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Reproductive - EXAM 1 > Embryology > Flashcards

Flashcards in Embryology Deck (50)
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1

______ forms in the upper thoracic to upper lumbar region. It develops from superior to inferior, and performs filtration from about ______ weeks gestation (though not all parts at once).

Mesonephros, 4-10

2

____ takes care of filtration for the embryo < 4 weeks

Pronephros

3

Eventually the mesonephros’ filtration function is replaced by the ____ which becomes the

metanephros, adult kidney.

4

Eventually, around week ____ the mesonephros’ filtration function is replaced by the ____ which becomes the

5, metanephros, adult kidney.

5

Primordial germ cells differentiate in _______ and migrate to the ______ at the ___ week

Neck of the yolk sac
Genital ridge
4-5th weeks

6

the "indifferent stage"

- Before 10 weeks
- both male and female genital ducts are present

7

Male duct system develops from the _______

Mesonephric / Wolffian Ducts

8

Female duct system develops from the _____

Paramesonephric / Mullerian Ducts

9

Mesonephric ducts form the _______ in males

epididymis,
ductus deferens,
efferent ducts,
ejaculatory duct

10

Paramesonephric ducts form the _____ in females

fallopian tubes,
uterus,
upper 1/3 to 2/3 of the vagina.

11

Genital duct differentiation begins

during 3rd month of gestation (8-9 weeks)

12

Genital duct differentiation begins

during 3rd month of gestation (8-9 weeks)

13

______ causes Wolffian (mesonephric) ducts to differentiate into male genital structures, the gonads to become testes

TDF (Testes determining factor)

14

The testes make _______ to cause the mullerian/paramesonephric ducts to regress

Mullerian Inhibiting Substance

15

Primary sex cords of testes containing the primordial germ cells, and are located __

Testes cords (spermatic cords), medulla of testes

**spermatic cords are solid until puberty, when then canalize and become Seminiferous Tubules**

16

Spermatic cords contain what two types of cells

(epithelial cells >>) Sertoli cells ("nurse" cells for sperm)

(primordial germ cells >>) Spermatoblasts

17

With puberty, spermatic cords become the

Seminiferous Tubules

18

Cells within the seminiferous tubules which make testosterone

Cells of Leydig

19

What if testes fail to ever develop in the fetus, or are removed from the fetus very early on?

Paramesonephric ducts will be uninhibited (by MIS) and will become female genetalia

20

What if ovaries fail to develop or are removed in the female fetus?

Has no effect on fetal sexual development– still female genitalia

21

What if ovaries fail to develop or are removed in the female fetus?

Has no effect on fetal sexual development– still female genitalia

22

a common opening shared by the digestive, reproductive, and the urinary tracts.

Cloaca

23

A ______ develops at the anterior end of the cloacal membrane/ Elongates to form the Phallus

genital tubercle

24

Fusion of the ______ makes the scrotum.
Fusion of the ______creates the penis and the elongated urethra.

Labioscrotal folds

Urogenital folds

25

Incomplete fusion of the ureteral folds.
Typically more distal, though proximal variations can occur.

Hypospadia

26

The testicles descend to the level of internal inguinal ring at about which time point during gestation?

7th month

27

The testicles descend to the level of internal inguinal ring at about which time point during gestation?

7th month

28

Ovary cannot be defined histologically until

10th week

29

The sex cords which become seminiferous tubules in males become what in females

Primordial follicles

30

Each primordial follicle consists of

Oogonium (from primordial germ cells)
Follicular cells (from surface epithelium, surround oogonium)

31

About how many oogonium remain to become primary oocytes at birth

2 million

32

by puberty about how many oocytes remain

500,000

33

by puberty about how many oocytes remain

500,000

34

Mesonephric ducts will form the _____ which will deliver sperm to the region of the prostate

Ductus Deferens

35

The paramesonephric ducts fuse to form_________ in the midline and will become the ______

a Y-shaped uterovaginal primordium
Uterus and superior portion of vagina

36

The uterine (fallopian) tubes develop from ____

the unfused, cranial part of the paramesonephric ducts.

37

When the paramesonephric ducts fuse, the process also brings together two sides of a peritoneal fold that, when folded together, form the

broad ligament

38

An enlargement at the end of the____ induces the formation of paired endodermal outgrowths called ____

urogenital sinus
sinovaginal bulbs.

39

The sinovaginal bulbs fuse to form a

vaginal plate.

40

The two sets of tissue which fuse and canalize to form the vagina

urigenital sinus
sinovaginal bulbs

41

The precursor for all steroid hormones is ___

cholesterol

42

Progesterone is both

an active steroid hormone and an important intermediary.

43

What would happen if 21α-hydroxylase was missing

Progesterone wouldnt be able to convert into Aldosterone and Cortisol

The extra progesterone instead would be converted to testosterone (/estrogens)

44

What would happen if 11 β-hydroxylase was missing

Same as 21α - Abundance of testosterone, shortage of Cortisol and Aldosterone

45

Congenital adrenal hyperplasia is usually due to deficiency in which enzyme

21α-hydroxylase


Deficiency of Cortisol (and sometimes Aldosterone) occurs, which causes fetal pituitary to make more ACTH.
With enough ACTH, finally cortisol is made… but MUCH MORE androgen is made as well.
The adrenals enlarge because of all the cortisol precursor they make

46

Urine test for CAH

Serum 17-OHP, will be elevated

47

A less-active form of estrogen, created in low levels in fat cells when steroids are stored there

Estrone

48

The major form of estrogen made by the ovaries
The most hormonally-active form of estrogen

Estradiol

49

Much less active form
Created in small amounts in the liver
Created in higher amounts in the placenta
Can be used as a marker for NTD’s

Estriol

50

Peripheral Hormone Conversions
occur in the presence of ______

Aromatase

Androstenedione >> Estrone

Testosterone >> Estradiol