Urinary System Flashcards
La sangre llega al riñón por medio de
La arteria renal, rama directa de la aorta abdominal
Histologicamente el hilio del riñón corresponde a
Médula del riñón
Las ramas que irradian a través de la médula renal se arquean entre la médula y la corteza donde producen cerca de un millón de ramas llamadas
Arteriolas aferentes
Cada arteriola aferente da origen a
Glomerulo renal
Es un ovillo capilar que desemboca en la arteriola eferente
Glomerulo
La sangre de la arteriola eferente sale del riñón a través de la médula renal constituyendo
Los vasos venosos del sistema de vasos rectos medulares
La unidad funcional del riñón
Nefrona
Numero de nefronas en cada órgano
Alrededor de un millón
La Nefrona está constituida por
Glomerulo Espacio de Bowman Cápsula de Bowman (hoja parietal) Tubulo contorneado proximal Porción descendente delgada del asa de Henle Porción ascendente gruesa del asa de Henle Tubulo contorneado distal Tubulo colector
En el glomerulo, el plasma de la sangre por mecanismos hidrodinamicos se sale de los capilares glomerulares constituyendo
Ultrafiltrado glomerular donde cae al espacio de Bowman
Esta delimitado por la cápsula de Bowman
Espacio de Bowman
Es una esfera que comunica con el inicio del tubulo contorneado distal
Cápsula de Bowman
El tubulo contorneado proximal absorbe
Proteinas, glucosa, sodio, agua ,cloro
El tubulo contorneado proximal deja la corteza y en la médula se continúa con
La porción descendente o delgada del asa de Henle
El asa de Henle es
Permeable al agua
El agua que pasa al intersticio medular renal es drenada por
Los vasos rectos que rodean al asa de Henle
A medida que el contenido luminal del asa de Henle penetra en la médula renal
Pierde agua
La porción ascendente del asa de Henle es impermeable al agua pero permeable a los iones especialmente
Sodio y cloro
Cuando el asa de Henle se acerca a la corteza hay un aumento de
Concentración de agua
Ya en la corteza el asa de Henle se continúa con
Tubulo contorneado distal
En el tubulo contorneado distal se extrae
Sodio, cloro y potasio del ultra filtrado y se continúa con el tubulo colector
El agua extraída del tubulo colector pasara al
interticio medular y caerá en los vasos rectos
La permeabilidad al agua en el tubulo colector es regulada por la presencia o ausencia de
La ADH
Si esta presente la ADH
Saca agua desde su luz al interticio medular
Si la ADH esta ausente
el agua permanece en el tubulo colector y es orinada
Es un tubo por ello se ve dos franjas de urotelio
Ureter
Es un recipiente muy grande en el que solo se verá una franja de urotelio
Vejiga
Se encarga de dotoxificar el plasma de la sangre
Sistema urinario
Regulation of arterial blood pressure , protease by cleaving circulating angiotesinogen to angiotensin by secretion of
Renin
Glycoprotein growth factor that stimulates erythrocytes production in red marrow when blood O2 level is low
Erythropoietin
Renal funtion that convert vitamin D to active form called
Calcitriol or 1,25 dihidroxyvitaminD
The excretory product of kidneys, passes through the ureters to the bladder for temporary storage and then released to the exterior through the urethra
Urine
Where nerves enter, the Ureter exits, and blood and lymph vessels enter and exit
Hilium
The hilium the upper end of the ureter expandes as the
Renal pelvis
The renal pelvis divide into two or three
Major calyces
Smaller branch of major calyces
Minor calyces
The area surrounding renal pelvis and calyces have
Adipose tissue
The renal médula consist of renal pyramids consisting in
8-12 conic structures
The renal pyramids are separated from cortex by
Renal columns
Constitute a renal lobe
Pyramids plus the cortical tissue
Cortical nephrons are located in
Cortex
Juxtamedullary nephrons (1/7 of the total) are located
Close to de medulla and have long loops of Henle
Normal cortical organization is lost and the formation of multiple large fluid filled cysts
Polycyctic kidney disease
Renal artery divides around the renal pelvis in
Interlobar arteries
Interlobar arteries extend between the renal pyramids toward the cortically junction divide again in
Arcuate arteries
Arcuate arteries divide in the base of pyramids in
Interlobular arteries
The interlobular arteries arise afferent arterioles forming s plexus called
Glomerulus
Blood leaves the glomerular capillaries by efferent arteries which branch again to form
Peritubular capillaries
From the juxtaglomerular corpuscles near the medulla, efferent arteries Make branches repeatedly to form parallel tassel like bundles od capillary loops called ….. That penetrate deep into the medulla in association with the loop of Henle and collecting ducts
Vasa recta
Renal function
