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140 Cards in this Set
- Front
- Back
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What is sexual differentiation? |
It is the pattern of development of gonads, genital ducts, external genitalia and secondary sexual characteristics that produces the differences between the male and female genders. (changes during development of body/organs of the reproductive system) |
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What is the central dogma for sexual differentiation? |
chromosomal sex --> gonadal sex --> phenotypic sex |
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How many autosomes and sex chromosomes do we have? |
Human somatic cells have 44 autosomes and 2 sex chromosomes
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How many chromosomes does a male have? What sex chromosomes do they have? |
*46 chromosomes *XY |
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How many chromosomes does a female have? What sex chromosomes do they have? |
*46 chromosomes *XX |
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What happens during gametogenesis? |
It is the process where the chromosomal number is reduced by half as a result of the first meiotic division. |
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After the first meiotic division, how many chromosomes do males and females have? |
*male sperms 23X 23Y *female ova 23X 23X |
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What happens at fertilization? |
The gamete cells fuse and restore the chromosomes number to 46 |
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When is the fetus sex determined? |
At fertilization (female 46 XX and male 46 XY) |
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When are gonadal ridges formed? |
At the third or fourth week of embryonic development |
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What happens at six weeks? |
Migration of germ cells is completed and the indifferent gonad is formed. It contains supporting cells, germ cells, and interstitial cells. |
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What happens by the seventh week? What happens if there is no Y chromosome? |
Under the Y chromosome influence, the indifferent gonads develop into testes. *If there is no Y chromosome, the indifferent gonad develops into ovaries by the eleventh week. |
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What happens during the eight weeks of the indifferent stage? |
The fetus has a dual genital duct system made of: *mesonephric/wolffian duct *paramesonephric/mullerian duct |
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In the male fetus testes, what do sertoli do? |
They secrete the hormone called Mullerian Inhibiting Factor (MIF). |
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What does Mullerian Inhibiting Factor do? |
It causes regression of the mullerian duct and stimulates the testes descent into the scrotum |
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In the male fetus testes, what do the interstitial leydig cells do? |
They secrete dihydrotestosterone and testosterone. |
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What do dihydrotestosterone and testosterone do in the male fetus testes? |
It stimulates wolffian ducts differentiation to form seminal vesicles, ductus deferens, and epididymus. |
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Without a Y chromosome or testes hormone, what does the mullerian duct develop into? |
It forms: *fallopian tubes *uterus *upper part of the vagina (the lower part comes from urogenital sinus) |
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During the indifferent stage, what three external genitalia structures do both males and females have? |
*genital tubercle *urogenital fold *labioscrotal fold |
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How does the external male genitalia develop under the influence of dihydrotestosterone and testosterone? |
*genital tubercle --> glans penis *urogenital folds --> urethra *labioscrotal folds --> scrotum |
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How does the external female genitalia develop? What hormones are required? |
*NO hormones are required *genital tubercle --> clitoris *urogenital folds --> labia minora *labioscrotal folds --> labia majora |
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What is Turner's syndrome? |
45 XO infertile female (44 are autosomal and only one sex chromosome is present) *one sex chromosome is lacking--develops into a female but they are infertile |
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What is Triple X Syndrome? |
47 XXX infertile female (44 are autosomal and three sex chromosomes are present) *sometimes called "superwoman" |
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What is Klinefelter's Syndrome? |
