lecture 15 Flashcards
what are exocrine glands?
Secrete stuff locally: sweat, saliva, breast milk (through ducts)
what are endocrine glands?
secrete hormones into the body and through blood system
what are the Two Main Types of Steroid Hormones
1) Cortisol (produced and secreted by the Adrenal Cortex - adrenal glands sit on top kidneys and the outer part is called adrenal cortex)
2) Sex Hormones (produced and secreted by the Gonads)
what are the Two Main Types of Sex Hormones
1) Androgens
e.g., Testosterone (TTT) (higher levels in males)
2) Estrogens
e.g., Estradiol (higher levels in females)
what are gonads
endocrine glands that are part of the reproductive organs
1) secrete Sex Hormones
2) produce/release gametes (sperm or eggs)
what are the male and female gonads called
Male Gonads: Testes
1) secrete hormone TTT
2) produce and release sperm (male gamete)
Female Gonads: Ovaries
1) secrete hormone Estradiol
2) produce (and release) ovum (egg) (female gamete)
(All eggs present at birth)
whats the genitilia
non-endocrine parts of the reproductive organs
(have external and internal structures)
what is testosterone (substrate) the precursor for ??
estradiol is the product
you need an enzyme (aromatase) to convert estradiol from testosterone
what does Genetic Gender (Xx vs XY) determine
the outcome of the Gonads (Male vs. Female)
in early development does genitilia look female like or male like in males and females
it will look female like for males and females anytime before 7 weeks and
Later in fetal development…..
TTT in utero (released by the Testes in Male Fetus) “Masculinizes” the Genitalia
(Without TTT, the genitalia continue to be Female Genitalia)
what are the 2 Gender Phenotype Anomalies
1) Female Masculinization
2) Testicular Feminization
what is Female Masculinization
- you have XX chromosomes (genetic female)
- you get exposed to test in utero
- sometimes adrenal cortex produces excess of adrenal androgens (testosterone)
OR
- anti miscarriage drugs mimic TTT
they have female gonads (ovaries) but are infertile
what is Testicular Feminization (gene mutation)
- genetic male - have XY chromosome
- But insensitive to TTT in utero (and always), because lacking (or dysfunctional) TTT receptors,
so TTT cannot activate genes inside cells
(hormones have to attach to receptors so if they dont exist then GAME OFF)
Genitalia (and general appearance) are female
(but have male gonads, i.e., testes)
after birth up until 12 the testes and ovaries are quiet until…
puberty
and they start producing TTT and estradiol by testes and ovaries because the Hypothalamus starts to release Gonadotropin Releasing Hormone
what are the Effects of Sex Hormones on Gonads?
- testes - male gonads(secrete TTT)
- Ovaries - female gonads (secrete Estradiol) -> Menstrual (reproductive) cycle
what are the Effects of Sex Hormones on Gender Phenotype?
Estradiol: broader hips, breast development
TTT: Bones and Muscles growth/strength, voice deepening, body hair
