PowerPoint Lecture Slides prepared by Ryan Barrow Blanche Ely...

PowerPoint® Lecture Slides

prepared by

Ryan Barrow

Blanche Ely High School

C H A P T E R

Copyright © 2010 Pearson Education, Inc.

27

The Female Reproductive System: Hormonal

Packet #31


Female Reproductive System – Hormonal Regulation &

Aspects Related to Hormonal Control

• The ovaries – pp104 – 1042

• The endometrium – p. 1044

• The mammary glands – pp. 1047 – 1048

• Physiology of the female reproductive system – pp.

1049 – 1058


The Female Anatomy

Front View Side View


Female Reproductive System

1. Breast – mammary

glands

2. Ovaries and follicle

development


THE BREAST & MAMMARY

GLANDS


Mammary Glands I

• Modified sweat glands

consisting of 15–25 lobes

• Areola: pigmented skin

surrounding the nipple

• Suspensory ligaments:

attach the breast to

underlying muscle

• Lobules within lobes

contain glandular alveoli

that produce milk


Mammary Glands II

• Milk lactiferous ducts

lactiferous sinuses

open to the outside at the

nipple

Copyright © 2010 Pearson Education, Inc. Figure 27.15

Skin (cut)

Pectoralis major muscle

Suspensory ligament

Adipose tissue

Lobe

Areola

Nipple

Opening of

lactiferous duct

Lactiferous sinus

Lactiferous duct

Hypodermis

(superficial fascia)

Intercostal muscles

Lobule containing

alveoli

(a) (b)

First rib


Breast Cancer: Detection and Treatment

• 70% of women with breast

cancer have no known risk

factors

• Early detection via self-

examination and

mammography

• Treatment depends upon the

characteristics of the lesion:

• Radiation, chemotherapy, and

surgery followed by irradiation

and chemotherapy


(b) Film of normal breast

(a) Mammogram procedure

(c) Film of breast with tumor

Malignancy


Breast Cancer

• Usually arises from the epithelial cells of small ducts

• Risk factors include:

• Early onset of menstruation and late menopause

• No pregnancies or first pregnancy late in life

• Family history of breast cancer

• 10% are due to hereditary defects, including mutations to the genes BRCA1 and BRCA2


OOGENESIS


Oogenesis

• Production of female

gametes

• Begins in the fetal period

• Oogonia (2n ovarian stem

cells) multiply by mitosis

and store nutrients

• Primary oocytes develop in

primordial follicles

• Primary oocytes begin

meiosis but stall in

prophase I


Ovaries (Oogenesis II)

• Follicle

• Immature egg (oocyte)

surrounded by

• Follicle cells (one cell layer

thick)

• Granulosa cells (when more

than one layer is present)


Follicles (Oogenesis III)

• Several stages of development

• Primordial follicle: squamouslikefollicle cells + oocyte

• Primary follicle: cuboidal or columnar follicle cells + oocyte

• Secondary follicle: two or more layers of granulosa cells + oocyte

• Late secondary follicle: contains fluid-filled space between granulosa cells; coalesces to form a central antrum


Ovaries (Oogenesis V)

• Vesicular (Graafian) follicle

• Fluid-filled antrum forms;

follicle bulges from ovary

surface

• Ovulation

• Ejection of the oocyte from the

ripening follicle

• Corpus luteum develops from

ruptured follicle after

ovulation

Copyright © 2010 Pearson Education, Inc. Figure 27.11a

Medulla

Tunica

albuginea

Germinal

epithelium

Cortex

Oocyte Granulosa cells

Late secondary follicle

Antrum

Primary

follicles

Oocyte

Zona

pellucidaTheca

folliculi

Ovulated

oocyte

Mesovarium and

blood vessels

Vesicular

(Graafian)

follicle

Corona

radiata

Developing

corpus luteum

Corpus luteum

Ovarian

ligament

Degenerating corpus

luteum (corpus

albicans)

(a) Diagrammatic view of an ovary sectioned to reveal the follicles in its interior


Oogenesis VI

• Each month after

puberty, a few primary

oocytes are activated

• One is selected each

month to resume

meiosis I

• Result is two haploid cells

• Secondary oocyte

• First polar body


Oogenesis VII

• The secondary oocyte

arrests in metaphase II

and is ovulated

• If penetrated by sperm

the second oocyte

completes meiosis II,

yielding

• Ovum (the functional

gamete)

• Second polar body


Meiotic events Follicle development

in ovaryBefore birth

Infancy and

childhood

(ovary inactive)

Primary oocyte

Primary oocyte (still

arrested in prophase I)

Vesicular (Graafian)

follicle

Primary follicle

Primordial follicle

Primordial follicle

Oocyte

Ovulated secondary

oocyte

In absence of

fertilization, ruptured

follicle becomes a

corpus luteum and

ultimately degenerates.Degenating

corpus luteum

Secondary follicle

Primary oocyte

(arrested in prophase I;

present at birth)

Oogonium (stem cell)

Each month from

puberty to

menopause

Meiosis I (completed

by one primary oocyte

each month in response

to LH surge)

