Ch 24: The Reproductive System, Part 2 doc

Ch 24: The Reproductive System, Part 2
Ch 24: The Reproductive System, Part 2
pp 723-747
pp 723-747
Gonads = ovaries
Gonads = ovaries
Gametes = ova (one/month)
Gametes = ova (one/month)
Unlike the male, mostly internal
Unlike the male, mostly internal
Female repro system
must produce gametes
AND maintain
developing embryo
Overview of Anatomy
Overview of Anatomy
Ovaries
Ovaries
Retroperitoneal
Retroperitoneal
Broad Ligament
Broad Ligament
Suspensory Ligament
Suspensory Ligament
Functions:
Functions:


Ovum production
Ovum production
Hormone production

Hormone production
Circulation:
Circulation:
Ovarian Artery and Vein
Ovarian Artery and Vein
Histology
Histology
•
Capsule: Tunica albuginea
Capsule: Tunica albuginea
•
Germinal epithelium (misnomer)
Germinal epithelium (misnomer)
•
Ovarian cortex with developing gametes
Ovarian cortex with developing gametes
•
Medulla has blood supply
Medulla has blood supply
Oogenesis
Oogenesis


(
(
= ovum production)
= ovum production)

Takes place inside ovarian follicles in
Takes place inside ovarian follicles in
ovaries as part of ovarian cycle
ovaries as part of ovarian cycle




Oogonia
Oogonia
(= stem cells) complete
(= stem cells) complete
mitotic divisions before birth
mitotic divisions before birth
At birth: ~ 2x10
At birth: ~ 2x10
6
6
primary oocytes
primary oocytes
At puberty: ~ 400,000 primary oocytes
At puberty: ~ 400,000 primary oocytes
40 years later: 0 (even though only ~ 500 used)
40 years later: 0 (even though only ~ 500 used)
⇒
⇒


Atresia

Atresia
Ovulation
Oogenesis
Oogenesis
Fig 24.15
Ovarian cycles start at
puberty under influence of
estrogen.
Oogenesis
Oogenesis
1.
1.
Primordial follicle
Primordial follicle
1.
1.
A dormant stage, ready to develop
A dormant stage, ready to develop
2.
2.
Each month some proceed
Each month some proceed
3.
3.
Most (99%) atrophy
Most (99%) atrophy
(atresia)
(atresia)
Oogenesis
Oogenesis

2
2
. Primary follicle (days 3-8)
. Primary follicle (days 3-8)
1. Double layer of theca cells
1. Double layer of theca cells
2. Enlargement due to estrogen
2. Enlargement due to estrogen
3. More atresia
3. More atresia
Oogenesis
Oogenesis
3.
3.
Secondary follicle (days 8-10)
Secondary follicle (days 8-10)
1.
1.
Liquor folliculi appears
Liquor folliculi appears
2.
2.
Theca more developed
Theca more developed
3.
3.
Granulosa cells producing estrogen, under
Granulosa cells producing estrogen, under
influence of FSH
influence of FSH

4.
4.
Zona pellucida visible
Zona pellucida visible
Oogenesis
Oogenesis
4.
4.
Tertiary (Graafian) follicle (days 11-14)
Tertiary (Graafian) follicle (days 11-14)
1. Ready for ovulation
1. Ready for ovulation
2. Theca well developed
2. Theca well developed
3. Granulosa cells secreting estrogen
3. Granulosa cells secreting estrogen
4. First meiosis completed
4. First meiosis completed
Tertiary or
Tertiary or
Graafian Follicle
Graafian Follicle
Spans entire width of cortex
First meiotic division being
completed: 1°oocyte divides into
one 2° oocyte and one polar body
Ovarian cyst
Ovarian cyst
Cyst = bag, usually filled
with fluid

Usually follicular or
luteal cysts.
Oocyte and follicular cells shed into abdominal
cavity and collected by fimbria
then
1. Empty follicle forms corpus luteum which produces
progesterone
2. Corpus luteum degenerates and becomes corpus
albicans
3. GnRH increases under low estrogen and progesterone
levels
Ovulation
Menstrual Cycle
Menstrual Cycle

Day 1: first day of menses (period)
Day 1: first day of menses (period)

Days 7-14: Proliferative phase
Days 7-14: Proliferative phase
–
Follicle develops, secretes estrogen
Follicle develops, secretes estrogen

Day 14: Ovulation
Day 14: Ovulation

Days 14-28 (luteal phase):
Days 14-28 (luteal phase):
–

Corpus luteum forms from follicle, secretes progesterone,
Corpus luteum forms from follicle, secretes progesterone,
eventually becomes corpus albicans
eventually becomes corpus albicans
Uterine Tube
= Fallopian tube =
= Fallopian tube =
oviduct = salpinx
oviduct = salpinx
Infundibulum
Infundibulum
with
with
fimbriae
fimbriae
–
Ampulla
Ampulla
(place of fertilization)
(place of fertilization)
–
Isthmus
Isthmus
–
Intramural portion
Intramural portion
Most common site of ectopic pregnancy
Most common site of ectopic pregnancy
Tubal ligation
Tubal ligation

