B8.002 Development of the Reproductive System Flashcards
(109 cards)
1
Q
conditions with gonadal failure
A
klinefelters (XXY)
turner (XO)
triple X females (XXX)
2
Q
gonadal migration failures
A
hydrocele
cryptorchidism
congenital inguinal hernia
3
Q
mullerian duct defects
A
abnormal uterine forms
4
Q
penile defects
A
hypospadias
epispadias
5
Q
disorders of sexual development
A
ambiguous external genitalia
congenital adrenal hyperplasia (females)
androgen insensitivity syndrome (males)
5 alpha reductase deficiency (males)
6
Q
for the first 6 weeks of human life…
A
no known phenotypic difference between males and females
7
Q
genetic sex
A
determined at fertilization/conception by the sperm
8
Q
gonadal sex
A
determined at about the 6th embryonic week when a bipotential gonad is induced to form either a testis by the SRY gene (on Y chromosome) or an ovary
9
Q
phenotypic sex
A
determined from the 7th embryonic week through birth and on to puberty
full differential requires proper hormone function
10
Q
psychological sex
A
imprinting and learning of sexual behavior
timing likely parallels behind phenotypic sexual development and both gender identity and sexual preference occur over a lifetime
11
Q
components of psychological sex
A
- gender identity
- gender roles
- gender orientation, the choice of sex partners
12
Q
what determines sex?
A
SPERM
can be X or Y
eggs can only be X
13
Q
X chromosome genes
A
essential for human life
2000 genes
one X randomly and permanently inactivated in females
just another reason that i don’t understand why historically men are regarded as the superior sex like we literally don’t even need their stupid DNA to survive but its fine its fine i wonder if we could take 2 X eggs and mush them together and eliminate the need for sperm altogether? like why are they even necessary
14
Q
turner syndrome
A
X sperm + O egg
gonadal dysgenesis
95% of infants are spontaneously aborted in the 1st trimester
15
Q
triple X syndrome
A
X sperm + XX egg
phenotypically normal
16
Q
lethal abnormal meiotic event
A
Y sperm + O egg
17
Q
klinefelters
A
Y sperm + XX egg
extra X inhibits testis development
seminiferous tubule dysgenesis
18
Q
Y chromosome genes
A
60 genes
23 proteins
holandric traits
19
Q
extra X chromosome
A
whether in males or females, often associated with an increased risk of learning disabilities and delayed development of speech and language skills
20
Q
phenotypes of XXX females
A
may be taller than normal
may produce normal offspring
delayed development of motor skills, weak muscle tone, and behavioral and emotional difficulties are possible, but vary widely among those affected
premature ovarian failure (< 40) is common
90% NOT DIAGNOSED AS THEY HAVE NO OR FEW SYMPTOMS
21
Q
klinefelters phenotype
A
small to normal penis small testicles (spermatogenesis not functional when extra X is present in germ line)
22
Q
turner syndrome phenotype
A
half have puffy hands and feet at birth in addition to wideness and webbing of neck (50% diagnosed at birth)
adults: infertility, short stature, lymphedema, webbed skin behind neck, low airline, widely spaced nipples, small breasts, brown spots, small finger nails, horseshoe kidney (15%), ovarian failure
normal puberty doesn’t occur without hormone therapy
NORMAL INTELLIGENCE
23
Q
cardio effects of turner
A
coarctation of the aorta (1 in 15)
bicuspid aortic valve
aortic dissection in adulthood
24
Q
risks of egg donation in turner
A
only 40% of pregnancies normal
high risk endeavor
25
male genetic signals
SRY
SOX9
SF1
26
female genetic signals
WNT4
DAX1
TAFII 105
27
3 cell types from which the gonads develop
1. coelomic (future peritoneal cavity lining)
2. underlying mesenchyme from intermediate mesoderm (mesonephros)
3. primordial germ cells which migrate from the yolk sac
28
origin of wolffian duct
mesonephric duct (2nd kidney stage)
29
origin of mullerian duct
paramesonephric duct
develops as an invagination of the coelomic epithelium
why oviducts are open to the peritoneal cavity
30
oogonia
primordial germ cells within the developing ovary
10% of cells within the ovary by weeks 7-9
divide mitotically
31
follicular cell origin
mesenchymal cells surround oogonia and become follicular cells
enter a protracted stage of meiosis
32
oocytes
female germ cell in meiosis
33
primordial follicles
oocytes surrounded by flattened follicular cells
| first seen at week 14
34
what happens if an oocyte isnt surrounded by follicular cells?
