21.2 Female Reproductive System Flashcards
cervix
The cervix is the lower part of the uterus, connecting it to the vagina. It allows menstrual blood to exit, sperm to enter, and expands during childbirth to help deliver the baby. The cervix also produces mucus that aids sperm movement during ovulation and acts as a barrier to prevent infections.
embryo
An embryo is the early stage of development in a fertilized egg, beginning after the zygote undergoes its first cell divisions. In humans, this stage lasts from fertilization until about the 8th week of pregnancy, after which it is called a fetus. During the embryonic stage, major organs and body structures, such as the heart, brain, and spinal cord, begin to form. It is a critical period for development, where the foundation for the organism’s structure is laid out
endometrium
The endometrium is the inner lining of the uterus. It plays a key role in the menstrual cycle and pregnancy. During the menstrual cycle, it thickens to prepare for a possible pregnancy. If fertilization doesn’t occur, the endometrium sheds, leading to menstruation. If pregnancy occurs, the embryo implants into the endometrium, where it provides nutrients and support during early development.
fimbriae
The fimbriae are finger-like projections at the ends of the fallopian tubes near the ovaries. They help capture the egg released during ovulation and guide it into the fallopian tube for potential fertilization. The fimbriae move in a waving motion to help direct the egg from the ovary into the tube, where sperm can meet it for fertilization.
glans clitoris
The glans clitoris is the external, highly sensitive part of the clitoris, located at the top of the vulva, where the inner labia meet. It contains a dense concentration of nerve endings, making it a primary source of sexual pleasure in many individuals. The glans is partially covered by a fold of skin called the clitoral hood, which protects it. It plays a key role in sexual arousal and response.
labia majora
The labia majora are the larger, outer folds of skin that form part of the vulva in females. They protect the inner reproductive structures, including the vaginal opening and clitoris. The labia majora are typically covered with pubic hair after puberty and contain sweat and sebaceous glands that help maintain skin health. Their size and shape can vary between individuals.
labia minora
The labia minora are the smaller, inner folds of skin within the vulva. They lie just inside the labia majora and surround the vaginal opening and urethra. The labia minora are rich in nerve endings and blood vessels, making them highly sensitive. They vary greatly in size, shape, and color among individuals. The labia minora also play a role in protecting the internal genital structures and can become more prominent or engorged during sexual arousal.
myometrium
The myometrium is the middle layer of the uterine wall, located between the endometrium (inner lining) and the serosa (outer layer). It consists of smooth muscle tissue and is responsible for the uterine contractions during menstruation, labor, and childbirth. The myometrium plays a crucial role in helping the uterus expand during pregnancy and contract during delivery to facilitate the birth of the baby.
oocyte
An oocyte is an immature egg cell found in the ovaries. It is produced during fetal development and remains dormant until it is activated later in life. Each month during the menstrual cycle, an oocyte matures and is released from the ovary during ovulation. If fertilized by sperm, it becomes a zygote and begins the process of embryonic development. Oocytes are crucial for reproduction, as they are the female gametes involved in fertilization.
oogenesis
Oogenesis is the process of egg (oocyte) development in females. It begins during fetal development, where primordial germ cells divide to form oogonia, which then develop into primary oocytes. These primary oocytes are arrested in prophase I of meiosis and remain dormant until puberty. Each month, during the menstrual cycle, a primary oocyte resumes meiosis, becoming a secondary oocyte that is released during ovulation. If fertilized, the secondary oocyte completes meiosis and becomes a mature egg (ovum). If not fertilized, the oocyte degenerates.
ovaries
The ovaries are the female reproductive organs responsible for producing eggs (oocytes) and secreting hormones, such as estrogen and progesterone. These hormones regulate the menstrual cycle, support pregnancy, and influence the development of secondary sexual characteristics like breast development and body hair. Each ovary contains thousands of follicles, which house the developing eggs. During each menstrual cycle, one or more follicles mature, and an egg is released during ovulation. The ovaries also play a role in hormonal balance and overall reproductive health.
ovulation
Ovulation is the process in which a mature egg (oocyte) is released from the ovary into the fallopian tube. This typically occurs around the middle of the menstrual cycle, triggered by a surge in luteinizing hormone (LH) and follicle-stimulating hormone (FSH). During ovulation, a dominant follicle in the ovary ruptures and releases the egg, which is then available for fertilization by sperm. If the egg is not fertilized within 12–24 hours, it disintegrates and is absorbed by the body. Ovulation is a key part of the female reproductive process and is essential for conception.
uterine tubes
The uterine tubes (also known as fallopian tubes) are a pair of narrow tubes that extend from the uterus toward the ovaries. They are responsible for transporting the egg from the ovary to the uterus. Fertilization typically occurs in the ampulla, the widest part of the fallopian tube, where the egg meets sperm. The fallopian tubes are lined with cilia and smooth muscle that help move the egg toward the uterus. If fertilization occurs, the resulting embryo travels down the tube to implant in the uterine lining.
uterus
The uterus is a hollow, muscular organ located in the female pelvis, where fetal development occurs during pregnancy. It is composed of three main layers: the endometrium (inner lining), which thickens and sheds during the menstrual cycle; the myometrium (middle muscular layer), which contracts during labor and menstruation; and the perimetrium (outer layer), a protective covering. The uterus is connected to the vagina via the cervix, and its primary functions include nurturing a fertilized egg, supporting fetal growth, and expelling the baby during childbirth.
vagina
The vagina is a muscular, tubular structure in females that connects the uterus to the outside of the body. It serves several functions, including the passage for menstrual blood to exit the body, the birth canal during childbirth, and the receptacle for sperm during intercourse. The vagina is lined with mucosal tissue that produces lubrication to facilitate sexual activity and protect against infections. It has a slightly acidic environment to help prevent harmful bacteria and infections.
