Lab 43.
Reproductive Physiology
• Be able to identify the following tissues
microscopically: testes (seminiferous tubules),
ovary (stages), sperm, mammary gland (active
vs not), prostate gland. Be able to identify a
follicle within an ovary.
• Be able to identify the following structures on a
model: testes, epididymis, ejaculatory duct,
prostate gland, bladder, urethra; ovary, Fallopian
tube, uterus, cervix, vagina, bladder, urethra
Structure of the Testes
Figure 28–4
Tunica Vaginalis
• Serous membrane that lines scrotal cavity
• Reduces friction between opposing
surfaces:
– parietal (scrotal)
– visceral (testicular)
Tunica Albuginea
• Dense layer of connective tissue rich in collagen
fibers
• Deep to tunica vaginalis
• Continuous with fibers surrounding epididymis
• Fibers extend into substance of testis
• Form fibrous partitions, or septa that converge
near entrance to epididymis
• Supports:
– blood and lymphatic vessels of testis
– efferent ductules
Structures of Testes
• Septa subdivide testis into lobules
• Lobules contain about 800 slender and tightlycoiled seminiferous tubules:
– Produce sperm
– About 80 cm long each
– Testis contains about 1/2 mile of tightly-coiled
seminiferous tubules
• Each Seminiferous Tubule Forms a loop
connected to rete testis: a network of
passageways
• 15–20 large efferent ductules connect rete testis
to epididymis
The Seminiferous Tubules
Figure 28–5b
Connective Tissue Capsules
• Surround tubules
• Areolar tissue fills spaces between tubules
• Spaces contain:
– blood vessels
– large interstitial cells (cells of Leydig)
• Produce androgens (male sex hormones)
including testosterone (most important androgen)
Contents of
Seminiferous Tubules
• Spermatogonia (stem cells, near outer surface)
• Spermatocytes at various stages of meiosis
(primary, secondary)
• Spermatids (immature)
• Spermatozoa (mature)
• Large sustentacular cells (Sertoli cells)
– Are attached to tubular capsule
– Extend to lumen between other types of cells
– Secrete inhibin, ABP, MIF
The Seminiferous Tubules
Figure 28–5c
Meiosis
• In seminiferous tubules: begins with primary
spermatocytes and produces spermatids
(undifferentiated male gametes)
• Basically, in meiosis one, you separate the
homologues (meaning each of the resulting
daughter cells gets only one of your two copies
of chromosome #4 and one of your two copies of
chromosome #21, etc. (Both cells contain 23
chromosomes with 2 chromatids each
(reductional division)
• Meiosis two is just like mitosis, only it is different
than mitosis in somatic cells because there are
only 23 chromosomes at this point yields 4 cells,
each containing 23 chromosomes (equational
division)
Spermatogenesis
Figure 28–7
Seminiferous Tubule
• Using low power, take a look around (you don’t have to
sketch what you see at low mag).
• Locate, by sight: tunica vaginalis, tunica albuginea,
septa, lobules, and the numerous seminiferous tubules.
• On medium or high power, sketch seminiferous tubules.
In your sketch, draw and clearly label one or two tubules
with: the lumen, interstitial space, interstitial cell (aka
Leydig cell), spermatogonia (the stem cells), primary or
secondary spermatocytes (cells midway through
meiosis), spermatids (immature sperm, products of
meiosis), sustentacular cells (aka, Sertoli cells).
A. What hormones do sustentacular cells secrete?
B. What do interstitial cells secrete?
The Female Reproductive
System
Figure 28–13
Organs of the Female
Reproductive System
•
•
•
•
•
Ovaries
Uterine tubes
Uterus
Vagina
External genitalia
Oogenesis
Figure 28–15
Oogenesis
• Begins before birth, pauses
• Continues at puberty
• Does not actually complete until
fertilization!
