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98 Cards in this Set
- Front
- Back
chromosome
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In the nucleus of every cell, the chromosomes contain the genetic material of an individual, in the form of Deoxyribonucleic acid (DNA). They are visible during cell division, and in humans there are 23 pairs of homologous chromosomes which code for the phenotype and genotype of each individual.
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sexual reproduction
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genes from two individuals coming together to form one individual with the same number or chromosomes.
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fetus
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developing human embryo 8 weeks after fertilization.
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semen
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whitish fluid secreted by male reproductive tract. carries sperm
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sperm
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single-celled swimming organisms in semen that propel themselves by beating tails. carries male genetic material. made of three sections head (chromosomes) body(energy/mitochondria), tail(propulsion).
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ovum
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egg. holds female genetic material
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fertilization
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The joining of a single egg and a single sperm cell so that the genetic material can combine to form a new, unique individual, fertilization is key to sexual reproduction.
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mitosis
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cell division where chromosome # remains constant.
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spindle
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fibrous attachment that connects chromosomes to centrioles during cell division.
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centromeres
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point of attachment of chromosomes to spindle during mitotic division.
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crossing over
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in meiosis, exchange of genetic material between maternal and paternal chromosomes, mixing genetic material (alleles) important to evolution.
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gametes
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reproductive cells of males and females
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oogonia
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primary germ cell which gives rise to ova.
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haploid
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half the # of chromosomes - of parent organisms, as in sperm and ova which come together through fertilization to form one individual with the correct # of chromosomes (diploid.)
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polar body
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non-functional infertile daughter cells formed during oogenesis, these are eventually reabsorbed.
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sexual differentiation
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process by which a human becomes male or female, depending on whether a Y chromosome is present. If present, changes happen at 7th week of gestation to create male versus female gender.
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X chromosome
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one of the human chromosomes responsible for determining gender. Females have two X chromosomes while males have one X and one Y sex chromosome.
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y chromosome
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when present, causes sexual differentiation into male gender at 7th week of gestation, causing development of male reproductive organs.
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diploid
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refers to organisms created via sexual reproduction having PAIRS of homologous chromosomes (one each from mom/dad) as opposed to one chromosome set which is termed as haploid.
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meiosis
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cell division in which chromosome # is half that of the parent cell. occurs in ovaries and testes to generate reproductive cells (haploid.)
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spermatogonia
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primary germ cell which gives rise to sperm daughter cells: spermatocytes which become sperm.
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genotype
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genetic makeup of an individual
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testes
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male sperm-producing organ
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testosterone
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male sex hormone produced by the testes which directs development of male reproductive organs and is secreted throughout life. testosterone secretion feeds back to hypothalamus to inhibit secretion of GnRH
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secondary sexual characteristics
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external characteristics which distinguish males from females - body shape, hair distribution, voice differences.
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primary sexual characteristics
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the main reproductive & genital structures of males and females
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seminiferous tubule
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long tubules in the testes through which sperm move to the epididymis.
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epidiymis
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the oblong body in males surrounding the testes where sperm move via the seminiferous tubule to be stored in and to mature.
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ejaculation
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reflex discharge of semen from the penis initiated by parasympathetic reflexes. sperm is forced into the urethra by contraction ofthe epididymus and seminal vessicles and mucous-like fluid is added from seminal vessicles.
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prostate
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supplies nutrients and other substances to fluid that is added to sperm
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gonadotropin-releasing hormone (GnRH)
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secreted at puberty by the hypothalamus, transported via blood to anterior pituitary which it stimulates to release LH and FSH.
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luteinizing hormone (LH)
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stimulates leydig cells to increase testosterone production.
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follicle stimulating hormone (FSH)
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acts on sertoli cells of testes, promotes spermatogenesis.
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sertoli cells
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cells in testicles, promote spermatogenesis, secrete inhibin
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leydig cells
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located in the testes, these produce testosterone
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inhibin
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acts on anterior pituitary to inhibit secretion of FSH. secreted from sertoli cells of testes.
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glans penis
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end muscular portion of penis - richly supplied with nerves.
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erection
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distension of the erectile tissue of the penis caused by increased arterial pressure and compression of venous sinuses in penis.
