Reproduction Flashcards
What are the three types of sexual differentiation?
Genetic
Gonadal-testes determining genes
Phenotypic -tubular and external structures
What is SRY?? What happens in absence of this factor?
Testis determining factor
Cortical sex cords develop into follicles and medullary sex cords degenerate =female
In presence of SRY, medullary sex cords differentiate to ______________ cells and cortical sex cords __________.
Sertoli
Degenerate
What is freemartinism?
Male and female co-twins with fused placental
Male produce anti-mullerian hormone and it circulates to female and inhibits her development of internal structures
What is sex reversal?
Disagreement between chromosomal and gonadal sex
XX sex reversal
-XX genotype with testicular development
SRY translocation
What are the three main classes of homones?
Steroids
Peptides
Eicosanoids
How are hormones delivered?
Endocrine Neuroendocrine Paracrine Neurocrine Autocrine
What hormone is neuroendocrine delivered?
Gonadotropin releasing hormone
Estradiol and FSH are delivered by?
Endocrine
What hormone is delivered by paracrine delivery?
Testosterone
Leydig cells to stertoil cells
What hormone is autocrine delivered?
Estradiol
Sertoli cells
The strength of hormone action depends on?
Secretion pattern
Half-life
Receptor density
Affinity receptor-hormone
What is the half life of a hormone?
The rate at which it is cleared from circulation
What is a hormone agonist?
Binds to receptor and has the same biological response of the native hormone
Hormone antagonist?
Bind to the receptor but it has a weak or not biological effect
What hormones are produced in the hypothalamus?
GnRH, and Oxytocin
What hormones are produced in the pituitary?
FSH, LH, and Prolactin
Protein hormones activate cellular responses by which mechanism?
Activate protein kinases via cAMP
Protein kinases produce new protein products
Steroids activate cellular responses by what mechanism?
Steroid diffuses through the plasma membrane and nuclear membrane. Bind to receptors and trigger mRNA production
Testosterone is ___________ in a non-reversible enzyme process to produce estradiol
Aromatized
Aromatase enzyme
Where is Estradiol-17B produced?
Follicular cells of ovary, placental
Also small amounts in adrenal, testis, and other sites
Where is Estraiol metabolized?
Liver
Cholesterol is made into adrotenedione in the ______ cells. Adrotenedione is made into estradiol in the ___________cells?
Theca
Granulosa
What are the functions of Estradiol?
Mediate sexual behavior and secondary sex characteristics Uterine development and function Cervical mucus Increase progesterone receptors Vaginal proliferation Mammary development Ovulatory LH surge Maintain pregnancy Bone health
Progesterone is produced mainly by the ?
Corpus luteum
What are the functions of progesterone?
Development of uterus Myometrium Closure of cervix, increased viscosity of cervical mucus Maintain pregnancy Mammary development Immune function
What are progestagens?
Class of hormones that bind to progesterone receptors
Progesterone-like actions
Where is testosterone produced?
Leydig cells of testes
Small amounts in adrenal and ovaries
What is the function of testosterone?
Masculinization Maturation of male repro structures Spermatogenesis Male sexual behavior Muscle mass and bone density (Anabolic) Erythropoietics Increase BMR
What are androgens?
Class of compounds binding to adgrogen (testosterone) receptors
Testosterone
Dihydrotestosterone
Androstenedione
What are the two functional areas of the female hypothalamus?
Tonic and surge centers
Presence of testosterone has what effect on the Brian?
“Defeminize” the brain
Testosterone crosses blood brain barrier and converted to estradiol
Estradiol eliminates surge center
GnRH to the pituitary stimulates the release of?
LH and FSH
FSH stimulates what in the female?
Follicle growh
What are the two feedback pathways of FSH
Follicle growth
Graafian follicles - positive feedback with estradiol to hypothalamus to stimulate LH surge
Negative feedback with Inhibin to regulate FSH release
What does LH stimulate in the female and what is its feedback loop?
Development of corpus luteum -> produces progesterone -> negative feedback regulates tonic release of LH and supports corpus luteum until PGF causes regression
The medulla of the ovary contains?
Vasculature, nerves, and CT
The Cortes of the ovary contains ?
Oocytes and follicles
Describe follicular development in the ovary.
Primordial follicle- oocyte surrounded by single layer of squamous cells
Primary follicle -single layer of cuboidal cells
Secondary follicle- oocyte with two or more layers and zona pellucida
Antral follicle -fluid in cavity
What is a committed follicle?
Commences development from resting pool
What is follicular development that is independent of FSH or LH?
Gonadotropin-independent growth
At what stage does a follicle become Gn-responsive?
Secondary
At what stage does a follicle become Gn-dependent?
Antral/ Graafian
What cells can be seen in an antral follicle?
Theca externa- CT
Theca interna - produce androgens under LH stimulation
Granulosa -produce estrogen, inhibin, and follicular fluid
->Columbus oophorus
-> corona radiata
-> zona pellucida
What structure is left in the ovary immediately after ovulation?
Corpus hemorrhagicum
Theca interna and granulosa cells proliferate to filled the _____________ ___________ and differentiate to produce luteal cells
Corpus luteum
Large luteal cells secrete?
Progesterone, oxytocin, and relaxin