urinary tract infection cure

Discover In Just 5 Minutes How To Beat Urinary Tract Infections WITHOUT Resorting To Antibiotics

Blood Supply and Circulation

1. Each kidney receives a renal artery-a branch from the abdominal aorta.

2. Anterior and posterior branches arise from the renal artery before it reaches the renal hilum

3. Interlobar arteries arise from the anterior and posterior branches in the renal hilum and penetrate the medulla between the medullary pyramids.

4. Arcuate arteries arise from the interlobular arteries and course along the arched border between the cortex and medulla.

5. Interlobular arteries arise at right angles from the arcuates; they penetrate the cortex between the medullary rays and lie at the borders between neighboring renal lobules.

6. Many afferent arterioles arise from each interlobular artery. Each afferent arteriole supplies a glomerulus.

7. An efferent arteriole carries blood away from the glomerulus.

a. Efferent arterioles of cortical nephrons branch to form a profusion of peritubular capillaries that carry absorbed products away from the proximal and distal tubules and converge to form the stellate veins of the peripheral cortex. These drain into the inter lobular veins.

b. Efferent arterioles ofjuxtamedullary nephrons give rise to numerous straight capillary loops--vasa recta-that descend into the medulla.

8. Vasa recta arise mainly from the efferent arterioles of the juxtamedullary nephrons; some may arise from the arcuate artery. The descending parts of the vasa recta carry isotonic blood into the medulla.

The blood loses water and picks up sodium as it passes deeper into the medulla. Unlike the loop of Henle, the ascending parts of the vasa recta are as permeable to salt and water as are its descending parts. As the blood ascends through the gradient, its tonicity equilibrates with that of its surroundings.

The blood carried away from the medulla is thus once again isotonic. The passive exchange of salt and water between the vasa recta and the interstitium is known as the countercurrent exchange mechanism.

It is important in carrying away water lost to the filtrate during its descent into the medulla and thus in maintaining the osmotic gradient set up by the countercurrent multiplier system of Henle's loop.

Blood in the ascending portions of these vessels drains into interlobular veins and exits through the veins that accompany the larger arteries. Urinary system

URINARY SYSTEM: GENERAL FEATURES OF THE URINARY SYSTEM

A. Components of the System: The urinary system includes the kidneys and the urinary tract.

1. Kidneys. These paired, bean-shaped, retroperitoneal organs are located in the posterior wall of the abdominal cavity. a. Structural and functional subdivisions, When sliced in the frontal plane, each kidney shows a dark-staining outer cortex and a light-staining inner medulla that partly surrounds the renal hilum, The hilum consists of a space, the renal sinus, that contains the larger renal blood vessels, the renal pelvis, and adipose tissue.

Each lobe consists of numerous renal lobules, each containing hundreds of nephrons, These are largely tubular structures that filter the blood, modify the filtrate to form urine, and empty into a series of collecting tubules and ducts which converge on the medulla and empty into the minor calyces. b. Blood supply. Because the kidneys are blood-filtering organs, their blood supply is crucial to their function. A pair of renal arteries--one to each kidney--branches from the aorta in the upper abdomen. Each artery undergoes successive branching to feed specialized capillary beds in both the cortex (glomeruli and peritubular capillaries) and medulla (vasa rectal).


B. General Functions of the System: The kidneys filter metabolic wastes and foreign sub stances from the blood; regulate the ion, salt, and water concentrations of the fluids that bathe the body's tissues; and produce renin and erythropoietin. It is followed by the reabsorption of important ions, small proteins, nutrients, and much of the water. These are returned to the blood in the peritubular capillaries and vasa recta in precise proportions.