Filtration
Secretion
Reabsortion
Inflammation within the glomeruli usually stems from humoral immune reactions involves the deposition of circulating antibody antigen complex elicit local inflammatory response
Glomerulonephritis
Diameter of a renal corpuscle
200 micrometer
Surround a renal corpuscle a double walled epithelial capsule called
Glomerular (Bowman) capsule
Glomerular (Bowman) capsule divide in
Visceral layer envelops the glomerular capillaries
Parietal layer forms the surface of the capsule
Between the two capsular layers is the…. Which receives the fluid filtered through the capillary wall and visceral layer
Capsular or urinary space
The visceral layer of a renal corpuscle consist of unusual stellate epithelial cells called… Which with the capillary endothelial cells compose the apparatus for renal filtration
Podocytes
From the cell body of each Podocytes ……. Extend and curve around a length of glomerular capillary
Primary process
Each primary process of Podocytes give rise to many parallel secondary process or
Pedicels
Between the interdigitating Pedicels are enlongated spaces or filtration slip pores (25 to 30) nm wide, spanning adjacent Pedicels and bridging the slit pores are zipper like
Slit diaphragm
The slit disphragm is composed by proteins called
Nephrins
Glomerular basement membrane GBM (300 -360 nm) is composed by
Fenestrated endothelial cells of capillaries
Podocytes
The most substantial part of the filtration barrier that separates the blood from the capsular space forms by fusion of the capillary and Podocytes
Glomerular basement membrane
This proteins bind integrins of Podocytes and capillaries
Laminin and fibronectin
Restricts passage of proteins larger about 70kDa
Type IV collagen and proteoglycans and polianionic GAGs are abundant and their negative charge restrict filtration of organic anions
The glomerular filtration barrier consist
Capillary endothelium
Glomerular basement membrane
Filtration slit disphragm
Filtrate includes
Water, glucose, aminoacids, ions, urea, many hormones, vitamins B and C, ketones, and a very small amounts of proteins
Percentage of the blood plasma that entering a glomerulus is filtered into the capsular space.
20%
The glomerular filter is altered and becomes much more permeable to proteins with the subsequent release of protein into the urine (proteinuria)
Diabetes mellitus and Glomerulonephritis
Capillaries of each Glomerulus have a total length of
1 cm
The total amount of circulating plasma averages
3L
Kidney filter the entire blood volume
60 times every day
The total glomerular filtration area of an adult has been estimated at
500 cm2 and the average Glomerular Filtration Rate at 125 mL/min or 180 L/ d
Renal corpuscle cells that are their surrounding matrix giving physical support of capillaries, adjust contraction of blood pressure
Mesangial cells
Simple cuboidal epithelium with long microvilli with lumen often occluded located in the cortex, main function is reabsortion of all organic nutrients, all proteins most water and electrolytes and secretion of anions and cations,H, and NH4
Proximal convulated tubule
Perform hydroxylation of vitamin D and release to the capillaries
Proximal convulated tubule
Simple squamous epithelium located in medulla and major function passive reabsortion of Na and Cl
Thin limbs loop of Henle
Simple cuboidal epithelium with no microvilli located in medulla and medullary rayos and major function reabsortion of various electrolytes
Thick ascending limb
Simple cuboidal epithelium, cells smaller than PCT short microvilli and basolateral folds more empty lumen located in cortex and main function is reabsortion of electrolytes
Distal convulated tubule
Most abundant cuboidal to columnar, pale staining distinct cell membranes
Principal cells
The thickening and loss of function in the GBM produced as part of the systemic microvascular sclerosis
Diabetic glomerulosclerosis
Adjust the salt content of the filtrate transport sodium and chloride ions out of the tubule making that compartment hyperosmotic
Thick ascending limb
Reabsorb sodium chloride NaCl but are impermeable to water
Thin ascending limbs
Occurs when the affected erythrocytes sickle in the vasa recta because of the low oxygen tension there
Sickle cell nephropathy
Established by the nephron loop and vasa recta is an important aspect of renal physiology
Countercurrent multiplier system
The ascending limb of the nephron is straight as it enters the cortex and forms
Mácula densa
The rate of Na absorption in DCT is regulated by An hormone from the adrenal glands
Aldosterone
Initial straight part of the DCT contact the arterioles at the vascular pole, its cells become more columnar and closely packed forming the
