13.2 Hormones and Sexual Development of the Body Flashcards
Do the chromosomes cause male and female differentiation entirely?
no, there are several other factors to consider, and males only develop when female program for development has been overruled
what are primordial gonads
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)
what aspect of primordial gonads can develop into an ovary
the Cortex
what aspect of primordial gonads can develop into a testis
the medulla
what occurs in the 7th week after conception in males
the Sry gene on the Y chromosome synthesizes the sry protein which causes the medulla of each primordial goad to grow into a thesis
what happens in the absence of Sry proteins
cortical cells grow into ovaries
What occurs if we inject Sry protein into the female fetus at 6 weeks
genetic female with testis
what occurs if we use drugs that bloc the effects of Sry on a male fetus
genetic Male with ovaries
what do we call individuals who are genetically one sex, but display the gonads of the other?
intersex
what do both males and females have at 6 weeks
wolffiann system and mullerian system
what is the wolffian system
capacity to dev into male reproductive ducts such has the seminal vesicles and the vas deference
what is the mullerian system
capacity to develop into female ducts ,such as the uterus, the upper part of the vagina, the Fallopian tubes
what occurs during the third month of male fetal development?
the testes secrete testosterone and mullerian-inhibitig substance
what does testosterone do in the third month of male fetal development
stimulates the development of the wolffian system
what does mullerian-inhibiting substance do in the third month of male fetal dev
causes the mullerian system to degenerate, and the testes to descend into the scrotum
what occurs to females injected with testosterone during the third month develop?
male reproductive tracts alongside the female ones
does the development of the mullerian system rely onn ovarian hormones?
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
what occurs to ovariectomized female fetuses?
develop mullerian ducts
what occurs orchidectomized male fetuses?
develop mullerian ducts
what is the difference between ovariectomy, orchidectomy and gonadechtomy?
ovariectomy is removal of ovaries
orchidectomy is removal of testes
gonadectomy (castration) is the surgical removal of gonads, either ovaries or testes
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
internal are differentiated between two precursor systems (wolffian and mullerian)
- external genitals are developed from the same precursor (biopotential precursor)
what are the four parts of the biopotential precursor at the end of the second month of pregnancy
glans, urethral folds, lateral bodies and labioscrotal swellings
what does the glans differentiate into in males and females
head of the penis for clitoris
what do the urethral folds differentiate into in males and females
fuse in the male, enlarge in the female to become the labia minora
what do the lateral bodies differentiate into in males and females
the shaft of the penis In the dude
the hood of the clitoris
what do the labioscrottal swellings form in males and females?
the scrotum
labia majora
what controls the development of the external genitals?
the presence or absence of testosterone
- if present at the appropriate stage, male genitals develop from the precursor
- if not, female
what is characteristic of children’s sex characteristics (3)
low levels of circulating gonadal hormones
immature reproductive organs
little general appearance differences
what is puberty
the transitional period between childhood and adulthood during which fertility is achieved, the adolescent growth spurt occurs, and the secondary sex characteristics develop
what action in the anterior pituitary is associated with puberty (2)
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)
what does the release of gonadptrnopic hormone and ACTH cause?
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
what is the general principle guiding typical pubertal sexual maturation?
in pubertal males, androgen levels are greater than estrogen levels and tf masculatio
I pubertal females, estrogens are dominant, and therefore feminization
what occurs to individuals castrated prior to puberty?
do not become sexually mature unless they receive replacement injections of androgens or estrogens
what is androstenedione
an androgen that is released primarily by the. adrenal cortex
- typically responsible for the growth of pubic hair and axillary hair in females
why does androstenedione critique the men are men assumption
bec androstenedione is an androgen that controls for female development
