Reproductive System Flashcards
What is a gamete?
sex cell
What is the name of a gamete in a female?
oocyte
What is the name of a gamete in a male?
spermatocyte
Where are the gametes produced?
The gonads
Where are spermatocytes produced?
The testes
Where are oocytes produced?
The ovaries
What type of cell are gametes produced by?
Germ cells
When a gamete matures, how many times does the cell divide?
Twice
When the gamete divides the first time, what process is used?
Mitosis
When the gamete divides the first time, how many cells are produced?
Two
When the gamete divides the first time, how many chromosomes are in the two new cells?
The whole set of chromosomes: 46
What process is used for the second division of the gametes?
Meiosis
When the gamete divides the second time, how many resulting cells (gametes) are produced?
Four gametes
When the gamete divides the second time, how many chromosomes are in each of the resulting cells?
Half of the set of chromosomes: 23
a haploid
What types of cells utilize mitosis?
ALL cells utilize mitosis
What types of cells utilize meiosis?
Reproductive cells are the only type of cells that utilize meiosis
How many chromosomes are in a gamete?
23 chromosomes
What is a zygote?
when the sperm gamete and the egg gamete combine to form a fertilized egg
when the sperm gamete and the egg gamete combine to form a fertilized egg
46 chromosomes
How does a zygote divide?
Mitosis
How are the characteristics of the offspring such as eye color and skin color determined?q
The 46 chromosomes
How is the offspring’s gender determined?
From the father’s sperm cell
How many X and Y chromosomes do males and females have?
Females have two X chromosomes, and Males have one X and one Y chromosome
What are the four internal organs of a female’s reproductive system
Ovaries
Oviducts
Uterus
Vagina
What are two other names for the Oviducts?
Fallopian tubes
Uterine tubes
What is the collective name of the female external genitalia?
Vulva
What is the main reproductive organ in females?
The ovaries
What are the names of the three ovarian ligaments?
Suspensory ligament
Ovarian ligament
Broad ligament
What is the function of the suspensory ligament?
It attaches the ovaries to the pelvis wall
What is the function of the ovarian ligaments?
It attaches the ovaries to the uterus
What is the function of the broad ligament?
It holds the ovaries in place in the pelvis
What is inside an ovarian follicle?
An immature egg
What is the definition of ovulation and when does it occur?
It is the release of a mature egg which happens approximately every 28 days
What does the ovarian follicle become after ovulation?
The corpus luteum
What does the corpus luteum do if the egg is fertilized?
It helps maintain pregnancy
What does the corpus luteum do if the egg is not fertilized?
It disintegrates
What are the three parts of the female reproductive duct system?
Oviducts
Uterus
Vagina
What are the three sections of the oviducts called?
Infundibulum (most lateral portion)
Ampulla (portion in the middle)
Isthmus (most medial portion)
What are the three coats of the oviducts?
Outer serous coat
Middle muscular coat
Inner mucosa coat
What are the three functions of the Fallopian tube?
- capturing an egg from the ovary at the time of ovulation
- nourishing the fertilized egg (zygote) during its early cell divisions
- delivering the developing embryo into the uterine cavity when it is time for implantation
What are fimbriae?
Finger-like projections on the infundibular end of the fallopian tube. This is not connected to the ovary.
How does an egg (oocyte) make it into the oviduct during ovulation?
The egg is swept into an oviduct by the combined action of the fimbriae and the beating of the cilia that line the oviducts
Where is an egg most often fertilized?
In the ampulla region of the fallopian tube
What does the mucosa layer of the ampulla do for the fertilized egg?
Provides nourishing fluid that allows for repeated cell divisions
What two forces (in combination) move the egg through the isthmus toward the uterus?
the combination of muscular contractions and cilia
Describe the uterus and its position
The uterus is a hollow, thick-walled muscular organ shaped like an inverted pear connecting the uterine tubes and the vagina and in a forward-tilted position between the bladder and the rectum
Describe the uterus and its position
The uterus is a hollow, thick-walled muscular organ shaped like an inverted pear connecting the uterine tubes and the vagina and in a forward-tilted position between the bladder and the rectum
What are the three areas of the uterus?
Fundus
Body
Cervix
What are the three layers of the uterus?
The outer serous perimetrium
The middle muscular myometrium
The inner glandular endometrium
What are the three ligaments of the uterus?
The broad ligament
The uterosacral ligament
The round ligament
What is the function of the broad ligament for the uterus?
It attaches the uterus to the walls and floor of the pelvis
What is the function of the uterosacral ligament?
It attaches the back of the uterus to the front of the sacrum
What is the function of the round ligament?
