Anatomy and physiology Flashcards
Anatomy and Physiology
The female reproductive system is designed to produce and transport ova (female sex cells), discharge ova from the body if fertilization does not occur, and nourish and provide a place for the developing fetus throughout pregnancy if fertilization occurs. The female reproductive system also produces the female sex hormones estrogen and progesterone, which play an important role in the reproductive process. These hormones are responsible for the development of secondary sex characteristics, such as breast development and regulation of the menstrual cycle.
Sex, or reproductive, organs visible on the outside of the body; are also called the vulva. Male genitalia include the penis, scrotum, and testicles.
External genitalia
Length of time from conception to birth
The human ____ period typically extends approximately 280 days from the last menstrual period. _____ (pregnancy) of less than 36 weeks is considered premature.
Gestation3x
Production and release of milk by mammary glands
Lactation
Lact: milk
Ation: process of
Mouth; entrance, or outlet of any anatomical structure
Orifice
Female Reproductive Structures
The female reproductive system is composed of the internal organs of reproduction and the external genitalia. (See Fig. 12-1.) The internal organs include the (1) ovaries, (2) fallopian tubes, (3) uterus, and (4) vagina. The external genitalia are collectively known as the vulva. Included in these structures are the (5) labia minora, (6) labia majora, (7) clitoris, (8) Bartholin glands, and mons pubis, an elevation of adipose tissue covered by skin and coarse pubic hair that cushions the pubis (pubic bone). The area between the vaginal orifice and the anus is known as the perineum.
Female Reproductive Organs
The female reproductive organs include the ovaries, fallopian tubes, uterus, and vagina. They are designed to produce female reproductive cells (ova), transport the cells to the site of fertilization, provide a favorable environment for a developing fetus through pregnancy and childbirth, and produce female sex hormones. Hormones play an important role in the reproductive process, providing their influence at critical times during preconception, fertilization, and gestation. (See Fig. 12-2, page 398.)
Ovaries
The (1) ovaries are almond-shaped glands located in the pelvic cavity, one on each side of the uterus. Each ovary contains thousands of tiny, saclike structures called (2) graafian follicles, each containing an ovum. When an ovum ripens, the (3) mature follicle moves to the surface of the ovary, ruptures, and releases the ovum in a process called ovulation. After ovulation, the empty follicle transforms into a structure called the (4) corpus luteum, a small yellow mass that secretes estrogen and progesterone. The corpus luteum degenerates at the end of a nonfertile cycle. Estrogen and progesterone influence the menstrual cycle and menopause. They also prepare the uterus for implantation of the fertilized egg, help maintain pregnancy, promote growth of the placenta, and play an important role in development of secondary sex characteristics.
Fallopian Tubes
Two (5) fallopian tubes (oviducts, uterine tubes) extend laterally from superior angles of the uterus. The (6) fimbriae are fingerlike projections that create wavelike currents in fluid surrounding the ovary to move the ovum into the uterine tube. If the egg unites with a spermatozoon, the male reproductive cell, fertilization (or conception) takes place. The fertilized egg then continues its journey to the uterus, where it implants on the uterine wall. If conception does not occur, the ovum disintegrates within 48 hours and is discharged through the vagina.
Uterus and Vagina
The (7) uterus contains and nourishes the embryo from the time the fertilized egg is implanted until the fetus is born. It is a muscular, hollow structure shaped like an inverted pear and is located in the pelvic area between the bladder and rectum. The uterus normally tilts forward (anteflexion) in the pelvic cavity and consists of three parts: the (8) fundus, the upper, rounded part; the (9) body, the central part; and the (10) cervix, also called the neck of the uterus or cervix uteri, the inferior constricted portion that opens into the vagina.
The (11) vagina is a muscular tube that extends from the cervix to the exterior of the body. Its lining consists of folds of mucous membrane that give the organ an elastic quality. During sexual excitement, the vaginal orifice is lubricated by secretions from (12) Bartholin glands. In addition to serving as the organ of sexual intercourse and receptor of semen, the vagina discharges menstrual flow. It also acts as a passageway for the delivery of the fetus. The clitoris, located anterior to the vaginal orifice, is composed of erectile tissue that is richly innervated with sensory endings. The clitoris is similar in structure to the penis in the male, but it is smaller and has no urethra. The area between the vaginal orifice and the anus is known as the perineum. During childbirth, this area may be surgically incised (episiotomy) to enlarge the vaginal opening for delivery.
Mammary Glands
Although mammary glands (breasts) are present in both sexes, they function only in females. (See Fig. 12-3.) The breasts are not directly involved in reproduction but become important after delivery. Their biological role is to secrete milk for the nourishment of the newborn, a process called lactation. Breasts begin to develop during puberty as a result of periodic stimulation of the ovarian hormones estrogen and progesterone and are fully developed by age 16. Estrogen is responsible for the development of (1) adipose tissue, which enlarges the size of the breasts until they reach full maturity. Breast size is primarily determined by the amount of fat around the glandular tissue but is not indicative of functional ability. Each breast is composed of 15 to 20 lobules of milk-producing glands that are drained by a (2) lactiferous duct, which opens on the tip of the raised (3) nipple. Circling the nipple is a border of slightly darker skin called the (4) areola. During pregnancy, the breasts enlarge and remain so until lactation ceases. At menopause, breast tissue begins to atrophy.
