Transcript Slides 16.38 - cloudfront.net

Essentials of Human Anatomy & Physiology
Seventh Edition
Elaine N. Marieb
Chapter 16
The Reproductive System
Slides 16.38 – 16.66
Lecture Slides in PowerPoint by Jerry L. Cook
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Introduction Video
• http://www.youtube.com/watch?v=NkLUA05Ex
HA&feature=related
Menstrual (“Uterine”) Cycle
• Uterus is receptacle in which the young embryo
implants and develops  but only for a short
period of time.
• This interval coincides exactly with the time
when a fertilized egg would begin to implant =
approx. 7 days after ovulation.
Menstrual (Uterine) Cycle
 = Cyclic changes of the endometrium
(mucosa) of uterus month after month
 It is approx. 28 days in length and involves
interaction between several glands,
hormones, & target sites
 Regulated by cyclic production and hormonal
changes of estrogens and progesterone
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Slide 16.38
Hormonal Control of Female Reproductive
Functions
• The female body remains reproductively
immature until about 8 years of age when
secretions of gonadotropins, FSH & LH, from the
pituitary gland increases.
• The time in which these hormones are secreted is
controlled by your hypothalamus.
Follicle Stimulating Hormone
• FSH is secreted from day 0 – 14 of the
reproductive cycle and causes the stimulation of
the primary oocyte and follicle to mature and
undergo meiosis I.
• **@ puberty, once each month, FSH stimulates one
primary oocyte to undergo meiosis I to give rise to
one secondary oocyte.
Luteinizing Hormone
• A surge of LH on the 14th day of the reproductive
cycle causes:
• The follicle to burst = ovulation
• Allowing the mature, secondary oocyte to be released
into the fallopian tube
• Follicle becomes the corpus luteum
SUMMARY
• FSH  causes maturation of follicle
• LH  causes ovulation
Hormone Production by the Ovaries
 Estrogens
 Produced by maturing follicle cells: days 1 - 14
 Causes and maintains secondary sex
characteristics:
 Enlargement of accessory organs
 Development of breasts & mammory glands
 Appearance of axillary & pubic (inguinal) hair
 Increase in fat beneath the skin
 Widening and lightening of the pelvis
 Onset of menses: priming of endometrium of
uterus
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Slide 16.40
Hormone Production by the Ovaries
 Progesterone
 Produced by the corpus luteum: day 14 - 24
 Production continues until LH diminishes in
the blood
 Targets endometrium of uterus
 Prepares uterus for implanation of zygote:
thickens lining & promotes formation of
glands and blood vessels
 Helps maintain pregnancy
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Slide 16.41
Hormonal Control of the Ovarian and Uterine
Cycles
Figure 16.12a, b
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Slide 16.39a
Hormonal Control of the Ovarian and Uterine
Cycles
Figure 16.12c, d
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Slide 16.39b
• Stages of the menstrual cycle:
• 1. Menses: days 1 - 5 – functional layer of the
endometrium is sloughed, or detached from uterus.
• 2. Proliferative stage: days 5 - 14 – regeneration of
basal functional layer – stimulated by estrogen levels,
ovulation occurs
• 3. Secretory (luteal) stage: days 15 - 28 –
endometrium increases in size and readies for
implantation – rise in progesterone
Female Reproductive Cycle
• 1. begins @ puberty, on day 0, hypothalamus
secretes a releasing hormone that targets the
pituitary gland to secrete FSH.
• FSH secreted day 0 – 14
• FSH targets primary, primordial follicles and causes it
to mature
• The maturing follicle secretes estrogen to target
secondary sex cells to mature and maintain
Female Reproductive Cycle
• 2. On day 14, hypothalamus secretes a second releasing
hormone that targets pituitary gland to secrete LH
• LH is secreted on day 14 only
• LH targets mature secondary follicle and causes it to burst
• Secondary oocyte is released into fallopian tube and
follicle becomes the corpus luteum
• Corpus luteum secretes progesterone:
• Progesterone secreted day 14 – 24 and targets uterine
endometrium to prepare for implantation
• Progesterone causes endometrium to become thick, glandular,
and vascular (hence bloating).
