week 4 Flashcards
daily potassium req
60-80 mmol/day or about 1mmol/kg
unsafe prescribing of KCl
20mmol /hour
40mmol/litre of fluid
140mmol/day
why is upper gut almost sterile?
gastric acidity, propulsive motility, pancreatic enzymes
pH of colon
5.5-7, so slightly acidic but is buffered by bicarbonate
beneficial metabolic activites of the gut
produces vitamins, bioactive molecule production, short chain fatty acid production. These help drive water absorption, can act as a fuel for colonic cells, promote healing and inhibit growth of pathogenic bacteria
pronephros
formed in the cervical region. regresses by week 4. is rudimentary and non-functioning. Formed of 7-10 solid cell groups. Appears at third week (day 20)
mesonephros
Unsegmented. Forms from week 4 and see appearance of the excretory tubules. Mesonephric duct is only structure which will remain. Contributes cells to the genital ridge
metanephros
the definitive kidney, forms from week 5 and is functional by week 11. Excretory units develop from the metanephric mesoderm
Two parts: ureteric bud - outgrowth of the metanephric duct which will form the collecting duct
metanephric cap - spherical shape, will go onto form each kidney’s excretory units
allantois
vessels contained in this will go onto form important parts of the umbilical cord. Important in nutrition and secretion. The urachus will from from this in weeks 5-7. Duct between the bladder and yolk sac
division of cloaca into urogenital and anal/rectal sinus happens?
weeks 4-7. The urorectal septum fuses with the cloaca membrane
where does the trigone form from?
the mesonephric ducts
when do the genital ducts develop?
weeks 5-6
gonads, when does initial development begin
week 5
what do leydig cells secrete?
testosterone
what do sertoli cells secrete ?
AMH
when do external genitalia begin to form?
week 3
klinefelter’s syndrome
genetic disorder which affects 1 in 5000 males.
Boys who are born with one or more extra X chromosomes
1/5000 males affected
Causes - infertility, gynaecomastia, impaired sexual maturation.
Low sperm production as leydig cells do not produce enough
testicular feminising syndrome
genetic males with female external phenotype. Can produce testosterone, just have mutation on their X chromosome which means they cannot respond to it (deficient in receptors)
uterus and vagina are absent
Turner’s syndrome
Only have an X chromosome. Partly or completely missing one X chromosome.
Primordial germ cells degenerate shortly after they arrive at the gonadal ridge- failure of gonadal development.
Infantile genitalia
location of production of steroid hormones
adrenal gland, gonads, and placenta
examples of conditions with hormone excess
PCS, granulosa cell tumour, teratoma
examples of conditions with hormone deficiency
hypogoinadism
turner’s
klinefelter’s
hypopituitarism
hormone resistance
testicular feminisation syndrome
5 alpha-reductase type 2 deficiency
endocrine disruptor
exogenous chemicals which disrupt normal endocrine function. Have a similar structure to endogenous hormones and either block or mimic the effect of the normal hormone