Kidneys inner medulla

Figure 3. Immunofluorescent localization of AQP2 in cryosections of kidney inner medulla, (a) In control rats, collecting ducts labeled prominently with antibodies against AQP2. No other structures were labeled, (b) After lithium treatment, only traces of labeling remained, (c) Thirsting for 48 h in the continued presence of lithium increased expression relative to lithium alone, but levels are still lower than seen in controls. Labeling was widely distributed throughout the cells.

The adrenal gland lies on the superior surface of each kidney. It is a double organ composed of an outer cortex and an inner medulla In response to ACTH secreted by the anterior pituitary, the adrenal cortex secretes several hormones (the glucocorticoids, the mineralocorticoids, and small amounts of sex hormones). 

The adrenal gland is located on the upper segment of the kidney (Fig. 42-1). It consists of an outer cortex and an inner medulla. The adrenal medulla secretes the catecholamines epinephrine (also called adrenaline) and norepineprhine (also called noradrenaline), which are involved in regulation of the sympathetic nervous system. The adrenal cortex consists of three histologically distinct zones zona glomerulosa, zona fasciculata, and an innermost layer called the zona reticularis. Each zone is responsible for production of different hormones (Fig. 42-2). 

Takenaka M et al. Gene expression profiling of the collecting duct in the mouse renal inner medulla. Kidney Int 2000 57 19-24. 

The kidneys are paired encapsulated organs, each weighing approximately 150 g, and typically 11x6x3 cm with a smooth outer surface. A longitudinal cut reveals two distinct layers the dark reddish coloured outer cortex which makes up about 70% of the tissue mass and the paler coloured inner medulla. 

The glands are situated above each kidney and consist of two parts, an outer cortex and inner medulla. The cortex... 

Adrenal glands are located at the superior poles of each kidney. Each adrenal gland is composed of an outer cortex and an inner medulla. The hormones associated with the adrenal cortex and adrenal medulla are described in the following sections. 

In urea-rich fishes and in the inner medulla of the mammalian kidney, there characteristically is found a set of methylammonium solutes whose effects on proteins are opposite to those of urea (figure 6.6). Different methylamines predominate in different species. For instance, TMAO and glycine betaine are the most prevalent methylamines in elasmobranchs, and glycerophosphorylcholine (GPC) may be especially important in mammalian kidneys (figures 6.1 and 6.2). Despite interspecific differences in the types of methylamines present in cells, a common effect is noted when urea and methylamine solutes are both included in experimental media, an algebraic additivity generally is observed in their influences on proteins. Thus, if urea shifts a property in one direction and a methylamine shifts it in the opposite direction, the net change in the property in a... 

It is instructive to compare the mechanisms used by mammalian kidney cells to adapt to hyperosmotic stress with the osmoregulatory mechanisms used by soil bacteria exposed to high ambient osmolality. The unity in diversity so commonly found in comparative biochemistry is well illustrated by this comparison. Cells of the inner medulla of the mammalian kidney, like hyperosmotically stressed bacteria cells, (i) accumulate compatible organic osmolytes when... 

Figure 6.17. Regulation of organic osmolytes by cells of the inner medulla of the mammalian kidney (after Burg et al., 1997). Thick arrows denote processes that are regulated by changes in osmolality. Activities and/or concentrations of enzymes and transporters involved in uptake and synthesis of osmolytes change slowly relative to activities of leakage pathways. PLase phospholipase, GPC-PDE glycerol phosphorylcholine-phosphodiester-ase.

The kidney can be divided into two main anatomic areas the major outer part— the cortex and the inner medulla, with the glomeruli, proximal convoluted tubules, and distal convoluted tubules located within the cortex—and the remaining parts of the nephrons lying within the medulla. The collecting ducts extend through the medulla to the renal papillae, which drain via the renal pelvises into the ureters and thence to the bladder, where fluid is stored prior to urination. There are some differences between species, and not all are related to body size and its proportionality (Davies and Morris 1993) (Table 4.1). 

Isolated rat kidneys perfused with a gassed (95 % O2 and 5 % CO2) albumin-Krebs-Henseleit solution, after 2 h displayed a characteristic pattern of cell necrosis, which was confined to the interbundle region of the outer medulla and was not evident in either the cortex or the inner medulla (Schurek and Kriz 1985). In the outer stripe only those proximal... 

Lymph nodes vary in size and are aggregates of lymphatic tissue. Kidney bean-shaped, each consists of a cortex containing germinal centers and an inner medulla. Reticuloendothelial ceils are located along trabecular connective tissue and act as a filtration system for particulate matter. An efferent lymph vessel exits at the hilum, along with a vein, and is accompanied by an artery. An afferent lymph vessel enters on the convex side through the capsule. 

The kidneys lie outside the peritoneal cavity in the posterior abdominal wall, one on each side of the vertebral column, slightly above the waistline. In the adult human, each kidney is approximately 11 cm long, 6 cm wide, and 3 cm thick. These organs are divided into two regions the inner renal medulla and the outer renal cortex. The functional unit of the kidney is the nephron (see Figure 19.1 and Figure 19.2). Approximately 1 million nephrons are in each kidney. The nephron has two components ... 

The vasa recta are modified peritubular capillaries. As with the peritubular capillaries, the vasa recta arise from efferent arterioles. However, these vessels are associated only with the juxtamedullary nephrons and are found only in the medullary region of the kidney. The vasa recta pass straight through to the inner region of the medulla, form a hairpin loop, and return straight toward the cortex. This structure allows these vessels to lie parallel to the Loop of Henle and collecting ducts. 

Adrenal gland A triangle-shaped organ positioned at the top of the kidney which functions as a double endocrine gland . The larger outer adrenal cortex secretes three classes of steroid hormones glucocorticoids (e.g., cortisol), minerlocorticoids (aldosterone) and small amounts of sex steroids (e.g., testosterone). The inner adrenal medulla secretes catecholamines (e.g., adrenaline and noradrenaline). 

Top of each kidney (two sections Medulla is inner and cortex surrounds medulla)... 

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