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emission
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contraction of the vas deferens, ampulla, seminal vessicles, and prostate, pushing semen to the base of urethra causing ejaculation.
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orgasm
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emission + ejaculation in males
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ovaries
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produce eggs or ova - 1/2 the genetic material required to make humans.
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fallopian tubes
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carry eggs to the uterus.
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uterus
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organ where fetus develops
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cervix
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narrowed end of uterus
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vagina
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canal which connects uterus to outside
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vulva
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collective term for female external genitalia.
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labia minora
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one of the pair of skin folds at the external opening of the vagina.
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clitoris
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erectile tissue in females, homologous to the penis, richly supplied with nerve endings.
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hymen
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thin membrane of tissue which may partially close the vagina.
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estrogen
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major female hormone secreted by the ovaries
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areola
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area surrounding the nipple
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menstrual cycle
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periodic maturation of an oocyte in the ovary, coupled with physical changes in uterus, once monthly over roughly a 30 yr. period.
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menarche
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first period, which begins menstruation.
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primary follicle
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flattened layer of cells in the ovary which oocytes are imbedded.
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graafian follicle
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primary follicles mature into secondary follicles, then grow, fill with fluid and mature further into graafian follicles.
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ovulation
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release of the ovum from the ovary into the fallopian tube.
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zygote
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fertilized ovum - diploid (combined sperm and ova genetic material)
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corpus luteum
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"yellow body" the name of the graafian follicle after it has burst to release the ovum. It fills with a yellowish fluid, secretes hormones that help to maintain the uterus if the ovum is fertilized.
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endometrium
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the lining of the uterus which exudes nutrient-rich secretions if a fertilized ovu reaches it.
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menstruation
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if fertilization doesn't occur, the uterus sheds the endometrium and some blood through the process called menstruation.
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progesterone
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secreted by the corpus luteum witho ovulation, progesterone stimulates growth, integrity and glandular function of the endometrium.
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premenstrual syndrome
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PMS cluster of symptoms preceding menstuation - cause is not well known.
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menopause
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cessation of menstrual cycle, accompanied by by diminished estrogen and progesterone secretion
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fertilization
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fusing of sperm with ovum to begin pregnancy.
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capacitation
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Once several hundred (of several million starting out) sperm make it into the uterus, they rest there and undergo capacitation, which is the removal of a layer of protein molecules from their surface. This then makes it possible for them to be able to fuse with, thus fertilizing, an ovum.
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activation
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changes that happen to sperm in region of the ovu to make sperm able to fuse with ovum. They take on a lurching motion during this process.
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embryo
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developing organism from fertilization until about 8 weeks.
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morula
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about three days after fertilization, multiple mitotic divisions transform the single cell into a morula - a compact body of about 16 cells.
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blastocyst
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additional cell divisions cause the morula to enlarge to become a fluid filled bundle of cells - blastocyst is therefore ready for implantation.
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placenta
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evident at five weeks, this structure connects the developing embryo and nourishes it from the mothers blood until birth.
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fetus
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at the end of the first trimester, the embryo is called a fetus.
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teratogens
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substances which produce birth defects, including alcohol.
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fetal alcohol syndrome (FAS)
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damage caused to the fetus by the mother consuming alcohol during pregnancy. malformed limbs and face and severe mental deficiency are symptoms.
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parturition
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birth
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oxytocin
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posterior pituitary hormone which plays an active role in lactation and in stimulation of uterine contractions during parturition.
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afterbirth
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following birth, the placental detachment and explusion from the uterine wall.
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lactation
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milk secretion from the breasts, stimulated by prolactin.
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prolactin
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hormone which stimulates milk production by breast glandular tissue
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milk let-down
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ejection of milk from the breast stimulated by oxytocin secretion from the posterior pituitary.
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condom
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barrier method of contraception - places a thin rubber sheath over the penis to prevent insemination of the uterus.
pro- prohibits STD's for the most part. Con - doesn't always work. |
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diaphragm
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barrier method where a circular ring of rubber is placed over cervix to act as a barrier to prevent insemination - used with spermicide. Pro - works sometimes. Con - doesn't always work, fiddly.
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cervical cap
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- like diaphragm only smaller. Con - doesn't always work
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sterilization
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methods by which people are made incapable of reproducing. includes tubal ligation and vasectomy. Pro: works. Con: doesn't prevent STD's, and is sometimes irreversible.