Female Reproductive Cycle
• 3. If implantation DOES NOT occur by day 24, corpus
luteum degenerates and levels of progesterone (and
estrogen) decline
• Decline occurs from day 24 – 28
• Hypothalmus detects this decrease and initiates a new cycle by
secreting a releasing hormone that targets the pituitary gland to
secrete FSH on day 0.
• FSH begins new cycle by maturing follicle
• FSH ends previous cycle through menstruation (blood pass)
of the endometrium
Female Reproductive Cycle
• If implantation DOES occur by day 24, corpus luteum
continues to secrete progesterone to maintain the
developing embryo, until the placenta is formed (end of
month 3)
• If fertilization occurs, embryo produces hormone similar
to LH which causes the corpus luteum to keep producing
progesterone.
• During this cycle, estrogen and progesterone inhibit the
release of LH and FSH
• **As the pituitary gland senses the fall in the concentrations of
these hormones, it secretes them again (negative feedback)
initiating a new menstrual cycle**
• http://www.youtube.com/watch?v=WGJsrGmWe
KE&feature=related
ECTOPIC PREGNANCY
• An ectopic pregnancy is an abnormal pregnancy that occurs outside the
(uterus). The fetus cannot survive, and often does not develop at all in
this type of pregnancy.
• The most common site for an ectopic pregnancy is within one of the
fallopian tubes. However, in rare cases, ectopic pregnancies can occur
in the ovary, stomach area, or cervix.
• Is often caused by a condition that blocks or slows the movement of a
fertilized egg through the fallopian tube to the uterus.
• This may be caused by a physical blockage in the tube by hormonal
factors and by other factors, such as smoking
• Up to 50% of women who have ectopic pregnancies have had swelling
(inflammation) of the fallopian tubes or pelvic inflammatory disease
(PID).
PID – Pelvic Inflammatory Disease
• Pelvic inflammatory disease (PID) occurs when bacteria move from the
vagina or cervix into the uterus, fallopian tubes, ovaries, or pelvis.
• Most cases of PID are due to the bacteria that cause chlamydia and
gonorrhea. These are sexually transmitted infections (STIs). The most
common way a woman develops PID is by having unprotected sex with
someone who has a sexually transmitted infection.
• However, bacteria may also enter the body during some surgical or
office procedures, such as:
• Childbirth
• Insertion of an intrauterinedevice (IUD) (morena)
• Miscarriage
• Therapeutic or elective abortion
MAIN IDEAS
• OVULATION:
• http://www.youtube.com/watch?v=NkLUA05Ex
HA&feature=related
• MENSTRUAL CYCLE / HORMONES:
• https://www.youtube.com/watch?v=WGJsrGmWe
KE&feature=related
Mammary Glands
 Present in both sexes, but only function
in females
 Modified sweat glands that are part of your
skin: anterior to pectoral muscles
 Function is to produce milk
 Stimulated by sex hormones (mostly
estrogens) to increase in size
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Slide 16.42
Anatomy of Mammary Glands
 Areola – central pigmented area:
surrounds a central, protruding nipple
 Nipple – protruding central area of areola
 Lobes – 15 – 25 internal structures that
radiate around nipple
 Contain lobules that have:
 Alveolar glands – clusters of milk
producing glands within lobules
 Lactiferous ducts – connect alveolar
glands to nipple
Slide 16.43
Production / Flow of Milk:
• 1. Milk is produced by alveoli and passes into
• 2. secondary tubules into
• 3. mammory ducts then into
• 4. lactiferous sinuses (near nipple) then into
• 5. lactiferous ducts and exits through the
• 6. nipple
Breast Cancer
• Leading cause of death in American women
• 1/8 will develop this condition
• Can have early detection from self-examinatios &
mammography
• Currently  american cancer society suggests
mammograms every 2 years starting at age 40 – 49 and
yearly after that
• To remove the cancer, options include radiation,
chemotherapy, mastectomy
