The female reproductive system undergoes changes during adolescence with the onset of puberty between ages 8-13. The ovaries and uterus mature and menstrual periods begin. During ovulation, an egg is released from the ovaries and travels through the fallopian tubes where fertilization may occur. If fertilization does not occur, the uterine lining sheds and a period starts. The male reproductive system also changes during puberty between ages 9-14 as the testes mature and produce sperm and sex hormones. Sperm develop in the testes and travel through the epididymis for storage and maturation before being emitted during ejaculation.
3. Adolescence
Puberty
Burst of hormones activate maturation of
the gonads: ovaries
Begins: 8-13 yrs of age
Abnormally early = precocious puberty
Delayed =Primary Amenorrhea
4. Function of Female Reproductive
System
Produce sex hormones
Produce functioning gamates [ova]
Support & protect developing embryo
5. General Physical Changes
Axillary & pubic hair growth
Changes in body conformation [widening
of hips, development of breasts]
Onset of first menstrual period
[menarche]
Mental changes
7. ovaries
Each ovary is about the size and shape of an
almond. In young women the ovaries are
about 1½ - 2 inches long, 1 inch wide & 1/3
inch thick. After menopause they tend to
shrink.
they produce eggs (also called ova) every
female is born with a lifetime supply of eggs
they also produce hormones:
Estrogen & Progesterone
Male Homolog = testes
8.
9. oogenesis
when the girl becomes sexually mature,
the primary oocytes recommence their
development, usually one at a time and
once a month.
The primary oocyte grows much larger
and completes the meiosis I, forming a
large secondary oocyte and a small
polar body that receives little more than
one set of chromosomes.
10. oogenesis
In humans (and most vertebrates), the
first polar body does not go on to meiosis
II, but the secondary oocyte does proceed
as far as metaphase of meiosis II and
then stops.
Only if fertilization occurs will meiosis II
ever be completed. Entry of the sperm
restarts the cell cycle
11. fallopian tubes [uterine tubes]
stretch from the uterus to the ovaries and
measure about 8 to 13 cm in length.
range in width from about one inch at the end
next to the ovary, to the diameter of a strand of
thin spaghetti.
The ends of the fallopian tubes lying next to the
ovaries feather into ends called fimbria
Millions of tiny hair-like cilia line the fimbria and
interior of the fallopian tubes. The cilia beat in
waves hundreds of times a second catching the
egg at ovulation and moving it through the tube
to the uterine cavity.
Fertilization typically occurs in the fallopian tube
12.
13. uterus
pear-shaped muscular organ in the upper female
reproductive tract.
The fundus is the upper portion of the uterus
where pregnancy occurs.
The cervix is the lower portion of the uterus that
connects with the vagina and serves as a
sphincter to keep the uterus closed during
pregnancy until it is time to deliver a baby.
the uterus expands considerably during the
reproductive process. the organ grows to from 10
to 20 times its normal size during pregnancy.
14.
15. endometrium
Functional zone – layer closest to the
cavity – contains majority of glands.
Thicker portion – undergoes changes with
monthly cycle
Basal zone – layer just under
myometrium, attaches functional layer to
myometrial tissue, has terminal ends of
glands. Remains constant
16. Uterine arteries
Arcuate arteries - encircle endometrium
Radial arteries – connect arcuate to
straight
Straight arteries – deliver blood to basilar
zone
Spiral arteries – deliver blood to functional
zone
17. The Cervix
the lower portion or neck of the uterus.
The cervix is lined with mucus, the quality and quantity of
which is governed by monthly fluctuations in the levels of
the estrogen and progesterone.
When estrogen levels are low, the mucus tends to be thick
and sparse, hindering sperm from reaching the fallopian
tubes. But when an egg is ready for fertilization, estrogen
levels are high, the mucus then becomes thin and slippery,
offering a “friendly environment” to sperm
at the end of pregnancy, the cervix acts as the passage
through which the baby exits the uterus into the vagina.
The cervical canal expands to roughly 50 times its normal
width in order to accommodate the passage of the baby
during birth
18. The Vagina
vagin = sheath
a muscular, ridged sheath connecting the
external genitals to the uterus.
functions as a two-way street, accepting
the penis and sperm during intercourse
and roughly nine months later, serving as
the avenue of birth through which the new
baby enters the world
19.
