Physio Test 2 Sexual Reproduction

Front 1

fertilization by the father's sperm

Back 1

A person's genetic sex determined at the time of ..

Front 2

Gametes

Back 2

(Ova and sperm) contain one member of each of the 23 pairs of chromosomes

22 pairs= autosomes
1 pair= sex chromosomes

Front 3

Genetic basis of sex determination

Back 3

normal female = xx
normal male- xy (y has SRY)
xx male with SRY traslocation = XX(one with SRY)

xy female with SRY missing = XY ( no SRY)

Front 4

Turner's Syndrome

Back 4

X0 genotype

Poor ovaries (formation requires 2 x chromosomes)

Still develop normal internam and external genitalia

Low hormonal levels.. need hormones pills to induce puberty and sexual maturation.

infertile (b.c no ovaries)

Front 5

Klinefelter's Syndrome

Back 5

XXY genotype

SRY=male

internal sex OK

Small testes

Low T

Low sperm (but sometimes fertile)

Gynecomastia

Front 6

DEVELOPMENT OF THE INTERNAL SEX ORGANS:

MUllerian system

Back 6

the embryonic precursors of the female internal sex organs

Front 7

DEVELOPMENT OF THE INTERNAL SEX ORGANS:

Wolffian system

Back 7

the embryonic precursors of the male internal sex organs

Front 8

DEVELOPMENT OF THE INTERNAL SEX ORGANS

anti-Mullerian hormone

Back 8

a peptide secreted by the fetal testes that inhibits the development of the Mullerian system, which would otherwise become the female sex organs.

Front 9

Persistant mullerian duct syndrome

Back 9

genetic male without anti-mullerian hormone or anti-mullerian hormone receptors
-SRY gene, so gonads become testes.
-Masculanization occurs (T) but no defeminization (AMH) - intermal male and female sex organs

External male organs (DHT)

Front 10

Androgen insensitivity syndrome

Back 10

Genetic Male (XY) w/o androgen receptors (mutation in gene for receptors ((x chromosome))

gonads forms into testes. Testes produce androgens and anti-mullerian hormone (AMH)

AMH produces internal defeminization; internal sex organs fail to develop

without T-and DHT- receptors, no internal or external masculinization.

Front 11

4 main steroid hormones

Back 11

progesterone
testosterone
estradiol
Dihydrotestosterone.

Front 12

SEXUAL DEVELOPMENT:
activiational effect

Back 12

the permanent effect of a hormone on tissue differentiation and development
ex. menstrual cycle, puberty onset, secondary sex characteristics, ect.

Front 13

SEXUAL DEVELOPMENT:
organizational effect (of hormone)

Back 13

the effect of a hormone that occurs in the fully developed organism

may depend on the organism's prior exposure to the organizational effects of hormones.

ex. T and AMH effects on structure/function; can't go back

Front 14

sexual maturation


Puberty

Back 14

triggered when the hypothalamus secretes gonadotropin releasing hormone (GnRH)...

anterior pituitary secretes FSH and LH..

gonads secrete T & E

Front 15

Puberty is starting earlier

Back 15

Probably b.c of better nutrition,
thinner girls go thru puberty later than than do obese girls
why?

Leptin is secreted by fat cells, so amt of leptin directly related to amt of fat on body.. give juvenile female mice leptin-- suppresses appetite and accelerates onset of puberty.

Front 16

Androgens and estrogen

Back 16

Initiate closure of growing portions of the bones, halting skeletal growth.

Front 17

Estrogen

Back 17

breast development
growth of lining of uterus
changes in deposition of body fat
maturation of female genitalia

Front 18

Androgens

Back 18

Growth of facial, underarm and pubic hair
(latter 2 occur in females under control of adrenal androgens)

lower the voice
alter hairline
muscular development
genital growth

Front 19

Menstrual cycle

Back 19

FSH & LH secreted by anterior pituitary
FSH stimulates grown of ovarian follicles (epithelial cells surrounding and ovum; usually, 1 per month)
Follicles secrete estradiol  buildup of uterine lining and feedback to anterior pituitary to release lots of LH
LH surge causes ovulation (follicle ruptures and ovum is released)
Ruptured follicle becomes corpus luteum, which secretes estrogen and progesterone
Progesterone maintains uterine lining, prevents maturation of another follicle, and promotes pregnancy (upon fertilization and implantation)
If no fertilization/implantation, corpus luteum stops making estrogen and progesterone, uterine lining sloughs off

Front 20

Hormonal Control of Sexual Behavior:

oxytocin

Back 20

a hormone secreted by the posterior pituitary gland

causes contraction of the smooth muscle of the milk ducts the uterus, and the male ejaculatory system.

Front 21

Hormonal Control of Sexual Behavior:

prolactin

Back 21

a hormone of the anterior pituitary gland

necessary for production of milk

has an inhibitory effect on male sexual behavior

Front 22

Copulating rats

Lordosis

Back 22

A spinal reflex seen in many four-legged animals; arching of the back in response to approach of a male or to touching the flanks, which elevates the hindquarters.

