LEC35: Reproductive Tract II Flashcards Preview

Structures: Part Deux > LEC35: Reproductive Tract II > Flashcards

Flashcards in LEC35: Reproductive Tract II Deck (64):
0

when are genitalia undifferentiated

4-7 weeks

1

what partitions cloaca, and what does it partition it into?

urorectal septum

posterior region: rectum

anterior region: bladder

2

what membranes form from cloacal partitioning?

urorectal septum

creates:

anterior: urogenital membrane

posterior: anal membrane

at 6 weeks!

3

when and how does the urethral plate form?

development of male external genitalia

endodermal cells proliferate, fold upon itself > urethral plate

2 edges of plate meet, ectoderm fuse, closing urethra inside penis

4

what forms spongy urethra area?

urogenital folds

5

how does penile (median) raphe form?

surface ectoderm of urethral plate meet, fuse as line down ventral side of penis

6

how does scrotal raphe get created?

labioscrotal swellings come together

7

what is urethral epithelium made of?

both spongy urethra and ectoderm; surrounded by connective tissue

8

which part of cloaca does spongy urethra come from?

distal part

9

what is meant by the urethra's dual origin?

canalizing betweeen spongy urethra (endoderm) and glandular part of spongy urethra (ectoderm) forms urethra urethral orifice at tip

10

what does prepuce form from and when

at tip of foreskin middle ectoderm cells die, form cleft week 12

11

what are the 2 penile rathes, where do they come from?

labio-scrotal fusion > scrotal rathe urethral folds fusion > penile rathe

12

where do labio scrotal folds first fuse?

dorsally/posteriorly

13

what forms labia minora

unfused urogenital folds

14

what forms labia majora

unfused labioscrotal folds

15

what produces estrogens > female genitalia development?

mostly placenta, some from fetal ovaries also

16

where is clitoris nestled

between labio-scrotal swellings

17

what is the hymen

tissue that hasn't canalized with the outside; thin membrane of tissue remains; breaks either at first intercourse or spontaneously

18

what are the parts of the labia majora that first form?

posterior fusion > posterior commissure anterior fusion > anterior commissure middle remains open > labia majora

19

homologous structures of urogenital sinus

male: bladder, urethra (part), prostatic utricle, prostate, bulbourethral glands female: bladder, urethra, vagina, para/urethral glands, bartholins

20

homologous structures from genital tubercle

male: penis female: clitoris

21

homologous structures from urogenital folds

male: ventral penis female: labia minora

22

homologous structures from labioscrotal folds

male: scrotum female: labia majora

23

typical sexual differentiation def'n

external and internal genitalia consistent with sex chromosome content

24

errors in sex determination and differentiation def'n

disorders of sexual development, incongruence between external genitalia, internal genitalia, sex chromosome content

25

ovotestis

both ovarian and testicular tissue present, either in same or opposite gonads majority 46XX, others 46XX/46XY or 46XY ovotestis nonfunctional - no egg or sperm produced ambiguous genitalia- clitoral enlargement/penile underdevelopment indistinguishable at birth causes poor understood, very rare

26

why might 46XX individual manifest/what do you see?

internal genitalia not different, external genitalia virilization due to exposure of female fetus to excess androgens

27

CAH

congenital adrenal hyperplasia cause- overexposure to androgens occurs b/c steroid hormones from adrenal gland, cholesterol based hormones metabolized - 12 hydroxylase precursors shunted to produce excess testosterone even in female who's missing 12 hydroxylase

28

how to treat CAH in known carrier

give pt high doses of steroids that overcome block in pathway, prevent masculinization of female penis

29

how does 46XY individual appear

male with feminized genitalia; opp of CAH variable external/internal genitalia due to inadequate testosterone, MIS production by fetal testes can have normal or very rudimentary testes 5 alpha reductase deficiency > many diff manifestations from this

30

androgen insensitivity syndrome

aka testicular feminization - normal-appearing females 46XY normal hormone produce, but cell surface receptors don't receive testosterone correctly - defect in androgen receptor female external genitalia; blind-ending vagina; absent/rudimentary uterus - vaginal plate doesn't break down