It attaches to the uterus anteriorly
What can be measured in regards to the uterus for some indications during pregnancy?
The upper part of the uterus is the fundus, the height of which can be measured from the top of the pubic bone during pregnancy to provide growth rates and a crude indication of an abnormality (breech presentation or twins)
What is the function of the body of the uterus?
The middle section, the body, receives the fertilized ovum where it becomes implanted in the endometrium to receive nourishment and develop from ovum to embryo to fetus and gestate until childbirth.
What are the three functions of the cervix?
As a note, the cervix connects the uterus to the vagina and changes in size and texture
- just prior to ovulation the cervix swells, softens and secretes mucus allowing sperm better access to and viability within the uterus
- when a woman become pregnant, a mucus plug develops in the cervix and prevents any bacteria or pathogens from entering the uterus, thus protecting the health of the developing fetus
- a firm, closed cervix also holds the developing fetus in the uterus until it reaches full term
What are the two functions of the muscular myometrium of the uterus during pregnancy?
- It expands during pregnancy to hold the growing fetus
2. It contracts during labor to push the baby out of the uterus
What is the function of the inner endometrium layer of the uterus during pregnancy?
It is where the embryo completes development
What happens to the inner endometrium layer of the uterus if there is no pregnancy?
It is shed monthly (approx every 28 days) and this is called menstruation or menses
What are the three layers of the vaginal wall?
An inner tissue layer
An intermediate muscle layer
An outer tissue layer
Where does the wetness and moisture of the vaginal surface come from?
Mucus from the cervix
What is the outer layer of the vaginal wall made of?
Elastic fibers
Blood vessels
Lymph vessels
Nerves
What is the function of the elastic fibers of the vaginal wall?
They give the vaginal wall its strength and elasticity
What are the two reasons is it important that the mucosal lining of the vagina lies in folds and can extend?
When the vagina serves as the birth canal
It also facilitates intercourse
What are the three functions of the vagina?
It receives the male penis during intercourse
It provides the outlet for menstrual blood during menstruation
It serves as the birth canal for a full term baby
Name each of the major parts of the external genitalia of the female
Mons pubis Clitoris Labia majora Labia minor urethral orifice vaginal orifice greater vestibular glands
What is the main source of sensations during intercourse for a female?
clitoris
What is the function of the greater vestibular glands?
release secretions that help lubricate the area for copulation
What is oogenesis?
The production of eggs in the ovaries which occurs during development of the fetus in the womb and is complete by the time of birth
How long is the reproductive lifetime of a female?
From puberty to about her 50th year of life
What is the end of the female reproductive lifetime called?
Menopause
What are sexual stem cells in a female called?
Oogonia
When one oogonia undergoes mitotic division, how many cells are created and what are these cells called?
Two cells are created and they are called primary oocytes
What happens with primary oocytes during fetal development?
The primary oocytes are covered by follicles known as primary follicles. This process is completed by the time the female is born.
What hormone does the anterior pituitary start to secrete when a female reaches puberty?
Follicle stimulating hormone (FSH)
What is the function of FSH?
It causes a few follicles to mature each month
What two cells are created when a primary oocyte in the follicle undergoes its first meiotic division
- the secondary oocyte
2. the first polar body
Under what circumstance does a secondary oocyte undergo the second meiotic division?
It only occurs if the secondary oocyte is united with a sperm after ovulation
What two cells are produced if a secondary oocyte undergoes the second meiotic cell division?
- a second polar body
2. an ovum with 23 chromosomes
What happens if the secondary oocyte does not combine with a sperm?
It dies and menstruation occurs
What hormone gets released around the time of ovulation from the anterior pituitary?
Luteinizing hormone (LH)
What is the purpose/function of LH?
It causes the follicle to become the corpus lutetium which is necessary for maintaining pregnancy
What two hormones do the ovaries release every month?
Estrogen and Progesterone
What are the three phases of the menstrual cycle?
- menstrual phase
- proliferative phase
- secretory phase
Describe the menstrual phase
- menstrual phase
- proliferative phase
- secretory phase
Describe the proliferative phase
The proliferative phase occurs during days 6-14 as the endometrium rebuilds in response to increasing estrogen levels. Ovulation of an egg typically occurs in the ovaries on day 14. This is a result of the anterior pituitary release of luteinizing hormone as a response to high levels of estrogen.
Describe the secretory phase
It occurs during days 15-28. During this phase the corpus luteum begins to secrete progesterone. Progesterone causes an increased blood supply in the uterus and secretion of nutrients and glycoproteins. This prepares the uterus for implantation if an egg is fertilized. If no fertilization corpus luteum dies and endometrium’s blood supply decreases as a result of decreased progesterone.