First polar body

Mitosis

Growth

Meiosis II of polar

body (may or may

not occur)

Polar bodies

(all polar bodies

degenerate)

OvumSecond

polar body

Meiosis II

completed

(only if

sperm

penetration

occurs)

Sperm

Ovulation

Secondary oocyte

(arrested in

metaphase II)

Follicle cells

Spindle


OVARIAN CYCLE


Ovarian Cycle

• Monthly series of events

associated with the maturation

of an egg

• Two consecutive phases (in a

28-day cycle)

• Follicular phase: period of

follicle growth (days 1–14)

• Ovulation occurs midcycle

• Luteal phase: period of corpus

luteum activity (days 14–28)


Follicular Phase

• Primordial follicle

becomes primary follicle

1. The primordial follicle

is activated

• Squamouslike cells

become cuboidal

2. Follicle enlarges to

become a primary (1)

follicle

Copyright © 2010 Pearson Education, Inc. Figure 27.18 (1 of 7)

Theca folliculi

Primary oocyteZona pellucidaAntrum

Secondary

oocyte

Secondary oocyteCorona radiata

1

23 4

5

6

7

8Primordial

follicles

1


Theca folliculi


Secondary

oocyte


1

23 4

5

6

7

8Primary

follicle

2


Follicular Phase

3. Primary follicle

becomes a secondary

follicle

• Stratified epithelium

(granulosa cells) forms

around oocyte

• Granulosa cells and

oocyte guide one

another’s development


Follicular Phase

4. Secondary follicle

becomes a late

secondary follicle

• Connective tissue (theca

folliculi) and granulosa

cells cooperate to

produce estrogens

• Zona pellucida forms

around the oocyte

• Fluid begins to

accumulate


Theca folliculi


Secondary

oocyte


1

23 4

5

6

7

8 Secondary

follicle

3


Theca folliculi


Secondary

oocyte


1

23 4

5

6

7

8

Late secondary

follicle

4


Follicular Phase

5. Late secondary follicle

becomes a vesicular

follicle

• Antrum forms and

expands to isolate the

oocyte with its corona

radiata on a stalk

• Vesicular follicle bulges

from the external surface

of the ovary

• The primary oocyte

completes meiosis I


Ovulation

• Ovary wall ruptures and

expels the secondary oocyte

with its corona radiata

• Mittelschmerz: twinge of pain

sometimes felt at ovulation

• 1–2% of ovulations release

more than one secondary

oocyte, which, if fertilized,

results in fraternal twins


Theca folliculi


Secondary

oocyte


1

23 4

5

6

7

8

Mature vesicular

follicle carries out

meiosis I; ready to

be ovulated

5


Theca folliculi


Secondary

oocyte


1

23 4

5

6

7

8

Follicle ruptures;

secondary oocyte

ovulated

6


Luteal Phase

• Ruptured follicle collapses

• Granulosa cells and

internal thecal cells form

corpus luteum

• Corpus luteum secretes

progesterone and

estrogen


Luteal Phase

• If no pregnancy, the

corpus luteum

degenerates into a corpus

albicans in 10 days

• If pregnancy occurs,

corpus luteum produces

hormones until the

placenta takes over at

about 3 months


Theca folliculi


Secondary

oocyte


1

23 4

5

6

7

8

Corpus luteum

(forms from

ruptured follicle)

7


Establishing the Ovarian Cycle

• During childhood, ovaries

grow and secrete small

amounts of estrogens that

inhibit the hypothalamic

release of GnRH

• As puberty nears, GnRH is

released; FSH and LH are

released by the pituitary, and

act on the ovaries

• These events continue until an

adult cyclic pattern is achieved

and menarche occurs



• During childhood, until

puberty

• Ovaries secrete small

amounts of estrogens

• Estrogen inhibits release

of GnRH



• At puberty

• Leptin from adipose tissue

decreases the estrogen

inhibition

• GnRH, FSH, and LH are

released

• In about four years, an

adult cyclic pattern is

achieved and menarche

occurs


Hormonal Interactions During a 28-Day Ovarian

Cycle

• Day 1: GnRH release

of FSH and LH

• FSH and LH growth of

several follicles, and

estrogen release

• estrogen levels

• Inhibit the release of FSH

and LH

• Stimulate synthesis and

storage of FSH and LH

• Enhance further estrogen

output



Cycle

• Estrogen output by the

vesicular follicle increases

• High estrogen levels have

a positive feedback effect

on the pituitary at

midcycle

• Sudden LH surge at

day 14



Cycle

• Effects of LH surge

• Completion of meiosis I

(secondary oocyte

continues on to metaphase

II)

• Triggers ovulation

• Transforms ruptured

follicle into corpus luteum



Cycle

• Functions of corpus

luteum

• Produces inhibin,

progesterone, and estrogen

• These hormones inhibit

FSH and LH release

• Declining LH and FSH

ends luteal activity and

inhibits follicle

development



Cycle

• Days 26–28: corpus

luteum degenerates and

ovarian hormone levels

drop sharply

• Ends the blockade of FSH

and LH

• The cycle starts anew


Hypothalamus

Late follicular and

luteal phases

1

1

2 2

2

3

4

5

5

6

8

8

7Slightly

elevated

estrogen

and rising

inhibin

levels.