47 XXY male with small testes, gynecomastia, and infertility (44 are autosomal and three sex chromosomes are present) *abnormal breast tissue growth |
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What is true hermaphroditism? |
*a condition in which a baby may have cells with 46 XY and cells with 46 XX chromosomes *ovary and testes exist separately or as ovotestis in the same individual *penis is not completely virilized (hypospadias) *testes are undescended in scrotum (cryptorchidism) *genitalia of both sexes may develop |
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What is male pseudohermaphroditism? |
A genetic male fetus (46 XY) develops female genitalia due to lack of or insensitivity to androgens. |
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What is female pseudohermaphroditism? |
A genetic female fetus (46 XX) develops male genitalia due to androgens. (adrenogential syndrome--AGS) |
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What causes chromosome disorders? |
There are errors that occur called non-disjunction. When the cells split, one daughter cell gets both X chromosomes and sperm adds an X (becomes triple X syndrome) or one daughter cell gets no X chromosome and sperm adds and X (Turner syndrome). |
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What structures are included in the male reproductive system? |
*penis *ductus deferens (sperm duct) *seminal vesicle (seminal fluid) *prostate (seminal fluid) *urethra (urine) *epididymis (sperm maturation) *scrotum (cools testis) *testis (sperm formation) |
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What is the scrotum? What is it's function? |
*sac of loose skin, fascia, and smooth muscle *divided into two pouches by a septum *function is temperature regulation of testes |
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What does sperm survival require? |
It requires 2 to 3 degrees lower temperature than core body temperature--controlled by the scrotum. |
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What is the cremaster muscle? Where is it found and what is it's function? |
*found in the scrotum *elevates or lowers the testes in response to arousal, cold, or warmth |
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What are testes? Where are they located? What do they contain? |
*paired oval glands *surrounded by dense white capsule called tunica vaginalis *septa forms 200 to 300 compartments called lobules *each lobule is filled with 2 or 3 seminiferous tubules where sperms are formed |
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What are seminiferous tubules? |
*They contain sperm forming cells (spermatogonia) and supporting cells (sertoli) *interstitial leydig cells between tubules secrete testosterone. |
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What are sertoli cells? |
*extend from basement membrane to lumen *form blood testis barrier *support developing sperm cells *produce fluid and control release of sperm into lumen *secrete inhibin which slows sperm production |
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Where does sperm maturation occur? |
In the epididymis |
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What does the ductus deferent sperm duct do?
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Transports sperm from epididymis out |
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What happens during spermatogenesis? |
*each of four spermatids develop into a sperm *second meiosis division give four spermatids, each with 23 single stranded chromosomes *first meiosis division gives two secondary spermatocytes, each with 23 chromosomes that become double stranded *primary spermatocyte with 2n=46 chromosomes *spermatogonium with 2n=46 chromosomes multiplied by mitosis |
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What is sperm adapted for? What does the head contain? What does the mid piece contain? What is the tail used for? |
*adapted for reaching and fertilizing the egg *head contains DNA and the acrosome contains enzymes for egg wall penetration *midpiece contains mitochondria to form ATP energy for motility *tail is flagellum used for locomotion |
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In a male, what does the hypothalamus secrete? The anterior pituitary secrete? |
*hypothalamus secretes gonadotropin releasing hormone (GnRH) *anterior pituitary secretes FSH and LH |
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What does FSH cause? |
It causes sertoli cells to secrete ABP and inhibin |
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What does LH cause? |
It causes interstitial cells to secrete testosterone |
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What do ABP and testosterone stimulate? |
They stimulate spermatogenesis. |
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What type of feedback controls testosterone and inhibin? |
The control is negative feedback by increasing testosterone and inhibin.