Stages of Pregnancy and
Development
 1. Fertilization
 2. Embryonic development
 3. Fetal development
 4. Childbirth
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Slide 16.44
Fertilization
 The oocyte is viable for 12 to 24 hours
after ovulation
 Sperm are viable for 12 to 48 hours
after ejaculation
 Sperm cells must make their way to the
uterine tube for fertilization to be
possible
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Slide 16.45
Mechanisms of Fertilization
 Membrane receptors on an oocyte pulls
in the head of the first sperm cell to
make contact
 The membrane(zona pellucida) of the
oocyte does not permit a second sperm
head to enter
 The oocyte then undergoes its second
meiotic division
 Fertilization occurs when the genetic
material of a sperm combines with that
of an oocyte to form a zygote
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Slide 16.46
Types of Fertilization
• 2 Types = External and Internal Fertilization
• Mechanisms:
• 1. In Vitro Fertilization  IVF is the process of
fertilization by manually combining an egg and sperm
in a laboratory dish.
» When the IVF procedure is successful, the process is combined
with a procedure known as embryo transfer, which involves
physically placing the embryo in the uterus.
In vitro
• http://www.youtube.com/watch?v=GeigYib39Rs
• 2. GIFT stands for "Gamete Intra-Fallopian
Transfer." - the female's eggs and the male's sperm, are
washed and placed via a catheter directly into the
woman's fallopian tubes.
• This usually involves a minor surgical procedure which
allows you to go home the same day with a minor degree
of pain that lasts for just a few days.
• With GIFT, fertilization occurs inside the woman's body
(not outside), and mimics the way a normally fertilized
egg would begin its journey to the uterus for implantation.
Only in vitro accepted by the catholic church.
GIFT
Normal vs GIFT
fertilization
50%
Pregnancy
Rate
Female receives
hormones prior to
procedure
Gametes are
washed &
prepared for
loading 3
hours before
ZIFT “zygote intrafallopian transfer”
• ZIFT is an assisted reproductive procedure similar to in
vitro fertilization and embryo transfer, the difference
being that the fertilized embryo is transferred into the
fallopian tube instead of the uterus.
• This procedure can be more successful than GIFT
because your physician has a greater chance of insuring
that the egg is fertilized.
• The woman must have healthy tubes for ZIFT to work.
The Zygote
 First cell of a new individual
 The result of the fusion of DNA from
sperm and egg
 The zygote begins rapid mitotic cell
divisions
 The zygote stage is in the uterine tube,
moving toward the uterus
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Slide 16.47
The Embryo
 Developmental stage from the start of
cleavage until the ninth week
 The embryo first undergoes division
without growth
 The embryo enters the uterus at the
16-cell state
 The embryo floats free in the uterus
temporarily & then implants
 Uterine secretions are used for
nourishment
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Slide 16.48
The Blastocyst
 Ball-like circle of cells
 Begins at about the 100 cell stage
 Secretes human chorionic gonadotropin
(hCG) to produce the corpus luteum to
continue producing hormones
 Functional areas of the blastocyst
 Trophoblast – large fluid-filled sphere which
later forms the placenta
 Inner cell mass
Slide 16.49
The Blastocyst
 Primary germ layers are eventually
formed
 Ectoderm – outside layer
 Mesoderm – middle layer
 Endoderm – inside layer
 The late blastocyst implants in the wall
of the uterus (by day 14)
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Slide 16.50
• The endoderm forms: the stomach, the colon, the
liver, the pancreas, the urinary bladder, the lining of
the urethra, the epithelial parts of trachea, the lungs
, the pharynx, the thyroid, the parathyroid, and the
intestines.
