Stem anatomy

FIGURE 29-1. Anatomy of the extrapyramidal system. The extrapyramidal motor system controls muscle movement through a system of pathways and nerve tracts that connect the cerebral cortex, basal ganglia, thalamus, cerebellum, reticular formation, and spinal neurons. Patients with Parkinson s disease have a loss of dopamine neurons in the substantia nigra in the brain stem that leads to depletion of dopamine in the corpus striatum. The corpus striatum is made up of the caudate nucleus and the lentiform nuclei that are made up of the putamen and the globus pallidus. 

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. 

The anatomy of softwoods will be described first because it is less complex than hardwoods. The two main cell types which constitute softwoods are tracheids, which conduct and support, and parenchyma which store food. These two cell types can be further classified as to their orientation, that is longitudinal or transverse. Cells oriented in the longitudinal direction have the long axis of the cell oriented parallel to the vertical axis of the tree trunk whereas transversely oriented cells have their long axis at right angles to the vertical axis of the tree stem. 

The anatomy of the tuber is shown diagrammatically in Figure 11.2. Parts that can be distinguished are the skin (periderm) with the lenticels, the eyes, the bud and stem ends, the cortex, the ring of vascular bundles, the perimedullary zone, and the pith with medullary rays which are homologous with the medulla of the stolon.7... 

Fig. 6-1. Main bark tissues young stem (A), mature bark (B) (Chang, 1954). (c) 1954 TAPPI. Reprinted from Anatomy of Common North American Pulpwood Barks, TAPPI Monograph 14, with permission.

NAGY, N.E., FRANCESCHI, V.R., SOLHEIM, H., KREKLING, T., CHRISTIANSEN, E., Wound-induced traumatic resin duct development in stems of Norway spruce (Pinaceae) anatomy and cytochemical traits., Amer. J. Bot., 2000, 87,302-313. 

Speck, T, O. Speck, A. Emanns, and H.-CH. Spatz. 1998. Biomechanics and functional anatomy of hollow stemmed sphenopsids II. Equisetum hyemale. Botanica Acta 111 366-376. 

The anatomy of the uterine artery has relevance to the procedure of UAE. When the uterine artery arises from the anterior division of the internal iliac artery, the contralateral oblique projection gives the best visualization of its origin, allowing for easier catheterization [4, 9]. When the uterine artery is arising from several stems, then the ipsilateral projection is the best for visualization [4,9]. 

Duan et al. (1998) studied a newborn/erret tracheal model to probe the contribution of tracheal submucosal gland stem cells to repopulating the surface mucosa. They used this model since it shows a very similar anatomy of submucosal gland distribution to that in humans. Mice have no submucosal glands in the lower cartilaginous airways. 

Another explanation, based on anatomy, is also possible. When the auxin is applied to a cut surface, most of it may be transported in the cortex. If so, the ethylene that it engenders would be near the stem surface, and thus be readily removed by the reduced pressure. But auxin produced by the living apex may be transported partly within the stele, so that the resulting ethylene would not be so freely exposed to the reduced pressure however, it would still inhibit the bud development since these primordia originate in the stele. 

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