13.2 Hormones and Sexual Development of the Body

Question 1

Do the chromosomes cause male and female differentiation entirely?

Answer 1

no, there are several other factors to consider, and males only develop when female program for development has been overruled

Question 2

what are primordial gonads

Answer 2

the gonad structure at 6 weeks were there is no difference between males and females
- composed of an other covering (cortex) and an. internal core (medulla)

Question 3

what aspect of primordial gonads can develop into an ovary

Answer 3

the Cortex

Question 4

what aspect of primordial gonads can develop into a testis

Answer 4

the medulla

Question 5

what occurs in the 7th week after conception in males

Answer 5

the Sry gene on the Y chromosome synthesizes the sry protein which causes the medulla of each primordial goad to grow into a thesis

Question 6

what happens in the absence of Sry proteins

Answer 6

cortical cells grow into ovaries

Question 7

What occurs if we inject Sry protein into the female fetus at 6 weeks

Answer 7

genetic female with testis

Question 8

what occurs if we use drugs that bloc the effects of Sry on a male fetus

Answer 8

genetic Male with ovaries

Question 9

what do we call individuals who are genetically one sex, but display the gonads of the other?

Answer 9

intersex

Question 10

what do both males and females have at 6 weeks

Answer 10

wolffiann system and mullerian system

Question 11

what is the wolffian system

Answer 11

capacity to dev into male reproductive ducts such has the seminal vesicles and the vas deference

Question 12

what is the mullerian system

Answer 12

capacity to develop into female ducts ,such as the uterus, the upper part of the vagina, the Fallopian tubes

Question 13

what occurs during the third month of male fetal development?

Answer 13

the testes secrete testosterone and mullerian-inhibitig substance

Question 14

what does testosterone do in the third month of male fetal development

Answer 14

stimulates the development of the wolffian system

Question 15

what does mullerian-inhibiting substance do in the third month of male fetal dev

Answer 15

causes the mullerian system to degenerate, and the testes to descend into the scrotum

Question 16

what occurs to females injected with testosterone during the third month develop?

Answer 16

male reproductive tracts alongside the female ones

Question 17

does the development of the mullerian system rely onn ovarian hormones?

Answer 17

no, ovaries are almost entirely inactive during fetal dev.

the mullein system with develop in any fetus not exposed to testicular hormones during the critical periods

Question 18

what occurs to ovariectomized female fetuses?

Answer 18

develop mullerian ducts

Question 19

what occurs orchidectomized male fetuses?

Answer 19

develop mullerian ducts

Question 20

what is the difference between ovariectomy, orchidectomy and gonadechtomy?

Answer 20

ovariectomy is removal of ovaries
orchidectomy is removal of testes
gonadectomy (castration) is the surgical removal of gonads, either ovaries or testes

Question 21

what is a major difference between the development of internal and expternal reproductive organs?

what do we call the relevant aspect of the external genitals

Answer 21

internal are differentiated between two precursor systems (wolffian and mullerian)

• external genitals are developed from the same precursor (biopotential precursor)

Question 22

what are the four parts of the biopotential precursor at the end of the second month of pregnancy

Answer 22

glans, urethral folds, lateral bodies and labioscrotal swellings

Question 23

what does the glans differentiate into in males and females

Answer 23

head of the penis for clitoris

Question 24

what do the urethral folds differentiate into in males and females

Answer 24

fuse in the male, enlarge in the female to become the labia minora

Question 25

what do the lateral bodies differentiate into in males and females

Answer 25

the shaft of the penis In the dude

the hood of the clitoris

Question 26

what do the labioscrottal swellings form in males and females?

Answer 26

the scrotum

labia majora

Question 27

what controls the development of the external genitals?

Answer 27

the presence or absence of testosterone

• if present at the appropriate stage, male genitals develop from the precursor
• if not, female

Question 28

what is characteristic of children’s sex characteristics (3)

Answer 28

low levels of circulating gonadal hormones
immature reproductive organs
little general appearance differences

Question 29

what is puberty

Answer 29

the transitional period between childhood and adulthood during which fertility is achieved, the adolescent growth spurt occurs, and the secondary sex characteristics develop

Question 30

what action in the anterior pituitary is associated with puberty (2)

Answer 30

increase of release

• growth hormone acts directly on obese and muscle tissue (only hormone that doesn’t act on another gland)
• gonadotropic hormone and adrenocorticotropic hormone (ACTH)

Question 31

what does the release of gonadptrnopic hormone and ACTH cause?

Answer 31

cause the gonads and adrenal Cortez to increase their release of gonadal and adrenal hormones which initiates the maturation of the genitals and the development of secondary sex characterisitcs

Question 32

what is the general principle guiding typical pubertal sexual maturation?

Answer 32

in pubertal males, androgen levels are greater than estrogen levels and tf masculatio
I pubertal females, estrogens are dominant, and therefore feminization

Question 33

what occurs to individuals castrated prior to puberty?

Answer 33

do not become sexually mature unless they receive replacement injections of androgens or estrogens

Question 34

what is androstenedione

Answer 34

an androgen that is released primarily by the. adrenal cortex
- typically responsible for the growth of pubic hair and axillary hair in females

Question 35

why does androstenedione critique the men are men assumption

Answer 35

bec androstenedione is an androgen that controls for female development