Lecture 5 - Kidney and urogenital development Flashcards
Allantois
Goes from cloaca to connecting stalk. Eventually it will meet up with the vitaline duct and make up the umbilical cord.
How does the cloaca get divided?
There is a urogenital septum that goes straight through the cloaca. Once this happens, the cloaca has two parts, the urogenital sinus and the anorectal canal.
What happens to the allantois?
What happens if what is supposed to happen doesn’t happen?
It fuses and turns fibrous and into what is called the median umbilical ligament. If it doesnt fuse properly then you can get an urachal cyst, urachal sinus, or urachal fistula. Can detect this if you see urine coming out of the umbilical cord.
What is the deal with urination and what are two conditions in which it is not working properly?
So generally the fetus just pees out of the mesonephric duct, through the urogenital sinus into the amniotic cavity and then he swallows the urine. It is a dynamic equilibrium.
Oligohydromnios - There is not enough amniotic fluid because of an issue in urinary tract.Can result in potter sequence.
Polyhydromnios - abnormally increased amount of amniotic fluid. Caused by interference with swallowing caused by disruption in GI tract or trouble with swallowing reflexes
Potter sequence
abnormalities in lung development, limb development, and facial development. Also has a flattened appearance. Results from oligohydromnios.
Horseshoe kidney
When the inferior mesenteric artery halts the “ascent” of the kidney. Makes it look like a horseshoe
What goes into the hilum or the kidney?
renal artery, renal vein, renal pelvis
Order of kidney starting from renal pelvis
renal pelvis –> major calyx –> minor calyx –> renal pappila, renal pyramid
Also a renal column in bettween each pyramid
Order of renal arteries
renal artery –> segmental arteries –> interlobar arteries–> arcuate arteries –> interlobular arteries
Differences between branches of the IVC in left and right side
Gonadal vein goes straight into IVC on right. On left, it goes into renal vein which then goes into IVC.
Right renal vein is very short, left renal vein is much longer because it has to pass the aorta directly under the superior mesenteric artery.
Constrictions
Areas in which the ureter gets smaller. It most happens right outside of the hilum, as it’s passing over the biforcation at the aorta, and right by the bladder. That makes these the most likeely places for stones.
- to break up the stones they use what is called extracorporeal shock wave lithotripsy.
areas of the male bladder
detrusor muscle - parasympathetically innervated
bladder trigone - incorporates mesonephric ducts
internal sphincter - sympathetically innervated
external sphincter - somatically innervated
why are the bladder and ureter diagnoally connected?
To prevent backward flow from the bldder to the kidney. Vesicouretal reflux.
autonomic in kidney and upper ureter inervation
- The sympathetics will be T10-L1, so they will incorporate the lesser splanchnics, least splanchnics, and lumbar splanchnics
- The parasympathetics will be T10-L1 and will incorporate vagus nerve and pelvic splanchnic nerves
autonomic in urinary bladder and lower ureter
- The sympathetics will incorporate L1 and L2 so it will be lumbar splanchnics and sacral splanchnics
- The parasympathetics will only be pelvic splanchnic nerves
Intermediate mesoderm breakdown
Part of mesoderm.
There are three layers, lateral plate, intermediate mesoderm, and paraxial mesoderm.
Intermediate mesoderm is broken down into the urogenital sinus and the anorectal canal.
Urogenital ridge is broken down into a nephrogenic ridge and a gonadal ridge.
The urogenital ridge is broken down into pronephros, mesonephros, and mesonephric duct.
COming from the mesonephric duct is the ureteric bud, which gives off the ureters, major and minor calyces, collecting tubules, and renal pelvis. The ureteric bud and metanephrogenic blastema induce each other to form their respective things. Ureteric bud does conduction. The mesonephric blastema does filtration. Mesonephric blastema makes nephrons and the cortex of the kidney
sensory innervation
in kidney and upper ureter is vagal trunks (T10-L2). in bladder and lower ureter it is pelvic splanchnic S2-S4
WHat are is the source of primordial germ cells?
yolk sac
TDF
MIF
TDF = testis determining factor. Causes the gonad to become the testis. In the absence, it will become the ovary. Once you have a testis, you will see littig cells, which create testosterone. In the presence of testrosterone and dihidrotestrosterone you will see development of the rest of the male sexual system.
Not only that, but you need to stop the development of all female characteristics (default is to become a female unless you have a Y chromosome). MIF (mularian inhibiting factor) is responsile for inhibiting the growth of the female stuff. MIF is made by the sertoli cells that are made by the testis.
WHat will dissapear in males vs. females?
paramesonephric duct will disappear in males and mesonephric duct will disappear in females.
what does paramesophric duct become?
There is two of them and they fuse to become the uterus.
In the male which patts are from the urogenittal sinus and which parts are from the mospnephric duct?
urrogenital sinus - bladder, urethra, prostate
mesonephric duct - seminal vesicle, vas defrens, ejaculatory duct
In female what comes from the paramesonephric duct and what comes from the urogenital sinus?
PD - uterine tubes, uterus, upper part of vagina
urogenital sinus - lower vagina, vestibule, urethra, bladder
Homologues of the external genitalia
Genital tubercle - M: head of penis F: clitoris
Urethral folds - M: ventral penis F: labia minora
labioscrotal folds - M: scrotum F: labia majora