20.
21. External genetalia
vulva—which runs from the pubic area downward to the
rectum.
Mons pubis or "mound of Venus" is the V-shaped area
covered with hair
Labia majora or "greater lips" are the part around the
vagina containing two glands (Bartholin’s glands)which
helps lubrication during intercourse. Male Homolog =
scrotum
Labia minora or "lesser lips" are the thin hairless ridges at
the entrance of the vagina, which joins behind and in front.
In front they split to enclose the clitoris
The clitoris is a small pea-shaped structure (equivalent to
penis in males ) It plays an important part in sexual
excitement in females. Male Homolog = penis
22. External genetalia
The urethral orifice or external urinary opening is
below the clitoris on the upper wall of the vagina
and is the passage for urine
The introitus or opening of the vagina is separate
from the urinary opening (unlike males) and
located below it.
The hymen is a thin cresentic fold of tissue which
partially covers the opening of the vagina.
medically it is no longer considered to be a 100%
proof of female virginity.
23.
24. Mammary Glands [ breasts]
Present in both sexes - normally only functional in
females
Developmentally they are derived from sweat glands
Contained within a rounded skin-covered breast anterior
to the pectoral muscles of the thorax
Slightly below center of each breast is a ring of pigmented
skin, the areola - this surrounds a central protruding
nipple
Internally - they consist of 15 to 25 lobes that radiate
around and open at the nipple
Each lobe is composed of smaller lobules- these contain
alveoli that produce milk when a women is lactating
non-pregnant women - glandular structure is undeveloped
- hence breast size is largely due to the amount of fat
deposits
25.
26. glands
Lesser Vestibular (Paraurethral, Skene's) Male
Homolog = prostate located on the upper wall of the
vagina, around the lower end of the urethra.
They drain into the urethra and near the urethral
opening Function - mucus production to aid
lubrication during intercourse
Greater Vestibular (Bartholin's) Male Homolog =
bulbourethral glands located slightly below and to the
left and right of the opening of the vagina. They
secrete mucus to provide lubrication, especially
when the woman is sexually aroused
27. Table 1. Production Rate of Sex Steroids in Women at Different Stages of the Menstrual Cycle
DAILY PRODUCTION RATE
SEX STEROIDS*
Early
Follicular
Preovulatory Midluteal
Progesterone (mg) 1 4 25
17-Hydroxyprogesterone
(mg)
0.5 4 4
Dehydroepiandrosterone
(mg)
7 7 7
Androstenedione (mg) 2.6 4.7 3.4
Testosterone (µg) 144 171 126
Estrone (µg) 50 350 250
Estradiol (µg) 36 380 250
From Baird DT. Fraser IS. Blood production and ovarian secretion rates of esuadiol-17β and estrone in women throughout the
menstrual cycle. J Clin Endocri-nol Metab 38: l009-1017. 1974. @ The Endocrine Society.
*Values are expressed in milligrams or micrograms per 24 hours.
28. The female hormones that control the cyclic growth and
shedding of the endometrium are estrogen and
progesterone.
Estrogen and progesterone are produced by the ovaries.
Estrogen causes the growth or proliferation of the
endometrium during the first 2 weeks of the menstrual
cycle.
After ovulation, the ovary produces progesterone.
Hormones and the menstrual
cycle
34. Adolescence
Puberty
Burst of hormones activate maturation of
the gonads: testes
Begins: 9 – 14 yrs of age
Abnormally early = precocious puberty
Delayed = eunuchoidism
35. General Physical Changes
Enlargement of the external and internal
genitalia
Voice changes
Hair growth
Mental changes
Changes in body conformation and skin
Sebaceous gland secretions
thicken/increase acne
37. Testes
Each testis is an oval structure about 5 cm long
and 3 cm in diameter
Covered by: tunica albuginea
Located in the scrotum
There are about 250 lobules in each testis. Each
contains 1 to 4 -seminiferous tubules that
converge to form a single straight tubule, which
leads into the rete testis.
Short efferent ducts exit the testes.
Interstitial cells (cells of Leydig), which produce
male sex hormones, are located between the
seminiferous tubules within a lobule.
38.
39.