apoptosis
35
steroid influence on ovarian development
little steroid production by fetal ovary
| is NOT necessary for development of female tubular/ductal structures or female external genitalia
36
3 step overview of ovarian development
1. ovarian development lags slightly behind testicular development
2. cortical sex cords differentiate into follicular cells and incorporate primordial germ cells, which will subsequently form oogonia. surrounding follicular cells inhibit completion of meiosis until puberty
3. clusters of follicular cells surround the central oogonium and inhibit female germ cells in the first meiotic division
37
primordial germ cells that enter the gonad at 6th week
1,300
38
oocytes at 20th week
300,000
39
oocytes at birth
295,000
40
oocytes at puberty
180,000
41
ovulated eggs during reproductive years
500
42
oocytes at menopause
0
43
importance of AMH levels
anti mullerian hormone
expressed in granulosa cells of growing follicles
expression highest in preantral and small antral follicles
levels decrease with age in premenopausal women
levels correlate strongly with # of antral follicles, aka they can reflect the size of your primordial follicle pool
44
relationship between genital system and urinary system
close conjunction
| male accessory repro organs develop from embryonic urinary system structures
45
inherent phenotype
FEMALE
THE FUTURE IS FEMALE
#FEMINISM
46
function of AMH in males
suppresses female structures
| comes from testicular sertoli cells
47
what does the paramesonephric (mullerian) duct form in females
oviducts
uterus
upper 1/5 of vagina
48
outline the development of the non gonadal female reproductive organs
caudal ends of paramesonephric ducts grow together as they join the urogenital sinus, forming a joint midline structure, the uterovaginal primordium
uterovaginal primordium forms 1/5 of the vagina and the cervix and uterus
where the uterovaginal primordium meets the urogenital sinus, it induces the sinusal tubercle forming the distal 4/5 of the vagina
49
discuss the presence of vestigial structures formed from urogenital ducts
in both males and females, remnant of embryonic urogenital structures can be present and cause little or no harm
50
female remnant of mesonephric ducts that did not undergo complete apoptosis
1. paroophoron
2. epoophoron
3. duct of Gartner
51
male remnants of paramesonephric ducts
appendix of the testis
52
prevalence of congenital uterine anomalies
5% of women
| 10% of women with recurrent pregnancy loss
53
examples of congenital uterine abnormalities
```
midline septum (septate uterus)
Y shaped (bicornate uterus)
one horn (unicornate uterus)
double uterus (didelphys)
```
54
midline septum problems
reduced fertility levels and 1st trimester loss
55
bicornate/unicornate uterus problems
low birth size and premature delivery
56
cloaca
```
expansion of rectum
separated into:
1. urogenital sinus
2. rectum
separated by formation of 3 folds (collectively the urorectal septum)
1. superior Tourneux
2. L and R Rathkes
```
57
subdivision of urogenital sinus in females
1. sinovaginal bulbs: form distal 4/5 of vagina from sinusal tubercle
2. urethra and bladder
58
why should you check newborns for the presence of an anus?
may have:
- rectoprostatic urethral fistula
- rectocloacal canal
- rectovaginal fistula
59
how is the broad ligament formed
fusion of paramesonephric ducts from each side bringing together peritoneal folds
ovaries located on posterior surface
60
vesicouterine pouch
anterior to uterus
61
rectouterine pouch
posterior to uterus
62
function of the broad ligament
supports the uterus in the midline
63
overview of development of the testis
primordial germ cells (gonocytes) migrate into the gonadal ridge
mesenchymal cells surround PGCs and differentiate into sertoli cells
this combo forms sex cords, the precursors to seminiferous tubules
mesenchymal cells also differentiate into interstitial Leydig cells between developing sex cords
64
function of embryonic sertoli cells
produce AMH
| prevents femal reproductive structures from forming from the mullerian ducts by inducing apoptosis
65
function of embryonic leydig cells
produce testosterone
induces male reproductive structure differentiation from the mesonephric duct structures (rescuing them from spontaneous apoptosis in normal females)
66
function of dihydrotestosterone in embryonic testis
external genitalia formation
| more potent than regular testosterone
67
structures derived from the mesonephric (wolffian) duct
epididymis
vas deferens
ejaculatory duct
seminal vesicle
68
origin of prostate gland
develops from invagination of prostatic urethra (urogenital sinus endoderm)
69
describe the differential migration of growing mesonephric ducts and ureter
mesonephric ducts continue to migrate inferiorly, ending up opening within the prostatic urethra, inferior to the bladder into the urethra
future vas deferens opens through the prostate gland into the urethra
70
two ligaments involved in descent of gonads
1. superior suspensory ligament
| 2. gubernaculum
71
describe the gubernaculum
extends from inferior pole of the gonad through the inguinal canal into the labioscrotal swellings
does not contain muscle, but rather a band of mesenchymal tissue
"pulling" = lack of growth while the embryo gets bigger
72
processus vaginalis
extension of peritoneum
hernaties through the abdominal wall just anterior to the path of the gubernaculum
carries layers of the extensions of the abdominal wall that will form the layers of the inguinal canal and in males the coverings of the spermatic cord and testis
73
final descent of testis into scrotum
mediated by T and insulin like growth factor 3 from leydig cells
hiccups or uterine contractions help push testes
74
deep inguinal ring
opening in transversalis fascia
75
superficial inguinal ring
opening in external oblique aponeurosis
76
when do the testes migrate to the deep inguinal ring?