Front 23

Copulating Rats

Back 23

In females, progesterone (w/ estrogen “priming”) produces sexual receptivity, proceptivity and attractiveness
Male sexual behavior also controlled by hormones
Refractory period
Coollidge effect
Oxytocin and Prolactin involved
Prolactin has inhibitory effect on male sexual behavior, so likely involved in refractory period


Hormones critical:
Estradiol
Progesterone
Testosterone
Oxytocin
Prolactin

Front 24

activational effects of hormones

Back 24

menstrual cycle
sexual behavior
but not development of the male or female. reproductive tracts..t

Front 25

organizational effects of hormones

Back 25

making the brain female or male...
defeminization (remember. "nature's impulse is to crease a female" ____ of androgens that prevent female sexual behavior


Masculanization: ____ of androgens that enable male sexual behavior

Front 26

Organizational effects of testosterone

Back 26

if a brain isn't exposed to androgens during critical period of development, animal will engage in female sexual behavior as an adults

Rodents: Around the time of birth, testosterone masulinizes and defeminizes sexual behavior

Front 27

Pheromones

Back 27

a chemical released by one animal that affects the hehavior or physiology of another animal

usually smelled or tasted

usually compounds are in urine

species (strain?) specific

VNO-accessory OB- amygdala- hypothalamus

Estrous cycle
Lee-Boot effect: female mice housed together stop cycling
Whitten effect*: those female mice, exposed to male odor, start cycling (& synchronized)
Vandenbergh effect*: acceleration of onset of puberty by odor of a male
Pregnancy
Bruce effect*: recently impregnated mouse miscarries when exposed to different male
*Only if male has not been castrated (& VNO system is intact).

Front 28

Pheromones

McClintock effect

Back 28

Women who live together cycle together
From compound(s) in fluids
ANDROGEN:
In male sweat
Increases alterness & positive mood in women; decreases positive mood in men
Activates hypothalamus (POA and VMH) in women but not in men
Does in homosexual men (2005 study)
ESTROGEN:
In female urine
Activates hypothalamus (PVN and DMH) in men but not in women

Front 29

how do sex hormones effect women?

Back 29

based -inpart- on hormones of the menstrual cycle
testosterone: amplifies the effects of estrogen.

Ovariectomized women given EST + testosterone  more sex fantasies, masturbation, intercourse, higher self-reported level of well-being (huh).

Front 30

how do sex hormones effect men?

Back 30

GnRH ant. -- decrease T-- decrease sex fantacy, interest, intercourse.

T also increases in anticipation of sexual activity or by viewing erotica
oxytocin and prolactin

both secreted during orgasm; both might be important in refractory period.

Front 31

sexual orientation

Back 31

evidence does not support social explanations of homosex...
not due to adult levels of sex hormones.

so what is it?

subtle differences in brain structure may be caused by differences in amount of prenatal exposure to androgens.

Front 32

Prenatal hormones and sexual orientation

Back 32

Congenital adrenal hyperplagia
Adrenal glands secrete too much testosterone leading to prenatal androgenization of genetic females
Boys develop normally; girls’ sex at birth can look ambiguous
Girls draw more boyish things, play with boy-typical toys
1/3 of CAH girls are homosexual or bisexual


Failure of androgenization of genetic males
Androgen insensitivity syndrome: XY but gender identity is female and sexual orientation (based on being female) is heterosexual

Front 33

THe human brain is sexually dimorphic

Back 33

2 hemipheres share more functions in female brain compared with mail

men's brains are larger

shape of corpus callosum

differences in sizes of some specific regions (in helencephalon and diencephalon)

all probably the result of different exposure to androgens early in development.

Front 34

In homesexual males and females, there are 3 brain regions that show differences (in home studies)

Back 34

Suprachiasmatic Nucleus:
larger in homosexual men compared to heterosexual men and to women


Anterior commissure
larger in homosexual men compared to heterosexual men and to women

sexually dimorphic nucleus of the hypothalamus...

Front 35

Sexually dimorphic nucleus of the hypothalamus

Back 35

Aka, third interstitial nucleus of the anterior hypothalamus
Larger in heterosexual men compared to homosexual men and to women
A sexually dimorphic nucleus in sheep:
8% of males show sexual preference toward other males (still male behaviors);
SDN is larger in males than females; similar in females and male-oriented males.

Front 36

sexual orientation and the brain

Back 36

Brain responds to pheromones differently: homosexual men show responses more like heterosexual women than heterosexual men

In transexual men, BNST (forebrain region) is small, like in women; there is no difference b/t heterosexual and homosexual men.
Also, similar between female to male transexuals and normal males.
Therefore, the correlation is to sexual identity; not sexual orientation!
Are these differences cause or effect of identity and behavior?

