Studied by 3 people
Genetic Sex
Genotype based on chromosomes
Gender Identity
Self-perception of gender
Sexual Orientation
the sex of whom one is physically attracted
Concepts of biological sex and gender
– Biological characteristics and qualities
– Gender-specific behaviors
– Gender identity
def 4 Gender-specific behaviors
Introspection
Upbringing
Societal expectations
Genetics, hormones
X chromosome _____ than Y
larger
X contains ___ genes, and Y contains __ genes.
800, 50
male and female genotype
male: XY
female: XX
X-linked diseases occur more often in… than…
men, women
What makes fetus develop as male
SRY: gene on Y chromosome
Encodes testis-determining factor (TDF)
Causes the development of testes and testicular hormones
what causes Sex Chromosome Abnormalities
Rarely, too few, or too many sex chromosomes
def turner syndrome
Partial or complete absence of one X chromosome in a female (XO genotype)
def Klinefelter syndrome
Extra X chromosome in a male (XXY genotype)
Differentiation of Fetus and Development of Gonads
male: wolffian duct
female: Mullerian duct
def sex hormones
steroids
develop from cholestoral
made of fatty tissue
male and female sex hormones
male: testosterone
female: estradiol
what releases sex hormones
endocrine glands
what regulates the endocrine glands
Pituitary gland
high concentration of androgens
men
high concentration of estrogens
women
how is estrogen made
Testosterone (androgen) + aromatase → estradiol (estrogen)
what don’t pass through cell membranes,
bind surface receptors.
protein hormones
what do pass through cell membrane, bind to
cytoplasmic receptors.
steroid hormones
Receptor concentrations ___ in different brain regions.
vary
what do testes release
androgen
Testosterone increase at puberty leads to development of…
secondary sex characteristics.
what do ovaries secrete
estradiol (estrogen) and progesterone (progestin)
Estrogen increase at puberty leads to maturation of… and development of…
maturation of female reproductive system and development of breasts.
Blood concentrations of sex hormones vary b/t male and female
male: levels fluctuate rapidly each day
female: levels fluctuate in 28-day cycle
Gonadotropins
LH and FSH
LH and FSH funct. in males
LH stimulates testosterone production; FSH aids sperm maturation
LH and FSH funct. in females
LH and FSH cause estrogen secretion.
def 2 phases of Menstrual cycle
follicular phase
luteal phase
Sexual response cycle
Arousal, plateau, orgasm, resolution
Cerebral cortex ctr Reproductive Organs
– Neural control of sexual response
Spinal cord ctr Reproductive Organs
– Mediates sexual response of genitals
External genitals
males: penis
females: labia and clitoris
what kind of muscles make up genitals
smooth muscle
what relaxes smooth muscle in penis and
clitoris
Neurotransmitters: Acetylcholine, vasoactive intestinal polypeptide (VIP), and nitric oxide (NO)
Activity from the sympathetic division of the ANS
Male orgasm: muscular contractions → ejaculation
females orgasm: muscular contraction
Polygyny
Male mates with many females.
Polyandry
Female mates with many males.
Monogamy
Male and female mate exclusively.
why are prairie voles social and monogamous
more oxytocin (female) and vasopressin (male)
what are montane voles asocial and promiscuous
fewer receptors for oxytocin and vasopressin
what do human plasma oxytocin levels increase
During breastfeeding in mothers
During sexual intercourse in men and women
Brain activation demonstrates…
strong reinforcing nature of partner and parental relationships.
what do fMRI studies show
Oxytocin and vasopressin play roles in human bonding.
who is more verbal and who is more spacial
women, men
*Larger differences between individuals than between sexes*
Steroids funct
Alter membrane excitability, sensitivity to neurotransmitters, neurotransmitter release
Modulate functions of various enzymes, channels, and transmitter receptors
Diffuse across outer cell membrane
Bind to specific steroid receptors in cytoplasm and nucleus
Organizational effects of hormones
Development, anatomy
Tend to be irreversible
Activational effects of hormones
Behaviors
Tend to be temporary
what normally determines hormonal funct.
genetic sex
Treatment with testosterone in early development of mammals leads to
reduced female reproductive behaviors
what causes an Androgen-insensitive genetic males
defective androgen gene on X chromosome
what causes Congenital adrenal hyperplasia in genetic females
abnormally large adrenals overproduce androgens → External genitals intermediate between normal clitoris and penis
def Gynandromorph
having both male and female tissues
Gynandromorphic zebra finch - brain differences
Female left side
Male right side
Role of genes in complex sex behaviors in fruit flies
Sexual behaviors encoded in genes
The fru and dsx genes
what causes increased sexual interest - male vs female
male: rise in testosterone
Women: rise in estrogen
what rises during pregnancy
Rise in leptin levels
how does interaction with offspring may alter male brain structure
increase density of dendritic spines
Increased vasopressin receptors
what has dramatic effects on hippocampal neuronal dendrites
Estradiol treatment
what coincides with female rat’s peak fertility
Increase in hippocampal spine numbers
May play a role in changing reproductive needs
Estradiol’s protective effect on neurons (in culture)
def 2 benefits of estrogen
May protect against stroke
May benefit women with multiple sclerosis
Interstitial nucleus of the anterior hypothalamus (INAH); INAH-3 is Twice as large in… than…
men, women
• INAH-3 in… similar to that in…
gay men, women
Spinal nucleus of the bulbocavernosus (SNB) larger in… during…
men, erections
Corpus callosum: splenium larger in… than…
females, males
dimorphisms are
subtle, few, and functions unknown.
Note 
Flashcard (68)