Repro: Sex Determination & Differentiation Flashcards
0
Q
Organized structure of DNA & protein. Coiled DNA containing many genes, regulatory elements and other nucleotide sequences.
A
Chromosome
1
Q
Humans display ________. Females and males are physically distinct.
A
Sexual dimorphism
2
Q
Produce gametes and sex hormones
A
Gonads
3
Q
Male gonads (testes) produce
A
Sperm
4
Q
Female gonads (ovaries) produce
A
Eggs/ova
5
Q
Humans have how many pairs of chromosome
A
23
6
Q
Chromosomes: 22 pairs of ________ & 1 pair of _________.
A
Autosomes. Sex chromosomes.
7
Q
Contain two complete sets of chromosomes. Example.
A
Diploid cells (2n). Somatic cells.
8
Q
Contain one complete set of chromosomes. Example.
A
Haploid cells (n). Gametes/sex cells.
9
Q
Complete set of genetic information (diploid) is distributed to each of two daughter cells. Observed in ________.
A
Mitosis. Somatic cells.
10
Q
Only a half set of genetic information (haploid) is distributed to each of four daughter cells. Observed in _______.
A
Meiosis. Gametes.
11
Q
Process of genetic inheritance that sets the gender of an individual at the moment of ________.
A
Sex determination. Fertilization.
12
Q
Development of differences between males and females from an undifferentiated _______.
A
Sex differentiation. Zygote.
13
Q
Sequential process of establishment of sex and sexual difference. Includes the process that determine:
A
Sex determination & differentiation. Chromosomal/Genetic, Gonadal, Phenotypic/Genital & Psychological sex. “C G PP”
14
Q
Established by genetic inheritance at the moment of fertilization
A
Chromosomal sex
15
Q
Male: embryo with ____ chromosomes.
A
XY
16
Q
Female: embryo with ____ chromosomes.
A
XX
17
Q
Depends on the combination of sex chromosomes
A
Genetic sex
18
Q
Development of primary sex organs in response to genetic sex
A
Gonadal sex
19
Q
Gonadal sex is determined by
A
Presence/Absence of SRY gene
20
Q
Sex determining region of Y chromosome (SRY) codes for production of
A
Testis Determining Factor “TDF”
21
Q
TDF directs differentiation of gonads
A
Testes
22
Q
Female has no
A
Y chromosome, so no SRY & TDF
23
Q
With no TDF, undifferentiated gonads in females develop into
A
Ovaries
24
Regulation by gonadal sex of the differentiation of the genital apparatus. Influenced mainly by _______ & _______.
Phenotypic/Genital sex. Genetics & Hormonal factors.
25
Testes secrete
Testosterone & Mūllerian-inhibiting factor
26
Testosterone is converted to
Dihydrosterone
27
Dihydrosterone promotes development of undifferentiated __________ along male lines. Example.
External genitalia. Penis & Scrotum.
28
Testosterone transforms _________ into male reproductive tract. Example.
Wolffian ducts. Seminal vesicles, Epididymis, Ductus deferens & Ejaculatory duct "SEDE"
29
Causes the degeneration of Mullerian ducts
Mūllerian-inhibiting factor
30
Non testosterone and mūllerian-inhibiting factor secreted
Ovaries
31
Absence of Mūllerian-inhibiting factor will lead to development of _________ into female reproductive tract. Example.
Mūllerian ducts. Oviducts & Uterus.
32
In female, Absence of testosterone will lead to the degeneration of
Wolffian ducts
33
In females, absence of testosterone will lewd to development of _____________ along female lines. Example.
Undifferentiated external genitalia. Clitoris & Labia.
34
Establishment of gender role, gender identity and sexual orientation. Influenced by _______ & _______ factors.
Psychological sex. Behavioral & Cultural.
35
Determined at a time of fertilization when ovum and sperm unite
Genetic sex
36
Genetic male (_______) = ____ pattern.
Heterogametic. XY.
37
Genetic female (_______) = ____ pattern.
Homogametic. XX.
