Exam 3 : Neuroscience of Sex Flashcards Preview

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Flashcards in Exam 3 : Neuroscience of Sex Deck (77)
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1
Q

Primary sexual characteristics include…

A

gonads, internal sex organs, external genitalia, influenced by organizational effects of steroid hormones

2
Q

Secondary sexual characteristics include…

A

female: enlarged breasts, widened hips
male: beard, deep voice
influenced by activational effects of steroid hormones (puberty)

3
Q

What are both primary and secondary sexual characteristics caused by?

A

hormones

4
Q

process by which individuals develop male-like or female-like bodies and behavior

A

sex determination

5
Q

egg carries ___ chromosome from mother

A

X

6
Q

___ or ___ chromosome provided by dad

A

X or Y

on SRY gene

7
Q

process by which individuals develop either male or female bodies and behaviors

A

sexual differentiation

8
Q

Female sexual system

A

Mullerian system

9
Q

Male Sexual System

A

Wolffian system

10
Q

embryos have early tissues for…

A

both male and female structures up until the 6th week of prenatal development

11
Q

embryos have early tissues for…

A

both male and female structures up until the 6th week of prenatal development

12
Q

organizational hypothesis of sexual differentiation

A

one steroid signal - androgens- masculinizes the body, brain, and behavior

13
Q

Natures impulse is to create…

A

females

14
Q

If _____ is not present, the nervous system will organize itself in a feminine fashion

A

androgens

15
Q

What does full masculine behavior require?

A

androgen during development and adulthood

16
Q

What does sex organ development depend on?

A

2 hormones released from the testes

17
Q

what gene stimulates testes formation?

A

SRY

18
Q

Testes produce _____ to block Mullerian system

A

anti-mullerian hormone

- induces withering of female sex organs

19
Q

Testes produce ______ to stimulate the Wolffian system

A

androgens

20
Q

testosterone is converted to ________ which induces development of external male genitalia

A

dihydrotestosterone (DHT)

21
Q

Testosterone is converted to ____ via aromatization process

A

estradiol

  • may induce development of masculine brain
  • A-fetoprotein in blood binds to estrogen and prevents estrogen from crossing BBB
22
Q

A-fetoprotein

A

binds to estrogen and prevents estrogen from crossing BBB

23
Q

Which system is the default that will develop unless it is inhibited

A

mullerian system

24
Q

mullerian system

A
  • no SRY gene
  • no anti-mullerian hormone (mullerian develops normal, uterus)
  • no testosterone (wolffian ducts do not develop, so no male genitalia)
    undeveloped system withers away
25
Q

secondary sex characteristics appear at

A

puberty

26
Q

Puberty is associated with secretion of gonadotropin-releasing hormones (GnRH) from…

A

the hypothalamus

27
Q

GnRH induces secretion fom the ____ of ____ and _____

A

anterior pituitary of FSH (follicle stimulating hormone) and LH (luteinizing hormone)

28
Q

FSH and LH are secreted in ____ and ____

A

females: develop ovum
males: stimulate development of sperm, secrete testosterone

29
Q

secreted by the gonads induces breast development

A

estradiol

30
Q

stimulate facial hair, lowered voice, muscle development

A

androgens

31
Q

males and females have marked sex differences in appearance

A

sexual dimorphism

32
Q

Examples of sexual dimorphism in human brain

A

PAG: shuts down pain, bigger in females than males (males are wusses)
Sex centers - hypothalamus - males have bigger sex drive
amygdala- emotion, females are more emotional - larger in females

33
Q

Sex differences: disease prevalence differences

A

males more likely to have autism, adhd, alcoholism, dyslexia

females: more likely to have anxiety, depression, eating disorders

34
Q

Male brains are physically larger, but is there a difference in brain region size?

A

NO

- no size difference in structures in the brain

35
Q

Is there sexual dimorphism in the human brain?

A

NO

- social constructs, cultural upbringing

36
Q

What alters the view of which structures are bigger vs smaller?

A

idea of sex vs gender

37
Q

In rats, sexually dimorphic nucleus of the pre-optic area (SDN-POA) of the hypothalamus is larger in ____ than ____

A

males than females

38
Q

SDN-POA lesions disrupt…

A

ovulatory and copulatory behaviors in females and males

39
Q

SDN-POA in humans

A

has same cell # and size of cells, but slightly different shape - elongated in women

40
Q

alters the development of the SDN-POA, resulting in a nucleus permanently larger in males than in females

A

testicular androgens

41
Q

androgen insensitivity syndrome

A

genetic mutation that prevents the formation of androgen receptors

  • gonads become testes (normal process)
  • defeminization
  • lack of masculinzation (the issue!!!)
42
Q

result of androgen insensitivity syndrome

A

an XY male with female external genitalia

  • have a women’s body but no internal female sex organs
  • find out when they do not get period during puberty
  • appear baby girl when born even though genetically male
43
Q

persistent mullerian duct syndrome

A

failure to produce anti-mullerian hormone and/or absence of receptors for this hormone

