anatomy of urinary system Flashcards
where is the location of the kidney?
- retroperitoneal position
- posterior in the body and receives some protection from the rib cage
- T12-L3
which kidney is lower?
the right kidney is lower as the liver is crowding the right side
how much of fluid does the kidney filter each day?
200 liters of fluid from the blood stream
under normal condition, renal arteries deliver one fourth of total cardiac output to the kidneys to each minute
what is the function of the kidney?
- regulate the total volume of water in the body and total concentration of solutes in the water
- ensure long term acid base balance
- excreting metabolic waste and foreign substances such as drugs or toxins
- produces EPO for rbc and renin too for blood pressure
- converting vit D to its active form
- carrying out gluconeogenesis during prolonged fasting
where is the junction which all the vessels and nerve join in the kidney?
helium
what is atop of each kidney?
adrenal gland
where is the inferior vena cava located at?
it is located closer to the right kidney
where is the aorta located at?
it is located nearer to the left kidney?
what is the function of renal vein?
it carries deoxygenated blood from the kidneys to the inferior vena cava and to the heart
what is the function of renal artery?
it is to transport oxygenated blood from the kidney from the aorta
what are the layer of the kidney?
renal fascia (outer most layer)
perineal fat capsule
fibrous capsule
what is the function of renal fascia?
it is a outer layer of dense fibrous connective tissue and it anchors the kidney and adrenal gland to the surrounding structures
to ensure the kidney does not drop down
what is the function of the perirenal fat capsule ?
it is a fatty mass that surrounds the kidney and cushions the kidneys against blows
what is the function of the fibrous capsule?
it is stuck to the kidney and prevents infection from surrounding to spread to the kidneys
what is the cortex of the kidney?
it is the outer layer and is light coloured
what is the medulla ?
it is deep in the cortex and is cone shaped which contains renal pyramids
what is renal column?
it separates the pyramids
what is renal papilla?
it is the opening to the pelvis
what are the components and structure of the pelvis ?
it is a funnel shaped tubule and is continuous with the ureter leaving the helium
the wall contains smooth muscles that contracts rhythmally to propel the urine by peristalsis
consist of major and minor calyx
what is the function of the renal pelvis?
it collects urine and drains continuously from the papillae and empty into renal pelvis and into ureter then bladder to be stored
what is one clinical of the renal pelvis ?
Pyelonephritis
- inflammation mostly caused by fecal bacteria in female and spread to urinary tract and kidney swells, abscesses and pus forms
How does blood enter the kidney?
the blood exit the aorta
divide into 5 segmental arteries and enter the kidney
it branches further to form several interlobar arteries
which renal artery is longer?
the right renal artery is longer as the aorta lies to the left of the midline
which renal vein is longer?
the renal vein on the left is longer
what is the nervous system that supplies the kidney?
the renal plexus has a variable network of autonomic nerve fibers ang ganglia that provides the nerve supply of kidney and its ureter
what is the structure of a nephron ?
- usually located in the cortex
- consist of a renal corpuscle and renal tubule
what is the structure of a cortical nephron?
- glomerulus is found in cortex (almost the whole nephron is located entirely in the cortex)
- has a short loop of Henle
- has peritubular capillaries
About 85% of the nephrons in the human kidney are cortical, and about 15% – juxtamedullary.
what is the structure of peritubular capillaries?
- it is found in cortical nephrons
- surrounds the PCT and DCT
- arise from efferent arterioles
- experience low pressure and porous capillaries is adapted for absorption
what is the function of the peritubular capillaries ?
they provided blood to the nephron and deliver waste to be secreted in urine
they also reabsorb the nutrients that the body needs
what is the structure of juxtamedullary nephrons?
- the glomerulus is close to the cortex medulla
- there is a long loop of henle
- it has vasa recta
what is the function of juxtamedullary nephron?
it produces urine that is concentrated and retains water in the body
what is the function and structure of vasa recta ?
it surrounds the loop of henle of juxtamedullary nephrons
they arise from efferent arterioles
they provide blood to the nephron and produce concentrated urine
what is the juxtaglomerular complex ?
each nephron has one
it has cells to regulate the rate of filtrate formation and systemic blood pressure
what are the components of the juxtamedullary complex?
it contains macular densa cells granular cells (juxtaglomerular cells)
where are the macular densa cells located at?
Between distal convoluted tubule
what are the function of the macula densa cells?
- has receptors that sense the low filtrate volume (low Na level) that enter the distal convoluted tubule
- trigger the contraction of afferent arteriole to reduce the flow of blood
where are granular cells found at? (juxtaglomerular cells)
they are found in the afferent arteriole walls
what is the function of granular cells ? (juxtaglomerular cells)
- secrete renin when the blood pressure falls and it increases the blood pressure via the RAS
what is the renal corpuscle made up of?
it is made up of glomerulus and glomerular capsule
what is the glomerulus made up of?
