Saturday, March 27, 2010

Roro Route From Manila To Zamboanga



The urinary tract is the set of organs whose main function is the production and urination (1) (2). It consists of two kidneys, two ureters, bladder and urethra (1). The structure through which emerge from the ureter, blood vessels, lymph vessels and nerves of the kidney is called renal hilar (1).

Urinary Organs
Taken from Rush University Medical Center
http://www.rush.edu/spanish/images/si_0273.gif


Kidneys
The kidneys are paired organs located in the abdomen on both sides of the spine, approximately at T12 and L3 (a) (2). Is said to be an organ retroperitonial because its location is posterior to the peritoneum of the abdominal cavity (2). The right kidney is at a lower level to the left due to the presence of the liver (2) (4). The typical size is 10 to 12 cm long, 5 to 7 cm wide and 3 cm thick (1). Average weight of 130 to 150 grams (2).

Internally, the kidney shows two distinct regions: a reddish surface and smooth texture called renal cortex and a deeper color called pardorojizo medulla (1). Each renal medulla is formed by 8 to 18 renal pyramids. These structures have a conical shape, whose base is in the direction of the renal cortex and its vertex, called renal papillae, facing the renal hilum. Between each pyramid are extensions of the renal cortex called renal columns. The concept of renal lobe relates to a renal pyramid, part of the cortex that surrounds it and half of each adjacent column (1). Each pyramid schemes

a small depression called minor calyx. Several minor calyces unite to form a larger cup. The union of the major calyces form the renal pelvis (3).

Some authors suggest that the parenchyma (functional portion) of the kidney is formed by the cortex and renal pyramids (1). Others mention all the renal medulla (2). The area known as the renal sinus cavity within the kidney where the hilus opens. Contains part of the renal pelvis, calyces and branches of the blood vessels and nerves (1). Within the kidney, all structures are surrounded by fatty tissue that helps to stabilize it in position (1) (2).

internal kidney structures
jnanayoga3.tripod.com Taken
http://jnanayoga3.tripod.com/sa/rinon1.jpg


The kidney is covered by three layers. The renal fibrous capsule is the deepest. The capsule fat and fascia or renal fascia is the most superficial (1). Are innervated by the renal nerves originate in the celiac ganglion sympathetic autonomic nervous system (2). These nerves form the renal plexus and innervate mostly blood vessels (2). Its irrigation is carried out through the right and left renal arteries, which originate in the abdominal aorta. Venous return of the kidney occurs through the right and left renal veins and are drained to the inferior vena cava (2). As noted above, the ureters, arteries, veins, lymph vessels and nerves emerge through the renal hilum.

Ureters, bladder and urethra

The ureters are small tubes that carry urine from the pelvis of a kidney through the hilum and to the bladder (1). Are approximately 35 and 45 cm long and about 0.3 cm in diameter. Perform peristalsis (wavelike contractions and periodic) to move urine to the bladder (3) (4), however the hydrostatic pressure and gravity also contribute to transport (1). The ureters are also considered retroperitoneal (2) and has three layers called the mucosa (innermost), muscular (smooth muscle) and adventitia (connective tissue vessels and nerves). The

bladder is a storage bag of urine (3). It is a hollow organ, distensible, muscular located in the pelvic cavity (1). In men is anterior to the rectum and the vagina women before and below the uterus (1). The bladder has a valve at the entrance of each ureter (1). Reflux of urine is controlled by the pressure exerted on the holes when the bladder is full (1). When this mechanism is not working properly, microorganisms can move up and get to where they can cause kidney infections. The average capacity is 700 to 800 ml (1). It has three layers, the deeper the mucosal Then the tunica media or the detrusor muscle and the outer adventitia call (1). Around the urethral orifice, forming internal and external sphincters of the urethra, the second in a lower position.

The urethra is the small tube that extends from the internal urethral opening to the outside of the body. Both men and women represents the final portion of the urinary tract (1). In women with an approximate length to 4cms and ends in the space between the labia minora. In men is approximately 20 cm and ends at the tip of the penis (1).

renal blood vessels

As noted above, arterial blood enters the kidney through the renal artery . This is divided into segmental arteries at the renal sinus (1) (2). At the level of renal columns (between the pyramids), the segmental arteries divide into interlobar arteries (1) (2) (3). In the limit of the cortex and medulla, the interlobar arteries divide into arcuate arteries (3), once they cross the renal cortex is subdivided into interlobular arteries (2) (3), which are named because they spend between kidney structures called lobules (1).

