Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
74 Cards in this Set
- Front
- Back
|
what portion of the mesoderm is the urogenital system derived from?
|
intermediate mesoderm
|
|
|
what do the three types of mesoderm each become?
|
paraxial -- muscloskeletal
intermediate -- urogenital lateral plate -- peritoneum, pleura |
|
|
what are the three successive types of "kidneys" that are formed?
|
cervical nephrotomes (pronephroi) -> mesonephroi -> metanephroi
|
|
|
what does the exstrophied mesonephric duct become?
|
the trigone
|
|
|
what will the mesonephric duct eventually become?
|
ductus deferens
|
|
|
cervical nephrotomes
|
develop out of intermediate mesoderm
they connect to the mesonephric duct as they become tubules, the more caudal ones develop, while the cranial ones regress they are non fxnl and are gone by day 24-25 |
|
|
are the mesonephroi fxnl?
|
yes! they contain fxnl nephric units consisting of glomeruli, Bowman's capsule, meonephric tubules, and mesonephric ducts
|
|
|
reciprocal relationship of uteric bud and blastema
|
uteric buds sprout from the distal portion of the mesonephric ducts on day 28...sevearl days later the bud penetrates sacral intermediate mesoderm (blastema) and begins to bifurcate. The bifurcation induces the growth of bastema around each bifurcation. The is the formation of the true kidney.
|
|
|
what does the uteric bud become?
|
collecting duct
renal pelvis ureter |
|
|
what does the blastema?
|
the stroma and the nephrons
|
|
|
what is a horseshoe kidney?
|
as the kidneys ascend, they get stuck under the IMA. their hila point anteriorly, and though they are attached, they are functionally independent.
|
|
|
what happens to the vasculature of the kidney as it ascends from the sacral region?
|
it is progressively revascularized by a series of arterial sprouts from the dorsal aorta (the original renal artery in the sacral region disappears)
|
|
|
how might a kidney end up with accessory renal arteries (i.e. extras!)?
|
due to failure of transient inferior renal arteries to regress while kidneys are ascending
|
|
|
what causes a horseshoe kidney?
|
the inferior poles of the two metanephroi may fuse during ascent, forming a U-shaped kidney that crosses the ventral side of the aorta
|
|
|
when do the kidneys start to ascend?
|
7th week
|
|
|
what is the cloaca?
|
the expanded area of the hindgut (most caudal) that will split. anterior: bladder
posterior: rectum a septum of mesoderm will eventually divide them |
|
|
what happens while the primitive urogenital sinus is forming? (hint: ureters)
|
the mesonephric ducts and uteric buds intercalate into its posterior wall
|
|
|
what does exstrophy refer to?
|
the eversion of a hollow organ
|
|
|
what is the superior part of the urogenital sinus continuous with?
|
the allantois, since the space forms the future bladder
|
|
|
what does the constricted pelvic urethra become?
|
membranous urethra in women
prostatic urethra in men |
|
|
how are the ureters formed?
|
the mesonephric ducts exstrophy into the back of the urogenital sinus, moving downwards and pulling the uteric buds with them
the uteric buds will become the ureters and the mesonephric duct will become the ductus deferens |
|
|
what will the definitive urogenital sinus become?
|
vestibule of vagina in females
penile urethra in males |
|
|
what can happen if the allantois, which was continuous with the bladder, doesn't constrict?
|
dribbling of urine out of umbilicus
due to urachal fistula, cyst, or a sinus |
|
|
what does the allantois become in adults?
|
the median umbilical fold
|
|
|
the cloacal membrane, by the early 7th week, has divided into two membranes (urogenital and anal), what happens if this doesn't occur?
|
the descending septum will have nothing to fuse with and a single channel will exist for both urine and feces
|
|
|
how does the penis form?
|
urogenital folds fuse around the definitive urogenital sinus but don't extend the full length. an epithelial invagination at the top descends to form full penile urethra
|
|
|
what do the labioscrotal folds give rise to in men? in women?
|
scrotum
labia majora |
|
|
what does the genital tubercle become in both sexes?
|
men -- glans and shaft of penis
women -- gland and shaft of clitoris |
|
|
what to the urethral and labioscrotal folds become in women?
|
u -- labia minora
l -- labia majora |
|
|
what does the pectinate line mark?
|
the junction between inferior end of rectum (derived from endoderm) and the superior end of the anal pit (derived from ectoderm)
|
|
|
how does the genital ridge form?
|
during 5th/6th week, forms in posterior abdominal wall just medial to developing mesonephroi in response to colonization of primordial germs cells migrating from the yolk sac
|
|
|
paramesonephric ducts
|
week 6
begin to form just lateral to mesonephric ducts in both males and females, arising from craniocaudal invagination of a ribbon of thickened coelomic epithelium lining the peritoneal cavity |
|
|
male gonad development
|
testes determining factor cause cortical cells to degenerate and medullary cords form sertoli cells
AMH causes cells of gonadal ridge to form Leydig cells (which produce T) and the paramesonephric ducts degenerate |
|
|
why does the tunica albuginea form?
|
to separate feminizing influence of regressing cortical cells from rete testis
|
|
|
in the developing male gonad, waht do the mesonephric tubules become?
|
rete testis, draining into ductus deferens
|
|
|
descent of the testes
|
week 7
gubernaculum begins to shorten, causing the testes to descend |
|
|
what do the seminal vesicles arise from?
|
ductus deferens (mesonephric duct)
|
|
|
what do the prostate and bulbourethral glands arise from?
