Upload
james-dauray
View
214
Download
0
Embed Size (px)
Citation preview
7/30/2019 Reproductive System Powerpoint Lecture
1/55
7/30/2019 Reproductive System Powerpoint Lecture
2/55
The gonads are the primary sex organs. Gonads produce gametes, or sex cells, and
sex hormones.
In males, the testes are the gonads and sperm arethe gametes.
7/30/2019 Reproductive System Powerpoint Lecture
3/55
7/30/2019 Reproductive System Powerpoint Lecture
4/55
7/30/2019 Reproductive System Powerpoint Lecture
5/55
The hormones required to stimulate andmaintain spermatogenesis are not fullyproduced until puberty.
Testosterone
Follicle-Stimulating Hormone (FSH) Spermatogenesis is also highly sensitive to
temperature changes. Optimal temperature is 2C below body
temperature.
Testes are kept in an external scrotum to maintain
this temperature.
7/30/2019 Reproductive System Powerpoint Lecture
6/55
A sperm stem cell,located in the
seminiferous tubules,undergoes mitosis,producing two exactcopies
One copy remains theseminiferous tubule.
One copy begins to migrate
towards the epididymis.
7/30/2019 Reproductive System Powerpoint Lecture
7/55
The sperm stem cellcopy undergoes
meiosis, whichresults in theproduction offourgenetically differentcells with only halfthe normal numberof chromosomes.
7/30/2019 Reproductive System Powerpoint Lecture
8/55
As the sperm cellsmature, they
develop threebody regions,including a head,body, and tail.
7/30/2019 Reproductive System Powerpoint Lecture
9/55
The vas deferens is a ductthat transports maturedsperm from the epididymis
to the ejaculatory duct. Sperm move by peristalsis,
the same rhythmiccontraction of smoothmuscles seen in theesophagus and intestines.
Sperm can also be stored in
the vas deferens.
7/30/2019 Reproductive System Powerpoint Lecture
10/55
7/30/2019 Reproductive System Powerpoint Lecture
11/55
UrinaryBladder
Symphysis
Pubis (Pelvis)Seminal Vesicle
Ejaculatory Duct
Rectum
Bulbourethral
Gland
Epididymis
Testicle
Scrotum
Urethra
Erectile
Tissue
Vas Deferens
Prostate
7/30/2019 Reproductive System Powerpoint Lecture
12/55
Three accessory glands secrete different substancesinto the sperm cells. This is called semen.
The seminal vesicles produce the majority (60%) of
semen. Their secretion contains: Fructose Provides nourishment for sperm cells. Prostaglandins stimulate smooth muscle contractions
along the male and female reproductive tract. Fibrinogen- Causes semen to temporarily clot inside the
vagina (so it doesnt leak back out). Alkaline Secretions Neutralizes acids produced by the
prostate gland and vagina. The is the beginning ofcapacitation (activation of
sperm cells)
7/30/2019 Reproductive System Powerpoint Lecture
13/55
The prostate gland secretes a milky fluid thatcontinues capacitation. (20-30% of semen)
This secretion adds fluid to the semen and containsnutrients to aid the sperm.
The bulbourethral gland adds a thick alkalinemucus (pre-ejaculate) to the semen.
This makes for easier transport through the urethra
and into the female and also neutralizes the acidity
of the urethra and vagina.
7/30/2019 Reproductive System Powerpoint Lecture
14/55
Made up of 3 major components
1. Spermatozoa- 20 million to 100 million sperm
per milliliter of semen 2. Seminal Fluid- fluid components produced by
the accessory glands.
3. Enzymes- important enzymes that dissolve
mucous secretions in the vagina, kill bacteria, andcause semen to clot.
7/30/2019 Reproductive System Powerpoint Lecture
15/55
The penis is the external male reproductiveorgan.
The erectile tissue of the penis is made oftwo large tubular structures that, when filledwith blood, produce an erection.
The urethra carries both urine and semen outthe penis.
7/30/2019 Reproductive System Powerpoint Lecture
16/55
Ejaculation of sperm and semen, which occurs aftera period of sexual stimulation, occurs in thefollowing order:
1. Sperm is released from the epididymis.2. Fluid is added from the seminal vesicles. Semen enters
the ejaculatory duct.Point of no return.
3. The prostate and bulbourethral glands add theirsecretions and sperm is expelled from the body.
During this time, the entrance from the bladder tothe urethra is closed, preventing sperm from
moving into the urinary tract.
7/30/2019 Reproductive System Powerpoint Lecture
17/55
In humans, adult men whochoose to be surgically
sterilized can have avasectomy, which severs thevas deferens above eachtesticle.
The male will still maketestosterone and semen as usual,
but sperm cells will not leave the
epididymis.
7/30/2019 Reproductive System Powerpoint Lecture
18/55
7/30/2019 Reproductive System Powerpoint Lecture
19/55
7/30/2019 Reproductive System Powerpoint Lecture
20/55
The gonads of the femalereproductive system are the
ovaries. The gametes are the ova, or
egg cells.
