Anatomy Chapter 16

Reproductive Systems

Sexual Reproduction

A male and female have intercourse and their gametes fuse to form a zygote that will develop into an embryo and a new human offspring.

Sexually Transmitted Infection

These can be caused by a variety of pathogens and are often called silent infections because early stages often don’t produce symptoms.

Bacterial STIs

Chlamydia, Syphilis, Gonorrhea

Virus STIs

Genital Herpes, Genital warts, Hepatitis B, HIV/AIDS, Human papillomavirus, molluscum contagiosum

Protozoan STIs

Trichomoniasis

Fungal STIs

Jock Itch, Yeast Infections

Parasite STIs

Pubic Lice (crabs), Scabies

Symptoms of STIs

Burning Sensation, lower abdominal pain, fever, swollen glands, irregular discharge from vagina or penis, pain itching or inflammation in the genital/anal area, pain during intercourse, sores blisters bumps or rash around mouth or genitals, itchy runny eyes, higher risk of cancer or infections, infertility.

19\.7 million; 15-24

__________(#)__ *new STI infections occur each year in the U.S., more than half among* ages _____________

Adolescents/young adults

_________ accounted for greatest percentage of new HIV infections than any other group.

1/4; 1/2

__________(#)__ sexually active teens have an STI and ______ sexually active youth will have an STI by age 25.

1/5 ; 90%

____ Americans have genital herpes infection and up to _____ of them don’t know it yet.

HPV

Teenagers are more susceptible to this STI and they are more likely to develop precancerous growths as a result.

False

True or false: contraceptive pills or shots protect against STIs and HIV

Prostate Gland

This structure secretes a milky fluid that plays a role in activating sperm.

Seminal Vesicle

This structure produces about 60% of fluid volume of semen. Seminal fluid nourishes the sperm as they enter the urethra together.

Bulbourethral Gland

This structure secretes a thick, clear mucus that is the first to pass through the urethra during arousal. It cleanses the urethra of traces of acidic urine and works to lubricate.

Epididymis

This structure provides a temporary storage site for immature sperm. It takes sperm about 20 days to travel along this structure and fully mature.

Testis

This structure contains the seminiferous tubules “sperm-forming factories” and the testosterone producing cells.

Scrotum

This structure is a divided sac of skin that hangs loosely to provide the testes with a temperature 3 degrees celcius below body temp. The scrotum can shrink to pull the testis closer to the body when the environment is too cold.

Prepuce

Loose skin covering the glans penis. May be removed by a surgical procedure called a circumcision.

Male Urethra

This carries both urine and sperm in the male to the exterior.

Erectile tissue of penis

This structure is a spongy tissue that fills with blood during sexual arousal. The penis enlarges and becomes more rigid to perform penetration.

Spermatic cord

This structure is a connective tissue covering that encloses the vas deferens, blood vessels, and nerves. Vas deferens propels live sperm from the epididymis into the urethra.

Seminiferous Tubules

Tubules where sperm are formed in the testis.

Vas deferens

This structure is a tube in which sperm travel through the spermatic cords.

Glans Penis

The sensory portion of the penis

Spermatogenesis

The production and division of sperm cells. This process begins when males reach puberty and continues for the duration of life.

Semen

Fluid containing sperm, prostate fluid, and (60%) seminal fluid. There are 50-130 sperm per milliliter of semen. The vast number is to ensure that one of the sperm can survive and fertilize the ovum.

Spermatogonium

Sperm stem cells located in the seminiferous tubules that go through rapid mitotic divisions to produce more stem cells up until puberty. When males have reached puberty they begin to divide differently.

Follicle-stimulating hormone (FSH)

This hormone is secreted by the anterior pituitary gland during puberty and stimulates spermatogonium stem cells to produce a type a and type b daughter cell.

Type B daughter cell

This daughter cell gets pushed toward the tubule lumen where it becomes a primary spermatocyte.

Primary spermatocyte

This cell undergoes meiosis and forms 4 gamete sperm cells called spermatids. These sperm cells are haploid and contain only 23 chromosomes.

Spermatids

Immature sperm cells that contain 23 chromosomes. They undergo further development during spermiogenesis. The sperm matures and consists of a head, a midpiece, and a tail.

Spermiogenesis

This is the process where spermatids mature into a sperm cell that consists of a head, midpiece, and tail. This sperm can move long distances in a short amount of time but still has some maturing to do in the epididymis.

Head

This portion of the sperm contains the DNA and just anterior to this portion is the acrosome.

Acrosome

Helmet-like membrane just anterior to the head of eth sperm. When it comes into close contact with an egg it breaks open to release enzymes to help the sperm penetrate through the follicle cells that surround the egg.