- endothelium capillaries that is fenestrated
- has a basement membrane
- has podocytes
- arise from afferent arterioles
what is the function of glomerulus ?
- maintains high pressure
- allow large amounts of solute rich but protein free fluid to pass from the blood into the capsule
what is the function of bowman capsule ?
it is continuous with renal tubule and completely surrounds the glomerulus
it is a filtration membrane
what are the different portion of the renal tubule?
proximal convoluted tubule
loop of henle (ascending and descending limbs)
distal convoluted tubule
what is the structure of proximal convoluted tubule?
made up of cuboidal epithelial cells with large mitochondria
has dense microvilli (increase surface area)
what is the structure of loop of henle?
descending limb is thin
ascending limb is thin then becomes thick
is the collecting duct part of the nephron?
no
structure of collecting duct and pathway of it
each collecting duct receives filtrate from many nephrons
they run side by side through medullary pyramids
as they approach the renal pelvis, they fuse together and deliver urine into minor calyces via papillae of the pyramids
what is the pathway of urine after it leaves the nephron?
collecting tubules collecting ducts papillary ducts minor calyx major calyx renal pelvis ureter
what is the function of ureter? where is the ureter located at?
it is retroperitoneal paired muscular tubules that transports urine from the kidney to the bladder
located at L2
how does the ureter transport urine?
by flow of gravity and peristalsis like GI tract
when the incoming urine distends the ureter and stimulate the muscularis to contract
and it propels urine into the bladder
what are the 3 layers of the ureter?
- mucosa
- transitional epithelium (inner most layer)
- lamina propria - muscularis
- longitudinal layer
- circular layer
3, adventitia
- cover external surface
what are the 3 narrowing of ureter
- pelvic- ureter junction (PUJ)
- cross pelvic brim (squashed by common iliac artery)
- at the bladder entry area
what are the clinical of ureter?
kidney stones
- when magnesium or calcium salts or uric acid are concentrated in urine and crystalize
- it obstructs the flow of urine and can cause pain
what is the structure of bladder?
- it is extra peritoneal (outside the cavity right from the start)
- is made up of a smooth collapsible muscular sac that stores urine temporarily
- thick walls that are thrown into folds (rugae)
- when it is moderately full it cam hold 500ml
what is the structure of the male bladder?
- retroperitoneally on the pelvic floor
- posterior to pubic symphysis
- anterior to rectum
- the prostate lies at the bladder neck
- between bladder and rectum is seminal vesicle
- has vas deferens
what is the anatomy of female bladder?
anterior to vagina and uterus
what does the uterus form when it enters the bladder?
it forms the trigone
what are the layers of the bladder wall?
- mucosa (transitional epithelium)
- allows expansion without tearing - thick muscular layer (detrusor)
- inner and outer longitudinal layer
- circular layer - fibrous adventitia
how does the nervous system control sympathetic control of the bladder?
the L1-2 of spinal cord prevents peeing
inhibit contraction of detrusor muscle
stimulate closure of internal urethra sphincter
how does the nervous system control the parasympathetic control of the bladder?
S2-4 of pelvis splanchnic nerves
contracts the detrusor muscles when the bladder is full
relaxes the internal urethral spincter
what is the function of urethra ?
it drains urine from bladder out of the body
what is the the wall of the urethra made up of?
it is a thin walled muscular tube
near the bladder: transitional epithelium
most of the urethra: pseudostratified columnar epithelium
near the epithelium : protective stratified squamous epithelium
what is the structure of the male urethra?
20cm (8 inches)
consist of 3 regions
- prostatic urethra
- runs within the prostate - membranous urethra
- runs through urogenital diaphragm - spongy urethra
- 15cm long
- passes through penis
- opens at external urethral orifice
what is the structure of female urethra ?
short length 3-4 cm
external urethral orifice opens anterior to the vaginal orifice
what are the two sphincters controlling urine called?
internal urethral sphincter (sphincter vesicae)
external urethral sphincter (sphincter urethrae)
the levator muscles of the pelvic floor also serves as a voluntary constrictor of urethra
what is the function and structure of internal urethral sphincter?
it is found at the bladder urethra junction(bladder neck) and is made up of smooth muscles
the involuntary sphincter is controlled by ANS and keeps the urethra closed when urine is not passed out
what is the function and structure of external urethral sphincter?
it surrounds he urethra as it passes through the urogenital diaphragm and is made up of skeletal muscles
it is voluntary controlled + levator muscles of the pelvic floor
what is the clinical of urethra?
urinary tract infection (UTI)
- colonisaztion of fecal bacteria
- painful urination
- increased urination
- foul and blood smelling urine
