Genitourinary Embryology and Histology (6) Flashcards
What forms much of the urogenital system
intermediate mesoderm
What are the three regions of the developing urinary system
pronephros
mesonephros
metanephros
What comes of the pronephros
degenrates early on, it may concentrate urine but doesn’t have ducts to excrete it
What comes of the mesonephros
the glomerulus surrounded by a capsule, the mesonephric tubule extends toward the capillary bed from the mesonephric duct (in function weeks 6-10)
What is the formation of the mesonephric (wolffian) duct
primary mesonephric ducts extend caudally and stimulate the formation of mesonephric tubules, then it becomes the mesonephric (wolffian) duct and attaches to the cloaca
What happens to the mesonephric (wolffian) duct in males and females
it develops the ureteric bud, and regresses in females, but becomes the ductus deferens in males
What comes of the metanephros
the ureteric bud grows into the posterior intermediate mesoderm and the ureteric bud elongates, branches, and becomes the collecting duct system
What is the metanephric blastema, and what does it do
it is the cells surrounding the metanephric duct, and it uses reciprocal inductive signals with the ureteric bud to create nephrons
what is a nephron, and what are its parts
it is the functional unit of the kidney
- Glomerulus
- bowmans capsule
- proximal convoluted tubule
- loop of henle
- distal convoluted tubule
- collecting duct
Where do the nephrons form from and are the inner or outer nephrons older
nephrons form from the ampulla, and the inner nephrons are older than the outer nephrons
How do you go from the ureteric bud to 1-3 million nephrons
the ureteric bud undergoes bifurcations
- first ampulla = renal pelvis
- week 6, 4 bifurcations = major calyces
- week 7, more bifurcations = minor calcyes
- week 32, many bifurcations = millions of nephrons
when is nephrogenesis completed
by birth
What happens in the migration of the kidneys
they migrate from the pelvis to the lateral abdomen and come in contact with the adrenal glands
What is the urogential sinus, and what is it continuous with
the urogenital sinus is a sinus that develops into the bladder, and its continuous with the base of the allantois
what is incorporated into the bladder
mesonephric ducts, and ureteric bud
What is congenital polycystic kidney
an autosomal dominant disorder where the kidneys are filled with cysts
What is horseshoe kidney
when the two kidneys fuse together
what is duplex ureter and kidney
when one side has two ureteric buds, so they form two ureters and kidneys on one side (the other side still has a normal kidney and ureter)
What is bilateral renal agenesis (oligohydramnios or potters syndrome)
when both kidneys fail to form
What are urachal fistulas and urachal sinuses
when the allantois is persistent a tube forms from the bladder to the umbilicus, which causes urine to flow out freely there. (URACHAL FISTULA)
when the allantois is partially persistent, less fluid, that is more viscus and mucousy comes out of the umbilicus (URACHAL SINUS)
What forms the male tubes of the urinary system?
what forms the female tubes of the urinary system
Mesonephric ducts form the males tubes, (and ureteric buds)
Paramesonephric ducts form the female tubes
What are other names for the mesonephric ducts and paramesonephric ducts
mesonephric = wolffian Paramesonephric = mullerian
What happens in male sexual duct differentiation
- sertoli cells secrete mullerian inhibiting substance (AMH) causing paramesoneprhic ducts to degenerate
- testosterone stimulates mesonephric ducts to develop into the ductus deferens
What happens in female sexual duct differentiation
- NO mullerian inhibitory factor or testosterone leads to the degeneration of the mesoneprhic ducts, and the paramesoneprhic ducts continue to develop
What are the parts of indifferent external genitalia and what do they develop into in males and females
genital eminence (M = Glans of penis genital tubercle (M = Penis, F = Clitoris) genital folds (M = fuse and make raphe, F = labia minora) urogenital sinus (M = gone, F = Urethra) genital swellings (M = scrotal pouch, F = labia majora)
From where do the vagina and uterus develop
from the mullerian ducts that contact the urogenital sinus, there epithelial proliferation induces formation of the uterovaginal plateq
What are some uterine abnormalities
uterus didelphys with double vagina uterus arcuatus (indented top of uterus) uterus bicornis (two uterus', one vagina) uterus bicornis unicollis Atresa of cervix Atresa of vagina
How does the digestive system work with the urinary system
it absorbs nutrients and excretes waste
how does the liver work with the urinary system
it adjusts the nutrient concentration in the blood
how does the cardiovascular system work with urinary system
when blood leaves the tissues it carries CO2 and organic waste products to be excreted
where are most organic wastes removed
by the urinary system
What are the parts of the urinary system
kidney (urine production)
ureter (transports urine from kidney to bladder)
Bladder (stores urine)
urethra (conducts urine to exterior, in males also carries semen)
What are the three functions of the urinary system
Excretion - removal or organic waste from body fliuds
Elimination - Discharge of waste products
Homeostatic regulation - regulates blood plasma volume and solute concentration
What are the different homeostatic functions of the urinary system
- regulates blood volume and pressure
- regulates plasma ion concentration
- stabilize blood ph
- conserves valuable nutrients
- assists liver to detoxify poisons
how does the urinary system regulate blood volume and pressure
- adjusting water lost in urine
- releasing erythropoietin
How does the urinary system regulate plasma ion concentration
- controlling amount of Na, K, and Cl lost in urine
- synthesizing calcitrol to regulate Ca
how does the urinary system stabilize blood ph
controlling loss of H ions and bicarbonate ions in urine
how does the urinary system help conserve valuable nutrients
preventing their excretion while excreting organic waste
Where are the kidneys found, and what holds them there
they are on both sides of the vertebral column with the left one being superior to the right one. The adrenal gland sits on top.
the peritoneum, other visceral organs, and connective tissues hold them in place
What are the three concentric layers of connective tissues around the kidneys
- fibrous capsule (innermost, made of collagen)
- perinephric fat capsule (midlle, made of adipose)
- Renal fascia (outermost, fibrous, holds kidney to structures)
What are the parts of the nephron
glomerulus glomerular capsule (bowmans capsule) Proximal convoluted tubule loop of henle distal convoluted tubule collecting duct
Where in the kidney is the nephron found
the cortex has all of the nephron, except the loop of henle, which is in the medulla
How do the cortex and medulla differ histologically
the cortex you can see the glomerulus and capsule, the medulla just looks like tubes
how do the proximal convoluted tubule and distal convoluted tubule differ histologically
the PCT has simple cuboidal epithelium and a wide lumen with brush border
the DCT has simple cuboidal epithelium, a very wide lumen, with no brush border
What does a ureter look like histologically
two layers of smooth muscle (3 in lower 1/3)
transitional epithelium
what does the bladder look like histologically
3 layers of smooth muscle, and urothelium
what is the urethra like histologically
goes from urothelium to pseudostratified colomnar, to stratafied squamous
