Menstruation

 

The loss of blood from uterine bleeding which occurs during the uterine (menstrual) cycle. It is a direct effect of the constriction of spiral arterioles which cause loss of blood to stratum compactum and spongiosum of the endometrium, leading to ischemia of these layers. The constriction of the said arterioles is as a result of low sex steroids (estrogen and progesterone) in blood.


Arteries (spiral arteries) which supply the mucosa run through the whole of the mucosa from the basale to the spongiosum. In the stratum basale these arterioles are turtous while they are straight in the stratum spongiosum and stratum compactum. They arise from the myometrium. During the period before menstruation, there is arteriolar constriction below the level of the compactum. This causes the strata compactum and spongiosum to loose their blood supply and become ischaemic. They then slough off and are seen as menstrual flow. The bleeding that is recognized as menstrual flow persists for 4-5 days. Glands are also found in the endometrium traversing the stratum. They secrete mucus and glycogen. These glands are destroyed during menstrual flow and are reconstructed in the proliferative stage.
 

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Hypermenorrhea- large volume loss with normal duration

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Menorrhagia- large volume loss with increase in duration of bleeding

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Amenorrhea- Lack of menses

bullet Dysmenorrhea- Painful menses


 

 

 

 

 

 

 

 

 

 

 

 

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