Reproduction Flashcards
(124 cards)
1
Q
What does the X chromosome encode for?
A
Androgen receptor
2
Q
Female internal genitalia develop from the ___ of the gonadal ridge.
A
Cortex
3
Q
Male internal genitalia develop from the ___ of the gonadal ridge.
A
Medulla
4
Q
What are the two types of cells in the ovary and what do they do?
A
- Granulosa cells: secrete and synthesize androgen, progesterone, and inhibin
- Thecal cells: secrete androgens and progesterone
5
Q
What receptors are found on granulosa cells?
A
LH and FSH
6
Q
What receptors are found on thecal cells?
A
LH
7
Q
What are the two types of cells in the testes and what do they do?
A
- Sertoli cells: make AMH and inhibin B
2. Leydig cells: make androgens
8
Q
What stimulates formation of the internal genitalia from the Wolffian duct? What happens without it?
A
Testosterone and DHT; the Wolffian duct regresses
9
Q
What does the genital tubercle become in males and females?
A
Males: glans penis
Females: clitoris
10
Q
What do the urogenital folds become in males and females?
A
Males: ventral penis
Females: labia minora
11
Q
What does the urogenital sinus become in males and females?
A
Males: prostate
Females: lower vagina
12
Q
What do the labioscrotal folds become in males and females?
A
Males: scrotum
Females: labia majora
13
Q
When does female oogenesis arrest?
A
First: meiosis I arrests in the diplotene stage of prophase until activation at puberty
Second: meiosis II at metaphase II until fertilized by pserm
14
Q
What causes the first arrest of female oogenesis?
A
Oocyte maturation inhibitor (OMI)
15
Q
When does male spermatogenesis arrest?
A
Mitosis until puberty
16
Q
What causes an XX genotype, male phenotype?
A
Presence of SRY gene
17
Q
What causes an XY genotype, female phenotype?
A
Mutation of SRY gene
18
Q
What causes an XO genotype, female phenotype?
A
Turner’s syndrome
19
Q
What are the symptoms of Turner syndrome?
A
Gonadal dysgenesis (no ovaries, streak of fibrous tissue instead), short stature, shield chest, webbed neck, upper torso deformities, no puberty, no menstrual cycles
20
Q
What causes an XXY genotype, male phenotype?
A
Klinefelter syndrome (meiotic nondisjunction)
21
Q
What are the symptoms of Klinefelter syndrome?
A
Small, hyalinated testes, infertile, low testosterone, micropenis, eunuchoid body (lower segment > upper segment), short arms, gynecomastia
22
Q
What is the genotype and phenotype in male pseudohermaphroditism?
A
XY, testes present with some/all female internal/external genitalia present
23
Q
What are two causes of male pseudohermaphroditism?
A
Complete and partial androgen resistance (loss or mutation of X-linked androgen receptor gene)
24
Q
What are the hormone levels in complete and partial androgen resistance?
A
Complete: high androgens, high LH, high to normal FSH
Partial: high androgens, high to normal LH, normal FSH
25
What is the phenotype in complete androgen resistance?
Female with blind vaginal pouch, no ducts, undescended testes, lack of androgen effects, high estrogen induces partial development of female characteristics
26
What is the phenotype in partial androgen resistance?
Ambiguous with blind vaginal pouch, only Wolffian ducts, undescended testes, gynecomastia
27
What is the genotype and phenotype in female pseudohermaphroditism?
XX, ovaries present with some/all male internal/external genitalia also present
28
What causes female pseudohermaphroditism?
Developmental defects such as fetal congenital adrenal hyperplasia (most common) and maternal androgen excess
29
What is the phenotype of female pseudohermaphroditism?
Virilization due to increased androgens, ambiguous genitalia, advanced skeletal age
30
Describe true hermaphroditism.
Testes and ovaries present, ambiguous genitalia, cryptorchidism, hypospadias, may be caused by possible SRY translocation or loss of RSPO1 gene, no spermatogenesis
31
LH stimulates ___ and FSH stimulates ___.
Steroidogenesis; gametogenesis
32
What cells form the blood-testes barrier?
Sertoli cells
33
What converts DHEA to androstendione?
