have more profuse cristae and thus a much larger area of inner membrane, contain more than three times as many sets of electron-transfer systems as liver mitochondria. The mitochondrial pool of coenzymes and intermediates is functionally separate from the cytosolic pool. The mitochondria of invertebrates, plants, and microbial eukaryotes are similar to those shown here, but with much variation in size, shape, and degree of convolution of the inner membrane. 

Korner C, Bannister P, Mark AF (1986) Altitudinal variation in stomatal conductance, nitrogen content and leaf anatomy in different plant life forms in New Zealand. Oecologia 69 577-588 Korner C, Cochrane PM (1985) Stomatal responses and water elations of Eucalyptus pauciflora in summer along an elevational gradient. Oecologia 66 443-455... 

Nappi G, Antonelli F, Coltorti M, Milani A, Renzulli A, Siena F (1998) Volca-nological and petrological evolution of the Eastern Vulsini District, Central Italy. J Volcanol Geotherm Res 87 211-132 Nazzareni S, Molin M, Peccerillo A, Zanazzi PF (2001) Volcanological implications of crystal chemical variations in clinopyroxenes from the Aeolian arc (Southern Tyrrhenian Sea, Italy). Bull Volcanol 63 73-82 Nicolich R (2001) Deep seismic transects. In Vai GB, Martini PI (eds) Anatomy of an Orogen. The Apennines and adjacent Mediterranean basins. Kluwer, Dordrecht, pp 47-52... 

Zaborszky L, Vadasz C (2001) The midbrain dopaminergic system anatomy and genetic variation in dopamine neuron number of inbred mouse strains. Behav Genetics 37 47-59. 

The detailed anatomy of the cerebral circulation is well described by Sheldon (1981). There is individual variation in arterial anatomy and thus in the territories of supply of the various major arteries, which can be asymmetrical and may change over time, depending on obstruction to vessel flow and the availability of functional collaterals (van der Zwan et al. 1992) (Fig. 4.3). Developmental anomalies of the major cerebral vessels include ... 

Schmahmann JD (2003). Vascular syndromes of the thalamus. Stroke 34 2264-2278 Schulz UG, Rothwell PM (2001). Major variation in carotid bifurcation anatomy a possible risk factor for plaque development Stroke 32 2522-2529 Scott BL, Jankovic J (1996). Delayed-onset progressive movement disorders after static brain lesions. Neurology 46 68-74 Wardlaw JM, Merrick MV, Ferrington CM et al. (1996). Comparison of a simple isotope method of predicting likely middle cerebral artery occlusion with transcranial Doppler ultrasound in acute ischaemic stroke. Cerebrovascular Diseases 6 32-39 Wardlaw JM, Lewsi SC, Dennis MS etal. (1999). Is it reasonable to assume a particular embolic source from the type of stroke Cerebrovascular Diseases 9(Supp 1) 14... 

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