31

hypospadias incidence, cause

incidence: 1/300 inadequate production of androgens and/or inadequate receptors > failure of canalization of ectodermal cord and/or failure of fusion of urogenital folds > incomplete spongy urethra forms most commonly, distal end of urethra, under urethral orifice- see opening in glans of penis

32

agenesis of external genitalia cause, presentation

very rare urethra opens into perineum near anus- no genital tubercle develops congenital absence of clitoris/penis

33

different causes of anomalies of uterus and vagina

1) incomplete fusion of paramesonephric ducts 2) incomplete development of a paramesnophric duct 3) incomplete canalization of vaginal plate to form vagina

34

uterus didelphys

incomplete fusion of distal/inferior part of paramesonephric duct

 

 

A image thumb
35

bicornuate uterus

incomplete fusion of upper part of paramesonephric duct; duplication only of superior part of body of uterus

A image thumb
36

bicornate uterus with rudimentary horn

unequal incomplete fusion- more rudimentary horn on 1 side than the other, 1 short and 1 long portion, pregnancy usu forms in longer portion hematocolpos - no communication between inside and outside

A image thumb
37

hematocolpos

no communication between inside and outside in bicornate uterus w/ rudimentary horn when woman menstruates, blood from endometrium and sloughs off starts to accumulate inside uterine cavity b/c has nowhere to go blood collects behind cervix very painful

38

septate uterus

abnormal fusion of septum - external uterus appears normal, internal septum present though one cause for recurrent miscarriages, but fixable very common!

A image thumb
39

unicornuate uterus

results from failure of 1 paramesonephric duct to develop, have only 1 half of uterus

A image thumb
40

why would vaginal atresia occur? common?

absence of vagina/uterus very rare - 1/80,000 failure of endoderm and ectoderm to fuse, failure of sinovaginal bulbs to develop and form vaginal plate, so get no canalization of vaginal plate, blockage of vagina

41

what do inguinal canals provide

pathway for descent of testes through anterior abdominal wall, into scrotum

42

gubernaculum

long connective tissue strand connecting gonad-labioscrotal swellings of scrotum pulls testes down into scrotum, through inguinal canal

43

what does inguinal canal form from

evagination of peritoneum ventral to gubernaculum

44

what forms coverings of spermatic cord/testes

layers of tissue from abdominal wall that get pulled down as testes descent into scrotum via gubernaculum pulling

45

what does gubernaculum become

tiny strand of tissue, anchoring down scrotum remains to scrotal sac

46

where do 2 inguinal canal rings form from

deep inguinal ring: external oblique m. superficial inguinal ring: transversalis fascia

47

what enables testes to pass through deep inguinal rings?

atrophy of paramesonephric ducts

48

what guides testes through inguinal canal?

processus vaginalis

49

what happens as testes descent?

enlarge, mesonephric kidneys atrophy, paramesonephric ducts atrophy, processus vaginalis guides thru canal

50

what helps testes descned through canal

increase in intra-abdominal pressure from enlarging abdominal organs

51

when do testes descend

26 weeks

52

where do testes move from/to

"relative movement" from posterior abdominal > inguinal canal > scrotum

53

do all newborns have descended testes?

no, 97% spontaneous descent no longer occurs after 1 yr

54

what does transversalis fascia become in testes coverings?

internal spermatic fascia

55

what does internal oblique m. become in testes coverings?

cremasteric m./fascia

56

what does external oblique m. become in testes coverings?

external spermatic fascia

57

what happens to processus vaginalis after testes descent

during perinatal pd, remnant of stalk of processus vaginalis obliterates tunica vaginalis remains as isolated peritoneal sac around testes

58

cryptorchidism

undescended testes anywhere along pathway of descent caused by androgen deficiency in fetal testes if remain undescended, increased risk of sterility, testicular cancer

59

ectopic testes cause

gubernaculum passing to abnormal location

60

congenital inguinal hernia

failure of complete closure btwn tunica vaginalis & peritoneal cavity persistent processus vaginalis remains

61

what does gubernaculum become in females

ovarian ligament, connects ovary-uterus, and round ligament

62

where does gubernaculum pull down into in female

labium majora, to labial-scrotal swellings

63

hydrocele

abdominal end of processus vaginalis has small opening, allows peritoneal fluid to pass through