What are the three functions of estrogen?
- Production of eggs
- Menstrual cycle
- Secondary sex characteristics
What are the secondary sex characteristics in a female that estrogen is responsible for?
enlarged breasts
widening of the pelvis
curvier figure because of fat deposits in the breast, hips, buttocks
What is the function of progesterone?
Necessary for the maintenance of pregnancy
Describe the makeup of the female breast
a female breast has one to two dozen (12-24) lobules. Each lobule has it’s own mammary duct that begins at the nipple and divides many times into other ducts that end in sacs called alveoli. If the woman is not lactating then there are many more ducts than alveoli.
Alveoli in the breasts are made up of cells that can produce what?
milk
Why is milk not produced during pregnancy?
because prolactin which is needed for lactation (milk production) to begin is suppressed by estrogen and progesterone
What is colostrum?
A few days after delivery, milk production begins prior to which the breasts produce a watery, yellowish-white fluid which is similar in composition to milk but contains more protein and less fat.
For fertilization to take place, why must sexual intercourse take place in the period that starts two days before and ends one day after ovulation?
Sperm are viable for about two days after ejaculation and an egg can survive for about two days after ovulation so for fertilization to occur, intercourse must take place by one day after ovulation and can occur as early as two days before ovulation.
When does pregnancy begin?
Pregnancy begins with fertilization of an egg by a sperm forming a zygote.
Explain in detail the fertilization of an egg by a sperm
In the oviducts, the egg releases chemicals that attract the sperm. When sperm reach the egg they release enzymes that break apart the corona radiate, follicle cells surrounding the egg. Once this is accomplished, more sperm release acrosomal enzymes that make a hole in the membrane of the egg, allowing the sperm to combine with the egg. When this union of egg and sperm occurs, the membrane of the egg changes chemically, preventing other sperm from penetrating the egg.
Describe the formation of the blastocyst from the zygote.
The zygote begins frequent mitotic cell divisions as it travels to the uterus. The zygote spends about three to four days undergoing mitosis in the oviducts forming the morula and another three to four days undergoing mitosis while unattached in the uterus, forming the blastocyst.
What is the identity and source of the substance that causes a positive home pregnancy test?
The presence of HCG in the urine, secreted by the blastocyst, results in a positive home pregnancy tes
List the three layers developed by the blastocyst and give two examples of body parts that develop from each layer.
The blastocyst develop three layers: the ectoderm, the mesoderm, and the endoderm. The skin and nervous tissue develop from the outer ectoderm layer. Glands (thyroid, parathyroid and thymus) and several solid organs (liver and pancreas) and the lining of the hollow organs of the digestive and respiratory systems develop from the inner endoderm layer. All other tissues, including the cardiovascular system, red blood cells and muscle develop from the middle mesoderm layer.
What is the function of the placenta?
The placenta is a temporary organ that carries out nutritive, respiratory, excretory and endocrine functions for the embryo.
In which trimester does a fetus regulates its own body temperature?
3rd
In which trimester does the brain, spinal cord, and limbs begin to form?
1st
In which trimester does the mother typically begin to feel fetal movement?
2nd
In which trimester does the head become disproportionately large?
1st
In which trimester does the heart form and begins to pump blood?
1st
In which trimester do the testes descend into the scrotum?
3rd
In which trimester do the genitals form?
1st
In which trimester does fat develop under the skin?
3rd
In which trimester do fingerprints develop?
2nd
In which trimester does the fetus begin to suck and blink?
2nd
Name and describe the first stage of delivery being sure to include its average duration.
The first stage: “dilation of the cervix” is the time it takes for the woman’s cervix to dilate to ten centimeters. During this stage the uterus contracts, which pushes the baby’s head against the cervix causing it to dilate. This stage of labor is the longest, lasting on average 6-10 hours.
Name and describe the second stage of delivery being sure to include its average duration.
The second stage, delivery of the baby, is the time it takes for the baby to be pushed out of the birth canal after full dilation has been accomplished. During this stage, a woman uses her abdominal muscles to push the baby, with the help of the uterus contracting, through the cervix and out the vagina. This stage is much shorter, lasting, on average, 50 minutes for a first delivery and 20 minutes for later ones.
Name and describe the third stage of delivery being sure to include its average duration.
The third stage, “delivery of the placenta” is when the placenta is pushed out of the birth canal. This occurs within 15 minutes of the birth of the child and is the shortest part of labor. The entire placenta needs to be removed after birth or uterine bleeding will continue.
What is a cesarean section and why is it performed?
