Reproduction during the lifetime L20 Flashcards
1
Q
What is sex determination?
A
Sex determination is the COMMITMENT of the indifferent, BIPOTENTIAL gonad to a Testes or an ovary
(determination = commitment)
-causes a change in the phenotype of the gonads but that is sexual differentiation
2
Q
What is the commitment of the indifferent bipotential gonad to a testes or an ovary called?
A
Sex determination (determination = commitment)
3
Q
What controls sex determination in humans?
A
Sex determination in Mammals is Genetically controlled
“the presence or absence of the Y chromosome (and SRY gene in particular) determines sex”
-human has 22 pairs of autosomes
-1x pair of sec chromosomes
-23 pairs altogether, and 46 chromosomes altogether
4
Q
What is the control of sex determination in mammals?
A
Genetically controlled (via chromosomes)
“the presence or absence of the Y chromosome (and SRY gene in particular) determines sex”
-23x pairs (one from each parent) of chromosomes altogether (46 single chromosomes)
-22x pairs of autosomes
-1x pair of sex chromosomes
5
Q
How many pairs of chromosomes do we have altogether?
A
-23x pairs (one from each parent) of chromosomes altogether (46 single chromosomes)
(-22x pairs of autosomes
-1x pair of sex chromosomes)
-these chromosomes lead to the genetic control of sex determination in mammals, and therefore humans
6
Q
How many chromosomes do we have altogether as humans?
A
23x PAIRS of chromosomes
46 x chromosomes altogether
7
Q
How many autosomes do humans have?
A
22x pairs of autosomes
8
Q
How many sex chromosomes do humans have?
A
1x pair of sex chromosomes
2x sex chromosomes individually
9
Q
What type of chromosomes do we have 22x pairs of?
A
autosomes
10
Q
What is the SRYs gene?
A
A gene/region on the Y chromosomes
(known as the SRY gene)(Sex-determining Region on the Y chromosomes)
Provides the PATHWAY for the testes to develop
11
Q
What provides the pathway for the Testes to develop?
A
the SRY gene on the Y chromosome
“Sex determining Region on the Y gene)
-PROVIDES a PATHWAY for the testes to develop
12
Q
Specifically what part of the genetic sex determination results in a male?
A
- Presence of the Y chromosomes
2. More specifically the presence of the SRY gene on the Y chromosome itself
13
Q
What does the presence of the testes determine?
A
sexual fate of the embryo, against the basic female trend (default pathway)
14
Q
What deters the sexual fate of the embryo from the basic female trend?
A
the presence of the testes
which is determined itself by the genetically controlled sexual determination of the Y chromosomes and the SRY gene on the y chromosome
15
Q
What happens if there is no SRY gene on the Y chromosome?
A
If There is no SRY gene on the Y chromosomes, the embryo will develop into a female (continue along the default female pathway)
- as the SRY gene is the single, isolated gene which solely determines sex (Testes/gonads commitment/production)
- masculinity must be imposed against an inherent trend towards femaleness: requires the action of the Y chromosome/hormonal intervention in order to stop the initial bipotential gonad of the embryo from becoming female
- prevents all the structures from becoming female
16
Q
Even if there is a Y chromosomes, how can the embryo still become a female?
A
There is no SRY gene on the Y chromosome
-there is nothing imposing against the inherent trend towards femaleness of the bipotential gonad-prevents all the structures from becoming female
17
Q
What solely determines masculinity?
A
the SRY gene
is a GENE which is located on the Y chromosome and it alone SOLELY determines masculinity
-by imposing against the embryo’s basic female trend, by providing Y chromosome/hormonal action and to stop the body from becoming female
-prevents all the structures from becoming female
18
Q
Does the Y chromosomes or the SRY gene solely determine masculinity?
A
SRY gene
it is the SRY gene which is the single, isolated gene on the Y chromosomes which SOLELY determines the testes/gonads commitment/production
-prevents all the structures from becoming female
19
Q
What is the SRY gene?
A
The single, isolated gene on the Y chromosomes which SOLELY determines the testes/gonads commitment/production
it is the Y-chromosomes and hormonal intervention which imposes against the bipotential gonad’s inherent trend towards femaleness to give masculinity - prevents all the structures from becoming female
20
Q
What does the presence of the testes determine the sexual fate of the embryo against?
