Oogenesis Flashcards
It is the developmental sequence of the female germ cells
Oogenesis
The sequence of oogenesis
Primordial germ cell - oogonium - primary oocyte
A pair of ______ complete the first meiosis
primary oocytes
True or False
Many oocytes (secondary
oocytes plus one polar body),
though, reach the second meiosis
and the subsequent ovulation
False (only a few)
Only a few oocytes (secondary
oocytes plus ________),
though, reach the second meiosis
and the subsequent ovulation
one polar body
Only a few oocytes (secondary
oocytes plus one polar body),
though, reach the _________
and the subsequent ovulation
second meiosis
The remaining oocytes that
mature each month become
_______.
atretic
While the oogonia transform
into ________ ______, they
become restructured so that
at the end of prophase I
, Each oogonium gets
enveloped by a single layer
of flat, follicular epithelial
cells (descendants of the
coelomic epithelium).
primary oocytes
While the oogonia transform
into primary oocytes, they
become _________ so that
at the end of prophase I, each oogonium gets
enveloped by a single layer
of flat, follicular epithelial
cells (descendants of the
coelomic epithelium).
restructured
While the oogonia transform
into primary oocytes, they
become restructured so that
at the end of ________, each oogonium gets
enveloped by a single layer
of flat, follicular epithelial
cells (descendants of the
coelomic epithelium).
prophase I
While the oogonia transform
into primary oocytes, they
become restructured so that
at the end of prophase I, each oogonium gets
enveloped by a single layer
of flat, follicular __________ (descendants of the
coelomic epithelium).
epithelial cells
While the oogonia transform
into primary oocytes, they
become restructured so that
at the end of prophase I, each oogonium gets
enveloped by a single layer
of flat, follicular epithelial
cells (________________________).
descendants of the coelomic epithelium
While the oogonia transform
into primary oocytes, they
become restructured so that
at the end of prophase I, each _______ gets
enveloped by a single layer
of flat, follicular epithelial
cells (descendants of the
coelomic epithelium).
oogonium
True or False
While the oogonia transform
into primary oocytes, they
become restructured so that
at the end of prophase I, each oogonium gets
enveloped by many layers of flat, follicular epithelial
cells (descendants of the
coelomic epithelium).
False (single layer of flat, follicular epithelial cells)
Oocyte + follicular epithelium
= ____________
primordial follicle
_________ + follicular epithelium
= primordial follicle
oocyte
Oocyte + _____________
= primordial follicle
follicular epithelium
Developmental sequence of a follicle
goes through various ________ stages
follicle
Primordial follicle -
__________ -
secondary follicle -
tertiary follicle (Graafian
follicle)
primary follicle
__________ -
primary follicle -
secondary follicle -
tertiary follicle (Graafian
follicle)
primordial follicle
Primordial follicle -
primary follicle -
_________ follicle -
tertiary follicle (Graafian
follicle)
secondary
Primordial follicle -
primary follicle -
secondary follicle -
________ follicle (Graafian
follicle)
tertiary
Tertiary follicle or the _________
Graafian follicle
Since a follicle can die at any
moment in its development
(= ________), not all reach the
tertiary follicle stage.
atresia
True or False
Since a follicle can die at any
moment in its development
(= atresia), not all reach the
tertiary follicle stage.
True
What are the two structures of the ovary?
