Anatomy: The study of form. Gross anatomy involves structures that can be seen with the naked eye. It is as opposed to microscopic anatomy (or histology) which involves structures seen under the microscope. Traditionally, both gross and microscopic anatomy have been studied in the first year of medical school in the U.S. The most celebrated textbook of anatomy in the English-speaking world is Gray's Anatomy, still a useful reference book. The word "anatomy" comes from the Greek ana- meaning up or through + tome meaning a cutting. Anatomy was once a "cutting up" because the structure of the body was originally learned through dissecting it, cutting it up. The abbreviation for anatomy is anat.
Balance: A biological system that enables us to know where our bodies are in the environment and to maintain a desired position. Normal balance depends on information from the inner ear, other senses (such as sight and touch) and muscle movement. See the entire definition of Balance
Bartholin's glands: A pair of glands between the vulva and the vagina that produce lubrication in response to stimulation. With a second pair of nearby glands called the lesser vestibular glands, they act to aid in sexual intercourse. Also called the greater vestibular glands.
Birth control : Birth control is the use of any practices, methods, or devices to prevent pregnancy from occurring in a sexually active woman. Also referred to as family planning, pregnancy prevention, fertility control, or contraception; birth control methods are designed either to prevent fertilization of an egg or implantation of a fertilized egg in the uterus. See the entire definition of Birth control
Bladder: Any pouch or other flexible enclosure that can hold liquids or gases but usually refers to the hollow organ in the lower abdomen that stores urine -- the urinary bladder. The kidneys filter waste from the blood and produce urine, which enters the bladder through two tubes called ureters. Urine leaves the bladder through another tube, the urethra . In women, the urethra is a short tube that opens just in front of the vagina . In men, it is longer, passing through the prostate gland and then the penis . Infection of the bladder is called cystitis . See the entire definition of Bladder
Blood: The familiar red fluid in the body that contains white and red blood cells, platelets, proteins, and other elements. The blood is transported throughout the body by the circulatory system. Blood functions in two directions: arterial and venous. Arterial blood is the means by which oxygen and nutrients are transported to tissues while venous blood is the means by which carbon dioxide and metabolic by-products are transported to the lungs and kidneys, respectively, for removal from the body.
Brain: That part of the central nervous system that is located within the cranium ( skull ). The brain functions as the primary receiver, organizer and distributor of information for the body. It has two (right and left) halves called "hemispheres." See the entire definition of Brain
Cervix: The cervix is the lower, narrow part of the uterus (womb). The uterus, a hollow, pear-shaped organ, is located in a woman's lower abdomen, between the bladder and the rectum. The cervix forms a canal that opens into the vagina, which leads to the outside of the body. See the entire definition of Cervix
Clitoris: A small mass of erectile tissue situated at the anterior apex of the vestibule.
Conception: 1. The union of the sperm and the ovum. Synonymous with fertilization. 2. The onset of pregnancy, marked by implantation of the blastocyst into the endometrium. 3. A basic understanding of a situation or a principle. From the Latin conceptio, conceptionis meaning conception, becoming pregnant; drawing up of legal formulae; and from the Latin conceptus meaning conceiving, pregnancy; collecting, or a collection.
Corpus: The body of the uterus (womb). See the entire definition of Corpus
Dominant: A genetic trait is considered dominant if it is expressed in a person who has only one copy of that gene. (In genetic terms, a dominant trait is one that is phenotypically expressed in heterozygotes). See the entire definition of Dominant
Egg: Ovum (plural: ova).
Embryo: The organism in the early stages of growth and differentiation from fertilization to, in humans, the beginning of the third month of pregnancy . After that point in time, it is termed a fetus. See the entire definition of Embryo
Environment: The sum of the total of the elements, factors and conditions in the surroundings which may have an impact on the development , action or survival of an organism or group of organisms. See the entire definition of Environment
Estrogen: Estrogen is a female hormone produced by the ovaries. Estrogen deficiency can lead to osteoporosis . See the entire definition of Estrogen
Fallopian tube: One of the two Fallopian tubes that transport the egg from the ovary to the uterus (the womb). In the diagram, the Fallopian tubes are not labeled but are well shown running between the uterus and ovaries. See the entire definition of Fallopian tube
Female: The traditional definition of female was "an individual of the sex that bears young" or "that produces ova or eggs". However, things are not so simple today. Female can be defined by physical appearance, by chromosome constitution (see Female chromosome complement), or by gender identification. Female chromosome complement: The large majority of females have a 46, XX chromosome complement (46 chromosomes including two X chromosomes). A minority of females have other chromosome constitutions such as 45,X (45 chromosomes including only one X chromosome) and 47,XXX (47 chromosomes including three X chromosomes).
Fertilization: Fertilization is the process of combining the male gamete, or "sperm," with the female gamete, or "ovum." The product of this combination is a cell called a zygote.
Fetus: The unborn offspring from the end of the 8th week after conception (when the major structures have formed) until birth. Up until the eighth week, the developing offspring is called an embryo.
