A&P 2 FINAL EXAM
Define embryo vs fetus.
*Embryo - conceptus from fertilization through week 8 *Fetus - conceptus from week 9 through birth
Describe the structure of the penis including: corpora cavernosa, corpus spongiosum, glans penis, prepuce (foreskin). In which column of the penis is the urethra located?
Corpus Cavernosa: paired dorsal erectile bodies Corpus Spomgiosum: surrounds urethra and expands to form glans and bulb (keeps urethra open). Glans Penis: End of penis Prepuce (foreskin): cuff of loose skin covering glans Urethra: *Prostatic urethra - surrounded by prostate *Intermediate part of the urethra (membranous urethra) - in urogenital diaphragm *Spongy urethra - runs through penis; opens at external urethral orifice
Where do the testes begin their development in an embryo? What is cryptorchidism?
About two months before birth, Testosterone stimulates migration of testes toward scrotum ****Gonads begin development in seventh week in males Cryptoechidism: The absence of one or both testes from the scrotum ( a risk factor of Testicular Cancer).
What is the function of accessory sex glands? Know the accessory glands in the male reproductive system and what they secrete.
Accessory sex glands: Empty secretions into ducts during ejaculation / Produce bulk of semen ****Remainder - sperm from testes -Seminal glands: On posterior bladder surface; smooth muscle contracts during ejaculation Produces viscous alkaline seminal fluid -Prostate: Encircles urethra inferior to bladder; size of peach pit; smooth muscle contracts during ejaculation Secretes milky, slightly acid fluid (1/3 semen volume) -Bulbo-urethral glands: Pea-sized glands inferior to prostate Produce thick, clear mucus during sexual arousal (Lubricate glans penis & neutralize traces of acidic urine in urethra)
What is an amniocentesis? Chorionic villi sampling? What is the maternal alpha-fetoprotein test?
Amniocentesis:Amniotic fluid withdrawn after 14th week; fluid and cells examined for genetic abnormalities ****Testing takes several weeks Chorionic villi sampling: Chorionic villi sampled at 8-10 weeks; karyotyped for genetic abnormalities; testing ****immediate Maternal alpha-fetoprotein test:
Describe what occurs in the penile tissue to cause erection.
Erection - erectile tissue fills with blood, causing penis to enlarge and become rigid *Arterioles normally constricted *Sexual excitement causes CNS activation of parasympathetic neurons **nitric oxide (NO) release ---> local vascular smooth muscle relaxation **arterioles dilate ---> corpora cavernosa expands, retards venous drainage **engorgement of erectile tissues with blood **enlargement and stiffening of penis **Longitudinal and circular collagen fibers around penis prevent kinking/buckling of erect penis
Name the hormones secreted by the ovary and the specific structure that secretes each.
Estrogen: Connective tissue (theca folliculi) and granulosa cells cooperate to produce estrogens Androgens: Inner thecal cells produce androgens in response to LH Progesterone: Corpus luteum secretes progesterone and some estrogen
How is estrogen connected to ovulation? (it's a positive feedback effect)
During childhood, ovaries grow and secrete small amounts of estrogens that inhibit hypothalamic release of GnRH As puberty nears, GnRH released; FSH and LH released by pituitary, and act on ovaries These events continue until an adult cyclic pattern achieved and menarche occurs 1. GnRH ---> release of FSH and LH 2. FSH and LH ---> growth of several follicles, and hormone release 3. inc plasma estrogen levels inhibit release of FSH and LH inc estrogen levels enhance further estrogen output Inhibin from granulosa cells also inhibits FSH release 4. When estrogen levels high ---> brief positive feedback on brain and anterior pituitary 5. Stored LH, and some FSH, suddenly released by anterior pituitary at midcycle ---> surge triggers ovulation ---> primary oocyte to complete meiosis I ---> secondary oocyte Secondary oocyte ---> meiosis II
Compare the events in the ovarian and uterine cycles.
