Reproductive Anatomy and Physiology in Girls

00:01 Hi. In this lecture we'll be reviewing pediatric GYN topics.

00:05 You may sometimes see these questions on the USMLE, so let's begin.

00:10 First, I wanna start with a question.

00:14 What is the most common foreign body in prepubertal girls? Not sure? That's okay.

00:22 Continue to listen to the lecture and I'll give you the answer.

00:25 So let's now talk about the reproductive anatomy in girls specifically types of hymen.

00:32 So here you can see a normal hymen with the normal external genitalia.

00:38 However, sometimes the hymen can have an incomplete perforation.

00:43 Typically, a patient can menstruate when she undergoes puberty and menarche with this type of hymen, but she may have also a septate hymen.

00:53 Again, there is enough of an opening to allow menstrual blood to come out.

00:59 You can sometimes have a cribriform hymen or a microperforate hymen.

01:04 This restricts blood flow more and sometimes we have a hymen that is imperforate.

01:10 These patients have hematocolpos.

01:12 When you do a physical exam on a young girl make sure to look.

01:16 Let's now review reproductive anatomy in girls.

01:20 In general we look at breast development and pubic hair.

01:24 We have different tanner staging and this is reviewed in another lecture called normal puberty.

01:30 Remember, that tanner stage does not include 0 and prepubertal girls should be stage 1 and as they develop go through stages 2, 3, 4 and eventually 5, which is an adult contoured breast.

01:45 Girls can also have prepubertal pubic hair.

01:49 They may have fine vellus hair but at stage 1 you really can't see it unless you have closed inspection.

01:56 Then as they start to develop and undergo puberche and adrenarche, you can see that the pubic hair starts to extend until finally in stage 5, it surrounds the thighs.

02:08 Here, you can see the reproductive physiology of a prepubertal girl.

02:13 When she's in utero in her mother's uterus hCG is what she's exposed to.

02:19 You see here at the mid-gestation that she actually has oogenesis and oogonia who make all the oocytes or follicles that she'll have for life.

02:29 These numbers decrease as she ages after birth.

02:33 Also, in the mid-gestation which parallels the rise in hCG can have a rise in FSH and LH.

02:42 At birth this return to quiescent values.

02:46 However, with the onset of puberty this increases as puberty requires FSH and LH to be secreted from the anterior pituitary.

02:56 As a young girl undergoes puberche and adrenarche, you will see a rise in DHEA, androstenedione and estradiol.