Outer Cortex and Inner Medulla
Structures of the ovary
________(ovarian
cortex) – contains the oogenic
cells at different stages
outer cortex
Structure of the Ovary
Outer cortex (________ cortex) – contains the oogenic
cells at different stages
ovarian
Structure of the Ovary
Outer cortex (ovarian
cortex) – contains the _________ at different stages
oogenic cells
Structure of the Ovary
_________ (ovarian medulla) – stroma
predominates with arteries,
veins and capillaries
Inner Medulla
Structure of the Ovary
Inner Medulla (ovarian
medulla) – _________
predominates with arteries,
veins and capillaries
stroma
Follicle Stages in the Ovary
In the __________
the oocytes
are present
within
the various
follicle
stages.
cortical compartment
Follicle Stages in the Ovary
In the cortical
compartment
the oocytes
are present
within
the ______________.
various follicle stages
Found in clusters within the
circumference of the ovarian
cortex
Primordial follicle
Primordial Follicle
Found in clusters ______________ of the ovarian
cortex
within the circumference
Primordial Follicle
Found in clusters within the
circumference of the _________
ovarian cortex
In this follicle,
Oocytes are covered with a single
layer of flat follicle cells
Primordial
Primordial follicle:
__________ are covered with a single
layer of flat follicle cells
Oocytes
Covered with a single layer or
multilayer of cuboidal cells
but bigger oocytes; follicles
do not appear in clusters
Primary Follicle
True or False
Primary Follicle
Covered with a single layer or
multilayer of cuboidal cells
but bigger oocytes; follicles appear in clusters
False ( do not appear in clusters)
Seen more towards the
medulla and represent the
next advanced stage of follicle
Primary follicle
Primary follicle is seen more towards the _______ and represent the
next advanced stage of follicle
medulla
Characterized by more layers
of follicle cells around the
oocyte
• Vacuoles form within the
growing layers of follicle cells
• Fluid filled vacuoles coalesce
to form one big vacuole
=antrum in the mature follicle
Secondary Follicle
Secondary follicle
Characterized by more layers
of follicle cells around the
oocyte
• _________ form within the
growing layers of follicle cells
• Fluid filled vacuoles coalesce
to form one big vacuole
=antrum in the mature follicle
Vacuoles
Secondary Follicle
Characterized by more layers
of follicle cells around the
oocyte
• Vacuoles form within the
growing layers of follicle cells
• ____________ coalesce
to form one big vacuole
=antrum in the mature follicle
Fluid filled vacuoles
Secondary follicle
Characterized by more layers
of follicle cells around the
oocyte
• Vacuoles form within the
growing layers of follicle cells
• Fluid filled vacuoles _________
to form one big vacuole
=antrum in the mature follicle
coalesce
Secondary Follicle
Characterized by more layers
of follicle cells around the
oocyte
• Vacuoles form within the
growing layers of follicle cells
• Fluid filled vacuoles coalesce
to form one big vacuole
=_________ in the mature follicle
antrum
Secondary follicle
Characterized by more layers
of follicle cells around the
oocyte
• Vacuoles form within the
growing layers of follicle cells
• Fluid filled vacuoles coalesce
to form one big vacuole
=antrum in the _______ follicle
mature
Discover of Mature Graafian Follicle
Rainier de Graaf
Covered by a thick glycoprotein = zona pellucida
Mature Graafian Follicle
Mature Graafian Follicle is covered by a thick _________ = zona pellucida
glycoprotein
Mature Graafian Follicle is covered by a thick glycoprotein = __________
zona pellucida
Mature Graafian Follicle
___________ – many layers of follicle cells immediately surrounding the oocyte; follicles
cells sitting on the basement membrane
Granulosa cells
Mature Graafian Follicle
Granulosa cells – many layers of follicle cells
immediately surrounding the oocyte; ________ sitting on the basement membrane
follicle cells
Mature Graafian Follicle
Granulosa cells – many layers of follicle cells
immediately surrounding the oocyte; follicle cells sitting on the _______ _______
basement membrane
Mature Graafian Follicle
___________- hillock of granulosa cells at
the side of the follicle within which is the
growing oocyte
Cumulus oophorus
Mature Graafian Follicle
Cumulus oophorus- _______ __ _______ _______at the side of the follicle within which is the
growing oocyte
hillock of granulosa cells
Mature Graafian Follicle
Cumulus oophorus- hillock of granulosa cells at
the side of the follicle within which is the
_______ ________
growing oocyte
Mature Graafian Follicle
_______ _______ – made up of 2-3 layers of follicle/ granulosa cells immediately surrounding
the oocyte
Corona radiata
Mature Graafian Follicle
Corona radiata – made up of _____ layers of follicle/ granulosa cells immediately surrounding
the oocyte
2-3
Mature Graafian Follicle
Corona radiata – made up of 2-3 layers of
___________ immediately surrounding
the oocyte
follicle/granulosa cells
Mature Graafian Follicle
Corona radiata – made up of 2-3 layers of follicle/ granulosa cells immediately surrounding
the ________
oocyte
Mature Graafian Follicle
_________ – corresponds to the coalesced antral
vacuoles found in the earlier stage; cleft or cavity
Antrum
Mature Graafian Follicle
Antrum – corresponds to the coalesced antral
vacuoles found in the earlier stage; _______ or cavity
cleft
Mature Graafian Follicle
Antrum – corresponds to the ________ ________ ______ found in the earlier stage; cleft or cavity
coalesced antral vacuoles
___________ – fluid inside the
vacuole which contains hormones,
enzymes etc.