A
against the basic female trend
-its hormonal intervetion
21
Q
What aspect of imposing masculinity against the basic female trend of the embryo is most important? i
A
hormonal intervention (from the SRY gene on the Y chromosome) as part of the Y -chromosomal activity
22
Q
What is the role of hormonal intervention in imposing against the basic female trend?
A
It is the hormonal intervention from the SRY gene on the Y chromosome) as part of the Y-chromosomal activity, which is the most important component of the presence of the testes imposing against the basic female trend of the embryo (default pathway of the embryo to become female)
-prevents all the structures from becoming female
23
Q
What is sexual differentiation?
A
AFTER the commitment of the gonad of the embryo to the pathway of becoming EITHER a ovary or testes (dependent on the imposing presence or absence/mutation of the y chromosome and solely determining SRY gene (which imposes masculinity against the inhere basic female trend of the bipotential gonad)
Differentiation is to do with phenotype
Sex Differentiation is the phenotypic development of the genital structures due to the actions of the hormones produced following gonadal development
Sexual differentiation affects the external and internal genetalia
24
Q
What 2x things does sexual differentiation affect?
A
- Internal genetalia
2. External genetalia
25
What affects the internal and external genetalia of a developing embryo's gonads?
Sexual differentiation
-the actions of the hormones produced following gonadal development, causes the phenotypic development of the genetal structures
26
What is the phenotypic development of the genital structures in sexual differentiation due to?
The actions of hormones produced, following gonadal development
-affects the external and internal genetalia
27
Is sexual differentiation before sexual determination, or is sexual determination before sexual differentiation?
1. sexual DETERmination (determination = commitment)
2. sexual differentiation
- determined to differentate
28
What is sexual differentiation due to?
the actions of hormones, produced following gonadal development
29
What is the difference between the sexual differentiation development of the testes and ovaries?
Sexual differentiation of the testes REQUIRES HORMONES TO BE MADE in order to Drive male differentiation
vs
Sexual differentiation of the ovary doesn't require/isn't directly driven by the presence of ovarian hormones, instead happens by default (therefore lags behind/development and regression occurs later/is slower)
30
What are the 2x hormones made by the ovary during sexual differentiation?
1. oestrogen
2. progesterones
- note: oestrogen and progesterones are NOT necessary - can remove them or remove the ovary and the process will still occur (basic female trend/inherent default pathway of the embryo/bipotential gonad towards femaleness)
31
What is the imposing action leads to the phenotypic differentiation of the bipotential gonad?
Sex specific hormones of the testes (the androgen testosterone form Wolffian duct development, and AMH/Mullerian Inhibiting substance for Mullerian duct regression) which leads to the differentiation of the internal and external sex organs of the male
32
Are oestrogens needed in the sexual differentiation of the female(ovary)?
No
the ovary occurs/develops by default
The ovary makes oestrogens and progesterones, but these hormones DO NOT drive the development of the internal genetalis
The female genetal duct : the mullerian duct just develops (but later on in internal genetalia development comparatively to males) to become the Internal female genetalis (uterus, fallopian tube, upper 1/3 of the vagina) and the male genital duct: the wolffian duct regresses naturally with time
33
What part of the internal genitalia eventually develops into the male reproductive system?
The Wolffian duct
(mesonpheric duct)
is the male internal genital duct
-its development occurs during sexual differentiation
-phenotypic development of the genital structures (ducts)
34
What part of the internal genetalis eventually develops into the female reproductive system?
The Mullerian duct
(paramesonephric duct)
is the female internal genital duct
-its development occurs during sexual differentiation
-phenotypic development of genital structures (ducts)
35
What 3x things does the initial internal undifferentiated state in an embryo refer to?
In the Internal genetalia
all three are present (both female and male internal structures are present):
1. Genital/gonadal ridges (its metoderm cells eventually become the bipotential gonad involved in sexual DETERmination(1st))
2. Female internal duct/genital structure = Mullerian duct = Paramesonephric duct
3. Male internal duct/genital structure = Wolffian duct = Mesonephric duct
36
When do the gonads develop?
