Reproduction and Development
Chapter 16
pg 510
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Unit Overview
Male reproductive system
Principle hormones in male
Female reproductive system
Principle hormones in females
Chromosomal and hormonal factors on gonads
Hormonal influence on primary and secondary sex characteristics
STI’s and their influence on fertility and reproduction
Process of fertilization and implantation
Development from fertilization to parturition
Major tissues or organs that develop from ectoderm, mesoderm,
endoderm
• Influence of environmental factors on embryonic development
• Reproductive technologies
What Do You Know???
Primary Sex Characteristics
• Physical characteristics directly involved in
reproduction
– Testis/ovaries
– Uterus
– Sperm/eggs
Male Reproductive System
pg 512-513
Structures of the Male Reproductive
System
• Testes – male gonads, produce sperm, hang
outside the body
• Seminiferous tubules – site of spermatogenesis
• Interstitial cells – between seminifrous tubules,
produce testosterone
• Sertoli cells- provide support to developing
sperm cells
Structures of the Male Reproductive
System
• Epididymides – along posterior boarder of
testis, coiled tubes, stores sperm cells
• Vasa (ductus) deferentia – tube that conducts
sperm towards urethra
• Cowper’s glands – contributes mucus rich
fluid to seminal fluid to protect sperm from
acids in the urethra
• Seminal vesicles- contributes fructose and
prostaglandins to the seminal fluid
Structures of the Male Reproductive
System
• Prostate gland – secretes buffers into the
seminal fluid that protect the sperm cells from
the acidic environment of the vagina
• Ejaculatory duct –tubule formed where the vasa
deferentia and seminal vesicles join the urethra
• Urethra – carries seminal fluid during ejaculation
• Penis
Spermatogenesis – pg 514
• Formation of sperm cells
Spermatogonia  Spermacytes  Spermatids
• Takes 9-10 weeks
• Developed in Sertoli Cells
• Mature in epididymis
Testes and Sperm
Seminal Fluid – pg 516
• Contributed to by 3 glands along the vasa
deferentia and ejaculatory duct
• Seminal Vesicles – fructose (energy) and
prostoglandins (chemical signal in female
reproductive system)
• Prostate Gland – alkaline buffer against acidic
vaginal fluids
• Cowper’s Gland – mucus rich fluids to protect
against acids found in the urethra
• Only live for 24-72 hours at body temperature
Principle Male Reproductive
Hormones – pg 517
• Testosterone
– produced in interstitial cells
– stimulates maturation of testes, penis, and
speramtogenesis
– Promotes development of secondary sexcharacteristics
– Associated with secretion of body oils (acne and
body odor)
– Associated with sex drive and aggressive behavior
• Follicle-stimulating
Hormone (FSH)
– Stimulates production of
sperm cells in the
seminiforous tubules
• Luteinizing Hormone (LH)
– Promotes the production of
testosterone by the interstitial
cells
• Gonadotropin-releasing
Hormone (GnRH)
– Stimulates the release of FSH
and LH
Secondary Sex Characteristics in Males
pg 517
 External features that are indicative of gender
• Hair
– Chest and abdomen
– Facial
– Armpits and pubis
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Enlarged Larynx (deeper voice)
Larger, stronger muscles
Fat deposits around the abdomen and waist
Coarser skin texture
Typically larger hands and feet than women
Angle from thigh to ankle forms a strait line
Cancers of the Male Reproductive
System
• Testicular
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Most common cancer in males between 15-34
Lump or enlarged testicle
Pain in scrotum
Dull ache in abdomen or groin
• Prostate
– Ususally detected through
screening
– Symptoms include
• Urinary problems
• Blood in urine or semen
• Pain in pelvic area
Vasectomy Video
Review
• Homework package
• Quiz tomorrow
The Female Reproductive System
pg 520
21-18
External Structures of the Female
Reproductive System
Structures of the Female Reproductive
System
• Ovaries – site of ovum maturation, contain
oocytes (immature ova, all present at birth)
• Fallopian tubes – connect the ovaries to the
uterus (oviduct)
• Uterus (Womb) – where fetus develops,
muscular outer lining, glandular inner layer
• Endometrium – inner lining of the uterus,
grows and sheds during the reproductive cycle
Structures of the Female Reproductive
System
• Cervix – muscular band that separates the vagina
from the uterus
• Vagina – muscular canal extending from the
cervix to outer environment (birth canal)
• Labia Majora – outer lips of the vulva
• Labia Minora – inner lips of the vulva
• Clitoris
• Urethra – not connected to reproductive system
in females
Oogenesis and Ovulation – pg 522
• Oogenesis – formation
of an ovum
• Occurs in follicles
• Begins when nutrient
follicle cells
surrounding the
secondary oocyte
begin to divide
• Fluid filled cavity is
formed
• Follicle pushes outward
ballooning ovary wall
• Constriction of blood
vessels weakens ovary
wall
• Outer wall bursts and
secondary oocyte is
released (ovulation)
• Surrounding follicle
cells turn in to corpus
luteum which secretes
hormones necessary
for pregnany
Menstrual Cycle – pg 524
• Includes
oogenesis,
ovulation,
thickening and
shedding of the
endometrium
• 4 phases
• Lasts and
average of 28
days
Flow Phase
• Only phase that
can be
determined
externally
• Approximately 5
days
• Shedding of the
endometruim
Follicular Phase
• Development of
follicles within
ovary
• Estrogen secreted
as follicles
develop
• Normally days 613
Ovulatory Phase
• Secondary
oocyte bursts
from ovary
• Follicular cells
differentiate into
corpus luteum
• Day 14
Luteal Phase
• Begins with
development of
corpus luteum
• Estrogen and
Progesterone are
secreted
• Progesterone
prepares uterus
for an embryo
• Progesterone
prevents further
ovulation,
prevents uterine
contractions,
firms the cervix
• Days 15-28
• If no
fertilization,