44
Q

results of persistent mullerian duct syndrome

A

chromosomal makeup? XY
external genitalia: male
defeminization does not occur, but masculinization does
person born with both sets of internal organs (female ones do not wither away)

45
Q

congenital adrenal hyperplasia (CAH)

A

adrenal gland secretes abnormal amounts of androgens

  • begins prenatally
  • causes prenatal masculinization
46
Q

CAH XY males vs XX females

A

XY males: typically developmental (just higher androgen levels)
XX females: masculinized external genitalia
- genetically female with normal internal reproductive organs
Intersex appearance: no anti-mullerian hormones, high DHT and testosterone masculinizes external genitalia

47
Q

Turner’s syndrome

A

individuals have only one sex chromosome: X

small stature and webbed neck are symptoms

48
Q

result of turner’s syndrome

A

essentially develop into females
however, no ovaries since two X chromosomes needed for that and we only have one
In puberty: not same level of hormonal surges, not normal breast development, fat distribution off

49
Q

Klinefelter syndrome

A

genetic males have extra X chromosome
- anti-mullerian hormone relatively normal
affects testicular growth, resulting in smaller than normal testicles and lower testosterone production

50
Q

Klinefelter syndrome results

A

internal organs - male
more feminized secondary sex - wider hips, less body hair
low sperm counts

51
Q

how many stages of reproductive behavior?

A

4

52
Q

first stage of reproductive behavior?

A

sexual attraction

53
Q

may be synchronized with physiological readiness to reproduce and earned associations, such as appearances

A

sexual attraction

54
Q

In some species, mated males and females form ______ living together before and long after copulation

A

lasting pair bonds

55
Q

when does sexual attraction happen?

A

after puberty

56
Q

transmitters involved in sexual attraction

A
  • mesolimbic dopamine

- norepinephrine

57
Q

motivation to find a mate is governed by…

A

mesolimbic dopamine system

58
Q

what is released during attraction?

A

norepinephrine

59
Q

mediates sperm production and sexual interest

A

testosterone

- boys who fail to produce testosterone show little interest in sex until given androgen supplements

60
Q

just thinking about sex can…

A

increase testosterone levels in males

- viewing pornography also increases testosterone in males

61
Q

GnRH antagonists ….

A

reduce sexual interest and intercourse because no testosterone will be released decreasing sexual drive

62
Q

testosterone patches

A

enhance sexual activity in women

63
Q

what impacts sexual interests in women?

A

estrogen

- sexual activity initiated by women more during ovulation

64
Q

women on hormonal birth control vs women with natural cycling

A

overall women report more interest in their current partner over someone else
- naturally cycling women show a peak in interest in both current partner and other men during ovulation when they are most likely to be fertile

65
Q

second stage of reproductive behavior

A

appetitive behaviors

66
Q

appetitive behaviors

A

establish, maintain, or promote sexual interaction

67
Q

what is a proceptive female?

A

one that wants to have sex

  • female rat may approach male or attract by “ear-wiggling”
  • production of progesterone increases proceptive behavior and activates receptivity
68
Q

male rat behaviors in appetitive stage

A

staying near female, sniffing, singing, nest-building

69
Q

transmitters involved in appetitive stage

A

mesolimbic dopamine system and oxytocin release

norepinephrine in arousal (makes you sweat because you cannot believe someone is talking to you)

70
Q

third stage of reproductive behavior

A

copulation

71
Q

copulation

A

penetrative sexual intercourse ending in ejaculation

  • involves one or more intromissions where male penis is inserted in female vagina
  • male ejaculates sperm bearing semen into female
72
Q

transmitters involved in copulation

A

norepinephrine and serotonin: erectile function (NE inc erection, serotonin dec erection)

dopamine: nigrostriatal dopamine: essential for movements during copulation. mesolimbic dopamine makes you feel good
oxytocin: inc during social bonding - makes you like the person you are having sex with

73
Q

fourth stage of reproductive behavior

A

postcopulatory phase

74
Q

postcopulatory phase

A

refractory phase - does not exist in women.

75
Q

coolidge effect

A

faster resumption of mating behavior with a different partner (random people)

76
Q

transmitters involved AFTER sex

A

prolactin: linked to sexual satisfaction in women and men. if sex is good prolactin will inc after ex. levels peak a few min after orgasm
vasopressin: inc in men after orgasm (water balance, social bonding - jealousy)
oxytocin: inc in women after orgasm

77
Q

where are vasopressin and oxytocin released from

A

posterior pituitary