7/30/2019 Reproductive System Powerpoint Lecture
21/55
The female reproductive system is responsible forproducing an ovum on a regular cycle, providing aplace for fertilization, implantation of the embryo,
and nourishing the fetus until it is ready for birth.
7/30/2019 Reproductive System Powerpoint Lecture
22/55
Ovary Fallopian Tube
Sacrum Ligament
ndometrium Myometrium
Bladder
Symphysis Pubis
Clitoris
VaginaAnus
Rectum
Urethra
Cervix
7/30/2019 Reproductive System Powerpoint Lecture
23/55
Ovary
Fallopian Tube
Myometrium
Endometrium
Cervix
Vagina
7/30/2019 Reproductive System Powerpoint Lecture
24/55
Each ovary is composed of hundreds of sac-like structures called follicles.
Each follicle consists of: An oocyte, or an immature egg cell.
Follicular cells, which produce the female
reproductive hormones.
7/30/2019 Reproductive System Powerpoint Lecture
25/55
Before birth, mitosis occurs inside the ovaries.
This produces all the oocytes the woman willneed in her lifetime.
These oocytes will not be released until puberty,when the brain releases follicle stimulating
hormone (FSH).
7/30/2019 Reproductive System Powerpoint Lecture
26/55
Every 28 days, one oocyte inside a follicle in one of the ovaries
begins to grow and mature. Meiosis begins, just like with sperm cells, but occurs in two separate
stages.
When Meiosis I occurs, one daughter cell receives most of thecytoplasm. This will be the oocyte. The other daughter cell receiveslittle, and is called the polar body.
The polar body degenerates, while the oocyte matures.
7/30/2019 Reproductive System Powerpoint Lecture
27/55
When the oocyte is mature, the follicleruptures, and it is released. This is ovulation.
The mature egg cell, called an ovum, beginstravelling down the fallopian tubes, headingtowards the uterus.
7/30/2019 Reproductive System Powerpoint Lecture
28/55
The ovum is gradually moved towards theuterus by the movement ofcilia.
The ovum lives for about 24 hours, sofertilization must occur here.
7/30/2019 Reproductive System Powerpoint Lecture
29/55
The ovum eventually reachesthe uterus, located betweenthe bladder and the rectum.
The uterus is a small muscular
pear shaped organ roughly 3inches long.
It is held in place by variousligaments.
The uterus is composed of 3layers of tissue. Endometrium (inner),
myometrium (middle),perimetrium (outer)
7/30/2019 Reproductive System Powerpoint Lecture
30/55
The uterus has four main functions, alldirectly related to a fertilized ovum.
Receiving the egg. Attaching to and holding the egg.
Nourishing the egg as it grows into a fetus.
Ejecting the fetus at birth
If the ovum is not fertilized, it is expelled outthe vagina along with the lining of the uterus.This is menstruation.
7/30/2019 Reproductive System Powerpoint Lecture
31/55
The cervix is a narrow canal that leads from theuterus into the vagina.
The vagina then leads to the exterior of the body.
Functions of the vagina include: The birth canal for a full-term fetus. Receiving the penis during sexual intercourse.
The vagina normally contains resident bacteria
in the cervical mucus. The metabolic activity of these bacteria create an
acidic environment which restricts the growth ofother, harmful pathogens.
7/30/2019 Reproductive System Powerpoint Lecture
32/55
The female reproductive system undergoes twomajor changes every 28 days:
A new oocyte matures into an ovum and is released. The wall of the uterus thickens with blood vessels, in
anticipation of a fertilized embryo.
All of the changes that occur during this 28 day
time period (on average) are called themenstrual cycle.
Can extend up to 35 days in healthy individuals
7/30/2019 Reproductive System Powerpoint Lecture
33/55
The Menstrual Phase ( Days 1-5 )
The thickened outer layer of the endometrium sheds,causing a blood-like secretion.
During this time, follicles in the ovary start growing andproducing estrogen.
The Proliferative Phase ( Days 6-14)
The follicles in the ovary continue growing. Estrogen levels will peak.
Whichever follicle produces a mature ovum first will ovulate.
The walls of the endometrium are repaired by multiplication
of epithelial cells.
7/30/2019 Reproductive System Powerpoint Lecture
34/55
The Secretory Stage ( Days 15-28 )
Once the ovum is released, the remaining folliculartissue begins producing a hormone called
progesterone. Progesterone stimulates the outer lining of the
endometrium to thicken and uterine glands increasetheir rates of secretion. This peaks around 12 days after ovulation
If fertilization occurs, the embryo will produce ahormone that stimulates the continued production ofprogesterone. The pregnancy hormone
7/30/2019 Reproductive System Powerpoint Lecture
35/55
7/30/2019 Reproductive System Powerpoint Lecture
36/55
If fertilization does not occur, thefollicular tissue degenerates, theuterine lining breaks down, andthe cycle repeats.
