What are the two most common testicular descent failures?
cryptorchidism and inguinal hernia
After testes develop, Sertoli cells begin to secrete anti-mullerian hormone (AMH), which causes:
differentiation of leydig cells
Differentiation of leydig cells leads to the production of testosterone and dihydrotestosterone, which results in development of the male duct system and development of the penis, scrotum, and accessory sex glands
Anti-mullerian hormone is produced by __________ cells
The embryologic duct system in males is known as the ____________ duct system
__________ describes the observed characteristics of an organism (i.e. morphology, development, blood type, etc.)
From a reproductive point of view, fetal maturation in the female would be indicated by:
development of the broad ligament
The fundamental requirement for pubertal onset is the secretion of __________ at the appropriate frequency and quantities to stimulate gonadotropin release by the anterior pituitary lobe
Gonadotropins will promote gametogenesis, steroidogenesis, and the development of reproductive tissues.
The major limiting factor for the onset of puberty is:
failure of the hypothalamus to produce significant quantities of GnRH to cause gonadotropin release
The uterus and vagina result from a fusion of the ____________
The embryologic duct system in females is known as the ____________ duct system
From a reproductive point of view, fetal maturation in the male would be indicated by:
descent of the testes into the scrotum
Several criteria can be used to define puberty in the female. What are the main three?
- Age at first estrus (heat)
- Age at first ovulation (sexual maturity)
- Age at which a female can support pregnancy without problems (breeding maturity)
In females, estradiol cannot affect the hypothalamus. This is because a protein called __________ binds estradiol and prevents it from crossing the blood brain barrier
This allows for development of the surge center
When primitive germ cells arrive in the genital ridge, they stimulate local connective tissue to proliferate. This results in the formation of compact strands of tissues called:
primitive sex cords
These proliferating sex cords cause the genital ridges to enlarge and push toward the developing kidney (mesonephros)
T/F: The GnRH surge center is present in both males and females
There is no surge center in the male!
Testosterone defeminizes the hypothalamus during embryogenesis and "eliminates" the GnRH surge center in the male
T/F: In the female, estrogen has positive feedback to the surge center and negative feedback to the tonic center
Testicular descent is made possible by rapid growth followed by rapid regression of this ligamentous structure:
An organism composed of cells from two different zygotes is called a:
Generally, __________ can be defined in both the male and the female as the ability to accomplish reproduction successfully
T/F: The female cow must develop a certain degree of "fatness" before reproductive cycles can be initiated
The relationship between metabolic status and function of GnRH neurons has not been completely described, but there is good evidence that metabolic signals effect the production of GnRH
___________ is determined by the sperm cell at the time of fertilization.
- Phenotypic sex
- Gonadal sex
- Chromosomal sex
- Future wealth
The __________ describes the chromosomal complement of an organism
The typical bovine reaches puberty at ____ months of age
The substance that controls the pathway toward either male or female development is called:
testis determining factor (TDF)
TDF is controlled by "sex determining region Y" (SRY) the Y chromosome. When TDF is synthesized by the sex cords within the primitive gonad, the development of the male reproductive system is stimulated. The absence of TDF results in the development of a female reproductive system.