Liquor folliculi
___________– (Gk. – theke = case) or
capsule; 2-layered envelope
enclosing the follicle
Theca
Theca – (Gk. – ______ = case) or
capsule; 2-layered envelope
enclosing the follicle
theke
Theca – (Gk. – theke = ______) or
capsule; 2-layered envelope
enclosing the follicle
case
Theca – (Gk. – theke = case) or
________; 2-layered envelope
enclosing the follicle
capsule
Theca – (Gk. – theke = case) or
capsule; __ -layered envelope
enclosing the follicle
2
Theca
______ ______ – outer to the
basement membrane, 2-3 layers of
rounded cells, produce estrogen
together with the follicle cells
Theca interna
Theca
Theca interna – ______ to the
basement membrane, 2-3 layers of
rounded cells, produce estrogen
together with the follicle cells
outer
Theca
Theca interna – outer to the
basement membrane,______layers of
rounded cells, produce estrogen
together with the follicle cells
2-3
Theca
Theca interna – outer to the
basement membrane, 2-3 layers of
______ ______, produce estrogen
together with the follicle cells
rounded cells
Theca
Theca interna – outer to the
basement membrane, 2-3 layers of
______ ______, produce estrogen
together with the follicle cells
rounded cells
Theca interna – outer to the
basement membrane, 2-3 layers of
rounded cells, produce ______
together with the follicle cells
estrogen
Theca interna – outer to the
basement membrane, 2-3 layers of
rounded cells, produce estrogen
together with the ______ _____
follicle cells
_______– layers of fibers
outer to the theca interna
Theca externa
_______– layers of fibers
outer to the theca interna
Theca externa
Theca externa – layers of fibers
______ to the theca interna
outer
Theca externa – layers of _______
outer to the theca interna
fibers
Theca externa – layers of fibers
outer to the ________ _______
theca interna
_________ _______: theca interna +
theca externa
Theca folliculi
Theca folliculi : _________ +
theca externa
Theca interna
Theca folliculi : theca interna +
_______ ______
theca externa
________ – a form of
physiological cell death
brought about by different
causes such as hormonal
changes
Atresia
Distinguished by disorganized
granulosa with many necrotic
cells present
Atretic follicle
Atretic follicle is distinguished by __________ ________ with many necrotic cells present
disorganized granulosa
Atretic follicle is distinguished by disorganized granulosa with many _____ cells present
necrotic
___________ – (L=zona –
girdle; pellucida –
transparent) – thick white or
greenish envelope separating
the germ cell from the follicle
cells; probably secreted by
germ cell and follicle cells
together
Zona pellucida
_________ _______ – inner layer
of columnar follicle cells of the
cumulus oophorus
immediately adjacent to the
zona pellucida
Corona radiata
• After the oocyte is ovulated
• Follicles cells are converted to
big secretory cells =
granulosa lutein cells – yellow
in fresh state indicating lipid
secretions of the progesterone
Corpus luteum (yellow body)
Stages of development
of Corpus luteum
1.) Young
2.) Active
3.) Regressing
Stages of development of Corpus luteum
_______ – newly formed corpora
lutea; prominent cavity = remnant
of antrum; filled with blood
Young
Stages of development of Corpus luteum