Foreskin: The fold of skin which covers the head (the glans) of the penis. Also called the prepuce. See the entire definition of Foreskin
Genital: Pertaining to the external and internal organs of reproduction. (Not to be confused with genetic.)
Gynecology: The branch of medicine particularly concerned with the health of the female organs of reproduction and diseases thereof. See the entire definition of Gynecology
Hormone: A chemical substance produced in the body that controls and regulates the activity of certain cells or organs. See the entire definition of Hormone
Implant: 1. To embed; to set in firmly. In embryology, the fertilized egg implants in the uterine lining 6 or 7 days after conception (fertilization). In medicine today, many things may be implanted. 2. That which is embedded. For example: lens implants, breast implants, cochlear implants, defibrillator implants, pacemaker implants, etc.
Labia: The lips , either the lips around the mouth (the oral labia) or the lip-like external female genitalia (the labia majora and labia minora ). See also: Labial ; Labrose . See the entire definition of Labia
Labia majora: The larger (major) outside pair of labia (lips) of the vulva (the female external genitalia).
Labia minora: The smaller (minor) inside pair of labia (lips) of the vulva (the female external genitalia).
Lips: Aside from the lips of the mouth, there are two pairs of lips at the entrance to the vagina. They are the labia majora (the larger outside pair) and the labia minora (the smaller inside pair). Together they form part of the vulva (the female external genitalia).
Luteinizing hormone: A hormone released by the pituitary gland in response to luteinizing hormone- releasing hormone. Abbreviated LH, it controls the length and sequence of the female menstrual cycle, including ovulation, preparation the uterus for implantation of a fertilized egg, and ovarian production of both estrogen and progesterone. In males, it stimulates the testes to produce androgen. Also known as interstitial-cell-stimulating hormone (ICSH).
Menopause : The time in a woman's life when menstrual periods permanently stop; it is also called the "change of life." Menopause is the opposite of the menarche. See the entire definition of Menopause
Menstrual: Pertaining to menstruation (the menses), as in last menstrual period, menstrual cramps, menstrual cycle, and premenstrual syndrome. From the Latin menstrualis, from mensis meaning month.
Menstrual cycle: The monthly cycle of changes in the ovaries and the lining of the uterus (endometrium), starting with the preparation of an egg for fertilization. When the follicle of the prepared egg in the ovary breaks, it is released for fertilization and ovulation occurs. Unless pregnancy occurs, the cycle ends with the shedding of part of the endometrium, which is menstruation. Although it is actually the end of the physical cycle, the first day of menstrual bleeding is designated as "day 1" of the menstrual cycle in medical parlance.
Menstruation: The periodic blood that flows as a discharge from the uterus. Also called menorrhea, the time during which menstruation occurs is referred to as menses. The menses occurs at approximately 4 week intervals to compose the menstrual cycle.
Mucous: Pertaining to mucus, a thick fluid produced by the lining of some tissues of the body. See the entire definition of Mucous
Mucus: A thick slippery fluid produced by the membranes lining certain organs such as the nose, mouth, throat, and vagina. Mucus is the Latin word for "a semifluid, slimy discharge from the nose." Note that mucus is a noun while the adjective is mucous.
Obstetrics: The art and science of managing pregnancy, labor and the puerperium (the time after delivery).
Organ: A relatively independent part of the body that carries out one or more special functions. The organs of the human body include the eye, ear, heart, lungs, and liver.
Ova: Plural form of ovum. See the entire definition of Ova
Ovary: The female gonad, the ovary is one of a pair of reproductive glands in women. They are located in the pelvis, one on each side of the uterus. Each ovary is about the size and shape of an almond. The ovaries produce eggs (ova) and female hormones. During each monthly menstrual cycle, an egg is released from one ovary. The egg travels from the ovary through a fallopian tube to the uterus. The ovaries are the main source of female hormones, which control the development of female body characteristics, such as the breasts, body shape, and body hair. They also regulate the menstrual cycle and pregnancy.
Ovulation: The release of the ripe egg from the ovary. The egg is released when the cavity surrounding it (the follicle) breaks open in response to a hormonal signal. Ovulation occurs around fourteen or fifteen days from the first day of the woman's last menstrual cycle. When ovulation occurs, the ovum moves into the fallopian tube and becomes available for fertilization.
Ovulatory: Relating to ovulation, the release of the ovum (the egg) from the ovary.
