Chapter 39 Section 3
The Reproductive System
Biology pgs. 1009-1015
Objectives
Describe
• ______________
sexual development
Explain
• _________________
the functions of the
male and female reproductive systems
Identify
• ______________
the four phases of the
menstrual cycle
• Sexual Development
• In humans, the reproductive system produces,
stores, and releases specialized
_________________known
as gametes.
sex cells
• These cells are released to create the fusion of
sperm and egg to form a zygote, the single cell from
which all cells of the human body develop.
Puberty
• ____________
is a period of rapid growth and
sexual maturation during which the reproductive
system becomes fully functional.
• When puberty ends, reproductive organs are fully
developed.
• Puberty usually begins between the ages of 9 and
15, and usually starts one year earlier in females
than in males.
begins
• Puberty __________
when the
hypothalamus signals the pituitary to
produce increased levels of two hormones
that affect the gonads.
• These hormones are follicle-stimulating
hormone (FSH) and luteinizing hormone
(LH).
• The Male Reproductive System
• Release of FSH and LH stimulates cells in the
testosterone
testes to produce _____________________.
• FSH and testosterone stimulate the development
sperm
of ___________.
– The main function of the male
reproductive system is to
_____________
and deliver sperm.
produce
The Male Reproductive System
Head
• A sperm cell
Nucleus
consists of:
Midpiece
head
• a __________,
which contains the
nucleus
• a midpiece, which
contains energyreleasing
mitochondria
• a tail, which propels
the cell forward
Mitochondria
Tail
The Male Reproductive System
• The testes are located in an external sac
scrotum
called the ______________.
• The scrotum is located outside the body
cavity, where it is between 1 and 3
degrees cooler than normal body
lower
temperature. The ______________
temperature helps sperm development.
• Within each testis are clusters of hundreds of
•
•
•
seminiferous
tiny tubules called ____________________
tubules.
The seminiferous tubules are tightly coiled and
twisted together.
Sperm are produced in the seminiferous tubules.
Sperm produced in the seminiferous tubules
epididymis
move into the __________________,
where
they mature and are stored.
• From there, sperm move into a tube called
vas deferens
the ___________________,
which
extends up from the scrotum into the
abdominal cavity.
• This merges with the urethra, the tube
that leads to the outside of the body
through the ____________.
penis
• Glands lining the reproductive tract
seminal fluid
produce ____________________.
• Seminal fluid nourishes sperm and
protects them from the acidity of the
female reproductive tract.
• The combination of sperm and seminal
semen
fluid is called _________________.
• The Female Reproductive System
• The primary reproductive organs in the female are
ovaries
the _____________________.
• The ovaries are located in the abdominal cavity.
– The main function of the female
reproductive system is to produce
eggs
_________________.
In addition, the
female reproductive system prepares the
female's body to nourish a developing
embryo.
The Female Reproductive
System
Fallopian tube
Ovary
Uterus
Urinary bladder
Cervix
Rectum
Pubic bone
Vagina
Urethra
• Puberty in females starts when the
hypothalamus signals the pituitary gland to
release FSH and LH.
FSH
• ______________
stimulates cells within
the ovaries to produce estrogen.
– Egg Development
• Each ovary contains about 400,000 primary
__________________,
which are clusters of
follicles
cells surrounding a single egg.
• The follicle helps an egg mature for release into the
reproductive tract, where it can be fertilized.
• Eggs develop within their follicles.
– Egg Release
• When a follicle has matured, its egg is released in
ovulation
a process called ___________________.
• The follicle breaks open, and the egg is swept
from the ovary into one of the two
Fallopian tubes.
________________________
• While in the Fallopian tube, an egg can be
fertilized.
• After a few days, the egg passes from the
Fallopian tube into the _______________.
uterus
• If the egg is not fertilized it passes through the
vagina
cervix, and finally out of the _______________.
• The vagina leads to the outside of the body.
• The Menstrual Cycle
• The menstrual cycle is controlled by internal
feedback mechanisms between the reproductive
system and the endocrine system.
• The cycle takes an average of 28 days. During the
menstrual cycle
_______________________,
an egg develops
and is released from an ovary.
• The uterus is prepared to receive a fertilized egg.
• If the egg is fertilized, it is implanted in the uterus
and embryonic development begins.
• If the egg is not fertilized, it is discharged.
• During the menstrual cycle, an egg develops
•
•
•
and is released from an ovary.
The uterus is prepared to receive a fertilized
egg.
If the egg is fertilized, it is implanted in the
uterus and embryonic development begins.
If the egg is not fertilized, it is discharged.
four
– The menstrual cycle has ___________
phases:
• follicular phase
• ovulation
• luteal phase
• menstruation
The Menstrual Cycle
Ovulation
• Menstrual Cycle
The Menstrual Cycle
• The follicular phase begins when estrogen levels in
the blood are low.
• The anterior pituitary secretes FSH and LH, which
cause a follicle to develop to maturity.
• As the follicle develops, cells surrounding the egg
enlarge and produce more estrogen.
Estrogen
• ______________________
causes the lining of the
uterus to thicken.
– Ovulation
• This phase occurs midway through the cycle and
lasts 3–4 days.
• The pituitary gland produces more FSH and LH.
• The release of these hormones causes the follicle
to rupture, and a mature egg is released into one
of the Fallopian tubes.
– Luteal Phase
• The luteal phase begins after the egg is released.
• As the egg moves in the Fallopian tube, the follicle turns
yellow and is called the _______________________.
corpus luteum
• The corpus luteum continues to release estrogen but also
begins to release progesterone.
– Progesterone stimulates growth and development of
the blood supply and surrounding tissue.
– Within a few days of implantation, the uterus and the
growing embryo will release hormones that keep the
corpus luteum functioning for several weeks.
– This allows the lining of the uterus to nourish and
protect the developing embryo.
– Menstruation
• If fertilization does not occur, the corpus luteum will
begin to disintegrate.
• The follicle breaks down and releases less
hormones, which makes the uterine lining detach.
• This tissue, blood, and the unfertilized egg are
discharged through the vagina.
menstruation
• This phase is _______________________,
and
it lasts 3–7 days.
• Sexually Transmitted Diseases
• Diseases that spread from one person to another
during sexual contact are called
________________________________
sexually transmitted diseases
(STDs).
• STDs are a serious problem in the U.S., infecting
millions of people each year and accounting for
thousands of deaths.
bacteria
• STDs caused by ______________
include
chlamydia, syphilis, and gonorrhea.
viruses
• STDs caused by ______________
include
hepatitis B, genital herpes, genital warts,
and HIV/AIDS.