40. scrotum
consists of skin and subcutaneous tissue
A vertical septum, of subcutaneous tissue in the center
divides it into two parts, each containing one testis.
Smooth muscle fibers, called the dartos muscle, in the
subcutaneous tissue contract to give the scrotum its
wrinkled appearance. When these fibers are relaxed, the
scrotum is smooth.
the cremaster muscle, consists of skeletal muscle fibers
and controls the position of the scrotum and testes.
When it is cold or a man is sexually aroused, this muscle
contracts to pull the testes closer to the body for
warmth.
41.
42. Epididymis
a long tube (about 6 meters) located along
the superior and posterior margins of the
testes.
Sperm that leave the testes are immature
and incapable of fertilizing ova. They
complete their maturation process and
become fertile as they move through the
epididymis. Mature sperm are stored in the
lower portion, or tail, of the epididymis
43. spermatic cord
contains the proximal ductus deferens,
testicular artery and veins, lymph vessels,
testicular nerve, cremaster muscle and a
connective tissue covering.
44. Ejaculatory Duct
Each ductus deferens, at the ampulla,
joins the duct from the adjacent seminal
vesicle (one of the accessory glands) to
form a short ejaculatory duct.
Each ejaculatory duct passes through the
prostate gland and empties into the
urethra.
45.
46. Urethra
extends from the urinary bladder to the
external urethral orifice at the tip of the
penis.
It is a passageway for sperm and fluids from
the reproductive system and urine from the
urinary system.
divided into three regions: The prostatic
urethra, the membranous urethra & the penile
urethra (also called spongy urethra or
cavernous urethra)
47. accessory glands
are the seminal vesicles, prostate gland,
and the bulbourethral glands. These
glands secrete fluids that enter the
urethra.
48. Seminal Vesicles
glands posterior to the urinary bladder.
Each has a short duct that joins with the
ductus deferens at the ampulla to form an
ejaculatory duct, which then empties into
the urethra.
The fluid is viscous and contains fructose,
prostaglandins and proteins.
49. Prostate
a firm, dense structure about the size of a
walnut that is located just inferior to the
urinary bladder.
encircles the urethra as it leaves the urinary
bladder.
Numerous short ducts from the prostate
gland empty into the prostatic urethra. The
secretions of the prostate are thin, milky
colored, and alkaline. They function to
enhance the motility of the sperm.
50. Bulbourethral Glands (Cowper's)
small, about the size of a pea, and located
near the base of the penis. A short duct
from each enters the proximal end of the
penile urethra.
In response to sexual stimulation, the
bulbourethral glands secrete an alkaline
mucus-like fluid
51.
52. Seminal Fluid or Semen
a slightly alkaline mixture of sperm cells and
secretions from the accessory glands.
Secretions from the seminal vesicles make up
about 60 percent of the volume of the semen,
with most of the remainder coming from the
prostate gland. The sperm and secretions from
the bulbourethral gland contribute only a small
volume.
The volume of semen in a single ejaculation may
vary from 1.5 to 6.0 ml. There are between 50 to
150 million sperm per milliliter of semen. Sperm
counts below 10 to 20 million per milliliter usually
present fertility problems.
53. penis
is a cylindrical pendant organ located anterior
to the scrotum and functions to transfer
sperm to the vagina.
consists of three columns of erectile tissue
that are wrapped in connective tissue and
covered with skin. The two dorsal columns
are the corpora cavernosa. The single,
midline ventral column surrounds the urethra
and is called the corpus spongiosum.
54. penis
3 parts: a root, body (shaft), and glans penis.
The root of the penis attaches it to the pubic arch
the body is the visible, pendant portion.
The corpus spongiosum expands at the distal end
to form the glans penis.
The urethra, which extends throughout the length
of the corpus spongiosum, opens through the
external urethral orifice at the tip of the glans
penis. A loose fold of skin, called the prepuce, or
foreskin, covers the glans penis.
55.
56. Erection
Involves increase in length, width &
firmness
Changes in blood supply: arterioles dilate,
veins constrict
The spongy erectile tissue fills with blood
Erectile Dysfunction [ED] also known as
impotence
57. Hormones
Follicle-stimulating hormone (FSH)
stimulates spermatogenesis
Interstitial Cell Stimulating Hormone
(ICSH) stimulates the production of
testosterone
testosterone stimulates the development
of male secondary sex characteristics &
spermatogenesis.