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What does the prostate secrete? |
It secretes 30% of milky, slightly acidic seminal fluid with an antibiotic to kill bacteria |
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What do seminal vesicles secrete? |
They secrete 60^ of clear, alkaline seminal fluid, with fructose sugar, ATP and prostaglandins for normal sperm nutrition and function. |
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What do Cowper's glands secrete? |
It secretes clear, alkaline mucus to buffer and lubricate the urethra. |
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What is semen? What does it contain? |
*mixture of sperms and seminal fluid *slightly alkaline, milky appearance and sticky *contains nutrients, clotting proteins, and an antibiotic to protect the sperms |
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What is the typical ejaculate volume? |
2.5 to 5 mL in volume |
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What is normal sperm count? When is a male considered infertile? |
*normal count is 50 to 150 million/mL *actions of many sperm are needed for one to enter an egg *male is considered infertile when they have less than 20 million/mL |
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What is an erection initiated by? |
Initiated by mental, visual, and physical stimuli that send afferent signals to the sacral region of the spinal cord via the internal pudendal nerve. |
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What nerve send efferent parasympathetic signals for an erection? |
The signals come from the spinal cord sacral region to the penis via the pelvic nerve. |
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What relaxes during an erection? What dilates? What becomes engorged with blood? |
*Trabecular muscle of penis erectile tissue relaxes *deep artery of the penis dilates *erectile tissue becomes engorged with blood and the penis becomes erect |
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How is erectile dysfunction defined? |
failure to obtain or maintain an erection |
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What is the erection pathway? |
sexual stimulation --> nitric oxide --> active guanylate cyclase --> cGMP --> vasodilation and erection |
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How does Viagra work? |
*in a normal person, cGMP causes vasodilation and erection *in a male with ED, the cGMP is degraded by PDE5 to cause a loss of erection *Viagra has phosphodiesterase inhibitors that keep the cGMP from being degraded, so the erection can happen |
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What happens during the emission stage? |
*efferent sympathetic signal from spinal cord (L1 to L2) *seminal fluids and sperm are propelled through ductus deferens, ejaculatory ducts, and ampulla into the penile urethra |
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What happens during the ejaculation stage? |
*efferent sympathetic signals from spinal cord (L1 to S4) *internal urethral sphincter contraction closes bladder *bulbocavernosus muscle rhythmic contractions squeeze semen out through the urethra |
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What do the ovaries produce? |
*eggs, also called oocytes *hormones |
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What do uterine tubes transport? |
They transport the eggs into the uterus |
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What happens in the uterus? |
This is where fetal development occurs. |
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How is the vagina defined? |
It is the birth canal. |
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What is the female external genitalia called? |
The vulva |
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What do mammary glands produce? |
Milk |
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What is an ovary? Describe it's histology. |
*pair of organs, size of unshelled almonds in the upper pelvic region *capsule is called tunica albuginea *cortex just deep to capsule contains follicles with egg cells *medulla is middle region composed of connective tissue, blood vessels, and lymphatics |
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What are the 3 functions of the ovarian follicles? |
*contain egg cells (oocytes) in various stages of development *secretes estrogens *mature (graafian) follicle releases an oocyte each month during ovulation |
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What are the 4 functions of estrogen? |
*growth and repair of uterine lining *regulation of monthly female cycle *female secondary sexual characteristics *maintenance of bone and muscle |
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What are the two stages of follicular development? Describe both stages. |
1. Primordial follicle: single layer of squamous cells around the oocyte. 2. Primary follicle: many layers of cuboidal granulosa cells around the oocyte *granulosa cels secrete estrogens |
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What is the secondary follicle and what does it contain? |
It is an antral cavity filled with antral fluid.
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Where does a follicle mature? What happens after it matures? |
*follicle matures in the graafian follicle *after it matures, it is ready to ovulate oocyte |
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How is an oocyte released? |
During ovulation, a follicle ruptures to release an oocyte. |
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After ovulation, what does an empty follicle become? What does it do? |
*An empty follicle becomes a corpus luteum *The corpus luteum secrete: progesterone, estrogen, relaxin, and inhibin. |
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What is the corpus albicans? |
It is the white scar tissue left after the corpus luteum dies. |
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What does progesterone do? |
It completes the preparation of uterine lining. |
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What does estrogen work with? |
It works with progesterone. |
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What does relaxin do? |
It relaxes the uterine muscle and pubic symphysis. |
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What does inhibin do? |
