Assigned Female at Birth

Internal Anatomy | External Anatomy
Puberty & Menstruation
Related Health Conditions

Internal Anatomy

  • Uterus: The uterus (also known as the “womb”) is a hollow organ that is about the size and shape of an upside-down pear, sitting between the bladder, which is in front of it, and the rectum, which is behind it. The uterus is where a fetus (unborn baby) develops and grows. It sheds its lining (endometrium) each month during menstruation (a period) if no fertilized egg (ovum) becomes implanted (pregnancy). 
  • Ovaries: Typically, there are two ovaries, where eggs are developed and stored. A person with a uterus is born with all the eggs they will ever have. Each month, one egg will mature and leave an ovary, which is called ovulation. The ovaries also make the hormones estrogen and progesterone, which help ensure a healthy pregnancy.
  • Fallopian tubes: There are typically two fallopian tubes, one next to each ovary. Once an egg leaves an ovary, it travels through the fallopian tube toward the uterus. An egg can only live for 12-24 hours. If there is sperm in the fallopian tubes when the egg leaves the ovary, the egg can be fertilized. If the egg does not meet with sperm, it disintegrates and the endometrial lining is shed.
  • Cervix: the cervix is the opening of the uterus. It has a tiny hole that semen (fluid containing sperm) travels through to get to the fallopian tubes. This hole is too small to allow anything else to get through. During birth, the cervix expands to allow the baby to pass through.
  • Vagina: The vagina is a muscular tube that serves three purposes: it is where the penis is inserted during sex, it is how menstrual blood leaves the body during periods, and it is the pathway for a baby to leave the body during childbirth (the birth canal). Because it is a muscle, it can stretch and lengthen to accommodate something as slim as a tampon and as wide as a baby.
External Anatomy

  • Vulva: The vulva is the external anatomy of a person assigned female at birth. All of the components below together make up the vulva.
  • Labia: the vulva has two sets of labia (lips). The inner labia are folds of skin around the vaginal opening. The outer labia are folds of skin and fat around the inner labia. Everyone’s labia look a bit different.
  • Hymen: The hymen is a thin piece of tissue that partially or completely covers the vaginal opening. The hymen may break the first time someone has vaginal sex, but it may also widen or break during activities, sports, or using a tampon. Some people do not have a hymen.
  • Vaginal Opening: The vaginal opening is the outside part of the vagina. It is where vaginal and menstrual fluid leave the body, where a tampon or penis is inserted, and where a baby leaves the body during childbirth.
  • Urethral (Urinary) Opening: The urethral opening is where urine (pee) leaves the body. It is just above the vaginal opening. Unlike the anatomy of a person assigned male, only urine leaves through this opening.
  • Clitoris: The clitoris is just above the urethral opening and extends inside the body. It is made of tissue and is full of nerve endings. Its purpose is to give sexual pleasure.
  • Mons Pubis: The mons pubis is a pad of protective tissue and skin over the pubic bone. During puberty, the area becomes covered with hair.
Puberty & Menstruation

If you’re between 8 and 14 years old, you’ve probably started to go through puberty. During this time, the body changes from a child to a young adult. Puberty happens earlier for some than others, but eventually everyone experiences it. 

This won’t happen all at once; changes will happen slowly over a few years and will include physical, emotional, and social changes.

  • Develop breasts
  • Hips get wider
  • Menstruation starts (you get your period)
  • Labia may change color and grow bigger
  • May get acne (zits or pimples)
  • Start to sweat more, and may have body odor
  • Grow hair in your armpits, on your arms and legs, and around your genitals
  • May have stronger/more intense emotions (including mood swings)
  • May experience more sexual thoughts and urges

During puberty, people with a uterus will start menstruating, or getting their period. The period is part of the menstrual cycle, which is how the body gets ready for a possible pregnancy each month. Changes in hormones, like estrogen and progesterone, tell your body to build up the lining of the uterus so that it will be ready for a fertilized egg (when sperm combines with an egg) to attach and start a pregnancy.

If there is no pregnancy, the body does not need the thick lining in the uterus. The lining will break down, and the blood, nutrients, and tissue flow out through the vagina – this is what is referred to as a period. Although it looks like a lot of blood, usually only a few tablespoons come out for the whole period. It happens about every 21-35 days, and lasts for between two and seven days. 