58.
59. Spermatogenesis
Sperm are produced within the
seminiferous tubules.
Interspersed within the tubules are large
cells which are the sustentacular cells
(Sertoli's cells), which support and nourish
the other cells.
60. Spermatogenesis
Each primary spermatocytes goes through the first meiotic
division, meiosis I, to produce two secondary
spermatocytes, each with 23 chromosomes (haploid). Just
prior to this division, the genetic material is replicated
During meiosis I, one chromosome, goes to each secondary
spermatocyte. In the second meiotic division, meiosis II,
each secondary spermatocyte divides to produce two
spermatids. There is no replication of genetic material in
this division, but a single-stranded chromatid goes to each
cell.
As a result of the two meiotic divisions, each primary
spermatocyte produces four spermatids.
each spermatid has 23 chromosomes (haploid), one from
each pair in the original primary spermatocyte.
61.
62. Spermatogenesis
The final step in the development the spermatids
formed from spermatogenesis become mature
spermatozoa, or sperm.
The mature sperm cell has a head, midpiece,
and tail. The head, also called the nuclear region,
contains the 23 chromosomes surrounded by a
nuclear membrane. The tip of the head is covered
by an acrosome, which contains enzymes that
help the sperm penetrate the female gamete. The
midpiece, metabolic region, contains
mitochondria that provide adenosine triphosphate
(ATP). The tail, locomotor region, uses a typical
flagellum for locomotion.
63.
64.
65. Spermatogenesis
The sperm are released into the lumen of the
seminiferous tubule and leave the testes. They
then enter the epididymis where they undergo
their final maturation and become capable of
fertilizing a female gamete.
Sperm production begins at puberty and
continues throughout the life of a male.
The entire process, beginning with a primary
spermatocyte, takes about 74 days. After
ejaculation, the sperm can live for about 48 hours
in the female reproductive tract.
Hinweis der Redaktion
They are among the first organs to be formed as a female baby develops in the uterus. At the 20-week mark, the structures that will become the ovaries house roughly 6 to 7 million potential egg cells. From that point on, the number begins to decrease rapidly. A newborn infant has between 1 million to 2 million egg cells. By puberty the number has plummeted to 300,000. For every egg that matures and undergoes ovulation, roughly a thousand will fail, so that by menopause, only a few thousand remain. During the course of an average reproductive lifespan, roughly 300 mature eggs are produced for potential conception.
The ovaries produce these hormones throughout the fertile period of a woman's life. It is the hormones that control the menstrual cycle. As you get older and menopause approaches, the ovaries make less and less of these hormones and the periods eventually stop altogether.
So the normal ovaries cannot usually be felt in a clinical examination except in young, thin women.
The ovaries are the main source of female hormones (estrogen and progesterone). These hormones control the development of female body characteristics, such as the breasts, body shape, and body hair. They also regulate the menstrual cycle and pregnancy.
What is estrogen?
Estrogen is a group of female sex hormones that stimulate the appearance of secondary female sex characteristics in girls at puberty. Estrogen controls controls the growth of the lining of the uterus during the first part of the menstrual cycle, cause breast development in pregnancy and regulates various metabolic processes.
Which chromosomes end up in the egg and which in the polar body is entirely a matter of chance.
(4 to 6 inches) = length
called fimbria (Latin for "fringes" or "fingers").each tube has about about 20 to 25
Millions of tiny hair-like cilia line the fimbria and interior of the fallopian tubes. The cilia beat in waves hundreds of times a second catching the egg at ovulation and moving it through the tube to the uterine cavity. Other cells in the tube's inner lining or endothelium nourish the egg and lubricate it's path during its stay inside the fallopian tube. Once inside the fallopian tube, the egg and sperm meet and the egg is fertilized. If an egg doesn't become fertilized within 24 to 36 hours after ovulation, it will deteriorate and be removed by the body's immune system like any other dead cell in the body.
Size = 3 in long x2 inch diameter
Weighs about 1-1.5 oz
Pregnancy – watermelon sized
Each month the uterus goes through a cyclical change, first building up its endometrium or inner lining to receive a fertilized egg, then, if conception does not occur, shedding the unused tissue through the vagina in the monthly process called menstruation
The vagina ends at the cervix,
(cervical mucus changes: employed by birth control pills, shots and implants. One of the ways they prevent conception is to render the cervical mucus thick, sparse, and hostile to sperm.)