|
primitive urogenital sinus
|
|
|
development of female gonads
|
paramesonephric duct develops to form oviduct
mesonephric duct degenerates cortical sex cords develop and regress to form follicle cells |
|
|
how are the uterus, upper vagina and uterine tubes formed?
|
by fusing in the midline of the paramesonephric ducts
|
|
|
how does the vagina form?
|
at 20 weeks, there is an outgrowth from the urogenital sinus and the inferior end of the vagina forms from the sinuvaginal bulbs on the posterior wall of the primitive urogenital sinus
|
|
|
how does the broad ligament form?
|
as the paramesonephric ducts are pulled away from the posterior body wall, they drage a fold of peritoneum with them, forming the broad ligaments
|
|
|
what are derivatives of the gubernaculum?
|
ovarian ligament
round ligament of the uterus labia majora |
|
|
what happens if there is a premature bifurcation of the uteric bud?
|
bifid ureter
|
|
|
what happens if there are two uteric buds?
|
complete duplicate ureters result
|
|
|
in heart development, what happens on day 19?
|
endocardial tues being to develop in the cardiogenic area (splanchnopleuric mesoderm) located cranial and lateral to the neural plate.
|
|
|
how are the endocardial tubes brought together?
|
late in the third week, the cephalic and lateral folding of the embryo brings the two lateral endocardial tubes into the thoracic region where they meet along the midline and fuse to form a single tube
this folding brings the cardiogenic area more ventrally into the thoraci region and lateral folds bring presumptive aorta in line with each other |
|
|
vitelline vein fxn
|
drain blood from heart
|
|
|
what does the bulbus cordis form?
|
part of outflow track and right ventricle
|
|
|
what does the atrioventricular sulcus form?
|
it will divide the primitive atrium from ventricle
|
|
|
looping of heart tube
|
bulbos cordus pushes down to become right ventricle, future left ventricle is shoved to the left and primitive atrium is shoved behind
|
|
|
atrial septation
|
1 endocardial cushion area between atrium and ventricle on anterior and posterior walls grow together to form two channels connecting ventricles and atria
2. septum primum comes down from back wall toward atrioventricular canal and separates nascent atria...this is the ostium primum THEN an incomplete septum secundum forms next to the septum primum (this is thick and muscular compared to the whispy primum) and formes the foramen ovale |
|
|
what forms the right to left shunt in the fetal heart?
|
septum primum and septum secundum (ostium secundum and foramen ovale, respectively)
|
|
|
how is the atrioventricular canal repositioned?
|
as the septum intermedium forms during the 5th week, teh heart is remodeled to align the developing left atrioventricular canal with left atrium and same on other side
|
|
|
what does the truncus arteriosus become?
|
outflow tract that needs to be septated to form pulmonary artery and aorta
|
|
|
what forms the atrioventricular valves?
|
ventricle myocardium arising from differentiation of the adjacent endocardial cusions
|
|
|
what do the aortic arches connect?
|
they are arteries connecting embryonic heart to the paired dorsal aortae in the cervical region of the embryo
|
|
|
which of the 6 aortic arches don't really go on to form anything of importance?
|
1st and 2nd mostly regress
5th never really develops |
|
|
3rd aortic arch
|
remains bilaterally symmetrical and develops into the carotid vessels
|
|
|
what does the 4th arch become?
|
aortic arch on the left and part of the subclavian artery on the right
|
|
|
what does the 6th aortic arch become?
|
ductus arteriosus on the left
regresses on the right pulmonary arteries arise from both sides of the 6th arches |
|
|
development of recurrent laryngeal nerve
|
during development, gets trapped around ductus arteriosus on left, but not on right because the 6h arch has regressed on that side. instead, get stuck under the fourth arch on the right (i.e. subclavian artery)
|
|
|
ventral branches of the fetal aorta
|
vitelline arteries to yolk sac arise from ventral aorta and give rise to the arterial supply to the GI tract
|
|
|
lateral branches of the dorsal aorta
|
supply organs of the posterior body wall (those that develops in retroperitoneal space: kidneys, renals, goands)
|
|
|
dorsal branches of the aorta
|
intersegmental branches that supply the back, the body wall, and the limbs (ex. accompany intercostal nerves)
|
|
|
how many venous systems does the embryo have?
|
3: umbilical, vitelline, cardinal
(umbilical is the only one that carries oxygenated blood) |
|
|
what is the ligamentum teres?
|
artifact of umbilical vein that carried oxygenated blood from mother to fetus
|
|
|
vitelline veins fxn in embryo
|
drain yolk sac in the embryo...one will regress, the other will be retained and drain the gut tube and associated structures in the adult
|
|
|
cardinal veins of embryo
|
drain the body wall and associated structures...forms teh caval and azygous systems in the adult
|
|
|
remodelling/regression to form right-sided venous system
|
left horn of sinus venosus regreses to form coronary sinus
anterior cardinal veins come together to form brachiocephalic veins right vitelline vein becomes the terminal segment of the IVC |
|
|
fetal circulation
|
umbilical vein -> ductus venosus shunt through liver -> right atrium -> oval foramen shunt rt to lt atrium -> aorta to umbilical arteries
note: any blood that moves from the rt atrium to ventricle is shunted to the aorta by the ductus arteriosus |
|
|
what do the vitelline artery and vein become in the adult?
|
vein -- portal system and liver sinusoids
artery -- arteries to GI |
|
|
what do the cardinal veins become in the adult?
|
caval and azygous venous
systems |
|
|
what do the umbilical arteries and veins become in the adult?
|
arteries -- medial umbilical ligaments
vein -- ligamentum teres |
