2 - male hormones/ female system

Size: px

Start display at page:

Download "2 - male hormones/ female system"

Virginia Morris
5 years ago
Views:

1 2 - male hormones/ female system May 7, :08 PM I) Testosterone: main androgen (male sex hormone) A) Intro to Testosterone: -steroid hormone produced by interstitial cells in testes -produced in response to luteinizing hormone (LH) from anterior pituitary gland -effects of lack of testosterone documented in livestock animals that have been castrated (testes removed) 1) meat more tender 2) lack of sex drive 3) lowered aggression (particularly sexual aggression) ***Human castration: 17 th -18 th C many boys had testes removed to halt puberty and retain soprano voices Castrati Reprod Page 1

CASTRATO, BBC Documentary Part 2 of 6 CASTRATO, BBC

stimulates spermatogenesis (in seminiferous tubules) 2)

signals of sexual maturity -facial & body hair -enlargement &

2 CASTRATO, BBC Documentary Part 2 of 6 CASTRATO, BBC Documentary Part 1 of 6 B) Functions of Testosterone 1) stimulates spermatogenesis (in seminiferous tubules) 2) stimulates development of secondary sexual characteristics: signals of sexual maturity -facial & body hair -enlargement & lengthening of larynx -increased production in body oils & pheromones Reprod Page 2

-increased musculature: both skeletal & smooth (ie, male dermis = 40% thicker than female) -change in bone structure & proportion 3) maturation of penis & testes during puberty (primary sexual

3 -increased musculature: both skeletal & smooth (ie, male dermis = 40% thicker than female) -change in bone structure & proportion 3) maturation of penis & testes during puberty (primary sexual characteristics: gamete production & delivery) 4) behavioral effects: sex drive Minute 12-17ish on Natl Geogr vid Testosterone 5) increased muscular development: anabolic steroids are testosterone-like drugs C) Regulation of Testosterone Production -at ~age 10, hypothalamus matures & releases gonadotropin releasing hormone (GnRH) which targets anterior pituitary (this occurs in both males & females) -in response, anterior pituitary releases 2 hormones with different target tissues 1) follicle stimulating hormone (FSH): target = testes -stimulates development & maintenance of seminiferous tubules Reprod Page 3

4 2) luteinizing hormone (LH): target = interstitial cells in testes -causes interstitial cells to make and release testosterone -testosterone can then act on its target tissues (ex: seminiferous tubules) -recall: hypothalamus = centre of homeostasis. It monitors testosterone levels in blood. -If testosterone is too high, hypothalamus reduces GnRH release -therefore, anterior pituitary reduces FSH and LH release -therefore, testes produces less testosterone & sperm cells -negative feedback loop: Reprod Page 4

5 Question: how can excessive use of steroid hormones (drugs) cause infertility & shrivelled testes in males? Explain (potential test bonus question) Reprod Page 5

6 Natl Geogr video 18:25-20:30 II) Female Reproductive Tract -designed to produce ova, receive penis & semen, house & nourish fetus, produce milk Reprod Page 6

connective tissue and pelvic ligaments -outside = single epithelial layer -inside =

7 A) Main structures 1) ovary (2) produce ova & hormones (estrogen & progesterone) -size & shape of almonds, close to wall of pelvic cavity, held in place with loose connective tissue and pelvic ligaments -outside = single epithelial layer -inside = loose connective tissue & ova (scattered in varying developmental stages) Reprod Page 7

1) follicles: contain maturing ova, mature in response to FSH from anterior pituitary -release 1 ovum during ovulation 2) corpus luteum: remnants of follicle left in ovary that become a temporary

8 1) follicles: contain maturing ova, mature in response to FSH from anterior pituitary -release 1 ovum during ovulation 2) corpus luteum: remnants of follicle left in ovary that become a temporary gland in response to LH from anterior pituitary -produces estrogen & progesterone -if no pregnancy, it disintegrates & becomes a scar called corpus albicans 2) oviduct (2) (aka fallopian tubes): receive ovum following ovulation -not directly connected to ovary: fingerlike fimbriae catch ovum as it bursts from ovary wall Reprod Page 8

ovum as it bursts from ovary wall -lined with beating cilia to sweep ovum down length. Also performs peristalsis -location of fertilization: ovum begins to disintegrate upon leaving ovary.

9 ovum as it bursts from ovary wall -lined with beating cilia to sweep ovum down length. Also performs peristalsis -location of fertilization: ovum begins to disintegrate upon leaving ovary. By end of oviduct, ovum no longer capable of becoming fertilized by sperm so fertilization must occur before this Look Who_s Ta... 3) uterus: receives ovum or zygote (fertilized ovum), and nourishes fetus during pregnancy -fist-sized, inverted-pear in shape -thick walls of smooth muscle -inner face is lined with membranous tissue: endometrium -many capillaries for lots of transport to and from Reprod Page 9

fetus -glandular tissue for secreting a nutrient medium to nourish zygote 4) cervix: narrow opening at base of uterus -usually plugged with mucus to prevent entry of bacteria but also = barrier for

10 fetus -glandular tissue for secreting a nutrient medium to nourish zygote 4) cervix: narrow opening at base of uterus -usually plugged with mucus to prevent entry of bacteria but also = barrier for sperm -during ovulation, mucus becomes watery so sperm can pass -allows endometrial layer to be shed during menstruation -keeps developing fetus inside uterus through pregnancy, but during birth, dilates to ~10 cm (diameter of baby s head) to allow exit Reprod Page 10

11 -common site for cancer, often caused by HPV, transferred from head of penis -detected by Pap Smear test 5) vagina: receives penis during sexual intercourse, Reprod Page 11

birth canal for exit of baby (& endometrium during menstruation) -stretch elastic muscular tube which leads from cervix to outside body 6) clitoris: organ of sexual stimulation,

12 birth canal for exit of baby (& endometrium during menstruation) -stretch elastic muscular tube which leads from cervix to outside body 6) clitoris: organ of sexual stimulation, analogous to male penis -in front of vagina, short (~2 cm) tissue with same nerve endings as head of penis -usually necessary to stimulate for female orgasm Ovulation ovulation (2) Reprod Page 12

9.4 Regulating the Reproductive System

9.4 Regulating the Reproductive System The Reproductive System to unite a single reproductive cell from a female with a single reproductive cell from a male Both male and female reproductive systems include