It decreases secretion of FSH and LH. |
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What is the basic definition of oogenesis? |
The process of an oogonia becoming an oocyte. |
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What is an oogonia? |
Germ cells from yolk sac migrate to the ovary to become a potential egg cell called oogonia. |
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What produces oogonia? What happens to the oogonia in a fetus? |
In a fetus, million of oogonia are produced by mitosis, but most of them degenerate (atresia). |
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What are primary oocytes? |
During fetal development, some oogonia develop into immature egg cells called primary oocytes. |
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How many primary oocytes are present at birth? At puberty? How many mature? |
*200,000 to 2 million present at birth *40,000 remain at puberty *only 400 mature during a woman's reproductive life |
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What happens to primary oocytes each month? |
Each month, about 20 primary oocytes become secondary oocytes but usually only one survives to be ovulated from the graffian follicle. |
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What are fallopian tubes? They extend from where to where? |
*narrow, 4 inch tubes *extend from ovary to the uterus *contains infundibulum, fimbriae, ampulla, and isthmus |
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In the fallopian tubes, what is infundibulum? |
It is an open, funnel shaped portion near the ovary |
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In the fallopian tubes, what are fimbriae? |
They are moving finger-like processes |
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What are ampulla in the fallopian tubes? |
They are the central region of the tube |
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What is the isthmus of the fallopian tubes? |
The narrowest portion that joins the uterus |
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What are the five functions of the fallopian tubes? |
*fimbriae sweep oocyte into tube *cilia and peristalsis move it along *sperm reaches oocyte in ampulla *fertilization occurs within 24 hours after ovulation *zygote reaches uterus about 7 days after ovulation |
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What is the uterus the site of? |
The site of menstruation and development of the fetus |
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Describe the uterus. |
*3 inches long by 2 inches wide and 1 inch thick *subdivided into the fundus, body, and cervix *interiorly contains uterine cavity connected to the cervical canal |
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What three layers are in the uterus? |
*endometrium *myometrium *perimetrium |
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Describe the endometrium of the uterus. |
*simple columnar epithelium *stroma of connective tissue and endometrial glands *functional layer shed during menstruation *basal layer replaces functional layer each month *this is where the fertilized egg is implanted |
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Describe the myometrium of the uterus. |
3 layers of smooth muscle |
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Describe the perimetric of the uterus. |
visceral peritoneum |
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What is the vagina used for? |
A passageway for fetus birth, menstrual blood flow, and intercourse. |
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Describe the vagina. |
*4 inches long, fibro-muscular organ ending at the cervix *lies between the urinary bladder and rectum *orifice partially closed with hymen membrane *externally covered by the vulva |
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What are the mammary glands? |
They are modified sweat glands that produce milk |
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What determines breast size? |
the amount of adipose tissue |
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What is the areola? |
the pigmented area around the nipple |
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Where do milk secreting alveoli open? |
They open by lactiferous ducts at the nipple |
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What do suspensory cooper's ligaments do? |
They suspend the breast from the deep fascia of pectoral muscles |
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In milk production and secretion, what does estrogen do? |
It develops the ducts system in the breasts |
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In milk production and secretion, what does progesterone do? |
It develops the milk secreting glands which are called alveoli. |
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In milk production and secretion, what does prolactin do? |
Stimulates milk synthesis in the alveoli |
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In milk production and secretion, what does oxytocin do? |
Stimulates milk ejection from the alveoli |
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What stimulates milk ejection? |
Nursing stimulates the hypothalamus to produce oxytocin |
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Where is oxytocin secreted from? What does it cause? What type of feedback is it? |
*secreted from posterior pituitary *causes smooth muscles around alveoli to contract and squeeze milk into lactiferous ducts, lactiferous sinuses and into the nipple *operated by positive feedback |
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What is the route of positive feedback for milk ejection? |
1. Receptors in nipples stimulated 2. Impulses propagated to spinal cord 3. Stimulation of hypothalamic nuclei 4. Oxytocin released 5. Milk ejected |
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What surges at each feeding? |
Prolactin surges, starts after pregnancy ends and routine feedings begin |
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What is the hormonal cycle? |
*monthly cycle of changes in ovary and uterus *controlled by monthly hormonal cycle from the hypothalamus, anterior pituitary, and ovary |
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What is the ovarian cycle? |