Gonads develop from the intermediate mesoderm during the 5th week of development
37
What happens in the 5th week of development?
Gonads develop from the intermediate mesoderm
38
What happens to the intermediate mesoderm?
in the 5th week, the gonads develop from the intermediate mesoderm
39
Where do the gonads develop from?
The intermediate mesoderm
| in the 5th week of development
40
What 3x things are present in the undifferentiated state of internal genetalia?
1. Gonadal ridges - bipotential gonad
2. Mullerian/Paramesonephric female internal genetalia duct
3. Wolffian/Mesonephric male internal genetalia duct
Both male and female internal structures are present initially
If unimposed, will automatically become an ovary (female mullerian development and wolffian regression)
Initial undifferentiated state of internal genetalia present in the 5th and 6th week of development
41
When is the undifferentiated state of the internal genetalia present?
In the 5th and 6th week of development
42
What is present in the 5th and 6th week of development?
The initial undifferentiated state of the internal genetalia
| -both male and female internal genital ducts+ genital/gonadal rediges
43
What will happen in the internal genetalia is unimposed?
The internal genetalia will automatically become an ovary
| -continue along basic female trend/default trend towards femaleness
44
Are both male and female internal structures/ducts present initially (in the 5th-6th weeks of development)?
Yes
| both are present intially
45
What does the bipotential gonad originate form?
the metodermic cels of the gonadal/genital risges
46
What happens to the metodermic cells of the gonadal ridges?
origination of/Forms the bipotential gonad
47
What 3x things happen in Male internal genetalia differentiation?
7th-8th week of development
Faster then Female internal genetalia differentiation, as it does have active hormonal intervention/mechanism to make structures develop and regress actively
1.1. Mullerian duct regression
7th-8th week
Occurs due to AMH/Anti-mullerian hormone/MIS/Mullerian Inhibiting Substance - is secreted by sertoli cells
2. Wolffian duct development and maintenance
7th-8th week
Occurs due to Testosterone
secreted by the Leydig cells, located in the testes
Wolffian duct develops into 3x structures (Epididymis, Vas deferens and seminal vesicles)
3. the Testis descend from its internal Para-renal (side of the kidney) High in the pelvic cavity/Ovary height level position --> down to the scrotum/
-descend in order to be external to the body for spermatogenesis. occurs in the 7th Month of development
- Failure to descend from the pelvic cavity: 1. risk of infertility 2. risk of developing testicular cancer later in life
48
When does the Mullerian duct regress in Male internal genetalia differentiation?
7th - 8th week of development
49
What happens in the 7th-8th week of Male internal genetalia differentiation?
the Female internal mullerian duct regresses
| the Male internal Wolffian duct develops and begins maintenance
50
What is the regression of the Female internal Mullerian duct due to in Male internal genetalia differentiation?
AMH/Anti-mullerian hormone/ MIS/Mullerian inhibiting substance
Is secreted by sertoli cells
51
What is another name for AMH?
Anti-Mullerian Hormone = MIS Mullerian Inhibiting substance
secreted by Sertoli cells inside testes
causes the regression of Mullerian duct in Male internal genetalia differentiation
52
What is another name for MIS?
Mullerian Inhibiting substance = AMH Antti mullerian Hormone
secreted by sertoli cells inside testes
causes regression of Mullerian duct in Male internal genetalia differentiation
53
What is AMH secreted by?
Sertoli cells
-in testes
causes regression of Mullerian duct in Male internal genetalia differentiation
54
What is MIS secreted by?
Sertoli cells
-in testes
causes regression of Mullerian duct in Male internal genetalia differentiation
55
What is the role of Sertoli cells in Male internal genetalia differentiation?
to secrete AMH (anti Mullerian Hormone) / MIS (Mullerian Inhibiting Substance)
-causes regression of Mullerian duct in Male internal genetalia differentiation
56
What are the 3x internal structures that the Wolffian Duct develops into?
1. Epididymis
2. Vas deferens
3. Seminal Vesicles
57
Where do the 3x internal genetalis structures of the 1. Epididymis 2. Vas deferens 3. Seminal vesicles come from?