• The mesoderm forms: skeletal muscle, the
skeleton, the dermis of skin, connective tissue, the
urogenital system, the heart, blood (lymph cells),
the kidney, and the spleen.
• The ectoderm forms: the central nervous system,
the lens of the eye, cranial and sensory, the ganglia
and nerves, pigment cells, head connective tissues,
the epidermis, hair, and mammary glands.
Derivatives of Germ Layers
 Ectoderm
 Nervous system
 Epidermis of the skin
 Endoderm
 Mucosae
 Glands
 Mesoderm
 Everything else
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Slide 16.51
Development from Ovulation to
Implantation
Figure 16.15
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Slide 16.52
Development After Implantation
 Chorionic villi (projections of the
blastocyst) develop
 Cooperate with cells of the uterus to form
the placenta
 The embryo is surrounded by the
amnion (a fluid filled sac)
 An umbilical cord forms to attach the
embryo to the placenta
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Slide 16.53
Development After Implantation
Figure 16.16
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Slide 16.54
Functions of the Placenta
 Forms a barrier between mother and embryo
(blood is not exchanged)
 Delivers nutrients and oxygen
 Removes waste from embryonic blood
 Becomes an endocrine organ (produces
hormones) and takes over for the corpus
luteum
 Estrogen
 Progesterone
 Other hormones that maintain pregnancy
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Slide 16.55
Placenta Eating – What’s the deal?
• http://www.youtube.com/watch?v=NkLUA05Ex
HA&feature=related
The Fetus (Beginning of the Ninth
Week)
 All organ systems are formed by the
end of the eighth week
 Activities of the fetus are growth and
organ specialization
 A stage of tremendous growth and
change in appearance, about 270 days
after fertilization the fetus is said to be
“full term” and ready to be born
 Development summary table 16.1
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Slide 16.56
Embryo & Fetal Growth
In The Womb Trailer
• https://docs.google.com/present/view?id=dfh23k6
7_961gkfkfchr Slide 31
Fetal Tests
• General Testing:
• Blood Test
• Urine Test
• Rh Factor Testing
• Paternity Testing
• Ultrasound
Fetal Tests
• 1st Trimester:
• Chronic Villi Testing = diagnostic test for identifying
chromosome abnormalities and other inherited
disorders.
• 1st Trimester Screen (blood test and ultrasound eval.):
does not detect neural tube defects.
Chorionic Villi Sampling
• 2nd Trimester:
• Amniocentesis = detects chromosome abnormalities,
neural tube defects and genetic disorders. Down
syndrome or Trisomy 21 is the most common
chromosome abnormality. Genetic disorders include
disorders like cystic fibrosis. The most common neural
tube defect is spina bifida.
• Cordocentesis = is a diagnostic test that examines blood
from the fetus to detect fetal abnormalities.
• Quad Screen & Triple Screen test = Looks for
specificpregnancy hormones
Amniocentesis
• 3rd Trimester:
• Biophysical Profile = evaluation with a nonstress test
(NST) and is intended to determine fetal health during the
third trimester.
• Glucose Challenge Screening = identifies if mother has
developed Gestational Diabetes
• Fetal Non-Stress Test = place belt over mother’s abdomen
and checks fetal hear rate and movement
• Group B Sptreptococcus = test for bacterial infection
found in pregnant women’s vagina that can be passed
onto fetus  affects 1/2000 babies in US.
In the Womb
• http://www.youtube.com/watch?v=tD4sjukHHW
U Min. 1.34
The Effects of Pregnancy on the
Mother
 Pregnancy – period from conception
until birth, & can be difficult for the
mother
 Anatomical changes:
 Enlargements of the uterus
 Accentuated lumbar curvature
 Relaxation & flexibility of the pelvic
ligaments and pubic symphysis due to
production of relaxin
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Slide 16.57
How does a woman know she is pregnant?
