L 1- intro Flashcards
significance of repro physiology
- for all ages
- evolutionary : survival + procreation
- industry: agriculture
- societal significance
- personal significance
human reproduction
- elements of
- mate for pleasure + procreation
- internal fertilization (provide aqueous enviro for sperm = more viable
- mating + courtship rituals
- internal fetal development in terrestiral environment
2 functions of internal fetal development?
- protect embryo form dehydration
- cushion embryo in fluid buffer
physiological definition of reproduction
- individual survival?
- how does repro work on chromosomal level?
definition =. perpetuation of species : production of robust offspring, fundamental for species survival
- not essential for individual survival
- integration of parental chromosomes: biological variation + adaptation to enviro pressures
4 overarching themes:
- pre-conception
2: pregnancy - post-partum
- emerging topics
key players in repro physiology
- additional important elements?
key: male repro system, female repro system
additional: hormones - endocrine, brain
regulatory systems involved in reproduction?
- gonads
- Hypothal, ant-pit
- NS
- hormones/endocrine
- intercommunication between systems
endocrine glands + hormones
what are hormones?
2 types of hormones?
how are hormones detected?
- chemical messengers: cell/body tissues are prompted to alter activity in response to specific hormones
- peptide + steroid ( cholesterol-derived)
- hormone receptors: distribution ensures targeted response
describe synthesis of progesterone
steroid hormone: cholesterol -> progesterone.
-secreted by ovaries
synthesis of androstenedione
cholesterol -> progesterone -> androstenedione
synthesis of estrogen from cholesterol
cholesterol -> progesterone -> androstenedione OR T – AROMATASE–> Estrogens:
- Estrone estradiol
- secreted by ovaries
synthesis of T
cholesterol -> progesterone -> androstenedione -> T. secreted by testes
synthesis of Dihydrotestosterone (DHT)
cholesterol -> progesterone -> androstenedione -. testosterone –5-a-REDUCTASE –> DHT
- produced in target tissue
- DHT is more potent form of T: responsible for 2-ary sex characters
what drives hormone synthesis?
- how mutations impact this?
genes code for enzymes = formation of sex hormones
- gene mutation = atypical steroid synthesis + secretion.
- may impact sexual development + function
what are 2 androgens?
DHT + T.
where is T synthesized?
testes mostly
- little bit by adrenal cortex in form of DHEA. less potent than T.
DHT - compared to T? synthesized by?
more potent than T
- synthesized by 5-a-reductase
are androgens found in females?
yes, secreted by ovaries in small amounts and by adrenal cortex
what are estrogens?
how is E produced
- is E present in males?
class of steroid hormones - estradiol (predominant), estrone and estriol (in pregnant women, produced by placenta).
- all E from androgens (androstenedione or T) via aromatization
- present in males. released from testes, converted from androgen by aromatase
how E in males relates to obesity?
if obese/more fat tissue = more aromatase in the fat tissue.
potential to convert T to E
what is progesterone?
major secretory product of the ovaries during specific times in menstrual cycle
- also produced in adrenal gland.
- secreted by placenta
- intermediate in synthesis of androgens, estrogens.
4 actions of gonadal steroids
- enter cells
- bind intracellular receptors to form hormone-receptor complex
- complex binds DNA in nucleus & modifies mRNA formation
- Modification of protein synthesis & circulating protein concentration
2 effects of gonadal steroids
- development of reproductive organs
2. secondary sexual characteristics
what does development of accessory repro organs look like?
- duct system carrying sperm + eggs
- breast development : ovarian hormones