Some people get cramps or other symptoms right before and/or during their period. This is called PMS, or Premenstrual Syndrome. Some people get PMS every time they have their periods, and others may only experience it every once in a while or not at all. PMS happens when the hormones that control the menstrual cycle cause changes to your body and emotions.

Some of the most common symptoms are cramps, bloating, acne, sore breasts, feeling tired, and mood swings. Cramps are one of the most common symptoms to have. Sometimes they can be pretty painful. Here’s more information on how to deal with cramps.

What to do when your period starts

It is okay to feel nervous or anxious about starting your period. It can help to talk with an adult you trust about what to expect, and it’s a good idea to carry some supplies just in case. There are a few ways to deal with period blood, and you may need to try more than one to find out which works best for you. It may even be a combination of different methods. 

  • Pads: Pads are made of cotton, and they come in a lot of different shapes and sizes. They have a sticky strip to attach to the underwear, and they absorb the blood after it leaves the vagina.
  • Tampons: A tampon is a cotton plug that is inserted into the vagina and absorbs the blood as it leaves the uterus. Most come with an applicator to help guid the tampon into place. Tampons should not be left in place for more than 8 hours, because this can increase the risk of a serious infection called toxic shock syndrome.
  • Menstrual cups: Menstrual cups are little bells or bowls made of rubber, silicone, or soft plastic. The cup is inserted into the vagina where it collects blood as it leaves the uterus. Most menstrual cups are reusable – they can be emptied, washed, and used again. Some are disposable and are thrown away after one use or one cycle.
  • Period underwear: Period underwear are just like regular underwear, but they have extra layers of fabric to absorb blood during your period. They can be worn on their own or with a tampon or menstrual cup for heavier flows. Then they are washed and can be used again and again.

Starting in the 2022-2023 school year, feminine hygiene products, specifically tampons and pads (sanitary napkins), are required by Rhode Island law to be available and free to public school students. These products should be in all female and gender-neutral rest rooms in Rhode Island public schools that serve students in grades 5-12.

Related Health Conditions

Urinary Tract Infections (UTIs)

A UTI is an infection in the bladder, often caused by bacteria from the skin or rectum. UTIs are not contagious, but it is still possible to get a UTI during sex, if bacteria already in the vaginal area is pushed into the urethra and makes its way to the bladder. Using spermicides and diaphragms may increase the risk of getting a UTI – if you use these methods and have had a UTI, you may want to consider a different method of contraception.

If you have a UTI, you may experience pain or burning when urinating, frequent urination (but very little may come out), fever, belly pain around the bladder (typically below the belly button), or your urine may smell bad, be cloudy, or have blood in it. If you experience any of these symptoms, you need to see a healthcare provider right away. UTIs won’t get better on their own, but they can be treated easily with antibiotics prescribed by a healthcare provider.  Learn more


Endometriosis is a serious and often painful condition that happens when tissue that looks and acts like the endometrium (lining of the uterus) grows outside the uterus. This tissue can grow on the ovaries, fallopian tubes, bladder, outer surface of the uterus, and the ligaments that support the uterus.

Endometriosis often causes very painful periods, heavy bleeding, and can even make it more difficult to become pregnant. There’s no cure, but treatment can help with the symptoms. Learn more

Polycystic ovary syndrome (PCOS)

Polycystic ovary syndrome (PCOS) is a condition related to an imbalance of hormones called androgens. With PCOS, small sacs of fluid (cysts) grow along the outer edge of the ovary. These cysts contain immature eggs that may not be released regularly during ovulation as they should.

People with PCOS may have irregular periods, or they may not have periods at all. Other signs of PCOS include obesity, severe acne, patches of thick, darkened skin, excess hair growth on the face, chest, abdomen, or upper thighs, and infertility. Learn more

Ovarian Cysts

An ovarian cyst is a sac of fluid on or in an ovary. Most cysts are tiny, but they can range in size. They are very common – most people with ovaries have cysts at some point in their life.

Most cysts disappear on their own, but occasionally they grow bigger and don’t go away. It’s rare, but sometimes cysts can break open (rupture). Sudden, intense pain on one side of your lower belly, vomiting, feeling faint, and having a fever are all signs to get medical care right away. Learn more

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