3-beta-HSD
34
What converts androstendione to testosterone?
17-beta-HSD
35
What converts testosterone to estradiol?
Aromatase
36
What converts testosterone to DHT?
5-alpha-reductase
37
Which has a higher binding affinity for androgen receptor, testosterone or DHT?
DHT
38
Describe the production of semen.
Sperm is produced in the seminiferous tubule. It matures in the epididymis and travels through the vas deferens. At the ampulla, seminal vesicle secretions are added. This travels through the ejaculatory ducts where prostate fluid is added. Bulbourethral fluid is added prior to entering the urethra.
39
What is secreted by the seminal vesicles?
Nutrients (fructose, citric acid, etc.), prostaglandins, alkaline substances
40
What is secreted by the prostate gland?
Alkaline secretions, proteolytic enzymes
41
What is secreted by the blubourethral gland?
Mucous (upon arousal)
42
What is the first fluid to be expelled in ejaculate?
Secretions from the prostate gland
43
What are the 4 phases of testicular descent?
1. Embryonic position
2. Transabdominal phase
3. Inguinoscrotal phase
4. Elongation of cord
44
Describe the development of sperm.
1. Stem cells lie along the basement membrane of seminiferous tubules.
2. Spermatagonia under continuous mitotic division; a minority commit to further differentiation which undergo meisosis and mature into spermatozoa.
3. Primary spermatocytes divide, producing 2 daughter cells (secondary spermatocytes) with 23 chromosome pairs.
4. 2 Secondary spermatocytes divide again, producing 4 spermatids with 23 single chromosomes.
5. The 4 spermatids become 4 functional spermatozoids.
45
Describe the interaction between Leydig and Sertoli cells.
Leydig cells produce testosterone, which acts on nearby Sertoli cells to increase local testosterone levels. Sertoli cells can convert some to estradiol, which is used by the Leydig cells to promote steroidogenesis.
46
What occurs in spermatogenesis?
Spermatogonia --> 4 haploid spermatids
47
What occurs in spermiogenesis?
Spermatids --> spermatozoa
48
What occurs in spermiation?
Release of spermatozoa from Sertoli cells into the lumen
49
When is maturation of sperm completed?
Upon entering the vagina (capacitation)
50
What are the 6 effects of DHT only?
1. Prostate growth
2. Beard growth
3. Sebum formation
4. Intrauterine differentiation of penis, scrotum, urethra, prostate
5. Pubertal differentiation of scrotum, prostate
6. Male pattern hair distribution
51
What are the 6 effects of testosterone only?
1. Increased VLDL/LDL, decreased HDL
2. RBC production
3. Increased muscle mass
4. Abdominal visceral fat
5. Larynx (male voice)
6. Intrauterine differentiation of epididymis, vas deferens, and seminal vesicles
52
What is the 1 shared effect of DHT and T?
Pubertal development of seminal vesicles and penis
53
What is the 1 shared effect of E2 and T?
Skeletal development (closing of epiphyseal plate)
54
What are the 3 effects of E, T, DHT?
Sperm production, imprint male pattern of gonadotropins, sex drive, behavior, and feedback suppression of gonadotropin secretion
55
Describe the process of penile erection.
1. ACh and NO released
2. ACh binds muscarinic receptors, stimulating PLC, increasing Ca2+, and activating NO synthase
3. NO causes vasodilation by stimulating guanylyl cyclase to make cGMP
4. Type 5 phosphodiesterase decreases cGMP
56
What does Viagra (sildenafil) do?
Inhibit Type 5 phosphodiesterase
57
What triggers the ejaculation reflex?
Entry of semen into bulbous urethra from prostatic urethra
58
What are two examples of primary hypergonadotropic hypogonadism and what are the hormone levels?
Klinefelter syndrome, enzyme deficiencies
high LH/FSH, low T/DHT
59
What are two examples of hypogonadotropic hypogonadism?
Kallman syndrome, panhypopituitarism
60
What are three testicular disorders?
Klinefelter syndrome, cryptorchidism, varicocele
61
What is the cyclic monthly pattern of hormone secretion in females?
