Session 1 - Introduction Flashcards
Where are the kidney located?
between T12 and L3
• Retroperitoneum on the posterior abdominal wall, either side of the vertebral column.
superior pole of right kidney = 11-12th rib
superior pole of left kidney = 12th rib
At what level are the hila and ureters found?
Level of L1 vertebra
Level of L1 vertebra
Descend anterior to the transverse processes of the lower lumbar vertebrae
What muscle do the kidneys sit on?
psoas major
What crosses the ureter in the pelvis in men and women?
In men Vas deferens crosses over the ureters. In women uterine artery crosses over it.
What is the normal length, width and mass of a kidney?
Length 9-14cm, width 6-7 cm, 140g
Which kidney is slightly higher and why?
left
- liver on right side pushing right kidney down
A difference of more than what length/width between kidneys requires further investigation?
2cm
A length of less than what may indicate CKD?
<8cm
What is the renal angle and what happens here during kidney inflammation?
Angle between 12th rib and erector spinae muscle. Renal angle tenderness.
What are the 2 main types of fat around the kidneys and where are they found?
Pararenal (external to posterior layer or renal fascia) and perirenal fat (within the renal fascial layers)
why is the kidney not fixed and can move?
they are not tethered by any ligaments
- fascia and fat anchor it in space
What is the posterior layer of renal fascia called?
Garota’s fascia
What is the length and diameter of ureter?
25-30cm length, 1.5mm diameter
What are the 3 different parts of the ureters?
Abdominal, pelvic and intramural
Where is the most common area of ureteric injury? What are the 3 common sites of ureteric injury?
Near pelvic brim
- Pelvic brim
- Beneath uterine artery
- At VUJ
How/where do the ureters enter the bladder wall and what do they coalesce with?
Runs obliquely through the bladder wall and coalesces with the detrusor muscle. Enter into the bladder more inferiorly.
What is the length of the intramural ureters?
1.2-2.5cm
What is the vesicouretal junction (VUJ) and is there a sphincter present here?
Junciton between the ureters and the bladder, there in no sphincter present
How is urine reflux into the ureters prevented without presence of sphincters?
Ureters pass diagonally through the bladder wall musculature, forming a one way flap valve, the internal pressure of filling bladder causing the intramural passage to collapse
Which part of the urinary tract is lined with urothelium?
Pelvis of the kindeys, ureters and bladder
What are some different positional changes of the ureters?
a) Both ureters entering one side of the bladder
b) Duplexed ureter both entering the bladder
c) Duplexed ureter, one not entering the bladder
d) Retrocaval position of the right ureter around the IVC
What can a duplexed ureter where one does not enter the bladder cause?
Urinary infection
What is the trigone?
Smooth triangular region of the internal urinary bladder formed by the two internal ureteric orifices and the internal urethral orifice
What is the trigone sensitive to?
Area is very sensitive to expansion and once stretched to a certain degree, the urinary bladder signals the brain of its need to empty
What is the urethral orifice in the bladder also called?
Internal urethral meatus - involuntary internal sphincter of bladder - due to detrusor muscle running circularly
What are the 2 sphincters of the urethra and which has greater importance in men and women?
internal urethral sphincter (men), external urethral sphincter (women)
Why is the internal urethral sphincter important in men?
Contracts and prevents movement of the semen into the bladder during ejaculation (retrograde ejaculation)
What part of the nervous system is responsible for closing the internal urethral sphincter?
Sympathetic nervous system (Point and Shoot)
What is the blood supply to the kidneys and where does it originate from?
Renal arteries, originates from abdominal aorta at the level of the kidneys
What does the renal artery first divide into?
Anterior and posterior renal artery branches
Describe the blood supply within the kidneys.
Renal artery → Segmental → Interlobar → Arcuate → Interlobular → Afferent glomerular arteriole
Whata re the bony landmarks used to approximate course of ureter?
• L1~thehilum
• Ureter runs along close to the tip of lumber
transverse processes,
• Often crosses the sacrum at approximately the SI joint and descends into the pelvis.
• The ischial spine is a secondary bony land mark that shows the approximate point at which the ureter ‘kink’ towards the bladder
• The ureters then run around the pelvis and enter the bladder posteriorly.
what is the anatomical position of bladder?
- When empty the bladder rests on the symphysis pubis
- Women – In front of vagina, uterus and rectum
- Men – in front of rectum
define urothelium
transitional epithelium
describe the bladder wall composition
detrusor muscle - mucosa form rug except within trigone which is smooth
describe the path of the ureters
The ureters enter the pelvic cavity from the abdomen by passing through the pelvic inlet. On each side, the ureter crosses the pelvic inlet and enters the pelvic cavity in the area anterior to the bifurcation of the common iliac artery. From this point, it continues along the pelvic wall and floor to join the base of the bladder. Entry points form the superior two corners of the trigone
What are 2 types of nephrons and which is more common?
Cortical and Juxtaglomerula
cortical - 85-90%
juxtaglomerular - 10-15%
what are the roles of the 2 types of nephron
cortical - Excretory and regulatory functions
juxta - Urine Concentration
what is the difference between the 2 types of nephrons?
juxta has a longer loop of henle
what is the epithelium lining the glomerulus?
simple squamous
what is the epithelium lining the PCT?
simple cuboidal cells and each cell is made up of millions of microvilli, forming a dense brush border that increases the surface area available for absorption of tubular filtrate. they also have lots of mitochondria to provide energy for transport of substances
what is the epithelium lining the loop of henle?
thin descending and ascending - simple squamous
thick ascending - simple columnar
what is the epithelium lining the DCT?
simple cuboidal
what type of cells are found in DCT?
- Principal cells (P cells) : these contain few mitochondria and respond to antidiuretic hormone (ADH) – also known as vasopressin
- Intercalated cells (I cells) : these contain lots of mitochondria and secrete hydrogen ions
what is the epithelium lining the collecting duct?
simple cuboidal without microvilli or many mitochondria
describe the juxtaglomerular apparatus
The juxtaglomerular apparatus is located where the thick ascending loop of Henle passes back up into the cortex and lies adjacent to the renal corpuscle and arterioles of its own nephron. It is the area of distal tubule associated with arterioles. The tunica media in the wall of the afferent arteriole contains an area of specialized thickened cells (granular cells), which secrete renin. The epithelium of the distal tubule forms specialized macula densa cells that respond to changes in the composition of the tubular fluid, especially the concentration of sodium ions in the filtrate. Extraglomerular mesangial cells or lacis cells are found outside the glomerulus, in association with the glomerular apparatus. They are contractile cells identical to the mesangial cells.