Changes in ovary during maturation of the follicle and oocyte, ovulation and corpus luteum formation |
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What is the uterine cycle? |
*preparation of the uterus to receive fertilized ovum *if implantation does not occur, the functional layer of the endometrium is shed during menstruation *changes in the uterine endometrium lining |
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What is GnRH secreted from? What does it stimulate? |
Gonadotropin Releasing Hormone (GnRH) is secreted by the hypothalamus. It stimulates the anterior pituitary gland to secrete follicle stimulating hormone (FSH) and Luteinizing Hormone (LH). |
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What do FSH and LH target? What do they do? |
They target the ovaries and drive the ovarian cycle secretion of estrogens and progesterone |
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What do estrogens and progesterone do? |
They are from the ovaries and drive the uterine cycle endometrial changes |
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What is the route of hormonal regulation of the reproductive cycle? |
GnRH --> FSH + LH --> estrogen + progesterone |
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What happens during the follicular phase of the ovarian cycle? |
*FSH from anterior pituitary stimulates follicle growth *primordial follicle grows into graafian (mature) follicle *granulosa cells of follicle secrete estrogens and inhibin *increasing levels of estrogens and inhibin inhibit FSH *increasing estrogens also stimulates secretion of LH |
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What happens during ovulation of the ovarian cycle? |
*LH stimulates the rupture of the graafian follicle and release of oocyte from ovary *fimbriae of fallopian tube picks up the ovulated oocyte |
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What happens during the luteal phase of the ovarian cycle? |
*LH stimulates development of corpus luteum from ovulated or ruptured follicle *corpus luteum secretes mostly progesterone and some estrogens *progesterone prepares endometrium for possible pregnancy |
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What happens during the proliferative phase of the uterine cycle? |
Rising estrogen levels from the growing follicle stimulates growth of the functional layer of the endometrium to 4 to 10 mm thickness |
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What happens during the secretory phase of the uterine cycle? |
*corpus luteum of ovary secretes progesterone |
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What does progesterone stimulate in the uterine cycle? |
*increased thickening of the functional layer of the endometrium to 12 to 18 mm *increased blood supply into the endometrium *growth of endometrial glands and secretion of uterine milk |
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What happens during the menstruation phase of the uterine cycle? |
*decline in progesterone levels causes functional layer of endometrium to discharge resulting in vaginal bleeding called menstruation *marks the end of one cycle and the beginning of the next cycle |
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If there is no pregnancy, what happens during menstruation? |
*increasing levels of progesterone causes negative feedback that inhibits LH secretion *after about two weeks corpus luteum atrophies to corpus albicans (white body) *progesterone and estrogen levels decline *functional layer of endometrium discharged into first five days and the next cycle |
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What declines when the corpus luteum dies? |
*progesterone levels *estrogen levels *inhibin levels |
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At the start of a new cycle, what stops? What starts? |
Inhibition of GnRH, FSH, and LH. The renewed secretion of these hormones starts a new cycle of follicle growth in ovaries and endometrium preparation in the uterus. |
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Where is the zygote implanted? What does it form? |
It is implanted in the endometrium and forms the blastocyte. |
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What secretes hCG? |
Human Chorionic Gonadotropin is secreted from the outer chorionic layer of the blastocyst |
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What does hCG do? |
It maintains the corpus luteum growth and secretion of progesterone and estrogens |
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What does the corpus luteum do for pregnancy? |
It maintains pregnancy for the first trimester until it degenerates at 12 to 17 weeks of gestation |
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What happens after the corpus luteum degenerates? |
The placenta then takes over and secretes progesterone, estrogens, human chorionic gonadotropic and somatomammotropin. |
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What is the duration of pregnancy? |
It is 280 days from the last menstrual period date |
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What is pregnancy term? |
It is described in three month intervals called trimesters.
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What are the four age based terminology terms used for a developing baby? |
*blastocyst: less than 2 weeks old *embryo: from 2 to 8 weeks old *fetus: 9 weeks to birth *neonate: newborn to 6 weeks old |
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What hormones start being produced at ovulation? |
hCG, estradiol and progesterone |
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Four to eight weeks after the last menstrual period, what hormone peaks during pregnancy? When does the hormone decrease? |
hCG--it decreases at week 24 and then stays constant |
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What hormones increase at 24 weeks past the last menstrual period? |
Estradiol and progesterone increase until pregnancy completes |
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What are the stages of childbirth? |
*early dilation stage *late dilation stage *expulsion stage *placental stage |
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What contraceptive devices are available? |
*male condom *female condom *diaphragm with contraceptive jelly *foam with applicator *birth control pills *IUD |