Developed and maintained Wolffian duct in Male internal genetalia differentiation
58
Which hormones is the development and maintenance Wolffian duct in Male internal genetalia differentiation due to?
Testosterone
| -secreted by Leydig cells, in the testes
59
What is the role of Leydig cells in Male internal genetalis differentiation?
secrete testosterone
| testosterone is the hormone which Develops and maintains the Wolffian duct in Male internal genetalia differentiation
60
Where are Leydig cells located?
```
In the testes
These Testis (male) Leydig cells secrete testosterone, which is the sex hormone which Develops and maintains the Wolffian duct in Male internal genetalia differentiation
```
61
When does the Wolffian duct begin development and maintenance in Male internal Genetalia differentiation?
7th-8th week of development
62
What is the descendance of the Testes part of?
Internal Male genetalia differentiation
63
When do the testes descend?
In the 7h month of development
64
What occurs in the 7th month of development?
Descent of the Testes down to the scrotum/external to the body for spermatogensis
65
What is the time line for Male internal genetalis differentiation?
7th-8th week of development: Mullerian duct regression due to sertoli cell secreted AMH/MIS
+ Wolffian duct development and maintenance due to Leydig secreted testosterone androgen
7th month: descent of the testes to the scrotum/external to the body for spermatogenesis
66
Where is the initial placement of the testes prior to descent in the 7th month of development, as part of male internal genetalis differentiation?
Para-renal (level of the kidneys)
Height of the ovaries
High in the Pelvic cavity
67
What does para-renal mean?
level of the kidneys
| -is the initial placement of the testes (high in the pelvic cavity, level of the ovary)
68
What is para-renal/height of the ovaries/high in the pelvic cavity?
The testes initial placement
69
What 2x things happen if the Testes do not descend to the scrotum from para-renal/height of the ovaries/high in the pelvic cavity?
1. risk of infertility
| 2. risk of testicular cancer later in life
70
What can increase the risk of testicular cancer later in life in males?
The testes FAILING to descend to the scrotum/external to the body for spermatogenesis from para-renal/height of the ovaries/high in the pelvic cavity position
71
What can increase the risk of infertility in males?
The testes FAILING to descend to the scrotum/external to the body for spermatogenesis from para-renal/height of the ovaries/high in the pelvic cavity position
72
Where do the testes descend to rom para-renal/height of the ovaries/high in the pelvic cavity?
The scrotum
| external to the body for spermatogenesis
73
Why do the testes need to fall from rom para-renal/height of the ovaries/high in the pelvic cavity position to the scrotum?
So the testes are external to the body for spermatogensis
74
What needs to occur during male internal genetalia differentiation for spermatogenesis?
The testes need to fall from its position para-renal (side of the kidney)/height of the ovary/high in the pelvic cavity --> to the scrotum
- so it is external to the body for spermatogenesis
75
What are main 2x features of Female Internal Genetalis differentiation?
Occurs about the 9th week (lags behind male internal genetalia differentiation at 7-8 weeks) Female internal genetalia differentiation is therefore slower, as it has no active hormonal intervention/mechanism to make structures develop and regress actively
(Secretion of Oestrogen and Progesterone from ovary has no driving effect)
1. Wolffian duct regression: from about 10th week of development, the Wolffian duct in female internal genetalia differentiation starts spontaneously regressing/degenerating SLOWLY
2. Mullerian duct development: 8th-9th week of development the mullerian duct in female internal genetalia differentiation PERSISTS. it develops to give rise to the 4x region of Female internal genetalis (1. Uterine/Fallopian tube, 2.Uterus, 3. cervix, 4. upper 1/3 of the vagina)
76
What 4x internal genetalis structures does the Mullerian duct in female internal genetalia differentiation persist and develop into?
1. Uterine/Fallopian Tube
2. Uterus
3. Cervix
4. upper 1/3 of the vagina
77
What does the 1. Uterine/Fallopian Tube, 2. Uterus, 3. Cervix and 4. upper 1/3 of the vagina collectively form?
The 4x internal genetalis structures the Mullerian duct in female internal genetalia differentiation persists and develops into in the 8th-9th week of development (relatively slower to male's internal genetalia differentiation and development)
78
What occurs to the Mullerian duct in female internal genetalia differentiation?