It was thought to be proof of virginity as it is broken after the first sexual intercourse. However it is stretchable, and may break due to vigorous exercises, cycling, gymnastics or tampon use.Therefore
Large sebaceous glands in the areola make it slightly bumpy & produce sebum that reduces chapping and cracking of the skin of the nipple
Autonomic NS controls smooth muscle fibers in the areola and nipple cause the nipple to become erect when stimulated by tactile or sexual stimuli & when exposed to the cold
Lobes are padded & separated from each other by fibrous connective tissue and fat
The connective tissue forms suspensory ligaments that attach the breast to the underlying muscle fascia
Progesterone causes the endometrial glands to secrete nutritive substances required by the embryo and to allow it to implant into the endometrial lining.
If fertilization and implantation do not occur, the progesterone falls and the endometrial lining is sloughed off - resulting in menstrual bleeding. If fertilization and implantation do occur, then the ovary continues producing progesterone and the endometrium remains intact to support embryo development and pregnancy.After ovulation, in the space where the egg used to be, a second small cystic area known as the corpus luteum develops and begins to secrete progesterone. The corpus luteum eventually gets reabsorbed by the ovary.
Once a mature egg has begun its trip through the fallopian tube, remnants of the winning follicle form the corpus luteum, or “yellow body.” Progesterone from the corpus luteum halts development of the remaining follicles and brings the lining of the uterus to peak preparedness.
Meanwhile, the follicle that held the egg still has a critical role to play. First it shrinks markedly, then begins to accumulate fatty substances, or lipids, that give it a yellowish tinge. The resulting structure, now called the corpus luteum (yellow body), produces progesterone and estradiol, two of the hormones critical to reproduction.
In a non-pregnant woman, the corpus luteum lasts for about 14 days, after which it shrinks and dries up, eventually becoming a speck of fibrous scar tissue. If conception occurs, however, a hormone from the developing placenta, which surrounds the baby in the uterus, stimulates the corpus luteum to maintain its production of progesterone during the first trimester of pregnancy
period when the endocrine and gamete – producing functions of the gonads have first developed to where reproduction is possible
the tunica albuginea, surrounds each testis and extends inward to form septa that partition the organ into lobules There are about 250 lobules in each testis. Each contains 1 to 4 highly coiled seminiferous tubules that converge to form a single straight tubule, which leads into the rete testis. Short efferent ducts exit the testes.
Interstitial cells (cells of Leydig), which produce male sex hormones, are located between the seminiferous tubules within a lobule
A vertical septum, or partition, of subcutaneous tissue in the center divides it into two parts, each containing one testis.
Smooth muscle fibers, called the dartos muscle, in the subcutaneous tissue contract to give the scrotum its wrinkled appearance. When these fibers are relaxed, the scrotum is smooth.
the cremaster muscle, consists of skeletal muscle fibers and controls the position of the scrotum and testes. When it is cold or a man is sexually aroused, this muscle contracts to pull the testes closer to the body for warmth
a long tube (about 6 meters) that is tightly coiled to form a comma-shaped organ located along the superior and posterior margins of the testes.
Sperm that leave the testes are immature and incapable of fertilizing ova. They complete their maturation process and become fertile as they move through the epididymis. Mature sperm are stored in the lower portion, or tail, of the epididymis
It is a passageway for sperm and fluids from the reproductive system and urine from the urinary system. While reproductive fluids are passing through the urethra, sphincters contract tightly to keep urine from entering the urethra.
saccular glands posterior to the urinary bladder.
Each gland has a short duct that joins with the ductus deferens at the ampulla to form an ejaculatory duct, which then empties into the urethra.
The fluid is viscous and contains fructose, which provides an energy source for the sperm; prostaglandins, which contribute to the mobility and viability of the sperm; and proteins that cause slight coagulation reactions in the semen after ejaculation.
a firm, dense structure that is located just inferior to the urinary bladder.
It is about the size of a walnut and encircles the urethra as it leaves the urinary bladder.