Menstrual rhythm
62
What are the physiological changes in the ovary and uterus in females?
Menstrual cycle
63
What is a follicle?
One oocyte surrounded by a cluster of granulosa cells
64
What is produced by theca cells?
Androgens and progestins (LH receptors only)
65
What is produced by granulosa cells?
Estrogens, inhibins, activins (LH and FSH receptors)
66
What are the three types of estrogens?
E1: estrone; high after menopause
E2: 17-beta-estradiol
E3: estriol; fetus
67
Estrogen is primarily bound to ___ in blood.
Albumin (60%); 38% bound to SHBG
68
ER-alpha mediates most ___ effects of estrogens. ER-beta mediates ___ effects.
Reproductive; non-reprodutive
69
What are SERMs?
Selective estrogen receptor modulators - specific agents designed to target estrogen receptors
70
What does Tamoxifen do?
Antagonize both ER receptors; used in breast cancer
71
What does Clomiphene do?
Antagonizes ER-alpha
72
What are the major functions of progesterone?
1. Prepare endometrium for implantation
2. Inhibit myometrial contractions
3. Stimulate mammary gland development
4. Antagonize estrogen actions
73
Describe the 4 follicular stages.
1. Primoridal: outer layer of pregranulosa cells + small oocyte
2. Primary: cuboidal granulosa cells + larger oocyte
3. Secondary: multilayered granulosa cells + enlarged oocyte + differentiation of stromal cells to thecal cells
4. Tertiary: formation of antrum, zona pellucida formation
74
What are the three phases of the ovarian cycle?
1. Follicular
2. Ovulatory
3. Luteal
75
What occurs in the follicular phase?
Growth of dominant follicle
76
Describe the three strata of granulosa cells.
1. Mural: farthest from oocyte, LH receptors
2. Cumulus: near oocyte, shed at ovulaton
3. Antral: face antrum, form luteal cells after ovulation
77
The dominant follicle is characterized by an enlargement of the ___ and appearance of the ___.
Antrum; cumulus oophorus
78
Recruited follicles produce inhibin B, which does negative feedback on FSH - why?
This ensures that only the follicle most sensitive to FSH survives
79
What occurs in the ovulatory phase?
Follicle rupture and oocyte release
80
In follicle maturation, the cumulus cell ___, the ___ forms, and the ___ detaches. The follicle forms a bulge agains the ovarian wall; this is known as a ___.
Expands; corona radiata; cumulus oophorous; stigma
81
What happens to the oocyte in the ovulatory phase?
Completion of meiosis I, arrest at metaphose in meiosis II as a secondary oocyte + polar body
82
During ovulation, the follicle ___ and releases the oocyte into the ___. ___ draw the free oocyte into the fallopian tubes. The remaining cohort of recruited follicles undergo ___. In the rupture Graafian follicle, the granulosa and theca cells remain in the follicular cavity and reorganize into the ___. Vascularization and inflammatory cytokines ___.
Rupture; peritoneal cavity; fimbriae; atresia; corpus lteum; increase.
83
The timing of the LH surge is determined by the ___.
Ovary
84
What occurs in the luteal phase?
Formation of the corpus luteum
85
What rescues the corpus luteum from degradation?
hCG
86
Describe the two compartment theory of E2 synthesis.
Thecal cells have LH receptors and synthesize androgens. Granulosa cells have LH and FSH receptors. FH stimulates expression of CYP19 (aromatase). Androstendione enters the granulosa cell from the thecal cell and is converted to estradiol-17-beta.
87
What are the three phases of the endometrial cycle?
1. Menstrual phase
2. Proliferative phase
3. Secretory phase
88
What are the three layers of the uterus?
1. Endometrium
2. Myometrium
3. Perimetrium
89
Vaginal epithelial cells are large, squamous, cornified with small or absent nuclei in the __ phase. They are small and basophilic with many leukocytes in the ___ phase.
Mid-to-late follicular; luteal
90
What is the fertile window?
24 hours post-ovulation (ovum) and 48-72 hours post-coitus (sperm)
91
Describe the acrosomal reaction.