Mullerian duct in female internal genetalia differentiation PERSISTS.
it develops to give rise to the 4x region of Female internal genetalis
(1. Uterine/Fallopian tube,
2.Uterus,
3. cervix,
4. upper 1/3 of the vagina)
79
When does the Mullerian duct in female internal genetalia differentiation persist and develop?
8th -9th week of development
80
What happens during the 8th-9th week of development?
the Mullerian duct in female internal genetalia PERSISTS and develops to give rise to the 4x region of Female internal genetalis
(1. Uterine/Fallopian tube,
2. Uterus,
3. cervix,
4. upper 1/3 of the vagina)
81
What occurs to the Wolffian duct in female internal genetalia differentiation?
Wolffian duct starts to Spontaneously Regress
SLOWLY
occurs from about week 10 of development
82
What happens during week 10 of development?
Wolffian duct in the female internal genetalis SPONTANEOUSLY starts to regress SLOWLY
83
When does the Wolffian duct starts to Spontaneously Regress
| slowly in female internal genetalia differentiation?
10th week of development
84
When does Female internal genetalia differentiation occur?
9th week of development
Occurs about the 9th week (lags behind male internal genetalia differentiation at 7-8 weeks) Female internal genetalia differentiation is therefore slower, as it has no active hormonal intervention/mechanism to make structures develop and regress actively
(Secretion of Oestrogen and Progesterone from ovary has no driving effect)
85
Why does Female internal genetalia differentiation occur later/is slower/lags being male internal genetalis differentiation?
female internal genetalia differentiation occurs about the 9th week (lags behind male internal genetalia differentiation at 7-8 weeks) Female internal genetalia differentiation is therefore slower, as it has no active hormonal intervention/mechanism to make structures develop and regress actively
(Secretion of Oestrogen and Progesterone from ovary has no driving effect)
86
Is Female internal genetalia differentiation earlier than male internal genetalis differentiation, or does male internal genetalis differentiation occur earlier than female internal genetalia differentiation?
Male internal genetalis differentiation occurs earlier (7th-8th week of development) than the female internal genetalis differentiation (9th to 10th week of development
-inherent basic female trend
Is due to the lack of active hormonal intervention/mechanism to make structures develop and regress acitvely
87
Is Female internal genetalia differentiation active?
No
It doesn't require oestrogen and progesterone that is produced by ovaries
-is the default inherent basic female trend of the bipotential gonad
88
Is male internal genetalia differentiation active?
Yes
Does require the action of hormones of AMH/MIS secreted by sertoli cells for Mullerian duct regression and the action of testosterone secreted by Leydig cells for Wolffian duct development and maintenance
Active hormonal intervention/mechanism to actively make structures develop and regress
89
What occurs in external genetalis differentiation?
The male and female external genetalia develop form a single bipotential precursor
-the external bipotential precursor looks very similar for both males and females, at its undifferentiated stage at 5 weeks
90
What does the male and female external genetalis differentiate from?
A single bipotential precursor
| -at its undifferentiated state of 5 weeks into development, looks very similar in both males and femlaes
91
What does the bipotential male and female external genetalis look like?
at its undifferntiated state of 5 weeks into development, looks very similar in both males and femlaes
92
When is the single bipotential male and female external genetalia in its undifferentiated state?
5 weeks into development
93
What occurs at 5 weeks into development?
the single bipotential precursor for external genetalia development is in its undifferentiated state of 5 weeks into development, looks very similar in both males and females
there is no action of androgens yet
94
What are the 3x components of the bipotential precursor that are effected in both male and female external genetalia differentiation?
1. Urethra folds
2. Labio-scrotal swellings
3. Genital tubercle/glans area
95
What do the 3x structures of the Urethral folds, Labio-scrotal swellings and genital tubercle/glans area form?
The 3x components of the bipotential precursor that are effected in both male and female external genetalia differentiation
96
How are the Urethral folds of the bipotential precursor of external genitalia affected during male external genetalia differentiation?
Fuse
Enclose the urethral tube
To form the shaft of the penis
97
How are the Urethral folds of the bipotential precursor of external genitalia affected during female external genetalia differentiation?
