Branching basal

Description Herbaceous biennial. Stems erect, single or few, 30-80 cm tall, sometimes branched. Basal rosette leaves peli-olate, linear-lanceolate, margins entire lower cauline leaves short-petiolate upper cauline leaves sessile, margins entire. Inflorescence a few-flowered raceme. Flowers small, perfect, pedicellate. Petals 4, yellow. Stamens 6 (tetradynamous), erect. Fruits 4-sided sUiques, thin, 3-10 cm long, 1-1.5 nun wide, whitish, hairy. Seeds ellipsoid, yellow-brown, up to 1.5 nun long. 

The normal coronary system consists of large epicardial or surface vessels (Rj) that offer little resistance to myocardial flow and intramyocardial arteries and arterioles (R2), which branch into a dense capillary network to supply basal blood flow (Fig. 11-1). Under normal circumstances, the resistance in R2 is much greater than that in Rj. Myocardial blood flow is inversely related to arteriolar resistance and directly related to the coronary driving pressure. 

Figure 11.1 Ultrastructure of the human lung alveolar barrier. The tissue specimen is obtained via lung resection surgery. (A) Section through a septal wall of an alveolus. The wall is lined by a thin cellular layer formed by alveolar epithelial type I cells (ATI). Connective tissues (ct) separate ATI cells from the capillary endothelium (en) within which an erythrocyte (er) and granulocyte (gc) can be seen. The minimal distance between the alveolar airspace (ai) and erythrocyte is about 800-900 nm. The endothelial nucleus is denoted as n. (B) Details of the lung alveolar epithelial and endothelial barriers. Numerous caveolae (arrows) are seen in the apical and basal plasma membranes of an ATI cell as well as endothelial cell (en) membranes. Caveolae may partake transport of some solutes (e.g., albumin). (C) ATII cells (ATII) are often localised in the comers of alveoli where septal walls branch off. (D) ATII cells are characterised by numerous multilamellar bodies (mlb) which contain components of surfactant. A mitochondrion is denoted as mi.

Another reason to consider a novel role for the cholinergic basal forebrain is that cholinergic axons exhibit exquisite structural plasticity, similar to that of monoaminergic axons, and in marked contrast to that of glutamatergic axons (Farris et ah, 1993 Woolf, 1996). Wholly new cholinergic axon branches bear-... 

Auxiliary cell cut off after fertilization from a basal cell of the carpogonial branch.Order Ceramiales... 

Auxiliary cell arising from a daughter cell of the basal cell of an assimilative branch.Order Rhodymeniales... 

Herbs with rhizomes, corms, or bulbs, or rarely woody climbers stems leafy or leaves basal, or radical, or rarely reduced to scales and then with the branches becoming cladodes a very large complex, the lilies, which is very difficult to delimit.Order Liliales... 

Also present in the epidermis are embedded macrophage-like Langerhans cells as well as pigmented melanocytes, cells with highly branched dendrites, which lie just above the basal stem cell layer. Each melanocyte contains hundreds of pigmented organelles called melanosomes. They contain not only the black or reddish melanin pigments but also the enzymes needed to form them (Chapter 25).n o... 

Jerusalem artichoke stems can grow to 3 m or more in height, though most clones are shorter. Dwarf clones have been selected (Zubr and Pedersen, 1993). The stems are stout and heavily trichomed when young. Initially the stems are quite succulent but become woody over time. Branches vary in number and position on the main stems. The stems arise directly from the seed tuber, with branches forming at nodes on the stem. Basal branches may form underground and at the soil surface appear to be stems hence, estimates of stem number per plant are variable. 

The anterior cerebral artery passes horizontally and medially to enter the interhemi-spheric fissure it then anastomoses with its counterpart of the opposite side via the anterior communicating artery, curves up around the genu of the corpus callosum and supplies the anterior and medial parts of the cerebral hemisphere. Small branches also supply parts of the optic nerve and chiasm, hypothalamus, anterior basal ganglia and internal capsule. 

The middle cerebral artery enters the Sylvian fissure and divides into two to four branches, which supply the lateral parts of the cerebral hemisphere. From its main trunk, a medial and lateral group of tiny lenticulostriate arteries and arterioles pass upwards to penetrate the base of the brain and supply the basal ganglia and internal capsule (Marinkovic et al. 1985). Some of these small penetrating vessels extend up into the white matter of the corona radiata in the centrum semiovale towards the small medullary perforating branches of the cortical arteries coming down from above. 

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