7th month
| takes about 4-5 days to get through inguinal canal
77
locations of cryptorchid testes
```
not all the way descended at birth
62% are within the inguinal canal
26% within abdominal cavity
8% at deep inguinal ring
4% at superficial inguinal ring
```
78
orchioplexy
placing testicle into scrotum
should be performed prior to 1 year of age for maximal changes of fertility
if child reaches 10, remove testicle due to cancer risk
79
cryptorchidism
failure of full descent of testes into scrotum
| 2-3% of full term newborns
80
hydrocele
persistent processus vaginalis large enough to only permit passage of peritoneal fluid
1-2% of newborn males
normally resolve in a few months
81
congenital inguinal hernia
persistent processus vaginalis that allows herniation of intestine into scrotum
1-2% of baby boys
spontaneously resolve by 2 years in some cases
82
layers in adult scrotum
from outer to inner
1. external abdominal oblique >>>external spermatic fascia
2. internal abdominal oblique >>> cremasteric fascia and muscle
3. transversus abdominus (doesn't contribute to scrotum)
4. transversalis fascia >>> internal spermatic fascia
83
descent of the ovaries
gubernaculum guides ovaries into the pelvis and forms the proper ligament of the ovary and round ligament of the uterus
84
female hydrocele
fluid collection along the canal of nuck (around round ligament of the uterus as it passes through the anterior abdominal wall into the labia majora)
85
4 common embryonic structures to external genitalia of both sexes
genital tubercle
urogenital folds
urethral groove
labioscrotal swelling
86
genital tubercle derivative
female: clitoris
male: penis (glans)
87
urogenital fold derivatives
female: labia minora
male: penis body/shaft
88
urogenital groos derivatives
female: opening of urethra and vagina
male: opening of urethra
89
labioscrotal swelling derivatives
female: labia majora
male: scrotal wall
90
hypospadia
failure of fusion of the urogenital fold to meet in a midline
opening of the urethra on the ventral surface of the penis or scrotum
1 in 125 male births
91
epispadia
opening on the dorsal surface of the penis
more unusual than hypospadia
1 in 30,000 males
92
should you circumcise boys w hypo/epispadias?
no
| need foreskin for repair
93
how are hypospadias classified
location of the meatus
94
what is a disorder of sex development (DSD)
discrepancy between external and internal genitals
| "hermaphrodite"
95
true hermaphrodism
individual born with ovarian and testicular tissue
| extremely rare
96
pseudohermaphroditism
child is born with external genitalia that doesn't match the expected gonadal tissue present
DSD
97
46, XX intersex
chromosomes of a woman, ovaries of a woman, but external genitals that appear male
female fetus exposed to excess males before birth
98
causes of 46, XX intersex
congenital adrenal hyperplasia (most common)
male hormones taken or encountered by mother during pregnancy
testosterone producing tumor (often ovarian) in mother
99
pathogenesis of congenital adrenal hyperplasia
defects in cortisol pathway in adrenal results in excess production of ACTH hormones and an excessive stimulation of adrenal fetal cortex
this leads to androgen production which tends to masculinize the external genitalia of genetic females
**male infants have no unusual phenotpe
1 in 15,000
100
genetics of CAH
autosomal recessive
95% of the time due to defective 21 hydroxylase which causes reduced aldosterone and cortisol and excess levels of adrenal androgens
101
other symptoms of CAH (not related to genitalia)
```
high rate of sodium loss in urine (due to lack of aldosterone) > dehydration
hyperkalemia
metabolic acidosis
cortisol deficiency
poor weight gain
vomiting
```
102
fate of children with CAH
vomiting, severe dehydration, and circulatory collapse by 2-3rd week of life
103
treatment of CAH
mineralocorticoids
karyotyping to determine sex
generally females are not surgically altered until female grows old enough to participate in decision making
104
46, XY intersex
chromosomes of a man
external genitals incompletely formed, ambiguous, or female
internal testes may be normal, malformed, or absent
105
causes of 46, XY intersex
```
problems with testes (not producing hormones)
problems with T receptor
problems with T
formation
AIS
```
106
androgen insensitivity syndrome
most common cause of 46, XY intersex
hormones are normal, but receptors to male hormones dont function properly
over 150 different defects in androgen receptor have been identified
phenotypic females, no internal structures (no androgen function to create male structures, but AMH still present to inhibit female structure)
107
appearance of individuals with 5-alpha reductase deficiency
cause of 46, XY intersex
can have either normal male external genitalia, ambiguous genitalia,or normal female genitalia
have internal male structures but usually have female external genitalia
often raised as girls
108
function of 5-ARD
converts T > DHT
| DHT helps masculinize external genitalia
109
puberty in 5-ARD deficient individuals
some individuals experience masculinization
| approx 60% choose to then live as males