Tail

This portion of the sperm is made of filaments which arise from centriole in the midpiece. It allows for whiplike movements that propel the sperm forward.

Midpiece

This portion of the sperm contains centrioles that make filaments for the tail and mitochondria to create energy for the tail’s movements.

Luteinizing Hormone (LH)

A hormone produced by the anterior pituitary gland that is produced during puberty. It stimulates the interstitial cells of the testes to produce the hormone testosterone after puberty.

Testosterone

A hormone that stimulates reproductive organs to develop to their adult size. It underlies the male sex drive. It also causes secondary sex characteristics to appear. It is released in varying amounts throughout the life span of males but in larger numbers following puberty.

Secondary Sex Characteristics

Caused by testosterone. Enlargement of the larynx which causes deepening of the voice, increased hair growth all over the body especially in the axillary, pubic, and facial regions, and enlargement of skeletal muscles and bones.

Female Reproductive system

The system that is responsible for producing eggs, providing a site for fertilization, and supporting fetal development. Consists of the female reproductive tract and mammary glands.

False, males have them but they normally function only in females.

True or false: Mammary Glands are only present in females.

Mammary Glands

These function in women to produce milk to nourish offspring and only become important after reproduction has been accomplished. They are modified sweat glands that are actually part of the skin. They are contained within female breasts. They produce milk when a women is lactating after birth.

Lactiferous Duct

Milk passes from the mammary glands into these ducts and out the protruding nipple.

Clitoris

This structure is similar to the male penis as it is hooded by a prepuce and composed of sensitive erectile tissue that becomes swollen with blood during sexual arousal.

Labia Majora

Larger outer tissue flap that protects the vaginal and urethra openings.

Labia Minora

Smaller, inner tissue flap that protects the vaginal and urethra openings.

Fallopian (uterine) tubes

This tube receives the ovulated oocyte and is the site where fertilization occurs. The oocyte is carried by peristalsis and beating cilia.

Ovary

This structure produces the secondary oocytes to be released by ovulation. Produces estrogen and progesterone.

Uterus

Hollow Organ that receives, and nourishes an egg throughout embryonic-fetal development. The innermost layer of mucosa is the endometrium. If an egg becomes fertilized it will burrow into the endometrium (implantation). If no egg is fertilized the endometrium will shed itself roughly every 28 days (menses).

Endometrium

The innermost layer of the mucosa membrane of the uterus. A fertilized egg will implant itself into the membrane and start development.

Menstruation

When the endometrium sheds itself every 28 days.

Vagina

The passageway for infant during birth, menstrual flow during menses, and receives penis during sexual intercourse.

Cervix

The narrow outlet of the uterus. Protrudes into the vagina.

Uterine Blood vessles

Provide oxygen and nourishment to the uterus and remove waste.

Ovarian Blood vessels

Provide oxygen and nourishment and remove waste from the ovaries.

Fimbriae

Fingerlike projections that partially surround the ovary. The fimbriae create fluid currents that act to carry the oocyte into the uterine tube. Some oocytes are lost in the peritoneal cavity.

Oogenesis

The production of eggs in females.

Oogonia

Egg stem cells that undergo mitosis when females are fetuses. They undergo mitosis and drastically increase in numbers. The daughter cells are called primary oocytes. These stem cells disappear by birth as they all form primary oocytes.

Primary Follicles

These form and surround primary oocytes after they form from oogonia. They surround the primary oocyte until stimulated by FSH during puberty.

False; all the oogonia are gone by birth as they mitotically divide to form primary oocytes. The ovary actually becomes inactive for 10-14 years after birth.

True or false: females continue to make oogonia throughout their lifetime so they have enough eggs to release and be fertilized.

\*Follicular Stimulating Hormone

\*This hormone is released by the anterior pituitary gland during/after puberty which stimulates a small number of primary follicles to develop into a mature follicle containing a primary oocyte.

Secondary oocyte

After being stimulated by FSh the primary oocyte undergoes meiosis I producing this cell and a polar body that disintegrates.

Mature Vesicular Follicle

Also known as the Graafian Follicle, this follicle contains the secondary oocyte and after maturing for 14 days and being stimulated by luteinizing hormone it releases the secondary oocyte.

\*Luteinizing Hormone

\*This hormone is released by the anterior pituitary gland and causes the secondary oocyte to be released from the mature vesicular follicle surrounded by a small follicle-cell capsule. It also causes the ruptured follicle to change into a gland called the corpus luteum.

Ovulation

When luteinizing hormone causes the secondary oocyte to be released from the graafian follicle surrounded by a follicle cell capsule.

