shafaf....x tau laaa aper yg sy faham ni,btol ker tak....surf dlm tenet,detail sgt plop......
spasm-sudden constriction of vessels
necrosis-death of tissue
"Spiral arterioles are unique to menstruating species. The classic studies conducted
more than 50 years ago by Markee demonstrated that steroid (estrogen/progesterone)
withdrawal produced severe vasoconstriction of the endometrial spiral arterioles
lasting 4–24 h ."
sudden reduction of estrogens and progesterone lead to following:
>spasms n necrosis of spiral arterioles....
"The vasoconstriction is followed by vasodilatation in
these vessels, causing increased blood flow. Ischemic damage induced by the
vasoconstriction causes blood to flow out of the vessels to the epithelial surface."
The interruption of blood supply and the acute tissue hemorrhage culminate in
shedding of the superficial functional layer of the endometrium.
>the vascular spasm is produced by locally secreted prostaglandins from phospholipds by enzymes ...bla bla...
>vasodilator substances, released from necrosis tissue(e.g. prostaglandins) and vasospasm>seeping of blood under necrotic function
"Several vasoactive agents likely mediate the response to steroid withdrawal. Local
prostaglandin (PG) production is proposed to affect endometrial vasoregulation by
increasing the ratio of the vasodilatory PGE2 relative to the vasoconstrictor PGF2a
at menstruation . "maksudnyer,prostaglandin ader 2 jenis,vasodilator dgn vasoconstrictor...tp,maser menstruation,vasodilator prostaglandin lg bnyk drpad vasoconstrictor prostaglandin....
yg sy paham,sequence of events dier camni:
decrease estrogen,progesterone-vasoconstriction(spasm)-ischemic damage-necrosis of spiral arterioles(death-,release vasoconstrictor prostaglandin(PGF2a)by enzymes released from lysosomal membrane breakdown of necrotic endometrial)-tmbhan lg,release of vasodilator substances(PGE2) from necrotic tissue-hemorrage(hemorrhagic spots appear)-blood flow out of vessel to epithelial surface-menstrual blood flow...
sy budak baru belajar,kalo salah tlg btolkan.....