Menstrual Cycle
Menarche, the initial menstrual period, occurs at puberty (about age 12), and menstruation continues for approximately 40 years, except during pregnancy. The menstrual cycle consists of a series of phases, during which the uterine endometrium changes as it responds to changing levels of ovarian hormones. (See Table 12-1.) The duration of the menstrual cycle is approximately 28 days. (See Fig. 12-4.)
Pregnancy
During pregnancy, the uterus changes its shape, size, and consistency. It increases greatly in size and muscle mass; houses the growing placenta, which nourishes the embryo-fetus; and expels the fetus after gestation. To prepare to serve as the birth canal at the end of pregnancy, the vaginal canal elongates as the uterus rises in the pelvis. The mucosa thickens, secretions increase, and the vascularity and elasticity of the cervix and vagina become more pronounced.
The average pregnancy (gestation) lasts approximately 9 months and is followed by childbirth (parturition). Up to the third month of pregnancy, the product of conception is referred to as the embryo. From the third month to the time of birth, the unborn offspring is referred to as the fetus.
Uterine endometrium sloughs off because of hormonal stimulation, a process accompanied by bleeding. The detached tissue and blood are discharged through the vagina as menstrual flow.
 menstrual days one through five
When menstruation ceases, the endometrium begins to thicken as new tissue is rebuilt. As the estrogen level rises, several ova begin to mature in the graafian follicles, usually with only one ovum reaching full maturity. At about the 14th day of the cycle, the graafian follicle ruptures, releasing the egg, a process called ovulation. The egg then leaves the ovary and travels down the fallopian tube toward the uterus.
Ovulatory day six – 14
The empty graafian follicle fills with a yellow material and is now called the corpus luteum. Secretions of estrogen and progesterone by the corpus luteum stimulate the building of the endometrium in preparation for implantation of an embryo. If fertilization does not occur, the corpus luteum begins to degenerate as estrogen and progesterone levels decrease.* With decreased hormone levels, the uterine lining begins to shed, the menstrual cycle starts over again, and the first day of menstruation begins.
Days 15–28 post ovulatory
Some women experience a loose grouping of symptoms called premenstrual syndrome (PMS). These symptoms usually occur about 5 days after the decrease in hormone levels and include nervous tension, irritability, headaches, breast tenderness, and a feeling of depression.
Pregnancy also causes enlargement of the breasts, sometimes to the point of pain. Many other changes occur throughout the body to accommodate the development and birth of the fetus. Toward the end of gestation, the myometrium begins to contract weakly at irregular intervals. At this time, the full-term fetus is usually positioned head down within the uterus.
Labor and Childbirth
Labor is the physiological process by which the fetus is expelled from the uterus. Labor occurs in three stages. The first is the stage of dilation, which begins with uterine contractions and terminates when there is complete dilation of the cervix (10 cm). The second is the stage of expulsion, the time from complete cervical dilation to birth of the baby. The last stage is the placental stage, or afterbirth. This stage begins shortly after childbirth when the uterine contractions discharge the placenta from the uterus. (See Fig. 12-5, page 402.)
Menopause
Menopause is the cessation of ovarian activity and diminished hormone production that occurs at about age 50. Menopause is usually diagnosed if absence of menses (amenorrhea) has persisted for 1 year. The period in which symptoms of approaching menopause occur is known as the change of life or the climacteric.
Many women experience hot flashes and vaginal drying and thinning (vaginal atrophy) as estrogen levels fall. Although hormone replacement therapy (HRT) has become more controversial, it is still used to treat vaginal atrophy and porous bones (osteoporosis), and it is believed to play a role in heart attack prevention. Restraint in prescribing estrogens for long periods in all menopausal women arises from concern that there is an increased risk that long-term usage will induce neoplastic changes in estrogen-sensitive aging tissue.
Blood, Lymphatic, and Immune
• The female immune system has special mechanisms that inhibit destruction of sperm cells.
• The female reproductive tract secretes enzymes and other substances that inhibit entry of pathogens into the internal reproductive structures.
Cardiovascular
• Estrogens lower blood cholesterol levels and promote cardiovascular health in premenopausal women.
Digestive
• Estrogens have an effect on the metabolic rate.
Endocrine
• Estrogens provide a feedback mechanism that influences pituitary function.
• Estrogens assist in the production of human chorionic gonadotropin (HCG) hormone.
Integumentary
• Female hormones affect growth and distribution of body hair.
• Female hormones influence the activity of sebaceous glands.
• Female hormones influence skin texture and fat distribution.
Male Reproductive
• The female reproductive system provides the ovum needed to make fertilization by sperm possible.
Musculoskeletal
• Estrogen influences muscle development and size.
• Estrogen influences bone growth, maintenance, and closure of epiphyseal plates.
Nervous
• Estrogen affects central nervous system development and sexual behavior.
• Estrogen provides antioxidants that have a neuroprotective function.
Respiratory
• Sexual arousal and pregnancy produce changes in the rate and depth of breathing.
• Estrogen is believed to provide a beneficial effect on the alveoli of the lungs.
Urinary
• Kidneys dispose of nitrogenous wastes and maintain the homeostatic mechanisms of the mother and fetus.
amni/o
amnion (amniotic sac) amni/o/centesis (ăm-nē-ō-sen-TĒ-sĭs): surgical puncture of the amniotic sac
-centesis: surgical puncture
Amniocentesis is performed under ultrasound guidance using a needle and syringe to remove amniotic fluid.
