My Reproductive System

(Appropriate for ages 14+)

(For this section we will focus mainly on the internal structures of the female reproductive system, but will briefly go over the structures of external structures as well)

Internal Structures: 

1. ovaries: In terms of structure, ovaries are very small and oval shaped containing on average 6 to 7 million eggs from the start of birth. No new eggs will be produced. We have two ovaries, one on either side of the uterus. Their function is the production of eggs and hormones. During the follicular phase of the menstrual cycle, the hormone FSH* will be secreted. Follicles* will form around eggs and eventually a dominant follicle will mature faster than the other ones. As this follicle continues to grow, estrogen* will be released, which will results in smaller follicles dying. During ovulation, LH* will be released and the final stages of maturation* for the egg in the dominant follicle. The increase levels of LH will cause progesterone* to be secreted. The matured egg will then be transported to the fallopian tubes. 
2. fallopian tube: In terms of structure, the fallopian tubes are narrow and are attached to the ovaries and the the upper part of the uterus. They are used to transport fertilized eggs into the uterus where it will implant on the lining of the uterus. Fertilization of an egg typically occurs in the fallopian tubes. During this process, known as ovulation, progesterone levels will increase to prepare the uterus lining for the potential of pregnancy.  
3. uterus: In terms of structure, the uterus is a hallow organ that appears to be pear-shaped. It is the home for a developing fetus. The lining of the uterus is called the endometrium. The endometrium will prepare for the possibility of pregnancy every month. This preparation is in the form of the lining thickening to protect the developing fetus. If a fertilized egg does not attach to the lining of the uterus then the lining will be shed through the vagina, commonly known as a menstrual period. This whole process is aided by estrogen and progesterone. 
4. cervix: In structure, the cervix is a small canal. It connects the uterus to the vagina. Its main function is to allow bodily fluids from the uterus to exit through the vagina. It also prevents objects that are inserted into one's vagina to slip into the uterus (a form of protection for the uterus). In particular the cervix produces mucus that has many functions including: accepting, filtering, preparing and allowing sperm entry to the uterus. At different points in a women's menstrual cycle the mucus produced by the cervix will be thinner or thicker making it easier or harder for sperm to enter the uterus. Furthermore, period blood will pass through the cervix in order to vaginally exit the body. During vaginal delivery the cervix will soften and widen (or dilate) to allow for the baby to exit through the vagina. 
5. vagina: In structure, the vagina connects the end of the cervix to the outside of the body. It is in the shape of a canal, that is often referred to as the birth canal. In order for reproduction, a male will insert their penis into the vagina, where if ejaculation occurs sperm may pass through the cervix, into the uterus and into the fallopian tubes to allow for fertilization. 

External Structure:

The external structures comprise what is called as the vulva. The structures in the vulva are as follows:

1. Mons Pubis: In structure it is a tissue mound of fat that is found right in front of (or anterior to) the pubic bone. Pubic hair will typically grow here. It has two main functions: It acts as a cushion during intercourse and its sebaceous glands* secrete pheromones.*
2. Labia Majora: In structure it is often described as the larger lips (skin folds) that envelop several other external structures such as the labia minora, clitoris, vulva vestibule, vestibular bulbs, Bartholin's glands, Skene's glands, urethra, and the vaginal opening.  
3. Labia Minora: In structure it is often described as the smaller lips. The anterior of the minora begins at the clitoris and envelops it (or encircles it) forming the hood of the clitoris and then it extends downward to create the boundaries of the vulva vestibule. The labia minora will also encircle the vulva vestibule. The posterior ends (the back ends) will be linked ending the labia minora between the vulva vestibule and the labia majora. 
4. clitoris: The clitoris is a sensory organ. In structure it can be discussed as the glans clitoris and the body of the clitoris. The only visible part of the clitoris is the glans clitoris. The body of the clitoris is really the underlying tissue called the corpus cavernous. This erectile tissue* merges together to protrude as the glans clitoris on the exterior of the vulva. There are thousands of nerves and many blood vessels in the glans clitoris making it very sensitive to stimulation.*
5. Vestibular bulbs: In structure the vestibular bulbs are comprised of a similar erectile tissue as that of the clitoris. There are two bulbs that are located close to the lower (inner) part of the clitoris. They extend towards the urethra and the vaginal opening. The two bulbs will split in order to surround the sides borders of the urethra and the vaginal opening. 
6. Vulva Vestibule: The vulva vestibule is the region between the labia minora (the space enclosed by the labia minora). It is here that the urethra and the vaginal opening are located. As stated before the borders of this structure are the clitoris at the anterior and the labia minora at the posterior. The vulva vestibule is a smooth surface.
7. Bartholin's glands: In structure the Bartholin’s glands are pea-sized and are located slightly to the side and behind (posterior to) the vaginal opening. These two glands produce a mucus-like substance that is secreted into the vagina and onto the surface of the vulva vestibule to act as a lubricant.*
8. Skene's glands: The Skene's glands like the Bartholin's glands are located in the vulva vestibular and are thought to be the lesser of the two types of glands located in the vulva vestibular. There are two Skene's Glands, one on either side of the urethra. They create a lubricant that acts as an antimicrobial* and helps prevent UTIs.*
9. Urethra: In structure it is the exterior opening of a channel-like tube that extends from the bladder from which we urinate. It is located below the clitoris and above the vaginal opening. 
10. Vaginal opening: The vaginal opening is the location of entry into the vagina. 

Vocabulary for Internal Structures:

* follicle: a fluid-filled sac that functions as a shell or outer-casing of an immature egg and works towards egg maturation  

* matured/maturation: occurs after an egg has re-entered meiosis for the second time making it now fertilizable 

      - meiosis: the type of cell division in our reproductive organs that divides one cell twice to result in four cells with half as much genetic info, also known as DNA

* fertilized/fertilization: the combining of a male's sperm with a female's egg to form a zygote (which is simply a fertilized egg)

* progesterone: a hormone that prepares the lining of the uterus for the possibility of becoming pregnant

* estrogen: one of the primary sex hormones in women that is necessary for several bodily processes, such as puberty, the menstrual cycle, pregnancy and bone strength

Vocabulary for Internal Structures: 

* sebaceous glands: glands that secrete an oil-like lubricant into the hair follicles on the mons pubis

* pheromones: a chemical that is secreted to draw a social response (attract) other members of the same species. In this context, it is a chemical that is secreted to sexually attract others.  

* stimulation: arousal usually through physical touch 

* erectile tissue: tissue with large vascular spaces that typically become engorged with blood when aroused 

* lubricant: a substance used to minimize friction 

* antimicrobial: antimicrobials substances that kill microorganisms such as bacteria 

* UTIs: urinary tract infection