Lecture 8 - Sex
Reproduction
● Sex refers to a set of biological attributes in humans and animals
○ Primarily associated with physical and physiological features including
■ Chromosomes
■ Gene expression
■ Hormone levels and function
■ Reproductive/sexual anatomy
○ Reproduction, ensuring survival of DNA
○ Sex as a pleasurable activity
● Asexual reproduction: Multiply as you are
● Sexual reproduction
○ Conjugation: exchange of genetic material
○ Creates genetic diversity
○ Increases chance of better adapted organism
Male and Female Genitals
● Factors present at birth, including
○ number and type of sex chromosomes
○ type of gonads - ovaries or testicles
○ sex hormones
○ internal reproductive anatomy (such as the uterus in females)
○ external genitalia
(Sex) Hormones
● Cholesterol -> Testosterone and Oestradiol
● Oxytocin
● Prolactin
● GnRH (FSH and LH)
Menstrual Cycle and Ovulation
● Wall of uterus consisting of three layers: Endometrium, Myometrium, Perimetrium
● Layers of importance because kinda like pillow for fertilized egg
○ Miscarriage if not thick enough
● Hormonal regulation of changes in the uterus and ovaries
○ Four Phases
■ Menstrual Phase
■ Follicular phase
■ Ovulation
■ Luteal phase
● Phases in the menstrual cycle (both taking place at same time)
○ 3 phases of follicle maturation
■ Phase 1: Follicles
■ Phase 2: Ovulation
■ Phase 3: Corpus Luteum
○ 3 phases of formation and breaking down of endometrium
■ Phase 1: Menstruation
■ Phase 2: Proliferative phase
■ Phase 3: Secretory phase
● Hormones involved in the menstrual cycle of women
○ Menstrual cycle regulated by hormones produced by
■ Hypothalamus - GnRH
■ Pituitary gland - LH and FSH
■ Uterus, ovaries - Estradiol, Progesterone
● Follicular phase:
○ Follicles ripe
○ Endometrium broken down during menstruation
○ Hypothalamus produces GnRH -> production of FSH and LH to the anterior pituitary -> Growth of follicles
○ Follicles produce low levels of estradiol (estrogen) -> inhibits GnRH -> keeps LH and FSH levels low
○ Hormone estradiol -> cause endometrial arteries to contract -> Menstruation
● Ovulation:
○ Follicle bursts open, raptures -> release of ovum (egg)
■ With higher age, more eggs released at same time
■ Women born with certain amount of eggs, diminishes over time, no production of new ones
, ○ Hypothalamus produces GnRH -> production of FSH and LH to anterior pituitary
○ LH and FSH stimulate maturation of one of the growing follicles
○ Growing follicles produce high levels of estradiol -> stimulates GnRH secretion -> rise in LH and FSH levels -> ovulation
■ Ovulation one day after peak in LH and FSH
○ High levels estradiol -> thickening of endometrium
● Luteal Phase:
○ Endometrium prepares for fertilized egg -> thickens
○ Hypothalamus produces GnRH -> production of FSH and LH to anterior pituitary
○ Corpus Luteum secretes estradiol and progesterone
■ Corpus Luteum = follicle shell that remains after ovulation
○ Production of estradiol and progesterone -> inhibition GnRH production by anterior pituitary
○ Estradiol and progesterone lead to further maturation of endometrium
○ Uterus preparing for either welcoming fertilized egg or breaking down, period
● PMS
○ Slow increasing estrogen levels makes you feel relaxed, good
○ Ovulation and fertile phase
○ PMS: drop in estrogen & progesterone can induce irritability, anger, sadness
○ Pain sensitivity, acne, and cramps
○ Start of menstruation
○ Repeat
● PCOS (Polycystic ovary syndrome)
○ Slightly higher amount of testosterone
■ Irregular periods
■ More (facial) hair
■ Large number of ovaries which look like cysts
■ Often difficulties with reproduction
● Menopause
○ Decreased estrogen production by ovaries, low E levels
○ Low testosterone levels
○ Unstable levels of estrogen and progesterone
○ Thinner vaginal walls
Sexual Development
● Virilization and Masculinization
○ Biological development of sex differences
○ Most of the changes of virilization (becoming female) produced by androgens (male hormones)
● Physiological changes during puberty
○ Fertility
○ Breast development (thelarche) & Pubic hair (pubarche)
○ Ovulation and first menstruation (menarche)
○ Growth spurt
○ Enlargement of scrotum and penis
○ Facial hair
● Decrease in age of menarche in Western European and North American Girls
○ due to higher SES
● Determinants of menarche onset
○ Age
○ Weight – BMI – fat mass
■ The higher the weight, the earlier the onset
○ Socioeconomic status
○ Age of menarche onset in mother [in part genetic]
○ Environmental factors/toxins
○ Psychosocial stress
● Food and Diet
○ Puberty onset and reproductive hormone axis activity require adequate nutritional status
■ China: 1963-1985 higher education > adequate nutrition available> earlier onset menarche
○ Intake of animal foods associated with earlier sexual development
○ Intake of vegetable protein related to delayed maturation
○ Childhood obesity related to the earlier onset of puberty in girls
■ Nowadays: abundance of nutrition, obesity related to
lower SES
● Genotype versus phenotype (picture)
, Cultural issues in sexual development
● Female Genital Mutilation
○ Comprises all procedures involving partial / total removal of external female genitalia, or other injury to the female genital
organs for non-medical reasons
○ Attempt to control sexuality, ideas about purity, modesty, beauty
○ Usually initiated and carried out by women, see it as source of honour, and who fear that failing to have their daughters
and granddaughters cut will expose the girls to social exclusion
● Gynodiversity versus Aesthetic vaginal surgery
○ Gynoplasty = Reparative or plastic surgery of female genital organs
○ Labiaplasty = Plastic surgery procedure for altering labia minora (inner labia) and labia majora (outer labia), the folds of
skin surrounding the human vulva
○ Process
■ Pathologization of genital diversity: create a normal versus abnormal
■ Protraying female genitals as important to wellbeing and sex life
■ Portraying female body as degenerative and improvable through surgery
■ Portraying surgery as safe, easy, and effective
Male and Female Brain
● Male
○ Testosterone converted into oestradiol -> masculinizes neurons of brain
● Female
○ Protected from masculinizing effects of oestradiol
○ Protein ‘alpha fetoprotein’ binds to oestrogen -> stops it entering the brain
● Gender
○ Usually conceptualized as a binary (girl/woman and boy/man)
○ Considerable diversity in how individuals & groups understand, experience,
express it
○ Sex and gender differences used in research: examining biological (sex) versus
sociocultural (gender) factors
○ Refers to the socially constructed roles, behaviors, expressions and identities of
girls, women, boys, men, and gender diverse people
○ Influences how people perceive themselves and each other, how they act and
interact, the distribution of power and resources in society
Lecture 9 - Drugs
Taking drugs
● Methods of administration
○ Inhaling (smoking)
■ Most effective way addiction, crosses brain fastest
○ Parental (injections)
○ Transmucosal (mucous membranes)
○ Oral
○ Rectal
○ Transdermal (on the skin)
● Drug effects are moderated by
○ Dosis
○ Method of administration
○ Expectations & mood
○ Personal characteristics
○ Tolerance
● Types of drugs
○ Full agonists
■ Facilitates maximum action of the synapse
○ Partial agonists
■ Facilitates partial action of the synapse
○ Antagonists
■ Inhibits the action of the synapse
○ Inverse agonists
■ Produce a response opposite to the agonist