Front 37

sex. orientation
Causes of differences in brain development

Back 37

Prenatal androgenization of males: maternal stress
Maternal stress  decreased T in male fetuses
Stress  endorphins and corticosterone  both antagonize Testosterone
Causes female behaviors (sexual and play) in male rats
Alters the size of the sexually dimorphic nucleus
Above results also seen in humans
In 2 out of 3 studies, moms of gay men reported more stress during pregnancy than moms of straight men

Front 38

Heredity and sexual orientation

Back 38

Male homosexuality: 52% concordance for identical twins; 22% concordance for fraternal twins
Female homosexuality: 48% concordance for identical twins; 16% concordance for fraternal twins

Front 39

sexual development
masulinizing effect

Back 39

an effect of hormone present early in development that promotes the later development of anatomical or behavioral characteristics of males

Front 40

sexual development

testosterone

Back 40

the principal androgen found in males

Front 41

Hormonal abnormalities of sexual development:

Hormonal abnormalities of sexual development

Back 41

genetic male without anti-mullerian hormone or anti-mullerian hormone receptors.

Front 42

Hormonal abnormalities of sexual development:

androgen insensitivity syndrome

Back 42

genetic male without androgen receptors

Front 43

Hormonal abnormalities of sexual development:

congenital adrenal hyperplagia

Back 43

genetic female with excess androgens

Front 44

Hormonal abnormalities of sexual development

5-alpha reductase deficiency

Back 44

genetic male that can't convert testosterone to dihydrotestosterone.

Front 45

sexual development


persistent Müllerian duct syndrome

Back 45

a condition caused by a congenital lack of anti-mullerian hormone or receptors for this hormone; in a male, causes development of both male and female internal sex organs.

Front 46

Klinefelter’s syndrome (XXY)

Back 46

Males, heterosexual orientation
Treated w/ testosterone, & treatment for other issues (learning disabilities, esteem)
In US, 1 in 500-1000 newborn boys affected
Some cells have XXY, others XY
Sometimes can father children
Increased risk of autoimmune disease & breast cancer

Front 47

Mosaic/mosaicism

Back 47

denotes the presence of two populations of cells with different genotypes in one individual, who has developed from a single fertilized egg.

Front 48

chimera

Back 48

the two or more genotypes arise from more than one zygote, while in mosaics, these genotypes arise from only a single cell.


formed from four parent cells (two fertilized eggs or early embryos fuse together) or from three parent cells (a fertilized egg is fused with an unfertilized egg or a fertilized egg is fused with an extra sperm). Each population of cells keeps its own character and the resulting animal is a mixture of mis-matched parts

Front 49

Turner’s syndrome (XO)

Back 49

98% spontaneously abort (10% of miscariages in US)
Incidence: 1 in 2500 live births
Gender identity is female, and sexual orientation is heterosexual
“Hyperfeminine” in play
Depressed visuospatial & quantitative skills
Other health risks include: high blood pressure, kidney problems, diabetes, cataracts, osteoporosis and thyroid problems, heart problems

Front 50

Congenital adrenal hyperplasia

Back 50

Inherited (autosomal recessive)
Only small minotiry of people with CAH are considered intersex… ambiguous genitalia is only one of many potential conditions caused by CAH
Others include precocious puberty or lack of puberty
Behavior: mixed b/t boy and girl
Gender identity is female
Sexual orientation more mixed, but majority are heterosexual
Incidence 1:10,000 to 1:21,000



Genetic defect
Low Corticoid synthesis
Adrenal cortex
Excess androgens
XY male ok
XX
No AMH
Wolffian Duct
External genitals
masculinized

Front 51

DHT deficiency

Back 51

incidence is 1:90 in Dominican Republic

can have normal male, ambigous or normal female genitalia

"phallus" increases in length to 4-8 cm. (when begin with female genitalia?)

Front 52

sexually diorphic behavior

Back 52

a behavior that has diff forms or that occurs with diff. probabilities or under diff. circumstances in makes and females.

Front 53

gamate

Back 53

a mature reproductive cell; a sperm or ovum

Front 54

gonad

Back 54

an ovary or testis

Front 55

sry

Back 55

the gene on the y chromosome whose product instucts the undifferentiated fetal gonads to develop into testes

Front 56

coolidge effect

Back 56

the restorative effect of introduing a new female sex partner to a male that has appartently become exhasuted by sexual activity

Front 57

lordosis

Back 57

a pinal sexual reflex seen in mayn 4 legged female mammals; arching of the back in response to approach of a male or to touching the flanks, which elevated the hind quarters.

Front 58

vomeronasal organ

Back 58

a sensory organ that detects the presence of certain chemicals, esp when a liquid is actuvely sniffed; mediates the effects of some phermones.

Front 59

medial preoptic area

Back 59

an area of cell bodies just rostral to the hypothalamus; plays an essential role in male sexual behavior

Front 60

parturition

Back 60

the act of giving birth

Front 61

prolactin

Back 61

a hormone of the anterior pituitary gland, necessary for production of milk; also facilitates maternal behavior

Front 62

lateral nucleus

Back 62

a nucleus of the amygdala that receives sensory info from the neocortex, thalamus, and hippocampus and sends projections to the basal, accessory basal, and central nucleus of the amygdala.

Front 63

central nucleus

Back 63

the region of the amygdala that receives info from the basal , lateral, and accessory basal nuclei and sends projections to a wide variety of regions in the brain; involved in emotional responses.

Front 64

threat behavior

Back 64

a stereotypical species- sypical behavior that warns antoerh animal that it may be attacked if it does not flee or show a submissive behavior.