Reproductive Structures and All That Jazz Test Flashcards
What is a description and the function of the bulbourethral (Cowper’s) gland?
- A pair of small glands that lie on either side of the urethra
- Secrete a clear mucous fluid prior to ejaculation that attempts to protect sperm from any acidic urine that might be present in the urethra.
What is a description and the function of the seminal vesicles?
- A pair of glands that lie behind and slightly below the urinary bladder
- Secrete a fluid containing fructose (for energy) and prostaglandins (stimukates the smooth muscles of the female reproductive tract).
What is a description and the function of the vas deferens?
- Tubes which run on either side of the abdomen
- Used to transport sperm.
What is a description and the function of the testes?
- Male gonads which descend from the abdominal cavity during embryonic development
- Produce sperm and secrete testosterone.
What is a description and the function of the urethra?
- Tube that runs through the penis
- Transports sperm and other secretions out of the body.
What is a description and the function of the penis?
- Consists mainly of blood vessels and erectile tissue
- Allow for the deposit of sperm in the female reproductive system.
What is the function of the seminiferous tubules?
Where sperm are produced.
What is a description and the function of the prostate gland?
- Large gland which lies below the urinary bladder and surrounds the urethra
- Secretes an alkaline buffer which helps to neutralize the acidic nature of the vagina.
What is a description and the function of the epididymis?
- Highly coiled structure lying on the outside of each testis
- Stores sperm until mature.
What is a description and the function of the scrotum?
- Outward fold of the body wall
- Helps to store sperm at appropriate temperature (2 degrees less than body temp).
What is a description and the function of the interstitial cells?
- Cells scattered around the seminiferous tubules
- Secrete testosterone.
What is a description and the function of the ovaries?
- A pair of structures located in the abdominal cavity, enclosed in a tough protective covering, attached to the uterus
- Secrete hormones and produce a viable egg each month.
What is a description and the function of the corpus luteum?
- Yellow body remaining in the ovary
- Secretes estrogen and progesterone
What is a description and the function of the fimbrea?
- Finger-like extensions
- Help to ensure secondary oocyte enters oviduct.
What is a description and the function of the follicles?
- Cells within the ovary
- Promote and support growth of the egg/secondary oocyte, secrete estrogen
What is a description and the function of the uterus?
- Thick, muscular, pear shaped organ, consists of two layers
- Site of implantation as well as further prenatal development
What is a description and the function of the cervix?
- Muscular ring at the base of the uterus, normally about the size of the head pin, closed over with mucus
- Prevents premature birth, holds the developing fetus in place.
What is a description and the function of the vagina?
- Thin walled muscular tube
- Receives sperm and serves as the birth canal
What is a description and the function of the fallopian tubes (oviducts)?
- Tubes running from the ovary to the uterus lined with cilia
- Allows for the transport of the egg/secondary oocyte
What is a description and the function of the myometrium?
- Strong OUTER muscular layer, stimulated by oxytocin
- Contracts to allow the fetus to move through the birth canal
What is a description and the function of the endometrium?
- INNER layer of the uterus that thickens and becomes more glandular and vascular
- Nourishes the zygote through early embryonic development
How long after ovulation can an egg/secondary oocyte be fertilized for?
24 hours
How long will sperm remain viable in the female reproductive tract for?
5 days
Where does fertilization usually take place?
The fallopian tube/oviduct, in the outer third.
How does the sperm get to its location?
- Sperm swim up the female repoductive tract, aided by muscular contractions of the uterus stimulated by prostaglandins in the semen
- The oocyte (egg) also secretes a chemical that attracts sperm
- The first sperm attaches to receptors in the zona pellucida which activates the acrosome cap of the sperm
What does the acrosome activation cause?
- The acrosome activation causes the release of digestive enzymes which break down the zona and allows the sperm to enter.
- This stimulates the release of granules that cause changes in the zona pellucida to prevent entry of other sperm, which prevents more than one sperm from entering.
What happens once the sperm penetrates the secondary oocyte/egg?
- Once the sperm penetrates the secondary oocyte/egg, it then goes through meiosis II so that a haploid nucleus is formed.
- After meiosis II is complete, the ootid (ovum) pronucleus (23 chromosomes) and the sperm pronucleus (23 chromosomes) will unite. Fertilization occurs when the 2 nuclei unite forming a diploid zygote.
What happens to the zygote following fertilization?
The zygote undergoes rapid mitotic cell division, called cleavage divisions
What does cleavage produce?
Cleavage produces a solid sphere of cells still surrounded by a zona pellucida, now called a morula.
What happens at 4.5-5 days after fertilization?
- Cells have developed into a hollow ball of cells called a blastocyst: a rapidly dividing ball of cells.
- It is at this stage that it enters the uterus
What happens at about 6-7 days after fertilization?
- The blastocyst implants, it secretes enzymes that allow it to penetrate/digest the endometrial wall
- This nourishes the blastocyst for about a week after implantation
What is the blastocyst composed of?
An outer layer of cells called the trophoblast, an inner cell mass, and a fluid filled cavity called the blastocoel.
What will the trophoblast and part of the inner cell mass form?
The membrane of the fetal portion of the placenta.
What forms the embryo?
The rest of the inner cell mass.
After 8-12 days what does the chorion secrete and what does it do?
Human chorionic gonadotropin (hCG). It keeps the corpus luteum intact for the first three months of pregnancy.
What structure secretes estrogen and progesterone after the third month/the corpus luteum stops?
The placenta.
What is the ectoderm?
A germ layer in the embryo responsible for tissues such as nervous system (including brain, eyes, skin, ears) also nails, hair, teeth.
What is the mesoderm?
A germ layer in the embryo responsible for tissues such as muscles and bones, circulatory system, kidneys, and reproductive structures.
What is the endoderm?
A germ layer in the embryo responsible for organs of the digestive system, along with the lungs.
What is the chorion?
-Secretes human chorionic gonadotropin hormone (hCG). This hormone ensures that the corpus luteum will remain intact and not degrade into the corpus albicans. The corpus luteum remains for a period of 3 months secreting estrogen and progesterone.
What is the amnion?
This membrane forms the amniotic sac and fluid. These help to protect, insulate and hydrate the developing fetus.
What is the allantois?
Blood vessels in the umbilical cord are formed from this layer.
What is the yolk sac?
This provides nourishment to the embryo in the very early stages.
What does the chorion develop into?
The fetal part of the placenta
What is the placenta?
Composed of both fetal and maternal tissues formed by chorionic villi and endometrium, it is the connection between mother and developing embryo.
What does the umbilical cord to?
The umbilical cord connects the fetus to the placenta. Contains large blood vessels that transport blood between the embryo and the placenta. The allantois is the embryonic membrane that produces these blood vessels.
What are the functions of the placenta?
- Transfer gasses
- Transfer nutrients
- Excretion of wastes
- Hormone production (temporary endocrine organ for estrogen and progesterone)
- Formation of a barrier – incomplete and non-selective since some substances can cross the placenta (alcohol, steroids, narcotics, anesthetics, some antibiotics)