Remain separate
| Form the Labia minora
98
How are the Labio-scrotal swellings of the bipotential precursor of external genitalia affected during male external genetalia differentiation?
Fuse in the midline
Form the EMPTY Scrotum (waiting for the testes to fall in the 7th month of pregnancy)
=this process is called scrotalisaiton
99
How are the Labio-scrotal swellings of the bipotential precursor of external genitalia affected during female external genetalia differentiation?
Remain separate
| Form the labia majora
100
How is the Genital Tubercle/Glans Area of the bipotential precursor of external genitalia affected during male external genetalia differentiation?
Expands
| forms the Gland penis
101
How is the Genital Tubercle/Glans area of the bipotential precursor of external genitalia affected during female external genetalia differentiation?
forms the clitoris
102
What fuses in the bipotential precursor of external genitalia during male external genetalia differentiation?
Fusion: of the urethral folds to enclose the urethral tube
-forming the shaft of the penis
AND
fusion of the libio-scrotal swellings to form the empty scrotum- of which the testes have to fall into during the 7th month of development
103
What enlarges in the bipotential precursor of external genitalia during male external genetalia differentiation?
the genital tubercle/glans area
| -to form the glans penis of males
104
What is another name for the glans area in the undifferentiated bipotential precursor of the external genitalia?
genital tubercle
105
What is another name for the genital tubercle in the undifferentiated bipotential precursor of the external genitalia?
glans area
106
What drives male external genetalia differentiation in the undifferentiated bipotential precursor of the external genitalia?
```
Androgen driven active differentiation of the external genetalis
The androgens (Testosterone --> 5aDHT) produced by the testes
ACTIVE intervention
Mainly 5aDHT (2x more potent)
```
107
Where are the androgens (Testosterone --> 5aDHT) involved in the active intervention of male external genetalia differentiation in the undifferentiated bipotential precursor of the external genitalia produced?
In the testes
mainly 5aDHT androgen active intervention
(is 2x more potent)
108
Which androgens (Testosterone or 5aDHT) involved in the active intervention of male external genetalia differentiation in the undifferentiated bipotential precursor of the external genitalia is mainly effective?
the androgen 5aDHT
is2x more potent
Active intervention
109
What is scrotalisation?
The process of the labioscrotal swellings of the bi-potential precursor of external genetalia fusing in the midline to form the scrotum in male external genitalia differentiation
110
What is the process of the labioscrotal swellings of the bi-potential precursor of external genetalia fusing in the midline to form the scrotum in male external genitalia differentiation called?
scrotalisation
111
What occurs if there is insufficient androgen in External genetalis differentiation of the bi-potential precursor of external genetalis?
Hypospadia
insufficient/lacking supply of androgens (testosterone and 5aDHT) secreted from the testes in males
Male differentiation will not occur (insufficient imposing on the basic female trend)
Urination in the males will occur from the side of the penis, not from the tip (incomplete fusion of the urethral folds, not enclosing the urethral tube correctly)
112
What sort of differentiation is the male differentiation of the undifferentiated bipotential precursor of the external genitalia ?
Androgen driven ACTIVE intervention of external genetalia differentiation
113
What is an example of an androgen driven process?
Male differentiation external genetalis differentiation of the undifferentiated bipotential precursor
114
What is Hypospadia?
Hypospadia
insufficient/lacking supply of androgens (testosterone and 5aDHT) secreted from the testes in males
Male differentiation will not occur (insufficient imposing on the basic female trend)
Urination in the males will occur from the side of the penis, not from the tip (incomplete fusion of the urethral folds, not enclosing the urethral tube correctly)
115
What is cuases hypospadia?
insufficient/lacking supply of androgens (testosterone and 5aDHT) secreted from the testes in males
Results in Male differentiation will not occur (insufficient imposing on the basic female trend)
Urination in the males will occur from the side of the penis, not from the tip (incomplete fusion of the urethral folds, not enclosing the urethral tube correctly)
116
What is it called when a male urinates from the side of his penis instead of the tip of the penis due to the incomplete fusion of the urethra folds to form the urethral tube in male differentiation of external genetalia from its bipotential precursor?
