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