• Missed period
• Changes in body, tenderness in breasts,
nausea…etc
• Pregnancy test – tests urine for hormone levels
Changes in women’s body during pregnancy:
Eating For Two
• “A pregnant woman is eating for two” has
encouraged many pregnant women to eat twice as
much amount of food as needed  leads to
excessive weight gain
• A pregnant woman needs only about 300
additional calories daily to sustain proper fetal
growth
Effects of Pregnancy on the Mother
 Physiological changes
 Center of gravity changes due to growing bulkiness of
abdomen
 Gastrointestinal system:
 Morning sickness is common due to
elevated progesterone
 Heartburn is common because of organ
crowding by the fetus displaces
esophagus and stomach
 Constipation is caused by declining
motility of the digestive tract
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Slide 16.58a
Effects of Pregnancy on the Mother
 Physiological changes
 Urinary System
 Kidneys have additional burden and
produce more urine
 The uterus compresses the bladder,
urination then becomes more frequent,
more urgent & sometimes uncontrollable
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Slide 16.58b
Effects of Pregnancy on the Mother
 Physiological changes
 Respiratory System
 Nasal mucosa becomes congested and
swollen
 Vital capacity and respiratory rate
increase
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Slide 16.59a
Effects of Pregnancy on the Mother
 Physiological changes
 Cardiovascular system
 Body water rises
 Blood volume increases by 25 to 40
percent
 Blood pressure and pulse increase
 Because the uterus presses on the pelvic
blood vessels, varicose veins are
common
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Slide 16.59b
Childbirth (Partition)
 Labor – the series of events that expel
the infant from the uterus
 Initiation of labor:
 Estrogen levels rise
 Uterine contractions begin
 The placenta releases prostaglandins
 Oxytocin is released by the pituitary
 Combination of these hormones produces
contractions
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Slide 16.60
Initiation of Labor
Figure 16.18
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Slide 16.61
Stages of Labor
 1. Dilation
 Cervix becomes dilated
 Uterine contractions begin and increase in frequency
 During last few weeks of pregnancy, estrogen levels
reach their highest and causes 2 important
consequences:
1. myometrium forms oxytocin receptors which
interferes with progesterone and therefore
influences uterine muscle
2. This results in weak, irregular uterine
contractions called braxton Hicks contractions =
“false labor”
 The amnion ruptures
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Slide 16.62a
Stages of Labor
 2. Expulsion
 Infant passes through the cervix and vagina
 Normal delivery is head first
 3. Placental stage
 Delivery of the placenta = “afterbirth”
 Tug on umbilical cord and pulls rest out to
prevent continued uterine bleeding
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Slide 16.62b
Stages of Labor
Figure 16.19
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Slide 16.63
Complications During Birth
• Placenta Previa:
• placenta is not attached
to the top of the uterus,
partially or fully blocks
the cervix, this can
cause bleeding during
pregnancy
Breech Birth
Ectopic Pregnancy
Gestational Diabetes
Developmental Aspects of the
Reproductive System
 Gender is determined at fertilization
 Males have XY sex chromosomes
 Females have XX sex chromosomes
 Gonads do not begin to form until the
eighth week
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Slide 16.64a
Developmental Aspects of the
Reproductive System
 Testes form in the abdominal cavity and
descend to the scrotum one month
before birth
 The determining factor for gonad
differentiation is testosterone
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Slide 16.64b
Developmental Aspects of the
Reproductive System
 Reproductive system organs do not
function until puberty
 Puberty usually begins between ages
10 and 15
 The first menses usually occurs about
two years after the start of puberty
 Most women reach peak reproductive
ability in their late 20s
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Slide 16.65
Developmental Aspects of the
Reproductive System
 Menopause occurs when ovulation and
menses cease entirely
 Ovaries stop functioning as endocrine
organs
 There is a no equivalent of menopause
in males, but there is a steady decline in
testosterone
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Slide 16.66