Reproductive Physiology Flashcards
What are the 3 levels of sex differentiation?
Genetic Sex
Gonadal Sex
Anatomical Sex
Genetic sex is predetermined by the configuration of the ___________
Sex chromosomes
Gonadal sex is determined by the ___________. The ___ chromosome is necessary for testes production.
Sex chromosomes
Y
Describe the process by which male gonadal sex develops
- Primitive gonads develop by the 6th week
- Due to the presence of the sex determining region on the Y chromosome (SRY) H-Y antigen is produced
- In the presence of H-Y antigen the testes form
- Androgen hormones are secreted
- Male anatomy forms
Describe the process by which female gonadal sex develops
- Primitive gonads develop by the 6th week
- Due to the absence of the Y chromosome, no H-Y antigen is produced
- In the absence of H-Y antigen the ovaries form
- No hormones are secreted
- Female anatomy forms
Define anatomical sex:
The apparent anatomical sex of a person depends on the genetically determined gonadal sex
Embryonic Sertoli cells secrete ___________________
Anti-mullarian hormone (AMH)
Embryonic Leydig cells secrete _____________
Testosterone
Anti-mullarian hormone causes regression of the _____________
Mullarian ducts
Testosterone causes growth of the ___________
Wolfian ducts
Describe how male external genitalia form:
- Embryonic testes produce testosterone
- Some testosterone is converted via 5α-Reductase to dihydrotestosterone
- Both Testosterone and Dihydrotestosterone (Mainly) produce growth of the penis and scrotum
Describe how female external genitalia form:
- Absence of embryonic testes
- No Testosterone or Dihydrotestosterone
- Female genitalia form
The genital tubercle develops into the _______ in males and the _______ in females
Glans
Clitoris
The urethral folds and labioscrotal swelling develop into the _______________ in males and _______________ in females
Urethra (Fusion of folds) and Scrotum
Labia minora and labia majora respectively
The urogenital slit develops into the _________
Vagina
The hypothalamus secretes _______ this causes the _______ pituitary to release LH and FSH.
GnRH
Anterior
What is the role of LH?
Stimulates the production of gonadal hormones
What is the role of FSH?
Stimulates growth and development of germ cells
GnRH release is ________ which is essential and is caused by the firing of ______________
Pulsatile
Many Hypothalamic neurons
Explain how GnRH secretion varies of development:
- High levels during neonatal period
- Period of quiescence in mid-childhood
- Sleep-entrained reactivation of GnRH at the onset of puberty
- Adult pattern of pulsatile release
In males GnRH is secreted approximately every ________ while in females it ____________________
2 hours
Varies with the menstrual cycle
In males LH causes ________________
Testosterone release
The major male reproductive systems functions are:
- Production of sperm
- Production of sex hormones
- Transport of sperm from the male to female
Spermatogenesis takes place within the ________________ that have a smooth muscles layer to provide _______
Seminiferous Tubules
Peristalsis
Seminiferous tubules contain:
Spermatogenic cells = the cells that divide and differentiate to for sperm
Sertoli/Nurse cells = provide mechanical and nutritional support for spermatogenic cells
Sertoli cells line the ____________ and are connected by __________. This separates ______ and ______ compartments and forms the ____________.
Seminiferous tubules
Tight junctions
Basal and central
Sertoli cell barrier