Transcript Female Reproductive System

Reproductive Hormones
Reproductive Hormones
Sex hormones are synthesized from
cholesterol (a fatty acid) and secreted
throughout a person's lifetime at different
levels.
 Male gonads (testes) produce sperm.
 Female gonads (ovaries) produce egg.
 Fusion of egg and sperm occur via
fertilization to produce a zygote.
 The zygote undergoes division to become
an embryo, which eventually becomes a
fetus.
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Male Reproductive System
Male Reproductive System
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Sex hormones: androsterone and testosterone.
Functions of Testosterone:
Testosterone is a male hormone which is produced by
the testes.once a boy reaches puberty. It triggers the
changes in a boy's body which turn him from a boy to
a man.
 * Functions of androsterone:
The function of the androsterone receptor protein is
to stimulate transcription of certain genes in
response to a hormone signal.
Male Reproductive System
Hypothalamus and pituitary gland control
production of sperm and sex hormones in the
testes.
 Anterior pituitary produces and stores:
The anterior pituitary produces six major
hormones, and the posterior pituitary stores
two hormones originating in the hypothalamus.
The pituitary's target endocrine glands are the
thyroid, adrenal gland, and the gonads.
Through these glands it Controls on the
development of sexual organs and Physical
properties that distinguish men from women
sound and body shape and size.
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Male Reproductive System
At puberty, hypothalamus secretes
gonadotropin-releasing hormone (GnRH).
 GnRH activates anterior pituitary to release
Follicle-stimulating hormone (FSH) and
Luteinizing hormone (LH).
 LH stimulates the development of the
testes.
 FSH activates the testes' sperm-forming cells"
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Once high levels of testosterone are
detected by the hypothalamus, a negative
feedback system is activated.
 Testosterone inhibits LH production by the
pituitary by deactivating the hypothalamus.
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Male Reproductive System
Negative Feedback for
FSH and LH.
Female Reproductive System
Female Reproductive System
Sex hormones:
Estrogen
Progesterone
Female Reproductive System
Oogenesis and Ovulation
 Ovaries contain fibrous CT and groups of
cells called follicles.
 Follicles: Primary oocyte (undergoes
meiosis to form ovum) and granulosa
cells (provides nutrition for oocyte).
 Each ovary contains 400 000 follicles at
puberty…many develop during each cycle,
but only one reaches maturity.
Female Reproductive System
Female Reproductive System
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FSH & LH released.
FSH stimulates growth of an ovarian body
LH also promotes growth of the corpus luteum (a yellow,
progesterone-secreting mass of cells that forms from an
ovarian follicle after the release of a mature egg) as the
ovary prepares to release the egg into the uterus.
Granulosa cells divide.
Primary oocyte undergoes meiosis I to form a secondary
oocyte and polar body.
As granulosa cells grow around the secondary oocyte, a
fluid-filled cavity forms (antrum).
Secondary oocyte presses against and eventually
ruptures the ovarian wall.
Female Reproductive System
Secondary oocyte released from ovary
and enters fallopian tubes.
 Remaining follicle cells form the corpus
luteum.
 If pregnancy does not occur within 10
days, the corpus luteum degenerates and
leaves a scar (corpus albicans).
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Female Reproductive System
After ovulation, the secondary oocyte
begins meiosis II.
 Unequal division occurs to form an egg
(ovum) and a polar body.
 Overall…one primary oocyte becomes 1
ovum and 3 polar bodies (discarded).
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Female Reproductive System
Female Reproductive System
Menstrual Cycle
 28 days.
 4 phases:
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menstruation
 follicular
 ovulation
 luteal
Female Reproductive System
Flow Phase (days 1 to 5)
 Shedding of endometrium (menstruation).
 Used to mark beginning of menstrual
cycle.
Female Reproductive System
Follicular Phase (days 6 to 13)
 Development of follicles in ovary.
 Estrogen secreted.
 Triggers
thickening of endometrium.
Female Reproductive System
Ovulatory Phase (day 14)
 Secondary oocyte released from ovary.
 Corpus luteum develops.
Female Reproductive System
Luteal Phase (days 15 to 28)
 Corpus luteum secretes estrogen and
progesterone.
 Progesterone
continues to stimulate growth of
endometrium and prepares uterus for an
embryo.
Female Reproductive System
If fertilization of ovum does not occur,
concentration of estrogen and
progesterone decreases.
 Weak uterine contractions cause
endometrium to pull away from uterine
wall.
 The shedding of the endometrium marks
the beginning of the next cycle.
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Female Reproductive System
Female Reproductive
System
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FSH & LH regulate control
of estrogen and
progesterone.
Estrogen and progesterone
control the FSH & LH.
*Males and females both have male and
female sex hormones, but in varying
levels.
‫‪ ‬عمل الطالب‪:‬‬
‫‪ ‬محمد احمد مهاجري‬
‫‪ ‬ماجد االسمري‬
‫‪ ‬هاني الغامدي‬
‫‪ ‬مشاري الحربي‬
‫‪ ‬فيصل المالكي‬
‫تحت اشراف‪ :‬د‪ .‬عبدالرحمن العجالن‬