Sex Flashcards
1
Q
What is sexual dimorphism?
A
- the condition where the two sexes of the same species exhibit different characteristics beyond the differences in their sexual organs
- differences may be subtle or exaggerated and can include differences in size, weight, color, behavior and cognition
- associated with genetic and hormonal differences, both before and after birth
2
Q
What is the triplewart seadevil?
A
- female is big large fish
- male is just a tiny, rudimentary creature that lives on his lady friend parasitically - basically just a sperm-producing appendage
3
Q
What are sexual dimorphic behaviours?
A
- behaviors that take different forms, or occur with different probabilities, or under different circumstances across males and females of the same species
4
Q
What are the most striking category of sexual dimorphic behaviors in mammals?
A
- reproductive behaviors
- courting, mating, parenting, and most forms of aggression
5
Q
What are differences in human behaviour?
A
- differences between the sexes, on average, in their mixture of talents, temperaments, and interests
6
Q
What is the brain in terms of sex?
A
- a sexually dimorphic organ
- gives rise to sexual dimorphic behaviors
- average size and interconnectivity of different brain regions vary according to sex
7
Q
Why are there sex differences in the brain?
A
- can be the result of biology, socialization, and the interaction of the two
8
Q
What is sex?
A
- defined at birth by the presence of particular sex chromosomes, sex hormones, and sex organs
9
Q
What is gender?
A
- the range of characteristics that pertain to, and differentiate between, masculinity and femininity
- these characteristics reflect biology and culture
10
Q
What is a gender expressions?
A
- expression of masculinity and femininity
11
Q
What is a gender role?
A
- the behaviors and attitudes that are deemed typical, appropriate, or desirable for people of a given sex
12
Q
What is sexual behaviour?
A
- the actual sex acts performed by the individual
13
Q
What is sexual orientation?
A
- one’s enduring romantic or sexual attractions
14
Q
What is sexual identity?
A
- an individual’s conception of themselves in terms of whether they identify (or not) with a sexual orientation
15
Q
What is gender identity?
A
- one’s personal sense of their gender
16
Q
Why is gender a social construct?
A
- consensual rules for determining gender (and race) designations differ across time and across cultures in a manner that is independent of changes in biology
- our brains and our behaviours (as well as our conceptions of them) are complex outcomes of both biological and cultural influences
17
Q
How do culture and biology determine gender?
A
- strength of the culture determines the strength of the biological influences
- biological differences are most influential in cultures where everyone is treated the same and gender isn’t taught
- cultures with strong and specific ideas about gender tend to mask the complexity and variability of the biology
18
Q
How do we socialize children?
A
- we pre-emptively encourage/discourage certain behaviours to ensure their expression is congruent with our values and the dominant culture
19
Q
What is reproduction?
A
- involves sex and the fusion of specialized cells known as gametes (one from each parent)
20
Q
What are gametes?
A
- mature reproductive cells made by gonads
- they are either ova or sperm
- only have one copy of each chromosome
21
Q
What are gonads?
A
- ovaries or testes
22
Q
What are ova?
A
- egg cells
23
Q
What are the sex chromosomes?
A
- one pair of chromosomes
- determine the organism’s sex
- come in X and Y varieties (XX or YY)
24
Q
What are the sex chromosomes for females?
A
XX
25
What are the sex chromosomes for males?
XY
26
What are the 5 factors present at birth that determine biological sex?
- sex chromosomes
- gonads
- sex hormones
- internal reproductive anatomy
- external anatomy
27
What are the 3 categories of sex organs?
- gonads
- internal reproductive anatomy
- external anatomy
28
What are intersex conditions?
- atypical combination of the five factors used to determine biological sex
- person cannot be distinctly identified as male or female
29
What do embryos contain?
- precursors for both female and male sex organs
30
What are undifferentiated gonads?
- Embryonic precursor of ovaries/testes
31
What is the Mullerian system?
- Embryonic precursors of female internal sex organs
32
What is the Wolffian system?
- Embryonic precursors of male internal sex organs
33
What happens during the second month of gestation?
- the undifferentiated gonads typically develop into ovaries or testes
34
What happens during the third month of gestation?
- either the Müllerian or Wolffian system develops while the other withers away
35
How do the male sex organs develop?
- the SRY gene
- development of testes
- embryonic testicular release of anti-Mullerian hormone and androgens (testosterone)
36
What is the SRY gene?
- normally located on the Y chromosome
- encodes a protein that causes undifferentiated fetal gonads to develop into testes
- gene overpowers XX-ovary instructions, so XXY individuals develop testes
37
What is the defeminizing effect?