Numerous short ducts from the substance of the prostate gland empty into the prostatic urethra. The secretions of the prostate are thin, milky colored, and alkaline. They function to enhance the motility of the sperm.
small, about the size of a pea, and located near the base of the penis. A short duct from each gland enters the proximal end of the penile urethra.
In response to sexual stimulation, the bulbourethral glands secrete an alkaline mucus-like fluid. This fluid neutralizes the acidity of the urine residue in the urethra, helps to neutralize the acidity of the vagina, and provides some lubrication for the tip of the penis during intercourse.
a slightly alkaline mixture of sperm cells and secretions from the accessory glands. Secretions from the seminal vesicles make up about 60 percent of the volume of the semen, with most of the remainder coming from the prostate gland. The sperm and secretions from the bulbourethral gland contribute only a small volume.
The volume of semen in a single ejaculation may vary from 1.5 to 6.0 ml. There are between 50 to 150 million sperm per milliliter of semen. Sperm counts below 10 to 20 million per milliliter usually present fertility problems. Although only one sperm actually penetrates and fertilizes the ovum, it takes several million sperm in an ejaculation to ensure that fertilization will take place.
the male copulatory organ, is a cylindrical pendant organ located anterior to the scrotum and functions to transfer sperm to the vagina.
consists of three columns of erectile tissue that are wrapped in connective tissue and covered with skin. The two dorsal columns are the corpora cavernosa. The single, midline ventral column surrounds the urethra and is called the corpus spongiosum.
spongy erectile tissue is a loose network of connective tissue with many spaces
ED – inability to achieve or maintain an erection
Affects approx. 30 mil men in USA. Not unusual to experience sometime – usually due to psychological problems: stress, depression, worrying, grief
Physical problems: nerve damage – usually accompanying diabetes or alcoholism
Atherosclerosis [fatty deposits] in arteries supplying penis
medications: HTN, antihistamines, antinausea & antiseizure, antidepressants, sedatives, tranquilzers
Cigarettes, marijuana & alcohol
Treat ED – eliminate problem. Medications: Viagra type enhance nitric oxide that is released with arousal and caused arterioles to dilate
Sperm are produced within the seminiferous tubules. A transverse section of a seminiferous tubule shows that it is packed with cells in various stages of development. Interspersed with these cells, there are large cells that extend from the periphery of the tubule to the lumen. These large cells are the supporting, or sustentacular cells (Sertoli's cells), which support and nourish the other cells
Each primary spermatocytes goes through the first meiotic division, meiosis I, to produce two secondary spermatocytes, each with 23 chromosomes (haploid). Just prior to this division, the genetic material is replicated so that each chromosome consists of two strands, called chromatids, that are joined by a centromere.
During meiosis I, one chromosome, consisting of two chromatids, goes to each secondary spermatocyte. In the second meiotic division, meiosis II, each secondary spermatocyte divides to produce two spermatids. There is no replication of genetic material in this division, but the centromere divides so that a single-stranded chromatid goes to each cell. As a result of the two meiotic divisions, each primary spermatocyte produces four spermatids.
During spermatogenesis there are two cellular divisions, but only one replication of DNA so that each spermatid has 23 chromosomes (haploid), one from each pair in the original primary spermatocyte. Each successive stage in spermatogenesis is pushed toward the center of the tubule so that the more immature cells are at the periphery and the more differentiated cells are nearer the center.
The final step in the development of sperm is called spermiogenesis. In this process, the spermatids formed from spermatogenesis become mature spermatozoa, or sperm.
The mature sperm cell has a head, midpiece, and tail. The head, also called the nuclear region, contains the 23 chromosomes surrounded by a nuclear membrane. The tip of the head is covered by an acrosome, which contains enzymes that help the sperm penetrate the female gamete. The midpiece, metabolic region, contains mitochondria that provide adenosine triphosphate (ATP). The tail, locomotor region, uses a typical flagellum for locomotion.
The sperm are released into the lumen of the seminiferous tubule and leave the testes. They then enter the epididymis where they undergo their final maturation and become capable of fertilizing a female gamete.
Sperm production begins at puberty and continues throughout the life of a male. The entire process, beginning with a primary spermatocyte, takes about 74 days. After ejaculation, the sperm can live for about 48 hours in the female reproductive tract.