In breech and other especially long and difficult deliveries, a cesarean section is performed, in which the baby is delivered through a surgical incision made through the abdominal and uterine walls.
Why does sterility occur if the testes do not descend?
because sperm can’t be produced at body temperature. the testes have to be outside the body at a cooler temperature to produce sperm.
Where do sperm spend their maturation time and how long is this period?
They spend their maturation time in the epididymis. it takes about 20 days.
Why do sperm need their maturation time?
The maturation is needed for the sperm to gain the ability to swim.
Trace the path of sperm from their site of production to the outside of the body.
Sperm produced by the testes mature within the epididymis. Once the sperm have matured, they are propelled into the vas deferens by muscular contractions. The vas deferens connects with the duct of the seminal vesicle to form the ejaculatory duct. The ejaculatory duct then connects with the urethra to provide a means for the sperm to exit the body.
Describe a vasectomy and how it prevents fertilization.
In a vasectomy, the vas deferens is cut and tied off which permanently prevents sperm from exiting the body to fertilize an egg.
List and describe the location of the 3 sections of the male urethra.
The three sections: prostatic urethra, membranous urethra, and spongy urethra.
Section 1: the prostatic urethra is surrounded by the prostate gland.
Section 2: The membranous urethra begins at the end of the prostatic urethra and travels to the penis.
Section 3: The spongy urethra runs through the penis and opens to the outside at the external orifice.
Describe the structure of the penis and how it functions during sexual intercourse.
The penis is a cylindrical organ that contains spongy, erectile tissue containing distensible blood spaces. During sexual arousal, nerve system reflexes cause an increase in arterial blood flow to the penis. This fills the blood spaces in the erectile tissue and the penis, which is normally limp, stiffens and increases in size. This allows the penis to be inserted into the vagina when sexually excited and deposit semen into the female’s reproductive tract.
Describe the action of the scrotum in maintaining the proper condition of sperm.
The scrotum is a pouch of skin that holds the testes outside of the body. The testes must be located outside of the body because sperm must be produced at a temperature lower than body temperature. The skin of the scrotum can adjust to outside temperature, contracting when outside temperatures are cold, allowing the sperm to get some heat from the body and expanding when temperatures are warm to keep sperm away from the higher body temperature.
What is semen?
Semen is a thick, whitish fluid that contains sperm and accessory gland secretions.
What 3 glands contribute materials to semen?
The fluids of the semen are contributed by three glands: the seminal vesicles, the prostate and the bulbourethral glands.
What is one material produced by the seminal vesicles that is contributed to semen?
The paired seminal vesicles contribute nutrients (fructose, vitamin C, and prostaglandins)
What is one material produced by the prostate gland that is contributed to semen?
The prostate gland contributes a milky alkaline fluid
What is one material produced by the bulbourethral glands that is contributed to semen?
The bulbourethral glands contribute lubricating mucus.
Describe the difference in production of sperm by males and eggs by females.
Production of sperm in males begins at the onset of puberty and continues during their lifetime. Women have all their eggs at birth.
What is the production of sperm known as?
Spermatogenesis
How long does the production of sperm (spermatogenesis) take?
Production of sperm (spermatogenesis) can take a total of 64-72 days to complete.
Describe, in detail, the production of spermatids.
Sperm are formed from spermatogonia in the seminiferous tubules located in the testes. The spermatogonia are stem cells that go through mitotic divisions beginning at birth until puberty. Once a male enters puberty his anterior pituitary gland begins to secrete follicle stimulating hormone (FSH). When FSH is secreted the spermatogonia undergo cell division; one of the cells continues the stem cell line. The other cell, known as the primary spermatocyte, undergoes meiosis producing four gametes known as spermatids.
What are the three parts of mature sperm?
the head
the midpiece
the tail
the head
the midpiece
the tail
the head is almost entirely nucleus containing the cell DNA with a crown called the acrosome which contains enzymes that breakdown the membrane of the egg to allow the sperm to penetrate.
Describe “the midpiece” of a mature sperm
The midpiece contains numerous mitochondria that generate the locomotive energy needed by the sperm.
Describe “the tail” of a mature sperm
The tail is a typical flagellum which is used to propel the sperm through the female reproductive tract.
When does the production of testosterone begin?
During puberty
How does the production of testosterone begin?
When the anterior pituitary gland secretes luteinizing hormone
What things does testosterone stimulate in males?
Testosterone stimulates the sex drive and growth in males. It also stimulates secondary sex characteristics.
What are the secondary characteristics in males?
such as broad shoulders, deep voice, increased muscle size and bone density, and increased hair.