______ - cavity is much reduced ;
bigger cells indicating they are
active secretory cells
active
Stages of development of corpus luteum
________ – corpus luteum is
invaded by fibers from the
stroma/ theca externa
Regressing
_________ ________
• The whole site of corpus
luteum replaced by dense
connective tissue appears
white or achromatic
(colorless)
• The scar tissue which was
originally occupied by the
growing follicle
Corpus albicans (white bodies)
The ovarian cycle: ______ ______
• Roughly 500’000 follicles that are
present in the two ovaries at the
beginning of sexual maturity,
• Only around 480 reach the
Graafian follicle stage and able to
release oocytes (ovulation)
• Derived by multiplying the
number of cycles per year (12)
and the number of years in which
a woman is fertile (40).
follicle maturation
The ovarian cycle:
follicle maturation
• Roughly ________ follicles that are
present in the two ovaries at the
beginning of sexual maturity,
• Only around 480 reach the
Graafian follicle stage and able to
release oocytes (ovulation)
• Derived by multiplying the
number of cycles per year (12)
and the number of years in which
a woman is fertile (40).
500,000
The ovarian cycle:
follicle maturation
• Roughly 500’000 follicles that are
present in the two ovaries at the
beginning of sexual maturity,
• Only around ______ reach the
Graafian follicle stage and able to
release oocytes (ovulation)
• Derived by multiplying the
number of cycles per year (12)
and the number of years in which
a woman is fertile (40).
480
The ovarian cycle:
follicle maturation
• Roughly 500’000 follicles that are
present in the two ovaries at the
beginning of sexual maturity,
• Only around 480 reach the
Graafian follicle stage and able to
release oocytes (ovulation)
• Derived by ___________
multiplying the
number of cycles per year (12)
and the number of years in which
a woman is fertile (40).
______ ________
• Hypothalamic-hypophysial (pituitary
gland) system with the two hypophysial
gonadotropins: FSH and LH - for a
normal control of the cyclic ovarian
function.
• Releases FSH and LH - both stimulate the
maturation of the follicles in the ovary
and trigger ovulation.
Hormonal Cycle
Hormonal Cycle
• _____________ with the two hypophysial
gonadotropins: FSH and LH - for a
normal control of the cyclic ovarian
function.
• Releases FSH and LH - both stimulate the
maturation of the follicles in the ovary
and trigger ovulation.
Hypothalamic-hypophysial (pituitary
gland) system
Hormonal Cycle
• Hypothalamic-hypophysial (pituitary
gland) system with the two hypophysial
gonadotropins: FSH and LH - for a
normal control of the cyclic ovarian
function.
• Releases FSH and LH - both stimulate the __________ in the ovary
and trigger ovulation.
maturation of the follicles
Hormonal Cycle
• Hypothalamic-hypophysial (pituitary
gland) system with the two hypophysial
gonadotropins: FSH and LH - for a
normal control of the cyclic ovarian
function.
• Releases FSH and LH - both stimulate the
maturation of the follicles in the ovary and trigger _______.
ovulation
During the ovarian cycle,
– ________ is produced by the theca
interna and follicular cells (follicle
phase)
– Progesterone produced by the
corpus luteum (luteal phase).