concentrations
of
progesterone
and estrogen
decrease
causing uterine
contractions
and
endometrial
shedding
pg 528
Female Reproduction Throughout Her
Lifespan
• Ovaries undergo continual decline after puberty
• At puberty, each ovary contains approximately
400 000 folicles
• During each cycle, many follicles develop but
usually only one is released (others are reabsorbed)
• Between 12-50, about 400 eggs will mature
• Suggested that older follicles have a greater
chance of genetic defect
• Menopause
– when ovulation ceases
– Drop in production of female hormones
Principle Female Reproduction
Hormones – pg 526
• Estrogen
– Inhibits growth of facial hair
– Initiates secondary sex characteristics
– Causes thickening of the endometrium
• Progesterone
– Inhibits ovulation
– Inhibits uterine contractions
– Firms the cervix
– Stimulates the endometrium
• Follicle Stimulating Hormone
– Regulate control of hormones
produced by ovaries
– Carried to ovaries during follicular
phase
– Follicle development is stimulated
• Luteunizing Hormone
– Regulate control of hormones
produced by ovaries
– Stimulated by by rise in estrogen
– LH secretion rises and ovulation
occurs
– Formation and maintenance of
corpus luteum
Secondary Sex Characteristics in
Females pg 520
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Enlarged breasts
Less facial hair than men
Hair growth in armpits and pubis
Wider at hips and shoulders
Fat deposits around buttocks and hips
More body fat than men
Hands and feet typically smaller and narrower
than males
• Angle from thigh to ankle is slightly bent
Tubal Ligation Video
– Detection
Cervical Cancer
• PAP test and Pelvic examination
– Possible symptoms
• abnormal bleeding from the vagina
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bleeding or spotting between regular menstrual periods
bleeding after sex
menstrual periods that last longer and are heavier than before
bleeding after menopause
• more discharge from the vagina than normal
• pain in the pelvis or lower back
• pain during sexual intercourse
– Risk Factors
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HPV infection (main risk factor)
not having regular Pap tests (a test used to detect both dysplasia and cervical cancer)
becoming sexually active at a young age
having many sexual partners or a sexual partner who has had many partners
smoking
having a weakened immune system (for example, from taking drugs after an organ
transplant or having a disease such as AIDS)
• using birth control pills for a long time
• giving birth to many children
Ovarian Cancer
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Types
– Epithelial cell cancer starts in the cells that cover the outer surface of the ovary.
– Germ cell tumours start in the egg cells within the ovary and generally occur in younger
women. Germ cell cancer can even develop in children.
– Stromal tumours start in the connective tissue cells that hold the ovary together.
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Risk Factors
– age – particularly after 50
– personal history of cancer
– a family history of ovarian cancer or breast cancer or if a woman has hereditary mutations on
certain genes
– never having been pregnant
– taking hormone replacement therapy (especially estrogen-only therapy) for a long period of
time
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Symptoms
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abdominal discomfort, pressure or pain
change in bowel habits
feeling full after a light mea
upset stomach
feeling that the bowel has not completely emptied
Nausea
Fatigue
pain in lower back or leg
Breast Cancer
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Risk Factors
– having had breast cancer before
– family history of breast cancer (especially in a mother, sister or daughter diagnosed before
menopause or if mutations on BRCA1 or BRCA2 genes are present)
– family history of ovarian cancer
– an above-average exposure to the hormone estrogen, which your body naturally produces,
perhaps because you:
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have never given birth or gave birth for the first time after age 30
began menstruating at a young age
reached menopause later than average
have taken hormone replacement therapy (estrogen plus progestin) for more than five years
– dense breast tissue (as shown on a mammogram)
– a history of breast biopsies showing certain breast changes, such as an increased number of
abnormal cells that are not cancerous (atypical hyperplasia)
– radiation treatment to the chest area (for example, to treat Hodgkin lymphoma), especially
before age 30
Some factors slightly increase your risk of breast cancer. You may be at slightly higher
risk if you:
– are obese (especially after menopause)
– drink alcohol
– take birth control pills (the Pill)
Breast Cancer
• Symptoms
– lump or swelling in the armpit
– changes in breast size or shape
– dimpling or puckering of the skin – thickening and dimpling
skin is sometimes called orange peel
– redness, swelling and increased warmth in the affected
breast
– inverted nipple – nipple turns inwards
– crusting or scaling on the nipple
• Early Detection
– Self-exam
– Mammograms
Review
• Homework Package
• Quiz Wednesday
Sex Determination – pg 535
• Females have 2 X chromasomes
• Males have 1 X and 1 Y
• Male and female fetus’ are the same until week 6
or 7
• SRY gene makes the developing gonad a testis
• Also determined by hormones circulating in the
blood stream
– Too much estrogen at the wrong time can form a male
organism that is outwardly female
– Over abundance of androgens can produce male sex
organs in a genetically female body
“The Disappearing Male”
• Things to consider
– Everyday exposures
– Dangers of common products
– What it would mean to society if males became
less common or predominantly infertile
– Could this become a political issue