Penis: The external male sex organ used to copulate and ejaculate semen and to convey urine outside the body. In Latin, the word "penis" originally meant "a tail ." The Latin "penis" is related to the verb pendere meaning "to hang down." See the entire definition of Penis
Pregnancy: The state of carrying a developing embryo or fetus within the female body. This condition can be indicated by positive results on an over-the-counter urine test, and confirmed through a blood test, ultrasound, detection of fetal heartbeat, or an X-ray. Pregnancy lasts for about nine months, measured from the date of the woman's last menstrual period (LMP). It is conventionally divided into three trimesters, each roughly three months long. See the entire definition of Pregnancy
Pregnant: The state of carrying a developing fetus within the body. See the entire definition of Pregnant
Prepuce: The fold of skin that covers the head of the penis. Also known as the foreskin. See the entire definition of Prepuce
Progesterone: A female hormone and the principal progestational hormone that is made mainly by the corpus luteum in the ovary and by the placenta. Progesterone prepares the lining (endometrium) of the uterus (the womb) to receive and sustain the fertilized egg and so permits pregnancy. Similarly refers to synthetic versions of the hormone. Also known as progestational hormone.
Puberty: A complex biologic and psychologic process involving sexual development, accelerated growth, and adrenal maturation heralded by the secretion of gonadotropin releasing hormone (GnRH) from a part of the brain called the hypothalamus . This event is the first known step in the reproductive cascade. It initiates the pulsatile release of gonadotropins , gonadal secretion of sex steroids, pubertal development, and gametogenesis (the production of sperm and ova ). See the entire definition of Puberty
Reproduction: The production of offspring. Reproduction need not be sexual. Yeast can reproduce by budding. See the entire definition of Reproduction
Reproductive system: In women, the organs that are directly involved in producing eggs and in conceiving and carrying babies. In men, the organs directly involved in creating, storing, and delivering sperm to fertilize an egg. See the entire definition of Reproductive system
Scrotum: A pouch of skin which contains the testes, epididymides, and lower portions of the spermatic cords.
Skin: The skin is the body's outer covering. It protects us against heat and light, injury, and infection. It regulates body temperature and stores water, fat, and vitamin D. Weighing about 6 pounds, the skin is the body's largest organ. It is made up of two main layers; the outer epidermis and the inner dermis. See the entire definition of Skin
Sperm: A sperm is the male "gamete" or sex cell. It combines with the female "gamete," called an ovum, to form a zygote. The formation process is called "fertilization." (see ovum, zygote).
Sweat: A colorless transparent acidic fluid with a distinctive odor secreted by the small tubular sudoriferous (sweat) glands situated within the skin and under it in the subcutaneous tissue . The sweat glands discharge their fluid through tiny openings in the surface of the skin. See the entire definition of Sweat
Trigger: Something that either sets off a disease in people who are genetically predisposed to developing the disease, or that causes a certain symptom to occur in a person who has a disease. For example, sunlight can trigger rashes in people with lupus.
Tubes: The "tubes" are medically known as the Fallopian tubes. There are two Fallopian tubes, one on each side, which transport the egg from the ovary to the uterus (the womb). The Fallopian tubes have small hair-like projections called cilia on the cells of the lining. See the entire definition of Tubes
Urethra: The transport tube leading from the bladder to discharge urine outside the body. In males, the urethra travels through the penis, and carries semen as well as urine. In females, the urethra is shorter than in the male and emerges above the vaginal opening, as indicated here:
Urine: Liquid waste. The urine is a clear, transparent fluid. It normally has an amber color. The average amount of urine excreted in 24 hours is from 40 to 60 ounces (about 1,200 cubic centimeters). Chemically, the urine is mainly an aqueous (watery) solution of salt (sodium chloride) and substances called urea and uric acid. Normally, it contains about 960 parts of water to 40 parts of solid matter. Abnormally, it may contain sugar (in diabetes), albumen (a protein) (as in some forms of kidney disease), bile pigments (as in jaundice), or abnormal quantities of one or another of its normal components.
Uterine lining: The inner layer of the uterus (womb); the cells that line the womb; anatomically termed the endometrium. See the entire definition of Uterine lining
Uterus: The uterus (womb) is a hollow, pear-shaped organ located in a woman's lower abdomen between the bladder and the rectum. The narrow, lower portion of the uterus is the cervix; the broader, upper part is the corpus. The corpus is made up of two layers of tissue. See the entire definition of Uterus
Vagina: The muscular canal extending from the cervix to the outside of the body. It is usually six to seven inches in length, and its walls are lined with mucus membrane . It includes two vaultlike structures, the anterior (front) vaginal fornix and the posterior (rear) vaginal fornix . The cervix protrudes slightly into the vagina, and it is through a tiny hole in the cervix (the os) that sperm make their way toward the internal reproductive organs. The vagina also includes numerous tiny glands that make vaginal secretions. See the entire definition of Vagina
Vaginal opening: The opening to the muscular canal extending from the cervix to the outside of the body. The word "vagina" is a Latin word meaning "a sheath or scabbard", a scabbard into which one might slide and sheath a sword. The "sword" in the case of the anatomic vagina was the penis. Love and war, it would seem, have been connected in the minds of people for millennia. See the entire definition of Vaginal opening
Womb: The womb (uterus) is a hollow, pear-shaped organ located in a woman's lower abdomen between the bladder and the rectum. The narrow, lower portion of the uterus is the cervix; the broader, upper part is the corpus. The corpus is made up of two layers of tissue. See the entire definition of Womb
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