Hypospadia
Hypospadia
insufficient/lacking supply of androgens (testosterone and 5aDHT) secreted from the testes in males
Male differentiation will not occur (insufficient imposing on the basic female trend)
Urination in the males will occur from the side of the penis, not from the tip (incomplete fusion of the urethral folds, not enclosing the urethral tube correctly)
117
What is involved in Male differentiation of the bipotential precursor of external genetalia?
The bipotential precursor changes more than in female external genetalia differentiation
1. Androgens are produced by the tests (Testosterone --> 5aDHT)
The androgens (mainly 5aDHT) brings about most changes in the external male genetalia
2. Urethral folds: Fuse together to enclose the urethral tube, and forms the shaft of the penis
-Note: Insufficient/lacking in androgens, Male differentiation will NOT occur. Also urination will occur from the side of the penis, not the tip = Hypospadia = is a cause for concern
3. Labio-scrotal folds: Fuse in the midline to form the scrotum (this process is called scrotalisation) = the scrotum will be empty, waiting for the testes to fall during the last month of pregnancy -otherwise risk of infertility and/or testicular cancer later on in life
4. Genital tubercle/Glans area: Expands to form the glans penis
118
What is involved in female differentiation of the bipotential precursor of external genitalia?
The bipotential precursor changes less than in male external genetalia differentiation
- no active hormone intervention = the basic female trend
1. Urethral folds: remains separate to form the Labia minora
2. Labio-scrotal swellings: remains separate to form the Labia majora
3. Genital Tubercle/Glans Area: forms the clitoris
119
What forms the clitoris?
The Glans area/Genital tubercle in female differentiation of the external genetalia differentiation of the bipotential precurors
120
When is there a beginning in the difference of the external genetalia between males and females?
5 weeks into development
121
What are the main features of androgen resistance syndrome?
1. person is XY
2. has testes (inside their labia) and produces testosterone
3. mutation in their androgen receptors (shows that you need working androgen receptors to actively impose trend to become a male)
4. This prevents the reception/function of androgen action
5. Results in the genital ducts/and or external genitalia of a female (normal breast development) by default (basic female trend)
6. No period
122
What is the syndrome in consequence of not working androgen receptors?
Androgen Resistance syndrom
1. person is XY
2. has testes (inside their labia) and produces testosterone
3. mutation in their androgen receptors (shows that you need working androgen receptors to actively impose trend to become a male)
4. This prevents the reception/function of androgen action
5. Results in the genital ducts/and or external genitalia of a female (normal breast development) by default (basic female trend)
6. No period
123
What could you potnetiall have if you do not get your period as a female?
Androgen resistance sysndrom
1. person is XY
2. has testes (inside their labia) and produces testosterone
3. mutation in their androgen receptors (shows that you need working androgen receptors to actively impose trend to become a male)
4. This prevents the reception/function of androgen action
5. Results in the genital ducts/and or external genitalia of a female (normal breast development) by default (basic female trend)
6. No period
124
What can you have if you are XY chromosome genetically, have testes inside your labia, appear as a female in your external genitalia and/or genital ducts?
Androgen resistance syndrome
| -due to lack of androgen action due to the mutation in the androgen receptors
125
What has happens to the androgen receptors in androgen resistance syndrome?
there is a mutation in the androgen receptors
1. person is XY
2. has testes (inside their labia) and produces testosterone
3. mutation in their androgen receptors (shows that you need working androgen receptors to actively impose trend to become a male)
4. This prevents the reception/function of androgen action
5. Results in the genital ducts/and or external genitalia of a female (normal breast development) by default (basic female trend)
6. No period
126
What are the diurnal changes of pulsatile release of LH at puberty?
1. First endocrine sign of puberty is the increase in plasma levels of LH when sleeping at NIGHT, EARLY in puberty
2. increase in LH is due to increase in GNRH release from the hypothalamus at night. GnRH cant be found in the blood due to Portal system, therefore the increase in LH releases the increase in GnRH release.
3. LATE in puberty: increase in pulses of LH release during the DAY
4. Increase in LH = increase in Sex steroid response (testosterone in male and oestradiol/follicular growth in females)
5. During 3-4 year period Frequency of Pulses of LH increase until an Adult pattern is established
