Sex Hormones
Endocrine glandsSecrete hormones internally (Bloodstream)
Hormone○ Complex chemical ○ Specific actions for specific organs
Exocrine glandsSecrete externally (aweat glands)
Sex Hormones
Hypothalamus Controls pituitary
Dual function○ As a gland
Reacts to hormonal levels in the bloodstream
○ As a part of the CNSReacts to higher brain functions (perceptions,
thoughts, feelings, moods)
Testosterone Bound and free
Men95% bound, not active for sexual desire5% free
Women97-99% bound1-3% free
Testosterone
Amount needed varies in individuals of both sexes. Women more sensitive.
More testosterone does not produce more sexual desire
Testosterone Additional testosterone has adverse effects
MenHair lossSalt and fluid retentionPossible testicular cancerAcneDigestive problemsIrritability and aggression
WomenFacial and body hairMuscle massSmaller breastsLarger clitorisVoice deeper
Gestational Development of Genitals First seven weeks
Undifferentiated2 gonads2 sets of ducts (Mullerian and Wolffian)
7th weekY chromosome turns gonad into testicle
Gestational Development of Genitals 10th-11th week
Absence of Y chromosome = ovaries develop.Both types of gonads start producing their respective
hormones.
Female:Absence of testosterone causes degeneration of
Wolffian ductsMullerian ducts form internal sex organs
Gestational Development of Genitals Male
Testes produce anti-Mullerian hormone, so they disappear
Wolffian ducts become internal sex organs
Gestational Development of Genitals Tubercle, folds and swelling develop into
external genitals for each sex
The default model is female
In the absence of any step to go to the male model, the child will be female
MENSTRUATION Onset
Menarche ○ Mean age: 12.6
1900Mean age 16Diet changes increases in body fat
20-36 days is normal range
Lasts until Age 45-55
MENSTRUATION
MENSTRUATION
MENSTRUATION
MENSTRUATION
MENSTRUATION
Changes in cervical mucus during cycle:Regular functions of mucus:
○ Lubrication○ Bacteriostatic○ pH regulation
It is cloudy, whitish, thick
MENSTRUATION
Ovulatory cervical mucus:Days 12-16 of cycle TransparentVery stretchy, like raw egg whiteFunctions:
○ To help sperm○ Regulating pH (normal to alkaline)○ Sugars○ Conveyor
MENSTRUATION Toxic Shock Syndrome
Presence of staphilococcus aureus (ubiquitous) Particularly when using tampons Can be fatal
Dioxin Bleaching chemicals Used in “sanitary” products Powerful carcinogen Can affect hormones Immunosuppressant Endometriosis
MENSTRUATION
Anovulatory cyclesAdolescents and menopause (climacteric)
AmenorrheaThe absence of a menstrual period in a
woman of reproductive ageAfter menopause
MENSTRUATION Dysmenorrhea
Painful menstruationProstaglandins
○ Hormone-like○ Secreted by uterus○ Cause uterine contractions
EndometriosisEndometrium grows outside uterusDysmenorrhea is a symptom
MENSTRUATION
PMS
Unhealthy diet No exerciseSmokingEndometriosis
Negative expectations Anxiety Physical symptoms
Pregnancy Prenatal period
Nine monthsThree trimesters
Perinatal periodFrom beginning of labour to 72 hrs.
postpartum
Conception
Requires the followingAdequate sperm countChanges in vaginal mucusOpen Fallopian tubesNormal ovulationNormal hormonal levels
Infertility
Most common reason for infertility:
STDs in both men and womenLead to infertilityBlocked Fallopian tubes or vas deferens
Pregnancy Stages of uterine development
Zygote:○ 1-14 days
Embryo:○ 3-8 weeks
Fetus:○ 9-40 weeks
Reproductive Technologies Artificial Insemination
Introducing sperm into woman’s vagina or uterus by artificial means
in vitro fertilization (IVF)Test tube or Petri dish used to mix gametesOnce dividing, surgically implanted into
woman’s uterus
Prenatal Diagnosis
Tests for chromosomal abnormalities and fetal infections
Amniocentesis11-14 weeks
Chorionic villus sampling (CVS)6-8 weeks
Physical and Psychological Changes During Pregnancy 1st trimester:
Enlarged, tender breastsAmenorrheaNausea (⅓ severe,⅓ mild, ⅓ none)Sleepiness (⅔)Aversion to some foods, odorsIncreased urinary frequency (hormonal)Mixed emotions, ambivalence, anxiety and
exhilaration
Physical and Psychological Changes During Pregnancy 2nd trimester:
Quickening○ Initial motion of the fetus in the uterus ○ As it is perceived by the pregnant woman
Increased girth and well-beingMostly positive outlook, energyPreparatory behaviors, prenatal classesSome who rejected pregnancy accept it
Physical and Psychological Changes During Pregnancy 3rd trimester:
Large abdomen, awkward○ Difficulty turning over in bed
Lost sleep due to○ Frequent urination (weight of uterus on
bladder)○ Activity of fetus
Anxiety increases (delivery, birth defects)Differences between fit and unfit women
Physical and Psychological Changes During Pregnancy Possible pregnancy complications
EdemaHypertensionGestational diabetes
○ ProteinuriaThreatened early labor
Physical and Psychological Changes During Pregnancy Male
Economic worriesFeeling left outCouvade
○ Experiences some of the same symptoms and behavior as the mother near the time of labor
○ Actual changes in hormonal levelsBefore birth, more prolactin and cortisolAfter birth, less testosterone
Teratogens
Teratogens Smoking
CO○ 200 times more affinity to Hgb than oxygen
Oxygen supply compromised (5% less)
Decreases sperm motility○ Lower fertility
Less progesterone○ Miscarriages
Placental problemsHigher morbidity and mortality
○ From 9/1000 to 33/1000Higher rates of cleft palate and hare lip
Teratogens Alcohol
FASD (fetal alcohol spectrum disorder)○ Brain abnormalities
learning difficultiesADDHMental retardation, etc.