Mácula densa
Part of the juxtaglomerular apparatus JGA that utilizes feedback mechanism to regulate glomerular blood flow and keep the rate of glomerular filtration relatively constant
Mácula densa
The smooth muscle of the afferent arteriole is modified by
Juxtaglomerular granular cells with Renin
Locate at the vascular pole are extraglomerular mesangial cells that have many of the same supportive contractile and defensive function
Lacis cells
Cleaves the plasma protein angiotensinogen into angiotensin I, secreted by JG cells
Renin
Renin Cleaves the plasma protein angiotensinogen into angiotensin I, angiotensin converting enzyme on lungs capillaries clips the further to angiotensin II, a potential vasocnstrictor that raises systemic blood pressure and stimulates the adrenal to secret
Aldosterone
Promote Na and water reabsortion in the DCT and connecting tubules, which raises blood volume to help increase blood pressure
Aldosterone
Last part of each nephron
Connecting tubule
Connecting tubule join together in the cortical medullary rays to form
Collecting ducts of simple cuboidal epithelium diameter 40 micrometers
In the outer medulla the collecting ducts merge further, running to the tips of the medullary pyramids with increasingly diameters reching 200 micrometers are called
Collecting ducts of Bellini
In the apex of the pyramids collecting ducts merge further as a
Papillary duct which delivers urine to the minor calyx
The collecting ducts are composed Mainly of
Principal cells
Sparse microvilli, most abundant, cuboidal to columnar locate in medulla rays and medulla regulate reabsortion of water and electrolytes , regulated secretion of K, rich in aquaporins
Principal cells
Hormone released from the pituitary glands as the body becomes dehydrated, males collecting ducts more permeable to water and increase the rate at which water molecules are pulled osmotically from the filtrate
Antidiuretic hormone ADH
Help maintained acid-base balance by secreting either H or HCO3, dark stain located in medullary rays
Intercalated cells
Obstruction in the renal pelvis or calyces usually from calcium salt (oxalate or phosphate) irritate the mucosa and can become large or uric acid
Renal canaliculi or kidney stones
Problem caused by such stones use to remove ultrasonic shock waves called
Lithotripsy
Urothelium cells are organized as three layers, also have a lamina propia and Submucosa follow by smooth muscle and adventitia
Single layer of small basal cells resting on a very thin basement
An intermediate region of columnar cells
A superficial layer bulbous cell called umbrella cells and proctect underlying cells against cytotoxic effects or hypertonic urine
Bacterial infection of the urinary tract can lead to inflammation of renal pelvis and calyces or
Pyelonephrotis
Umbrella cells apical surface consist of asymmetric unit membranes composed of lipids and proteins call
Uroplakins
Lamina propia and dense irregular connective tissue are highly vascularized
Bladders
Bladder in average adult can hold
400 to 600 ml of urine with the urge to empty appearing at about 150 to 200 ml
Bladder muscularis consist of three poorly delineated layers called
Detrusor muscle most distinctly at the neck of bladder near the urethra
All urinary passages are covered externally by adventitial layer except
The upper part of the bladder that is covered by serous peritoneum
Inflammation of the bladder mucosa can be caused by immunodeficiency, urinary chatherization, radiation, or chemotherapy
Cystitis
Organs mucosa with prominent longitudinal folds
Urethra
The male urethra is longer consist of three segments
Prostatic urethra 3 to 4 cm long extends through the prostate glands line by urothelium
Membranous urethra passes through An external sphincter of striated muscle line by columnar and pseudostratified epithelium
Spongy urethra about 15 cm in length enclosed with erectile tissue of the penis line by stratified columnar and pseudostratified columnar epithelium with stratified squamous distally
urethra 3 to 4 cm long extends through the prostate glands line by urothelium
Prostatic
urethra passes through An external sphincter of striated muscle line by columnar and pseudostratified epithelium
Membranous
urethra about 15 cm in length enclosed with erectile tissue of the penis line by stratified columnar and pseudostratified columnar epithelium with stratified squamous distally
Spongy
The female urethra is … Long
4 to 5 cm line initially with urothelium then by stratified squamous epithelium and some areas of pseudostratified columnar epithelium
Part of female urethra surrounded by the external striated muscle sphinter
Middle part