- Effect of anti-Müllerian hormone early in development, which prevents development of the female-typical internal anatomy
38
What does anti-Mullerian hormone do?
- Stops development of Mullerian system
39
What is the masculizing effect?
- Effect of androgen hormones early in development, which triggers development of male-typical anatomy
40
What are androgens?
- Male sex hormones
- Testosterone
- released by the testes, and it triggers development of the Wolffian system
- Some testosterone is converted into dihydrotestosterone, which is what triggers development of external male sex anatomy
41
What do androgens do?
- Triggers development of male sex organs
- Wolffian system develops
- external genitalia develop
42
How do female sex organs develop?
- XX chromosome
- development of ovaries
- largely silent until puberty
- no anti Mullerian hormone = Mullerian system develops into internal female reproductive anatomy
- no androgen release = external female sex organs develop while the Wolffian system withers away
43
What is puberty triggered by?
- hormones released from gonads
44
What is Turner syndrome?
- when you only have one sex chromosome (X0)
- gonads do not develop (nether testes nor ovaries)
- female-typical sex organs develop normally
- infertile
- do not naturally experience puberty
- associated with other developmental abnormalities on account of missing a full chromosome
45
What is Swyer syndrome?
- when you are XY but have a bad SRY gene
- gonads do not develop (nether testes nor ovaries)
- female-typical sex organs develop normally
- infertile
- do not naturally experience puberty
46
What happens when there are two or more X chromosomes with an SRY gene?
- results in typical male development patterns but also infertility
47
What happens when there is XY chromosomes and SRY gene but insufficient anti-Mullerian hormone signaling?
- will cause insufficient anatomical defeminization
- both male and female internal sex organs will develop and get tangled together
- often functional external male genitalia
- Mullerian and Wolffian systems both develop and androgens cause external male organs to develop
48
What is androgen insensitivity syndrome?
- results in anatomical defeminization with partial or no masculinization
- anti-Mullerian hormone makes Mullerian system wither away
- no androgens cause Wolffian system to wither away and cause external female organs to develop
49
What happens in severe cases of androgen insensitivity syndrome?
- no internal sex organs develop
- people typically develop normal external female genitalia and identify as heterosexual women
- infertile and have a short vagina
50
What happens in mild cases of androgen insensitivity syndrome?
- the external genitalia is fully masculinized
51
What happens in intermediate cases of androgen insensitivity syndrome?
- ambiguous external genitalia
52
What are organizational effects?
- Sex hormones influence the development of the body and brain
- These effects are permanent and put you on a particular trajectory going forward
53
What are the types of organizational effects?
- behavioural defeminization
- behavioural masculinization
54
What is behavioural defeminization?
- organizational effect of androgens on the brain that prevent animals from displaying female-typical behaviors in adulthood
55
What is behavioural masculinization?
- organizational effect of androgens on the brain that enables animals to engage in male-typical behaviors in adulthood
56
What are activational effects?
- Puberty causes sex hormones to be released by the gonads, which influence both body and mind
- production of sperm, ovulation, and general horniness
- How the mind and body respond to activational hormone signaling in adulthood depends on how the body and brain were organized by hormone signaling in utero
57
What is kisspeptin?
- Neuropeptide produced by neurons in the hypothalamus
- initiates puberty
- maintains reproductive ability
- triggering release of gonadotropin-releasing hormone
58
What is gonadotropin-releasing hormone?
- Hypothalamic hormone
- stimulates anterior pituitary gland to secrete gonadotropic hormones
59
What are gonadotropic hormones?
- Hormones of pituitary gland
- have stimulating effect on cells of gonads
60
What are the types of gonadotropic hormones?
- follicle stimulating hormone (FSH)
- luteinizing hormone (LH)
61
How does testosterone impact males?
- normal levels of testosterone, males can be fertile
- without testosterone, sperm production ceases, and so does the ability to have sex
- castrated male rat will cease sexual activity, but it can be reinstated with an injection of testosterone
62
What happens when men take a gonadotropin-releasing hormone antagonist?
- not show testicular release of androgens
- have a decrease in sexual interest and intercourse
63
What is estrogen?
- class of sex hormones released by the ovaries
- cause maturation of the physical features and characteristic of females
64
What is estradiol?
- principal estrogen of many mammals, including humans
- starts being released at onset of puberty
65
What are menstrual and estrous cycles controlled by?
- the two ovarian hormones estradiol and progesterone
66
What is the menstrual cycle?