38
Mutation of genes on an X chromosome results in transmission of. Example.
X-linked traits. Hemophilia & Color blindness.
39
Presence of _________ is the single most consistent determinant of maleness. Contains ________ responsible for sex determination. Necessary for testes and masculine genital pattern development.
Y chromosome. SRY gene.
40
Presence of additional _________ does not alter fundamental maleness dictated by Y chromosome. Example.
X chromosome. Klinefelter syndrome (XXY)
41
Discovered by Barr & Bertram in 1949. One of the two copies of the X chromosome present in females is inactivated ( ______ hypothesis)
Sex Chromatin Test. Lyon.
42
In Sex Chromatin Test, nucleus of somatic cells of females contain a plano-convex mass adherent to inner side of nuclear membrane known as
Sex chromatin mass/Barr body
43
In Sex Chromatin Test, presence of 1 Barr body means that an individual has 1 X chromosome in excess ( ___ X chromosomes total). Result is
2. Normal female.
44
In Sex Chromatin Test, presence of 2 Barr bodies means that an individual has 2 X chromosome in excess ( ___ X chromosomes total). Result is
3. Super female.
45
Specimens for Chromatin Test
Nerve cells, Buccal smear, Blood smear & Vaginal smear. "NBBV"
46
In buccal smear, _______ scraping.
Inner cheek
47
In buccal smear, if 20% positive
Genetic female
48
In buccal smear, if 0-4% positive
Genetic male (4% error margin)
49
In blood smear, presence of ___________ in nucleus of neutrophils in genetic females. Low positiveness (6/500 neutrophils)
Drumstick appendage
50
Noninvasive screening for large populations in sports competition. Assurance that individual joining female division sport competition is a normal genetic female.
Hair root test
51
In hair root test, Pluck ____ strands of normal scalp hair. Tease the rooth hair, stain with fluorescent stain, look for _________. Part of the Y chromosomes present only in _____ (15/100 cells) and invariably absent in _________.
3-4 strands. Fluorescent body. Males. Females.
52
Requires use of tissue culture. Most accurate method, Gold standard. Done by geneticists. Required for patients who will undergo gender reassignment surgery.
Karyotyping
53
Must be determined for those who want gender reassignment or those with ambiguous genitalia.
Genetic sex
54
Karyotyping duration before results are available
10 days
55
Three test for genetic sex
Sex Chromatin Test, Hair Root Test & Karyotyping.
56
Development of primitive gonad into either testes or ovary
Gonadal sex
57
In Gonadal sex, outer cortex is composed of
Coelomic epithelial cells
58
In Gonadal sex, inner medulla is composed of _________ which surrounds cords of epithelial cells.
Stromal mesenchyme.
59
At what week of gestation do all embryos have potential gonads
4-6 weeks
60
SRY gene produces this which initiates the production of multiple proteins that cause gonad medulla to differentiate into a testis.
Testis-determing SRY protein
61
Secrete testosterone. Controls development of Wolffian duct into accessory structures and male external genitalia via _____.
Leydig cells. DHT.
62
Secrete Anti-Mūllerian hormone which causes regression of Mūllerian duct.
Sertoli cells
63
In male gonadal development: enlarges to become the testis.
Embryonic medulla
64
In male gonadal development: it regresses
Embryonic cortex
65
In male gonadal development: at what week do the formation of Seminiferous tubules and Sertoli cells occur
6-7 weeks
66
In male gonadal development: formation of Leydig cells at what week
8-9 weeks
67
In male gonadal development: Leydig cells secrete _____ in response to ____.
Testosterone. HCG.
68
In male gonadal development: at what week does a definitive testes is present and secretion of testosterone is established
9 weeks
69
In male gonadal development: testes descend normally through inguinal ring in what month
7-9 months of gestation
70
In female gonadal development: ________ proliferates to become ovaries.
