7.1 Urinary Flashcards
what is the funtion of the kidneys
- keys functoin is to maintain bodys internal environment
- > filters 200L plasma/day, allowing toxins, metabolic wastes and excess ions leave body in urine
- regulates total water volume and total solute concentration
- ensures long term acid-base balance
- produces erythropoietin (reg RBC production) and renin (reg blood pressure)
- activates vitamin D
- carries out gluconeogenesis
what are the main structures of the urinary system
- renal artery
- renal hilum
- renal vein
- kidney
- ureter
- urinary bladder
- urethra
where are kidneys located?
- retroperitoneal
- in superior lumbar region (btwn T12-L3)
- concave medial surface with renal hilum leading to internal kidney space (renal sinus)
- convex lateral surface
- ureters, renal BV, lymphatics and nerves enter and exit at the hilum
what are the 3 layers of tissue surrounding the kidney
renal fasia
perirenal fat capusle (fatty cushion)
fibrous capsule
describe the renal fasia
most external of 3 tissue layers supporting kidney
- anchors outer layer of dense fibrous connective tissue
describe the perirenal fat capsule
what is a potential complicaiton of it
aka fatty cushion
middle of 3 layers
- protects kidneys from moving in retroperitoneal cavity
- rapid weight loss can decrease the capsule causing renal ptosis -> kinking of ureters causing back up of urine called hydronephrosis -> can cause necrosis and renal failure
describe the fibrous capsule
most visceral layer of the 3 layers of supportive tissue surrounging kidney
- transparent capsule that prevents spead of infection to the kideny
what are the 3 internal regions of the kidney
renal cortex
renal medulla
renal pelvis
describe the renal cortex
outermost layer of internal kideny
- granular-appearing superficial region
describe the renal medulla
- deep to cortex, composed of cone-shaped medullary renal pyramids
- broad base of pyramid faces the cortex, filters down to apex (papilla) which points internally
-
what separates renal pyramids
renal columns -> inward extensions of cortical tissue
describe the renal pelvis
- inside ther is a funnel shaped tube that is continuous with ureter
- has minor and major calyces
- minor: cup shaped areas that colelct urine draining from pyramidal papillae
- major: areas that collect urine from minor calyces -> empty urine into renal pelvis
how does urine flow
Renal pyramid -> minor calyx -> major calyx -> renal pelvis -> ureter
what is Pyelitis
Infection of renal pelvis and calyces
what is pyelonephritis
- infection or inflammation of entire kidney
- > infection in feales caused by fecal bacteria entering urinary tract
- severe cases can cause swelling of kidney and abscess formation, pus may fill renal pelvis
- if left untreated, kidney damage may result
- noramlly treatmed sucessfully with antibitoics
describe arterial flow in kidneys
aorta -> renal -> segmental -> interlobar -> arcuate -> cortical radiate
then goes ut afferent arterioles to glomerulus and back out by efferent arteriles feeding into pericubular capillaries or vase recta
Ryans, Stuck, In Amy’s Cat
venous blood flow through kidneys
cortical radiate -> arcuate -> interlobar -> renal veins
*no segmental veins
what types of cells exist in the nerphon
- Parietal layer of glomerular capsule
- stratefied squamous
- Visceral alyer of glomerular capsule
- have fenestrated endotherlium of glomerulus, podocyte, basement membrane
- Proximal convoluted tubule
- cuboidal cells
- apical microvilli and lots mitochondira
- Distal convoluted tubule
- less microvilli
- simple sequamous in desending, mix of squamous, cuboidal and columnar in ascenind limb
- Colecting duct
- principal and intercalated cells
descirbe the glomerulus
- tuft of capillaries composed of fenestrated endothelium
- highly porous capillaries that allow for efficient filtrate formation (plasma - protiens and - RBCs)
* filterate = plasma-derived fluid that renal tubules process to form urine
describe the glomerular capsule
- cup shaped, hollow structure with a two layers
- > Parietal layer: simple squamous epithelium
- > Visceral layer : clings to glomerular capillaries; branching epithelial podocytes, extensions terminalt in foot processes clings to basment membrane,
cribe the proximal convoluted tubule
- cuboidal cells with dense microvilli that forms brush boarder
- large mitochondira bc key area for ion and water abs
- fuctions in reabsorption and secretion
- confined to the cortex
describe the nrphron loop
*formerly loop of henle)
- has descending limg: continuous with PCT, mae of simple squamous epithelium
- ascending limb: thin (squamous) and thick (cuboidal or columnar)
describe the distal convolutubed tubule structure
cuboidal cells with very few microvilli
- function more in secretion thatn reabsorption
- confiend to cortex
nephron under microscope
- PCT: fuzzy lume due to long microvilli
- DCT: clear lumen
cortical nephron vs Juxtamedullary nerphron
- Cortical
- short nephron loop
- glomerulus further from cortex-medulla junction
- almost fully in cortex
- efferent arteriole supplies peritubular capillaries
- makes up 85% of neprons
- Juxtamedullary
- long nephron loop
- glomerulus closer to cortex-medulla junction
- deeply invaes medulla
- efferent arteriole supples vasa recta and peritubular capillaries
- ascening limbs have thick and tin segments
- important for porcution of concentrated urine
describe peritubular capillaries of the nephron capillary beds
- low pressure, porous capillaries
- adapted for absorption of water and solutes
- arise from efferent arterioles
- adjacent to renal tubles in cortex
descirbe vasa recta capillaries of the nephron capillary beds
- parallel to nephron loops of juxtamedullary nerphrons
- arise from efferent arterioles serving juxtamedulalry nephrons
- function in formaiton of concentrated urine
what is the juxtaglomerular Complex
specialized structure formed by the distal convoluted tubule and the glomerular afferent arteriole
-regulate blood pressure and the filtration rate of the glomerulus.
what are the 3 types of cells in the JGC
macula denda
granular cells (juxtaglomerular or JC cells)
extraglomerular mesangial cells
describe the macula densa cells
one of 3 cells in Juxtaglomerular Complex
- tall closely packed cells of ascening limb that contain chemoreceptors that sense NaCl content of filtrate
describe the granular cells
aka juxtaglomerular or JG cells
(one of 3 cell populations)
- enlarged, smooth muscle cells of arteriole that act as mechanoreceptors to seond BP in afferent arteriole
- secrete renin
describe the extraglomerular mesangial cells
- located between arteriole and tubule cells that are interconnected w/ gap junctions and may pass signals btwn macula densa and granualr cells