Estrogen
During the ovarian cycle,
– Estrogen is produced by the _______ _______ and follicular cells (follicle
phase)
– Progesterone produced by the
corpus luteum (luteal phase).
theca interna
During the ovarian cycle,
– Estrogen is produced by the theca
interna and _____ ______ (follicle
phase)
– Progesterone produced by the
corpus luteum (luteal phase).
follicular cells
During the ovarian cycle,
– Estrogen is produced by the theca
interna and follicular cells (follicle
phase)
– _________ produced by the
corpus luteum (luteal phase).
Progesterone
During the ovarian cycle,
– Estrogen is produced by the theca
interna and follicular cells (follicle
phase)
– Progesterone produced by the
_______ ________ (luteal phase).
corpus luteum
Comparison of
Vertebrate Ovaries
•Frog
–_________
in form
• Mammalian
–compact
and
almond-
shaped
saccular
Comparison of
Vertebrate Ovaries
•Frog
–saccular
in form
• Mammalian
- ________ and _________
compact and almond-shaped
________ Ovaries
Amorphous (formless) sac
containing ova or egg cells
at different stages of
development
• paired
• female gonads, glands that
produce eggs or ova and
secrete the female
hormone estrogen
• Immature ovary – contains
young egg cells – oogonia
• Mature ovary – contains
older cells – growing
oocytes and oogonia
Frog
_________ – loose connective
tissue surrounding the ovary
Theca interna – thin connective
tissue surrounding each oocyte;
derived from the extension of
theca externa
Follicle cells – small, flat, ovoid
cells located in between the
theca interna and the plasma
membrane of an oocyte
Theca externa
Theca externa – loose connective
tissue surrounding the ovary
_________ – thin connective
tissue surrounding each oocyte;
derived from the extension of
theca externa
Follicle cells – small, flat, ovoid
cells located in between the
theca interna and the plasma
membrane of an oocyte
Theca interna
Theca externa – loose connective
tissue surrounding the ovary
Theca interna – thin connective
tissue surrounding each oocyte;
derived from the extension of
theca externa
___________ – small, flat, ovoid
cells located in between the
theca interna and the plasma
membrane of an oocyte
Follicle cells
________ – clusters of small cells
with darkly stained nuclei and
homogeneous, compact
cytoplasm; at the periphery of the
cytoplasm
Growing oocytes – medium to
large-sized cells characterized by
large nucleus, large nucleoli, and
large amount of cytoplasm
Follicle cells – small, flat, ovoid cells
located in between the theca
interna and the plasma membrane
of an oocyte
Oogonia
Oogonia – clusters of small cells
with darkly stained nuclei and
homogeneous, compact
cytoplasm; at the periphery of the
cytoplasm
____________ – medium to
large-sized cells characterized by
large nucleus, large nucleoli, and
large amount of cytoplasm
Follicle cells – small, flat, ovoid cells
located in between the theca
interna and the plasma membrane
of an oocyte
Growing oocytes
Oogonia – clusters of small cells
with darkly stained nuclei and
homogeneous, compact
cytoplasm; at the periphery of the
cytoplasm
Growing oocytes – medium to
large-sized cells characterized by
large nucleus, large nucleoli, and
large amount of cytoplasm
_________ – small, flat, ovoid cells
located in between the theca
interna and the plasma membrane
of an oocyte
Follicle cells
Oocyte, HPO
• _______ ________ –
contain a large
nucleus or
germinal vesicle
containing
numerous
germinal spots or
nucleoli
Larger oocytes
_____
Loosely used and does not
always mean ovum
• Primary oocytes – annelids,
nemerteans, and molluscs
• Can be classified according to
the main patterns cleavage
– Holoblastic
– Meroblastic
Egg
Egg
Loosely used and does not
always mean ovum
• _____________ – annelids,
nemerteans, and molluscs
• Can be classified according to
the main patterns cleavage
– Holoblastic
– Meroblastic
Primary oocytes
Egg
Loosely used and does not
always mean ovum
• Primary oocytes – annelids,
nemerteans, and molluscs
• Can be classified according to
the main patterns cleavage
– ________
– _______
Holoblastic, Meroblastic