Embryonic cortex
71
In female gonadal development: at what week do primordial follicles are discernible
Weeks 11-12
72
In female gonadal development: ovaries reaches maximal development by
Weeks 20-25
73
In female gonadal development: regresses and become the hilum of mature ovaries
Embryonic medulla
74
In female gonadal development: development starts during ______ in the absence of signal for testis formation.
9th week of gestation
75
Development of phenotypic sex requires
Differentiation of genital ducts, external genitalia & hypothalamic
76
Differentiation of the internal and external genitalia requires presence of ________ & ___________.
Hormones & Chemical messengers
77
Cells in distant endocrine gland secrete hormones into bloodstream to regulate or induce differentiation in distant target tissues.
Classic Endocrine Mechanism
78
Example of Classic Endocrine Mechanism: testosterone secreted by _________, induces differentiation of anlagen of ________.
Fetal leydig cells. External genitalia.
79
Dissemination of hormone by local diffusion through the extracellular spaces.
Local Paracrine Regulatory Mechanism
80
Example of Local Paracrine Regulatory Mechanism: Action of ____ on Mūllerian duct. Action of testoterone on _________.
MIF. Wolffian duct.
81
At what week does fetus contains both male and female primordial genital ducts
7th week
82
Have the potential of differentiating into seminal vesicles, epididymis & vas deferens.
Wolffian duct/Mesonephric duct
83
Serves as the anlagen of the fallopian tube, uterus, cervi & upper vagina
Mūllerian duct/Paramesonephric duct
84
In a male embryo, directs the medulla of the bipotential gonad to develop into testis
SRY protein
85
Cause the Mūllerian ducts to disappear
Anti-Mūllerian hormone
86
Coverts Wolffian duct into seminal vesicle, epididymis & vas deferens
Testosterone
87
Controls prostate development
DHT
88
Becomes ovary in the absence of SRY protein
Gonadal cortex
89
Cause Wolffian duct to degenerate
Absence of testosterone
90
Absence of Anti Mūllerian hormone allows the _________ to become the fallopian tube, uterus, cervi & upper vagina.
Mūllerian duct
91
Responsible for differentiation of Wolffian ducts to male internal genitalia at ________. Secreted by _______. Does not have to be converted to its active product (________) to act on Wolffian ducts.
Testosterone. 9-10weeks. Fetal Leydig cells. Dihydrotestosterone.
92
Glycoprotein hormone secreted by _________. Induces dissolution of Mūllerian ducts, therefore inhibiting differentiation of female internal genitalia.
MIF. Sertoli cells.
93
In contrast with internal genitalia, external genitalia in both sexes develop from common _______.
Anlagen.
94
Growth and development of the male external genitalia require
Dihydrotestosterone
95
In males: becomes glans penis, corpus cavernosum & corpus spongiosum.
Genital tubercle
96
In males: fuse around the urethral groove to form the penis (ventral shaft)
Genital/Urethral folds
97
In males: fuse to form scrotum and prepuce
Genital/Labioscrotal swelling
98
In males: develops into prostate gland, male urethra & cowper's gland.
Urogenital sinus
99
In females: develops into female urethra, bartholin's gland, lower vagina & skene's glands.
Urogenital sinus
100
In females: do not fuse but develop into labia majors
Genital/Labioscrotal swellin
101
In females: genital folds do not fuse and develop into labia minora.
Genital/Urethral folds
102
In females: becomes clitoris and vestibular bulb.
Genital tubercle
103
In normal females, hormones may not be _______ in differentiation.
Essential
104
Growth of labia to normal size requires
Estrogen
105
Exposure of normal female fetus to excess testosterone during differentiation causes
Virilization
106
In virilization: if exposed early, may result to
Male pattern
107
In virilization: if exposed after differentiation may result to
Enlargement of clitoris
108
For newborn with ambiguity of external genitalia
Postpone signing of Birth certificate & do screening test
109
In hypothalamic differentiation, control of gonadal function is mediated by 2 gonadotrophins namely
FSH & LH
110
Pattern of gonadotrophin secretion in males, pulsatile but relatively constant sustained manner.