PID
PID
Uterine Tube Histology
Ciliated and non-ciliated
Ciliated and non-ciliated
simple columnar
simple columnar
epithelium
epithelium
Ciliary movement and
Ciliary movement and
periodic peristaltic
periodic peristaltic
contractions move ova
contractions move ova
Secretion of nutrient
Secretion of nutrient
substances
substances
The Uterus = Womb
Fundus, Body, Isthmus, Cervix
Fundus, Body, Isthmus, Cervix
Uterine wall
Uterine wall
~ 1.5 cm
~ 1.5 cm
made up of
made up of
1.
1.

Endometrium,
Endometrium,
2.
2.
Myometrium,
Myometrium,
3.
3.
Incomplete perimetrium (visceral
Incomplete perimetrium (visceral
peritoneum)
peritoneum)
Blood supply
Blood supply
–
Uterine arteries from internal iliac
Uterine arteries from internal iliac
–
Ovarian arteries from abdominal
Ovarian arteries from abdominal
aorta (inferior to renal arteries)
aorta (inferior to renal arteries)
fig 24.11
Histology of Endometrium

Functional zone
Functional zone
–
–
deciduum, sheds during

deciduum, sheds during
menses
menses


–
menstruation - flow sheds
menstruation - flow sheds
functionalis layer of
functionalis layer of
endometrium
endometrium
–
proliferative phase - under
proliferative phase - under
influence of estrogen basal
influence of estrogen basal
cells proliferate
cells proliferate
–
secretory phase - progesterone
secretory phase - progesterone
maintains functionalis
maintains functionalis

Basilar zone
Basilar zone
–
–
permanent

permanent
layer, deep to functionalis
layer, deep to functionalis
Functions of Uterus
Functions of Uterus

Protection of
Protection of
embryo/fetus
embryo/fetus

Nutritional support
Nutritional support

Waste removal
Waste removal

Ejection of fetus at birth
Ejection of fetus at birth
Cervix and Vagina

Cervix
Cervix
attaches to vagina at ~ 90°
attaches to vagina at ~ 90°
angle
angle
–
Fibrous connective tissue
Fibrous connective tissue


Fornix
Fornix
–
–
pocket surrounding uterine
pocket surrounding uterine
cervix
cervix


(surgical access to pelvic cavity;
(surgical access to pelvic cavity;
location of birth control device)
location of birth control device)

Vagina
Vagina
–
–
fibro-muscular tube serving
fibro-muscular tube serving
as
as
–
receptacle for intercourse
receptacle for intercourse
–
passageway for menstrual products
passageway for menstrual products

–
birth canal
birth canal

External genitalia
External genitalia
–
Labia majora and minora
Labia majora and minora
–
Clitoris
Clitoris
–
Urethral papilla
Urethral papilla
Fertilization
•
Acrosomal Reaction
•
Enzymes in acrosome
dissolve part of zona
pellucida
•
Cortical Reaction
•
Destroys receptors for
further spermatozoa
•
Fertilized zygote enters
uterus at ~ day 4

Pregnancy
Pregnancy
•
Implantation (day 6)
•
Blastocyst + trophoblast
•
Loss of zona pellucida
•
Trophoblast proliferates
•
Attachment to
endometrium
Pregnancy
Pregnancy
•
Placenta
•
Formed from trophoblast
and endometrum which is
now called the chorion
•
Chorionic villi contact
maternal blood supply
•
becomes an endocrine gland:
•
HCG (similar to LH) maintains
the CL for 3 months
•

Later, estrogen and
progesterone
•
Relaxin and human placental
lactogen
•
Provides nutrition and waste removal
Parturition
Parturition

Gestation ~ 280 days
Gestation ~ 280 days
(266 days after last
(266 days after last
menstruation)
menstruation)

Stages
Stages
–
Dilation
Dilation
–
Expulsion
Expulsion
–
Placental
Placental
The Mammary Gland
Modified sweat gland, holocrine

Modified sweat gland, holocrine
secretion
secretion
Overlaying the pectoralis major
Overlaying the pectoralis major
muscle
muscle
15-20 separate lobes separated by
15-20 separate lobes separated by
suspensory ligaments; each lobe
suspensory ligaments; each lobe
contains several secretory lobules
contains several secretory lobules
Lactiferous ducts
Lactiferous ducts
leaving lobules;
leaving lobules;
converge into 15-20 lactiferous
converge into 15-20 lactiferous
sinuses
sinuses
Site of most breast cancers
Site of most breast cancers
Milk stored in lactiferous sinus until
Milk stored in lactiferous sinus until
released at tip of nipple, influenced
released at tip of nipple, influenced
by oxytocin
by oxytocin