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tubal ligation
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surgical cutting and tieing off of fallopian tubes in a female - prevents ovum from reaching fallopian tubes. Pro- works. Con - irreversible, doesn't prevent STD's.
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vasectomy
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cutting and tieing off of the vas deferens in males. prevents sperm from entering seminal fluid. Pro- works. Con - sometimes irreversible, doesn't prevent STD's.
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oral contraception.
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alters hormonal patterns in females so that ovulation cannot occur. Pro - usually works if taken properly. Con - sometimes not taken properly, doesn't prevent STD's.
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intrauterine device.
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small plastic or metal device placed in uterus by a doctor. causes localized inflammatory response which prevents implantation of embryo, and hinders fertilization. Pro -works most of the time. Cons - Doesn't prevent STD's, and can cause uterine disease and even infertility.
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rhythm method
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method of trying to determine by basal temperature, when ovulation will occur, and abstaining from intercourse during that method. Pro- natural and fun. Con - usually results in pregnancy, and doesn't prevent STD's.
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RU486
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post fertilization chemical method of preventing zygote from implanting in uterus - works by blocking action of progesterone. Pro - works to eliminate pregnancy as result of rape. Con - hard on the body, and doesn't prevent STD's. NOt to be used as a contraception method. The "post-rape" anti-pregnancy drug"
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FSH in female versus male
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male - stimulates sperm production
female - stimulates follicles to secrete estrogen. |
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How prolactin and oxytocin function to ensure lactation
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prolactin - stimulates milk production by breast glandular tissue. After birth, prolactin increases stimulation of breasts.
Oxytocin - then is secreted by the posterior pituitary which stimulates milk let-down (ejection.) |
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Sequence of events - male to develop from an XY sex chromosome zygote.
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Y chromosomes codes for early development of male gonads. So, if the Y chromosome is present, the testes begin to develop around week seven of gestation. (Otherwise, the testes instead become ovaries.) The developing testes then begin to secrete increasing levels of testosterone, which in turn causes the male reproductive organs to develop further. In the absence of this testosterone, female organs instead develop.
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testosterone level feedback system
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1. hypothalamus releases GnRH to blood at onset of puberty
2. GnRH arrivves at anterior pituitary via blood, stimulating release of FSH and LH to blood. 3. in testes FSH causes sertoli cells to mature, permitting spermatogenesis. 4. sertoli cell maturation causes secretion of inhibin to blood. 5. inhibin release to blood causes anterior pituitary to inhibit secretion of FSH. 6. LH stimulates leydig cells of testes to produce testosterone. 7. increased testosterone levels feed back to hypothalamus, inhibiting secretion of GnRH, which inhibits anterior pituitary secretion of LH. |
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endocrine functioning in maintaining a pregnancy
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during first 5-6 weeks, ovaries secrete increased levels of estrogen and progesterone. Then, placenta, as maturing, secretes estrogen and progesterone. From then on, placental hormone secretions are sufficient to maintain the pregnancy.
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primary and secondary sexual characteristics in males at puberty
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Primary: Enlargement of the testes, scrotum, and penis occur ( major reproductive anatomy) Secondary: Body hair distribution changes, facial and pubic hair develop, and the larynx and vocal cord enlargement mean that the voice deepens. The muscles develop further, while bone growth ceases, meaning that adult stature is reached, and further adult muscular definition takes place.
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development of sperm versus oocytes
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sperm: undergoes mitosis and regenerate throughout life after puberty.
create four haploid daughter cells through meiosis. oocytes: don't undergo mitosis. remain at anaphase I of meiosis until fertilization. Meiosis results in one secondary oocyte, (haploid) and one polar body. other polar bodies die. |
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menopause symptoms
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hot flashes, mood swings, headaches, depression, muscular aches. can last for years. brought on by diminished estrogen and progesterone. decreased breast size and vaginal lubricants.
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structures which sperm must pass through to fertilize the egg.
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vagina-> cervix-> uterus (including cilieary motion of uterus) ->stays in uterus for some time until capacitation occurs (removal of protein layer) -> fallopian tubes -> activation -> lurching motion of sperm in area of ovum, and ONE sperm makes it through.
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