Positive

feedback exerted

by large in

estrogen

output.

Mature follicleCorpus luteum

Ovulated

secondary

oocyte

Ruptured

follicle

LH surge

Progesterone

Estrogen

Inhibin

Hypothalamus

Early and midfollicular phases

Travels via

portal blood

Granulosa

cells

Inhibin

Androgens

Convert

androgens to

estrogens

Thecal

cells

Anterior pituitary

GnRH

FSH LH

Copyright © 2010 Pearson Education, Inc. Figure 27.20a

(a) Fluctuation of gonadotropin levels: Fluctuating

levels of pituitary gonadotropins (follicle-stimulating

hormone and luteinizing hormone) in the blood

regulate the events of the ovarian cycle.

FSH

LH

Copyright © 2010 Pearson Education, Inc. Figure 27.20b

(b) Ovarian cycle: Structural changes in the ovarian

follicles during the ovarian cycle are correlated with

(d) changes in the endometrium of the uterus during

the uterine cycle.

Primary

follicleSecondary

follicle

Vesicular

follicleOvulation

Corpus

luteum Degenerating

corpus luteum

Follicular

phaseOvulation

(Day 14)

Luteal

phase


UTERINE CYCLE

Menstrual Cycle


Uterine (Menstrual) Cycle

• Cyclic changes in endometrium in response to

ovarian hormones

• Three phases

1. Days 1–5: menstrual phase

2. Days 6–14: proliferative (preovulatory) phase

3. Days 15–28: secretory (postovulatory) phase

(constant 14-day length)


Uterine Cycle

• Menstrual phase

• Ovarian hormones are at

their lowest levels

• Gonadotropins are

beginning to rise

• Stratum functionalis is

shed and the menstrual

flow occurs


Uterine Cycle

• Proliferative phase

• Estrogen levels prompt

generation of new

functional layer and

increased synthesis of

progesterone receptors in

endometrium

• Glands enlarge and spiral

arteries increase in number


Uterine Cycle

• Secretory phase

• Progesterone levels

prompt

• Further development of

endometrium

• Glandular secretion of

glycogen

• Formation of the cervical

mucus plug


Uterine Cycle

Copyright © 2010 Pearson Education, Inc. Figure 27.20c

(c) Fluctuation of ovarian hormone levels:

Fluctuating levels of ovarian hormones (estrogens

and progesterone) cause the endometrial changes

of the uterine cycle. The high estrogen levels are

also responsible for the LH/FSH surge in (a).

Progesterone

Estrogens


Endometrium

• Stratum functionalis (functional layer)

• Changes in response to ovarian hormone cycles

• Is shed during menstruation

• Stratum basalis (basal layer)

• Forms new functionalis after menstruation

• Unresponsive to ovarian hormones

Copyright © 2010 Pearson Education, Inc. Figure 27.13b

Lumen of uterus

Uterine glands

Smooth muscle fibers

Straight artery

Radial artery

Arcuate artery

Uterine artery

Endometrial vein

Capillaries

Venous sinusoids

Epithelium

Spiral (coiled) artery

Lamina propria of

connective tissue

(b)

Copyright © 2010 Pearson Education, Inc. Figure 27.20d

(d) The three phases of the uterine cycle:

• Menstrual: Shedding of the functional layer of the

endometrium.

• Proliferative: Rebuilding of the functional layer of

the endometrium.

• Secretory: Begins immediately after ovulation.

Enrichment of the blood supply and glandular secretion of

nutrients prepare the endometrium to receive an embryo.

Both the menstrual and proliferative phases occur before ovulation, and

together they correspond to the follicular phase of the ovarian cycle. The

secretory phase corresponds in time to the luteal phase of the ovarian cycle.

Menstrual

phase

Menstrual

flow

Endometrial

glands

Blood vessels

Functional layer

Basal layer

Proliferative

phase

Secretory

phase

Days


Uterine Cycle

• If fertilization does not occur

• Corpus luteum degenerates

• Progesterone levels fall

• Spiral arteries kink and spasm

• Endometrial cells begin to die

• Spiral arteries constrict again, then relax and open wide

• Rush of blood fragments weakened capillary beds and the functional layer sloughs


EFFECTS OF ESTROGENS


Effects of Estrogens

• Promote oogenesis and

follicle growth in the

ovary

• Exert anabolic effects on

the female reproductive

tract

• Support the rapid but

short-lived growth spurt

at puberty



• Induce secondary sex

characteristics

• Growth of the breasts

• Increased deposit of

subcutaneous fat (hips and

breasts)

• Widening and lightening of

the pelvis



• Metabolic effects

• Maintain low total blood cholesterol and high HDL

levels

• Facilitates calcium uptake


Effects of Progesterone

• Progesterone works with

estrogen to establish and

regulate the uterine cycle

• Effects of placental

progesterone during

pregnancy

• Inhibits uterine motility

• Helps prepare the breasts

for lactation


REVIEW


Ovarian Cycle


Fertilization {Sea Urchin}


ChildBirth

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