- female reproductive cycle of most primates, humans
- characterized by menstruation, concealed ovulation, and the absence of a mating season
- sexual arousal is somewhat influenced by ovarian hormones, but ability to mate is not
- exhibit sexual activity throughout the cycle
67
What is the estrous cycle?
- Female reproductive cycle of most mammals
- not menstruate; they reabsorb their endometrium
- display clear outward signs of ovulation and fertility
- typically only sexually active during the estrous cycle phase of their cycle (being in heat)
- change in physiology and behavior alters the behavior of nearby males
68
How can we masculinize or feminize the brain of rodents?
- by altering hormone signaling immediately after birth, after the anatomical development of their sex organs is complete
69
What happens when male rodents are castrated at birth?
- develop some female-typical behaviours
70
What happens when castrated male rodents are injected with female sex hormone in adulthood?
- try to get other males to have sex with them
71
What happens when non-castrated male rodents are injected with female sex hormones?
- have relatively small behavioural consequences
72
What happens when female rodents are given injections of estrogen and progesterone when fully grown?
- result in female sexual behaviour
73
What happens when female rodents are given injections of testosterone when fully grown?
- no resulting sexual behaviour
74
What happens when female rodents are given injections of testosterone at birth and estrogen and progesterone when fully grown?
- no resulting sexual behaviour
- defiminization
75
What happens when female rodents are given injections of testosterone at birth and again when fully grown?
- results in male sexual behaviour
- masculinization
76
What are adrenal glands?
- present in men and women
- secrete a small amount of androgens
- some people’s adrenal glands secrete abnormally large amounts of androgens, which can start either before or after birth
77
What happens when there is excess androgen signaling from adrenal glands in males?
- has minimal effect
- their testes already secrete tons of androgens
78
What happens when there is excess androgen signaling from adrenal glands in females?
- can cause some degree of masculinization of either the body or brain or both
- sex organs can become slightly masculinized
- brain anatomy and function can also be masculinized
79
What is congenital adrenal hyperplasia (CAH)?
- excess androgen signaling from adrenal glands present at birth
80
What is CAH in females?
- have a higher likelihood of identifying as a man and being sexual attracted to women
81
What can sexual orientation and gender identity be determined by?
- the timing and effectiveness of androgen signaling in the brain during early development
82
What is the female sexual behaviour neural circuitry pathway?
VMH → PAG → nPGi → motor neurons in spinal cord
83
What is the VMH?
- ventromedial nucleus of hypothalamus
- large nucleus in hypothalamus
- plays essential role in female sexual behavior
84
What does the VMH do in rodents?
- Electrical stimulation of VMH facilitates female sexual behavior
- Injections of estradiol and progesterone directly into VMH also stimulates sexual behavior, even in females whose ovaries have been removed
- Female with bilateral lesions of VMH will not display lordosis, even if she is treated with estradiol and progesterone
85
What is the male sexual behaviour neural circuitry pathway?
mPOA → PAG → nPGi → motor neurons in spinal cord
86
What is the mPOA?
- Medial Preoptic Area
- Nucleus in the anterior hypothalamus
- plays essential role in male sexual behavior
87
What does the mPOA do in rodents?
- Electrical stimulation of mPOA in rodents elicits male copulatory behavior
88
What is the sexually dimorphic nucleus (SDN)?
- within the mPOA
- preoptic area
- nucleus is much larger in males than in females
89
What happens when the mPOA is lesioned in female rats?
- does not affect their sexual behavior
- does cause them to ignore their offspring
90
How many mammalian species form long-lasting, fairly monogamous pair bonds?
- 5%
91
What does the formation of pair bonds relate to?
two peptides in brain:
- vasopressin
- oxytocin
92
What are vasopressin and oxytocin?
- compounds/peptides in brain
- released as neuropeptides in the brain
- released as hormones in the blood
- levels are elevated during sex, childbirth, and breastfeeding
93
How does the prairie vole species form long term pair bonds?
- have more vasopressin and oxytocin receptors in their ventral forebrain than other species do
- pharmacologically blocking or activating these receptors influences who they pair up with and when
- artificially increasing the expression of these receptors in non- monogamous prairie vole brains causes them to form life-long, monogamous-ish pair bonds
94
What does love and addiction affect?
- not affect overall intelligence
- they skew priorities and choice behaviour
95
What do love and addiction have in common?
- Getting over a devastating breakup is somewhat like recovering from addiction
- Healing a broken heart is difficult and often involves relapses into obsessive behavior