interlobular arteries are divided into efferent arterioles and afferents that form a special capillary network where the blood is drained through another arteriole rather than a venule (3). This structure is called the glomerular capillary or glomerulus that is considered part of the cardiovascular and urinary tract (1).


renal arteries Diagram
Monografias.com Taken
http://www.monografias.com/trabajos32/insuficiencia-renal/insuficiencia-renal.shtml


The efferent arterioles give rise to a second network called the peritubular capillaries (2). These are located around the renal tubules and are coupled to peritubular venules form (1) which in turn are coupled in interlobular veins (3). Then the blood is drained into the veins arcuate and interlobular veins in luento found between the renal pyramids (1), adjacent to the arteries of the same name. Interlobular veins join and leave the kidney as a unique renal venal ends in the inferior vena cava (3).

Nefrona

The nephron is the functional unit of the kidney (1) (3) (4) (5) and is responsible for the formation of urine (3). Each kidney contains about one million nephrons (1) (3) (4), each composed of small tubules and blood vessels (3). The proximal nephron is composed of the glomerulus, proximal tubule and descending loop of Henle. The distal nephron contains the ascending loop of Henle, distal tubule and collecting tubule (5).


nephron structure
emagister.com Taken
http://grupos.emagister.com/imagen/nefrona/1102-129599

Another way to describe the components of the nephron is divided into renal corpuscle consists of the glomerulus and the glomerular capsule (or capsule of Bowman) and renal tubules formed by the proximal tubule, loop of Henle and distal tubule (1) (3).

The loop of Henle is a U coming down to the renal medulla (1) (3). The renal corpuscle and proximal and distal tubules are considered part of the renal cortex (1). The collecting duct, which receives the liquid from the distal tubules of the nephron, also flows through the renal cortex, which is called the papillary duct and finally reach one of the minor calyces of the renal pyramids (1).

Diagram of the Bowman capsule
Taken from the blog of medicine and pharmacology
http://medicinafarmacologia.blogspot.com/2009/08/capsula-de-bowman.html

glomerular capsule has a visceral layer that surrounds the glomerular capillaries and an outer parietal layer. Visceral layer contains epithelial cells called podocytes.

The space between the two layers are attached to the proximal tubule and it is precisely in this space where it is deposited glomerular filtration rate (3). Afferent and efferent arterioles enter and exit through the vascular pole of the glomerulus, while the filtrate exits the urinary pole (5).

The number of nephrons is constant from birth. The kidney enlargement is due to the growth of individual nephrons and not because the structures are capable of reproducing (1). They can also be adapted to handle a heavier load than usual, for example when one kidney is removed (1).

juxtaglomerular apparatus

the juxtaglomerular apparatus is the region of each nephron where the afferent arteriole in contact with the last portion of the loop of Henle (3). It consists of the macula densa and juxtaglomerular cells (a) (5). The macula densa is the set of columnar epithelial cells along the distal tubule and have the characteristic of being very close together between them (1). The juxtaglomerular cells are found to along the afferent arterioles and their walls contain smooth muscle (1).

(BC) Bowman's capsule (Pod) podocytes (MD) Dense Bone (JG),
juxta glomerular cells (DC) Distal convoluted tubule
Taken from http://
Medical Histology
www.medicalhistology.us/twiki/bin/view/Main/UrinarySystemAtlas17


juxtaglomerular cells, too (called epithelioid) secrete renin (1). The macula densa is composed of epithelial cells are in contact with the glomerular vascular pole (5). References



(1) Tortora, Gerald. Derrickson, Bryan. 2006. Principles of Anatomy and Physiology. 11 th. Edition. Editorial Médica Panamericana. Mexico DF. Mexico. Cap 26.

(2) Cutillas Arroyo, Blanca. Urinary System: Anatomy. Virtual infermeria. Barcelona, \u200b\u200bSpain.
Available online:
http://www.infermeravirtual.com/ca-es/activitats-de-la-vida-diaria/la-persona/dimensio-biologica/sistema-urinari/pdf/sistema-urinari.pdf

(3) Fox, Stuart. 2008. Human Physiology. 10 th edition. Editorial McGrawHill. Madrid, Spain. Cap 17.

(4) Montalvo Diago, Jane A. Anthology Human Physiology. American University. San Jose, Costa Rica.

(5) Bustos, Jorge. Presentation of Renal Physiology. Human Physiology course. American University. San Jose, Costa Rica.