• Ceases at menopause
• Ovarian Cycle Includes monthly oogenesis
between puberty and menopause
Oogenesis
Oogenesis
• Oogonia = females reproductive stem cells
– complete mitotic divisions before birth (not thought to
happen at all after birth, but…)
• Between third and seventh months:
– primary oocytes begin meiosis but stop at prophase
of meiosis I
• At birth, a baby girl’s ovaries have about 2
million primordial follicles each containing a
primary oocyte arrested in prophase I of
meisosis
• At puberty rising FSH triggers start of ovarian
cycle
Oogenesis
• Each month thereafter some primary oocytes
are stimulated to develop further by FSH
• One per month will complete meiosis I and
become a secondary oocyte just prior to
ovulation
• Ovary releases secondary oocyte (not mature
ovum) that is suspended in metaphase of
meiosis II
• Meiosis II is only completed upon fertilization
The Ovarian Cycle
Figure 28–16 (1 of 2)
The Ovarian Cycle
Figure 28–16 (2 of 2)
Before Ovarian Cycle
• Ovarian Follicles specialized structures in
cortex of ovaries where oocyte growth and
meiosis I occur
• Primary Oocytes Are located in outer part
of ovarian cortex:
– near tunica albuginea
– in clusters called egg nests
• Primordial Follicle: each primary oocyte in
an egg nest is surrounded by follicle cells
The Ovarian Cycle
• Formation of primary follicles
– follicle cells become granulosa cells
– Thecal Cells surround follicle, work with granulosa
cells to produce estrogens
• Formation of secondary follicles
– Follicular fluid accumulates between inner and outer
layers of follicle
• Formation of tertiary follicle
– Antrum (cavity surrounded by granulosa cells)
enlarges and fills with follicular fluid
– Just before ovulation, oocyte becomes secondary
oocyte and floats free in the anrtum
The Ovarian Cycle – Luteal Phase
• After ovulation, formation of corpus
luteum:
– produces steroid hormone progesterone
which prepares uterine lining for pregnancy
• If fertilization does not occur corpus
luteum degenerates about 12 days after
ovulation fills with scar tissue to become
corpus albicans
Ovaries
Slide- “Ovary immature”
• On low power, take a look around. On medium power,
take a closer look at the numerous primordial follicles.
Slide- “Ovary-Graafian follicle”
• Draw and clearly label the ovary. Indicate the different
follicles. Find and sketch a secondary or tertiary follicle
(Graafian follicle). Label: the primary oocyte, antrum,
granulosa cells, theca cells. (Note: when viewing
follicles, realize that the oocyte may not be in the plane
of view).
Slide- “Ovary - Corpus luteum”
• Draw and clearly label an ovary containing a corpus
luteum (and/or corpus albicans). Indicate the corpus
luteum in your sketch.
A. What important hormone is secreted by the
corpus luteum?
B. What important function does this hormone have
in terms of the menstrual cycle?
The Uterus
Figure 28–18a
Uterine Wall
• Has a thick, outer, muscular myometrium
• Has a thin, inner, glandular endometrium
(mucosa)
• Uterine Glands open onto endometrial
surface, extend deep into lamina propria
2 Divisions of Endometrium
• Functional zone: layer closest to uterine cavity
– Contains most of uterine glands
– Contributes most of endometrial thickness
– Undergoes dramatic changes in thickness and
structure during menstrual cycle
• Basilar zone: adjacent to myometrium
– Attaches endometrium to myometrium
– Contains terminal branches of tubular endometrial
glands
The Uterine Wall
Figure 28–19
Uterus
• If slide is available, draw and clearly label
the uterus. Label: myometrium,
endometrium and uterine cavity. Within
the endometrium, indicate the basilar zone
and functional zone. Label endometrial
glands.
Endometrium in Uterine Cycle
Figure 28–20
The Mammary Glands
Figure 28–23a
Mammary Glands
Figure 28–23b, c
Mammary Gland Ducts
• Leave lobules, Converge to form single
lactiferous duct in each lobe
• Forms expanded chamber (lactiferous
sinus)
• 15–20 lactiferous sinuses open to each
nipple (Why?)
Active Mammary Gland
• Consists of multiple glandular tubes
ending in secretory alveoli
• Does not complete development unless
pregnancy occurs
• Near complete at about 6 months
gestation, but milk is usually not let down
in any great amounts until delivery (Why?)
Mammary glands
•
Look at both inactive and active
mammary gland tissue. Draw and
clearly label active tissue: secretory
alveoli, and lactiferous ducts.
A. What is in the ducts?
B. How do the two tissues look different?
Slides
• Seminiferous Tubules
• Ovaries:
– Ovary immature
– Ovary- Graafian follicle
– Ovary - Corpus luteum
• Uterus
• Mammary glands
– Active
– Inactive