MSAP Renal Anatomy Flashcards
Functions of the Kidney
- Excretion (waste removal)
- BP regulation (by renin angiostensin - system)
- Vitamin D activation (hydroxylation)
- Blood volume regulation (water conserving or eliminating)
- Red cell production
- Plasma modification (NA, K, CL, P)
Anatomy and location of the Kidneys
Paired retroperitoneal organs (behind the peritoneal)
between the peritoneum and posterior abdominal wall
- Between T12-L3 vertebral levels
Why is the RT kidney lower than the LT?
The liver is on top of the RT kidney
What brings blood to the kidneys?
The abdominal aorta
Common Illiac veins
Common iliac veins (receives blood from RT and LT kidney) come together to form IVC
What does the upper part of the LT kidney sit on?
llth rib on the LT side
What does the upper part of the RT kidney sit on?
sits on the 12th rib
Hilus
Medially located
Port of entry for the renal artery
- Port of exit for the renal vein and ureter
Renal lobe
renal pyramid and cortical structures overlying the pyramid
Renal Lobule
each collecting duct and the nephrons it drains (A medullary ray and surrounding cortical tissue)
Path of urine
Urine formed in nephron–> drains into collecting ducts–> Minor calyces join together to make the major calcyces–> renal pelvis–>out ureter
Glomerulus
Tuft of capillaries
The sit of filtration of the plasma
Glomerular/Bowman’s capsule
Double layered conduit into which the filtered plasma enters: Parietal layer and Visceral layer
Renal tubules
- proximal convoluted tubule
- Loop of Henle; thick descending limb; think ascending limb (countercurrent mechanism that removes sodium and other ions as necessary)
- Distal convoluted tubule (blood is sensed in this area to determine if there is sufficient water coming out)
Juxtamedulllary Nephron
few
Renal corpuscles (in the inner cortex near the medulla)
Loop of Henle (long and extension deep into the medulla)
Long loop means more water is forced to leave the LOH and back into the blood system
Cortical Nephrons
The majority
Renal corpuscles (in the outer part of the cortex)
Loop of Henle (Short and located mainly in the cortex with superficial extension into the medulla)
Cortical Collecting Ducts
Each DCT (distal convoluted tubules) empties into colleting tubules in the cortex
Medulallary Collecting Ducts
In the medulla the smaller collecting tubules join the collecting ducts; at the apex of the renal pyramid they joint the larger ducts, Papillary ducts or ducts of Bellini
Renal Cortex
Proximal and Distal convoluted tubules
Renal Glomeruli
Afferent arteriole
blood towards glomerulus
tuft of capillaries
responsible for producing filtrate that will become urine
efferent arteriole
Blood leaving from the glomerulus
Parietal layer of bowman’s capsule
covers inside of capsular space
Visceral layer of bowman’s capsule
covers the capillaries
proximal convoluted tubule
Filtrate released from the glomeruli leave via the proximal convoluted tubule; composed of cuboidal cells with microvilli at their apical surfaces
Renal Medulla
Absence of renal corpuscles
Loops of Henle
Medullary collecting ducts
Intrarenal arteries
Renal artery–>splits into lobar arteries near the hilus of the kidney–> splits again to give an interlobar artery–> turns at 90 degree angle and it becomes the arcuate artery–>gives rise to the interlobular artery which go into the lobules of the kidney
Ureters
- From the kidneys to the bladder
- The muscular conduit for urine
- Paired retroperitoneal muscular tube
- Epithelium= transitional (found in the ureters and bladder); when the bladder needs to expand the cells can reform themselves (rearrange and stretch) ( goes from 6 layers deep down to 4 layers deep); intact apical layer to maintain structural integrity of bladder
- Urine is squeezed into the bladder by peristalsis by ureters
Urethral sphincters innervations and function
Internal Urethral Spincter
located at the neck of the bladder
autonomic innervation
Detrusoor
smooth muscle contracts to squeeze urine out
autonomic innervation
Sphincter Urethrae (External urethral Sphincter)
skeletal muscle (voluntary)
innervated by the pudendal nerve
Ureter Constriction Sites
3 constrictions:
At the UPJ (uretopelvic junction): between the ureter and renal pelvis
At the pelvic brim: as it enters the pelvic outlet
At the UVJ (uretovesical junction): the port of entry of the ureters into the bladder wall
Clinical Correlation: Renal Calculi and the symptoms experienced by the patient
Calculi are also known as kidney stones
Calculi can become urter constriction sites
Smooth muscle in the walls of the ureters contract forcefully in an effort to move the stone and this results in excruciating pain
Ureters lie close to the gonadal vessels and may be ligated accidentally in surgeries such as hysterectomy (removal of the uretus)
Bladder and its function
Location: Pelvic visceral structure; anchored at its neck by the pubovesical ligament (Female) and puboprostatic ligaments (Male)
Posterior to the pubic symphysis and separated from it by the retropubic space
Function: a temporary reservoir for the urine
Bladder interior: Fundus, body, ureteric orifice’s, trigone, neck, uvula
Bladder Trigone-smooth area of the bladder in the non-distended state
Ureters- open into the posterior, inferolateral aspect of the bladder
Urethra- commences at the neck of the bladder
Female Urethra
Internal and external urethral sphincter; close together
- Shorter and wider
- Close to vagina and rectum
- Prone to infection (honeymoon cystitis)
Male Urethra
Internal urethral sphincter above prostate gland just at neck of bladder
external urethral sphincter is inferior aspect of the prostate
Different portions of male urethra: prostatic uretha, membranous urethra, and penile urethra
Urethral Injuries
Common in males
Frequently in the bulbous urethra
Usually due to trauma (ex. Bicycle injury)
