Puberty and Development of Male and Female Systems

Question 1

What are the two most common testicular descent failures?

Answer 1

cryptorchidism and inguinal hernia

Question 2

After testes develop, Sertoli cells begin to secrete anti-mullerian hormone (AMH), which causes:

Answer 2

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

Question 3

Anti-mullerian hormone is produced by __________ cells

Answer 3

Sertoli

Question 4

The embryologic duct system in males is known as the ____________ duct system

Answer 4

Wolffian

Question 5

__________ describes the observed characteristics of an organism (i.e. morphology, development, blood type, etc.)

Answer 5

phenotype

Question 6

From a reproductive point of view, fetal maturation in the female would be indicated by:

Answer 6

development of the broad ligament

Question 7

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

Answer 7

GnRH

Gonadotropins will promote gametogenesis, steroidogenesis, and the development of reproductive tissues.

Question 8

The major limiting factor for the onset of puberty is:

Answer 8

failure of the hypothalamus to produce significant quantities of GnRH to cause gonadotropin release

Question 9

The uterus and vagina result from a fusion of the ____________

Answer 9

paramesonephric ducts

Question 10

The embryologic duct system in females is known as the ____________ duct system

Answer 10

Mullerian (paramesonephric)

Question 11

From a reproductive point of view, fetal maturation in the male would be indicated by:

Answer 11

descent of the testes into the scrotum

Question 12

Several criteria can be used to define puberty in the female. What are the main three?

Answer 12

• Age at first estrus (heat)
• Age at first ovulation (sexual maturity)
• Age at which a female can support pregnancy without problems (breeding maturity)

Question 13

In females, estradiol cannot affect the hypothalamus. This is because a protein called __________ binds estradiol and prevents it from crossing the blood brain barrier

Answer 13

alpha-fetoprotein

This allows for development of the surge center

Question 14

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:

Answer 14

primitive sex cords

These proliferating sex cords cause the genital ridges to enlarge and push toward the developing kidney (mesonephros)

Question 15

T/F: The GnRH surge center is present in both males and females

Answer 15

False

• There is no surge center in the male!*
• Testosterone defeminizes the hypothalamus during embryogenesis and “eliminates” the GnRH surge center in the male*

Question 16

T/F: In the female, estrogen has positive feedback to the surge center and negative feedback to the tonic center

Answer 16

True

Question 17

Testicular descent is made possible by rapid growth followed by rapid regression of this ligamentous structure:

Answer 17

gubernaculum

Question 18

An organism composed of cells from two different zygotes is called a:

Answer 18

chimera

Question 19

Generally, __________ can be defined in both the male and the female as the ability to accomplish reproduction successfully

Answer 19

puberty

Question 20

T/F: The female cow must develop a certain degree of “fatness” before reproductive cycles can be initiated

Answer 20

True

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

Question 21

___________ is determined by the sperm cell at the time of fertilization.

• Phenotypic sex
• Gonadal sex
• Chromosomal sex
• Future wealth
• IQ

Answer 21

Chromosomal sex​

Question 22

The __________ describes the chromosomal complement of an organism

Answer 22

karyotype

Question 23

The typical bovine reaches puberty at ____ months of age

Answer 23

11

Question 24

The substance that controls the pathway toward either male or female development is called:

Answer 24

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.