Corpus Luteum

This gland is formed from the ruptured follicle when it comes into contact with LH. It released the hormone progesterone.

Progesterone

This hormone is released by the corpus luteum and stimulates the endometrium blood supply and glands to increase and secrete nutrients into the uterine cavity which will sustain a developing embryo for short term if fertilization occurs. If no fertilization occurs the corpus luteum degenerates stopping progesterone release.

Menstruation

This occurs when the corpus luteum degenerates and stops producing progesterone when no fertilization occurs. This will cause the endometrium to spasm and kink and the dying cells are shed along with blood through the vagina.

\*Menstruation

\*Days 1-7 of the menstrual cycle. Progesterone is no longer being produced by the corpus luteum as the oocyte was not fertilized. The blood vessels of the endometrium kink and twist and the endometrium is shed through the vagine.

Follicular Phase

Days the 8-12 of the menstrual cycle. FSH is being released and the follicle and oocyte begins maturing. The endometrium is thin at this time.

\*Ovulation

\*Days 13-15 of the menstrual cycle. At this time LH levels drastically spike causing an egg to be released. Estrogen is also released in larger numbers. The endometrium is thicker than before.

Luteal Phase

Days 16-28 of the menstrual cycle. At this time the corpus luteum has formed causing progesterone levels to rise. Estrogen levels are also high. This causes angiogenesis and lots of blood supply to the endometrium to prepare for a potentially fertilized egg. The endometrium is thick with a good blood supply.

Fertilization

When sperm fertilizes the secondary oocyte and it goes through meiosis II producing another polar body. This also means that the corpus luteum doesn’t degenerate and progesterone levels remain high. This also means that another primary follicle will not mature.

Menopause

Oocytes mature from puberty until this time; this generally occurs at age 50 or earlier. After this the female will be infertile and produce no more eggs.

12-72 hours

How long do sperm retain fertilizing power?

12-24 hours

For how long are oocytes generally viable.

Fertilization Window

No more than 72 hours before ovulation and no later than 24 hours after.

Acrosome

This structure releases digestive enzymes that break down the out follicular-cell capsule.

False, the fist sperm to break through the follicular cell capsule and make contact withe the oocytes membrane receptors on the jelly like coat called the zona.

True or false: the first sperm to reach the agg is the sperm to fertilize it.

\*Head

\*Which portion of the sperm is pulled into the oocyte and passes the genetic information on to the nucleus of the oocyte.

Zona

This jelly-like layer of the oocyte changes and hardens so that no more sperm can fertilize the egg.

Meiosis II

After the sperm penetrates the oocyte the nucleus of the oocyte moves to the opposite end of the cell and undergoes this process forming a haploid cell and a polar body.

Zygote

When the two nuclei of the sperm and the egg fuse in fertilization they form this cell. This new diploid cell with 46 chromosomes is the first cell of the new organism.

In vitro fertilization

A process in which the egg and sperm are fertilizes externally in a test tube. First FSH is injected into the ovaries of the women and the eggs are collected. Then sperm is collected and combined with the oocytes in a test tube to form a zygote. Then the fertilized egg (zygote) is placed in the uterus of the women to develop.

Dizygotic Twin

When more than one secondary oocyte is fertilized and two zygote are formed. These twins are becoming more and more common with the rise of fertility treatments.

Monozygotic Twins

Twins that are formed when the early developing cells of the embryo separate and form genetically identical twins. These twins share the same placenta and can even share the same amniotic sac.

Peristalsis and beating cilia.

How does the zygote travel down the the uterine tube?

Cleavage

Rapid mitotic divisions that occur as the zygote travels down the uterine tube and result in an embryo.

3 days

After how many days will the embryo reach the uterus?

Endometrium

When the embryo reaches the uterus it will float freely and continue to divide while using the secretions from this structure.

Blastocyst

After the embryo has 100 cells it hollows out to form a hollowed out structure called this. THis structure begins to secrete hCG.

hCG

This hormone is released by blastocysts and is the hormone that at-home pregnancy tests respond to. It stimulates the corpus luteum to produce progesterone to maintain the pregnancy.

14 days

After how many days does the blastocyst implant into the wall of the endometrium.

Placenta

This structure begins to form when the outer part of the blastocyst called the trophoblast begins forming a network of blood vessels with the tissues of the mother’s blood-rich endometrium. It attaches to the amniotic sac by the umbilical cord.

Amnion

The fluid filled sac that surrounds the developing embryo.

Umbillical Cord

A blood vessel-containing stalk of tissue that attaches the amnion to the placenta.

3 weeks

How long does it take for the placenta to mature and be fully functioning to deliver nutrients and oxygen to the embryo and removes wastes from embryonic blood.