Chapter 14: Carrying Life Forward: The Female Reproductive System Summary

Parts of the female reproductive system

Ovaries: The female system has two ovaries which produce an ovum every month. They are located on each side of the uterus and behind fallopian tubes. The ovary has stroma containing fibrous connective tissue referred to as tunica albuginea.

The germinal epithelium is found outside the tunica albuginea. The germinal epithelium extends in the ovary before birth causing primary follicles to separate from the main ovary body.

• At puberty, the following activities occur:
  • The hypophysis anterior lobe produces follicle-stimulating hormone which activates primordial (primary) follicles to begin mitotic division.
  • The oocyte transforms into an ovum and the cells that remain surround the ovum.
  • The follicles of the ovum towards the surface of the ovary as the ovum matures and produces estrogen hormones that activate the endometrium to be generated for pregnancy to occur.
  • When estrogen levels in the blood rise, the pituitary gland secretes luteinizing hormone (LH)and stops FSH. LH promotes the rupture of Graafian follicles on ovaries and promotes ovulation.
  • The ovum gets into the coelom and fimbriae sweeps it to the fallopian tube.

The corpus luteum is formed on the ovary surface. The gland progesterone hormone that activates the uterine wall for implantation of the fertilized ovum, prevents Graafian follicle maturity, ovulation, and estrogen secretion which prevents menstruation.

The uterus is found between the rectum and the urinary bladder. Its upper end is called the fundus, the lower end is called the cervix which opens in the vagina, and the middle part is the body.

The vagina is the muscular channel that connects the uterus and the outer side of the body. It contains elastic mucous membranes that enlarge during delivery.

A hymen is the connective tissue membrane that covers the vaginal canal opening and it can only be ruptured after sex or other physical activities.

Role of meiosis in zygote formation

Each gamete (sperm or ovum) has to contribute half its chromosome number for the fertilization process to succeed. This is where a meiosis role is needed.

The first meiotic division generates haploid gametes. The second phase of meiosis generates four haploid sperm cells and one haploid ovum that is functional.

During fertilization, the zygote has 23 pairs of homologous chromosomes totaling t 46 chromosomes. The zygote then undergoes mitosis to produce more cells.

Embryology

Fertilization happens in the fallopian tube within 24 hours after ovulation.

After the sperm penetrates the ovum,  they fuse to form a zygote. The zygote moves to the uterus through the fallopian tube while undergoing mitosis division. After a few days of mitosis, a hollow ball called blastocyst is formed. The outer layer is called trophoblast while the inner layer is called the blastocoele.

The blastocyst then attaches to the endometrium and the blastocyst cells (totipotent embryonic stem cells) organize into a mass of cells called embryonic disk. The disk then forms the amniotic cavity.

Formation of a baby from a fetus

• Trimesters are periods of pregnancy. Organogenesis occurs during the first trimester of pregnancy. The fetal systems develop during the second trimester. Organ systems function completely in the third trimester.
• Fetal development milestones include:
  • After the second month, the head is bigger than the body and all limbs are still short.
  • In the third month, the head grows slowly and the body grows faster. Bone ossification and formation of all body systems occur.
  • In the fourth month, legs straighten and skeleton ossification continues.
  • Within the fifth month, the skeletal muscles are activated and movement can be felt by the mother. Soft hair also develops to cover the skin.
  • By the sixth month, there is eyelash and eyebrows formation. The skin is reddish, wrinkled, and wrinkled. The redness is caused by the dermal blood vessels.
  • During the seventh month, the fetus gains a subcutaneous fat and the eyelids open.
  • In the eight months, the subcutaneous fat is enlarged and baby-like proportions are seen. The fetus turns upside down.
  • Within the ninth month, the fetus gains more subcutaneous fat. Extension of fingernails occurs.

Urinary Bladder
-Holds urine

Urethra
-Passageway for urine to exit the body

Ovaries
-Two almond shaped glands
-Store, ripen, and release ovum once a month
-Produce and secrete female sex hormone: estrogen and progesterone

Fallopian Tubes
-Passageway for the released ova to travel from the ovaries to the uterus.
-The ends of the Fallopian tubes have finger-like structures called fimbria
-The fimbria swell up and wave back and fourth at the time of ovulation to draw the released ova into the opening of the Fallopian tube
-The opening inside the Fallopian tube is only the width of a few human hairs
-The Fallopian tube is usually the sight of fertilization

Uterus
-A pear shaped,smooth,muscular organ that is the sight of implantation into the bloody lining of uterus called the endometrium
-Also know as the womb
-The bottom is called the cervix
-Cervix allows fluid to travel from the uterus to the vagina or the vagina to the uterus.

Vagina
-Sight of sexual intercourse where sperm is ejaculated for sexual reproduction.
-Also called the birth canal
-Also allows the endometrium to exit the body

Ovulation
-Released egg form the ovaries

Fertilization
-The joining of the sperm to the egg

Implantation
-Egg gets planted into the endometrium

Menstrual Cycle
-Science- 28 days
Ovulation- Day 14

Follicle Stimulation Hormones
FSH- Stimulates the follicles of the ovaries to ripen another ova.
-Occurs during the beginning of cycle
-It climbs at the time of ovulation
-Than it goes back down

Luteal Hormone
-Stays low and spikes at ovulation
-Occurs during ovulation
-Is the cause for the follicle to rupture
-The rupture makes ovulation

Estrogen
-Increased before fertilization to increase female sex-drive
-Helps with reproduction.

Progesterone
-Builds up endometrium to prepare for a fertilized egg.
-Progesterone stays high is egg is fertilized
-Progesterone drops off and cycle starts again if egg is not fertilized.

Menopause
the remaining ova no longer no longer ripen or developed

Libia Minora
the two smaller folds of tissue which lie just within the libia majora

Fallopian Tube
two tubes shaped like arched and twisted bridges, high on either side of the uterus

Urethra
below the clitoris, the opening to the bladder

Progesterone
a hormone that can help release an egg and it prepares the uterus for the baby

Uterus/ Womb
the organ in the lower body of the woman where offspring are convinced in which they gestate for birth

Clitoris
a small pea-shaped bump at the front of the of the libia that contains erectile tissue

Vagina
passageway between the uterus and the outside of a womens body

Menstruation
release of dead endometrium tissue and blood

Ectopic Pregnancy
the egg tries to grow in the fallopian tube

Endometrium Lining/ Uterine Lining
the lining of the uterus

Lamia Majora
the tow major folds of skin running from the mons pubis to below the viginal opening

Ovaries
organs holding a women’s egg

Estrogen
the hormone responsible for secondary sex characteristics and for the sex drive in females

Ovulation
time when the egg is released from the ovary

What are some diseases of the female reproductive system (3-4)?
PMS, Toxic Shock Syndrome, Dysmenorrhea, Vaginitis

What is a pap smear/ pap test and why is it important?
a cervical smear that takes a sample of secretions and superficial cells of the uterine cervix and uterus. It is important because it checks to see if you have cervical cancer