Sperm binds to ZP3 protein on zona pellucida, which triggers increased calcium in sperm, leading to exocytosis of hydrolytic enzymes; the sperm and oocyte membranes fuse and the sperm bind to ZP2 proteins.
92
Describe the cortical reaction.
Sperm penetration triggers increased calcium in the oocyte, resulting in the fusion of cortical granules with plasma membrane, which releases enzymes that harden the zona pellucida. The oocyte also completes meiosis II and the second polar body is extruded.
93
What occurs in the hatching of the embryo?
Dissolution of zona pellucida by trophoblast cells
94
What happens to the blastocyst at implantation?
Trophoblast differentiates into cytotrophoblast and syncytiotrophoblast
95
Embryo invasion involves a balance between ___ (defense) and ___ (offense)
Decidual cells; trophoblast migration
96
___ from trophoblasts and ___ from decidual cells battle during embryo invasion.
Matrix metalloproteinases (MMP) and IGF-2
MMP inhibitors and IGF binding proteins
97
What are fluid filled spaces in the syncytium that make contact with the maternal blood?
Lacuna
98
What happens in order to form the chorionic villus?
Cytotrophoblasts proliferate and invade the syncytiotrophoblasts
99
Vascular remodeling at the site of implantation converts ___ vessels to ___ vessels.
High R, low capacity --> low R, high capacity
100
What are the 3 hallmark symptoms of eclampsia?
Hypertension, proteinuria, edema
101
What are the two hormones secreted by the syncytiotrophoblasts?
1. hCG
| 2. hPL
102
What are the two major functions of hPL?
1. To act like GH (counter-regulate insulin, mobilize glucose, stimulate fetal IGF-1)
2. To act like Prolactin (stimulate mammary gland development)
103
What are the 3 imperfections of the placenta as an endocrine gland?
1. Cannot synthesize cholesterol (gets LDL from mother)
2. Cannot convert progesterone to other steroids (lacks CYP17)
3. Cannot make enzyme required to make E3
104
What are the three zones of the fetal adrenal gland?
1. Definitive zone (future z. glomerulosa)
2. Transitional zone (future z. fasciculata)
3. Fetal zone (future z. reticularis)
105
What hormone inhibit myometrial contractions and is produced by the placenta?
Relaxin
106
In pregnancy, what happens to maternal mean arterial blood pressure?
Decreases
107
In pregnancy, what happens to maternal TPR?
Decreases
108
In pregnancy, what happens to maternal pulmonary pressures?
Stay the same
109
In pregnancy, what happens to maternal venous pressure?
Increases
110
In pregnancy, what happens to maternal regional blood flow?
Increase to uterus, skin, kidney
111
In pregnancy, what happens to maternal blood volume?
Increased
112
In pregnancy, what happens to maternal respiration?
Diaphragm is elevated, TV increases
113
In pregnancy, what happens to maternal renal function?
Increased renal blood flow and GFR
114
In pregnancy, what happens to maternal GI system?
Decreased GI motility, decreased LES tone
115
In the first half of pregnancy, the mother is in a ___ state; in the second half, a ___ state.
Anabolic; catabolic
116
What is the most dominant signal in parturition?
Decreased ratio of P4:E2
117
What happens in Phase 0 of labor?
Nothing (uterus inactive via progesterone)
118
What happens in Phase 1 of labor?
Activation of uterus, release from inhibitory mechanisms, activation of factors promoting uterine activity
119
What happens in Phase 2 of labor?
Active uterine contractions facilitated by increased prostaglandins, OXY, CRH (Decreased P4:E2 ratio increases prostaglandins, E2 increases OXY receptors, CRH increases fetal HPA axis, which increases E2, uterine contractions stimulate OXY, which stimulates more prostaglandin release)
120
What happens in Phase 3 of labor?
Expulsion of fetus and placenta
121
___ stimulates myometrial quiescence and cervical rigidity. It has not role in local OXY production.
P4
122
___ stimulates all the other effects in parturition except matrix metalloproteinase production.
E2
123
What is the first milk produced?
Colostrum (high protein)
124
How do oral contraceptives work?
P4 hormone prevents LH secretion (blocks surge), E2 inhibits FSH release