○ Possible damage to eyes, ears, immune system, internal organs, joints, limbs
○ Low birth weight○ Increased prematurity, miscarriage and
stillbirth risk
Teratogens
AlcoholFASD (fetal alcohol spectrum disorder)
○ Growth retardation○ Facial and cranial malformations○ Dose and timing related○ No safe dose○ There is no cure for FASD○ Leading cause of preventable mental
retardation
Teratogens Maternal Diseases
RubellaToxoplasmosisCMV
Radiation High temperature (hot bath) Environmental Pollution
Phthalates Drugs
Prescription○ Thalidomide
RecreationalInteractions
Teratogens
Maternal stressAcute or chronic (worse)Adrenaline, corticosteroids
○ Compromise oxygen supply for infant
After birthDigestive problemsLow birth weightIrritability
Teratogens Maternal age
No more obstetrical complications (if healthy)
Increased Down’s syndrome
Other effects of these variablesAffect maternal-infant interactionAbuseNeglectRejection
Maternal Nutrition First trimester
Usually not an issue
Second trimesterQuality
Third trimesterQuality and quantity
Folic acidPrevents neural tube defects (spina bifida)
Maternal Nutrition Infant Optimal Weight
7½ - 8 lbs. (European stock)
Low Birth Weight5½ lbs. or 2,500 g
Montreal Diet Dispensary500 extra daily calories:
○ 1 qt. milk○ 1 egg○ 1 orange
Birth
LABOUR Fetal hormone signals mom’s
hypothalamusProduced when fetal lungs ready to
breathe Hypothalamus stimulates pituitary
Pituitary secretes oxytocin○ Oxytocin makes uterus contract
Labour begins
Labour First stage:
Early first stage○ Longest (hours or days)○ Mild contractions, relatively short ○ Relatively large intervals
Late first stage○ Shorter than early stage○ Contractions longer and at much shorter intervals
Transition○ Shortest○ Most intense○ Random pattern of contractions.
All along, cervix dilating and effacing (thinning)
Labour
Second stage:Cervix fully dilated (10 cm)Baby moves down birth canalCrowningDuration
○ Primiparas About 1 hr.
○ MultiparasFaster
Head first, rotation
Labour
Third stage:After 10-15 min interval
○ Expulsion of placenta
During interval between stages 2 and 3:Lungs start to work graduallyCord delivers last of maternal blood to infantHeart valves closeCord must not be cut until white and not
pulsing
Labour
POSITIONS FOR LABOUR Lithotomy Position
Weight of uterus and its content on abdominal aorta
○ Can cause reduced blood flow to fetus○ Slows down labour○ Importance of gravity’s help
Labour
Better PositionsSitting up reclinedLying on her sideOn hands and knees
Unmedicated, undisturbed birth best90-95% births do not need intervention.
RISKS OF INDUCING LABOUR Induction of labour with pitocin
Contractions too hardLead to more analgesics and anestheticsUterine rupture and to brain damage
(pressure on the skull)
If lungs not ready, leads to respiratory distress due to lack of surfactin
POSSIBLE COMPLICATIONS (5-10%)
Placenta previa abruptio placenta
Separation of the normally located placenta
Transverse or breech presentation Prolapsed cord Cord pinched or wrapped around neck
POSSIBLE COMPLICATIONSAll carry risk of hypoxia or anoxiaHypoxia
Reduced oxygenAnoxia
NO oxygenConsequences
Brain damageDetectable or subclinical
Common interventionsC-section
Major abdominal surgeryPossible lack of adrenaline/noradrenaline in babyN. American C-sec rates too high
Pain medication (analgesics and anesthetics)Can slow down labour and decrease oxygen delivery to baby
EFFECTS OF ANESTHETICS AND ANALGESICS
Slow down labour (leading to pitocin use)Sluggish babyMother zonked, weakCan interfere with bondingCan interfere with lactationCan interfere with rooming-in
HUMAN LACTATION Mammals perfected milk for their young over
millions of years of evolution
Each species has the perfect milk for its own young, for optimal adaptation to environmental demands Chemical composition very varied
Production of both prolactin and oxytocin respond to demand More sucking = more hormonal output.
Advantages for infant
NutritionalSmooth adaptation period from intra to
extra-uterine life ○ (Shortened gestation – 9 months instead of 12
as other primates)
Species-specific○ Each species has different developmental
needs○ Right amounts of the right nutrients
Advantages for infant
Nutritional (Cont’d):Non-allergenic100% digestible, no waste
○ Bioavailability of nutrientsLower renal soluteunlikely to overfeed due to changing
composition through a feed○ Lower risk of later obesity
Brain development
Immunological advantages Fresh antibodies in each drop
Infant has immature immune systemMammary gland makes antibodies in situ
when a new pathogen appears in the environment
Lactobacillus bifidus prevents gut colonization by harmful bacteria
Lower morbidity and mortality
Benefits for lactating mother Uterus back to pre-pregnant state due to
oxytocin-induced contractions Contraception** Breast cancer protection Skeletal calcium deposits (lower
osteoporosis risk) Weight loss Stress control (hormonal) Bonding