The most fertile point in thewomans cycle is the days
immediately following ovulation. This timing is not consistent,
however, and can vary by severaldays with each cycle.
The Woman ofWilldendorf22,000-21,000 BCE.
Fertility statue.
7/30/2019 Reproductive System Powerpoint Lecture
37/55
The birth control pill is taken daily,and comes in 4-week packs.
21 of the pills contain a combination ofprogesterone and estrogen.
7 of the pills are placebos, given tomaintain the daily habit of taking the pill.
The two hormones inhibit the brainfrom producing FSH, preventing afollicle (and ovum) from developing.
7/30/2019 Reproductive System Powerpoint Lecture
38/55
Humans have a surgery called tubal ligation,where the fallopian tubes are cut and tied off,preventing ova from reaching the uterus.
Complications from this surgery are more likely thanfrom a vasectomy.
In domesticated animals, spaying removes theovaries.
7/30/2019 Reproductive System Powerpoint Lecture
39/55
7/30/2019 Reproductive System Powerpoint Lecture
40/55
7/30/2019 Reproductive System Powerpoint Lecture
41/55
Sperm cells have three distinct regions:
The head contains the DNA and a specialized
organelle called the acrosome. The acrosome is a large, specialized lysosome that
contains enzymes to help the sperm penetrate the outerlayer of the egg cell.
The midpiece is wrapped by mitochondria togenerate ATP for movement.
The tail is a flagella used for movement.
7/30/2019 Reproductive System Powerpoint Lecture
42/55
Sperm swim up through the cervix, uterus, andinto the oviducts.
When one sperm fertilizes the egg, it begins the
second phase of meiosis. Its cell membrane alsochanges, preventing any other sperm cells fromentering.
The ovum again gets most of the cytoplasm,leaving a polar body behind to degenerate.
The 23 chromosomes of the sperm and egg cellcombine into one nucleus, forming a zygote.
7/30/2019 Reproductive System Powerpoint Lecture
43/55
The zygote will begin undergoing mitosis within 24hours of fertilization.
The cell keeps dividing for about 7 days until it finallyimplants into the uterus.
7/30/2019 Reproductive System Powerpoint Lecture
44/55
When the embryo implants into the uterus, itis a ball of about 100 cells called a blastocyst.
The blastocyst secretes a hormone thatstimulates the ovaries to continue producingprogesterone.
7/30/2019 Reproductive System Powerpoint Lecture
45/55
The uterus will generate theplacenta, the amniotic fluid,and the umbilical cord at this
time. The placenta forms a blood
barrier between the motherand embryo.
Nutrients, oxygen, and waste areexchanged, but blood is not. The placenta also takes over the
role of producing progesterone forthe remainder of the pregnancy.
7/30/2019 Reproductive System Powerpoint Lecture
46/55
7/30/2019 Reproductive System Powerpoint Lecture
47/55
Third Trimester
Eyes open.
Arms and legs are at the finalproportions.
Skin and hair develop.
Subcutaneous fat develops.
7/30/2019 Reproductive System Powerpoint Lecture
48/55
Multiple anatomical changes occurin the mother during pregnancy.
The uterus enlarges to accommodatethe fetus.
The ligaments of the pelvis relax.
Curvature of the lumbar vertebrae
increases.
7/30/2019 Reproductive System Powerpoint Lecture
49/55
Digestive System
Morning sickness caused by increased
hormones. Heartburn due to the fetus crowding
the stomach.
Constipation due to progesterone
relaxing smooth muscles throughoutthe body.
(Decreases peristalsis)
7/30/2019 Reproductive System Powerpoint Lecture
50/55
Urinary System
Kidneys process more
blood and produce moreurine.
Fetus crowds the bladder.
7/30/2019 Reproductive System Powerpoint Lecture
51/55
Respiratory System
Lung capacity and respiratory rate increase.
Cardiovascular System Blood volume increases.
Blood pressure and pulse rate increase.
7/30/2019 Reproductive System Powerpoint Lecture
52/55
As birth initiates, estrogen levels rise and theuterus begins contracting.
The cervix dilates up to 10cm in diameter. The amniotic sac ruptures.
Breaking the water.
7/30/2019 Reproductive System Powerpoint Lecture
53/55
Once the cervix issufficiently dilated,
expulsion can begin. Infant exits the body
through the cervixand vagina.
Normal delivery ishead first.
7/30/2019 Reproductive System Powerpoint Lecture
54/55
The last stage is the placental stage, wherethe placenta, umbilical cord, and afterbirth
are expelled.
7/30/2019 Reproductive System Powerpoint Lecture
55/55
The entire design of both the male and femalereproductive system, hormones, organs, fluids,and feelings of pleasure are all intended tomaximize the possibility ofproducing ahealthy, fertile offspring.