Tonic release
111
Pattern of gonadotrophin secretion in females, pulsatile but cyclic
Cyclic release
112
Hypothalamic-Pituitary-Gonadotrophin Unit: pulsatile secretion of LHRH by
Hypothalamus
113
Hypothalamic-Pituitary-Gonadotrophin Unit: pulsatile secretion of FSH & LH by
Pituitary
114
Hypothalamic-Pituitary-Gonadotrophin Unit features: matures in _____. Supressed during _______. And Reactivated at the onset of _______.
Fetus. Childhood. Puberty.
115
In males: gonadal cortes
Regresses
116
In males: gonadal medulla forms
Testis
117
In males: Wolffian duct forms
Seminal vesicle, Epididymis & Vas deferens "SEV"
118
In males: Mūllerian duct
Regresses
119
In males: Genital tubercle forms
Glans penis, Corpus Cavernosum & Corpus Spongiosum "GCC"
120
In males: Genital folds form
Penis (ventral shaft)
121
In males: Genital swelling forms
Scrotum & Prepuce "SP"
122
In males: Urogenital sinus forms
Prostate gland, Male urethra & Cowper's gland "PMC"
123
In females: gonadal cortex forms
Ovaries
124
In females: Gonadal medulla
Regresses
125
In females: Wolffian duct
Regresses
126
In females: Mūllerian duct forms
Fallopian tube, Uterus, Cervi & Upper vagina "FUC U"
127
In females: Genital tubercle forms
Vestibular bulb & Clitoris "VC"
128
In females: Genital folds form
Labia minora
129
In females: Genital swelling forms
Labia majora
130
In females: Urogenital sinus forms
Female urethra, Bartholin's gland, Lower vagina & Skene's gland "FBLS"
131
Psychological sex or Gender identity: ________ as either male or female. Applicable only to _______. Formed in ________.
Identification. Humans. Early childhood.
132
Psychological sex or Gender identity: independent of _________ and even ______ of the individual.
Hormonal regulation. Phenotype.
133
Psychological sex or Gender identity: dependent on rearing ______ and ________.
Cues. Culture.
134
Considered as socially, culturally, historically and psychologically determined
Psychological sex or Gender identity
135
Exact biologic basis has not been established
Homosexuality
136
In homosexuality, region _____ of the X chromosome has been controversially dubbed as the gay gene.
Xq28
137
In homosexuality, brain studies reveal: 1.7x larger ___________ in homosexual males. ________ is 18% larger in heterosexual females and 14% larger in heterosexual males.
Suprachiasmatic nucleus. Anterior commissure.
138
Established defect in gametogenesis. Chromosomes fail to separate therefore both go to one of the daughter cells during meiosis the other has none.
Nondisjunction
139
Complete absence of one sex chromosome (Barr body). Leads to monosomy X _______. Short stature
Turner syndrome. XO genotype. Shield chest.
140
Meiotic disjunction leads to a _______. Testicular atrophy, eunuchoid body shape, tall long extremities, gynecomastia and female hair distribution.
Klinefelter syndrome. 47 XXY genotype.
141
Only one X chromosome is active, two Barr bodies are present. Usually no distinguishable difference between triple X and normal females. Some says increased risk for menstrual irregularities and ________.
Superfemale/Triple X syndrome. Learning disorders.
142
Disorder of sexual differentiation. Born with both ovarian and testicular tissues.
Hermaphroditism
143
Type of Hermaphroditism: functional gonads
True hermaphroditism
144
Type of Hermaphroditism: phenotype & genotype do NOT match (nonfunctional gonads)
Pseudohermaphrodites
145
Genetic males whose target cells lack receptors for testosterone are feminized. _______ insensitivity.
Testicular feminization. Androgen.
146
Male genotype, Female phenotype
Male pseudohermaphrodites
147
Adrenal androgen overproduction in the fetus. Female pseudohermaphroditism: female genotype, male phenotype, Virilization of an XX fetus and ambiguous genitalia.
Congenital Adrenal Hyperplasia