OVARIAN CYCLE: Monthly series of events associated with maturation of egg Two consecutive phases (in 28-day cycle) Follicular phase - period of follicle growth (days 1-14) Ovulation occurs midcycle Luteal phase - period of corpus luteum activity (days 14-28) Only 10 - 15% women have 28-day cycle Follicular phase varies Luteal phase constant - always 14 days from ovulation to end of cycle UTERINE CYCLE: Cyclic changes in endometrium in response to fluctuating ovarian hormone levels Three phases Days 1-5 - menstrual phase Days 6-14 - proliferative (preovulatory) phase Days 15-28 - secretory (postovulatory) phase (constant 14-day length)
Know the structures and functions in the mammary glands: lactiferous ducts, areola, nipple, suspensory ligaments, alveoli.
lactiferous ducts: areola: pigmented skin surrounding nipple nipple: suspensory ligaments: attach breast to underlying muscle alveoli: produce milk
Describe the following parts of the vulva: mons pubis, labia majora, labia minora, clitoris, vestibule, external urethral orifice, greater vestibular (Bartholin's) glands.
mons pubis: fatty area overlying pubic symphysis labia majora: hair-covered, fatty skin folds (counterpart of male scrotum) labia minora: skin folds lying within labia majora (join at posterior end of vestibule ----> "fourchette") clitoris: anterior to vestibule (counterpart of penis) ****Glans of the clitoris - exposed portion ****Prepuce of the clitoris - hoods glans vestibule: recess within labia minora external urethral orifice: greater vestibular (Bartholin's) glands: Flank vaginal opening, release mucus into vestibule for lubrication (homologous to bulbo-urethral glands)
Describe the location and function of the following: epididymis, vas deferens, spermatic cord, inguinal canal, seminal vesicle, prostate gland, bulbourethral gland.
*Epididymis: Head - contains efferent ductules; superior aspect of testis; body and tail on posterolateral area of testis Duct of the epididymis ~ 6 m in length if uncoiled Microvilli (stereocilia) absorb testicular fluid and pass nutrients to stored sperm Nonmotile sperm enter, pass slowly through (~ 20 days), become motile; can be stored several months During ejaculation epididymis contracts, expelling sperm into ductus deferens *Vas Deferens: Ductus deferens (vas deferens) ~ 45 cm Passes through inguinal canal to pelvic cavity Expands to form ampulla; joins duct of seminal vesicle to form ejaculatory duct Smooth muscle in walls propels sperm from epididymis to urethra *Spermatic Cord: Encloses nerve fibers, blood vessels, and lymphatics that supply testes *Inguinal Canal: *Seminal Vesicle: On posterior bladder surface; smooth muscle contracts during ejaculation Duct of seminal gland joins ductus deferens to form ejaculatory duct *Prostate Gland: Encircles urethra inferior to bladder; size of peach pit; smooth muscle contracts during ejaculation *Bulbourethral Gland: Pea-sized glands inferior to prostate Produce thick, clear mucus during sexual arousal (Lubricate glans penis & neutralize traces of acidic urine in urethra)
Review the disorders in the homeostatic imbalance section at the end of the chapter.
*Erectile dysfunction - parasympathetic nerves of penis release too little NO *Infertility - gradual decline in male fertility past 50 years *Ectopic pregnancy - Oocyte fertilized in peritoneal cavity or distal uterine tube begins developing there, normally abort naturally with substantial bleeding *Pelvic inflammatory disease (PID) - spread of infection from reproductive tract to peritoneal cavity, may cause scar tissue ---> infertility *Cervical cancer - 450,000 women worldwide each year - killing half, most common between 30 - 50 *Testicular cancer - rare; most common cancer in men 15-35, sign - painless, solid mass in testis ; cryptorchidism is risk factor
Know the composition of semen.
*Milky-white mixture of sperm and accessory gland secretions *2-5 ml semen ejaculated, contains 20-150 million sperm/ml, contains fructose for ATP production *70% volume of semen (Seminal Glands - produces viscous alkaline seminal fluid, fructose, citric acid, coagulating enzyme (vesiculase), and prostaglandins Yellow pigment fluoresces with UV light) *1/3 semen volume (Prostate Gland - secretes milky, slightly acid fluid Contains citrate, enzymes, and prostate-specific antigen (PSA) Role in sperm activation Enters prostatic urethra during ejaculation).
Describe the following: ovarian follicle, mature (Graafian) follicle, corpus luteum, corpus albicans, granulosa cells, zona pellucida, corona radiata.
*ovarian follicle: *mature (Graafian) follicle: corpus luteum: Develops from ruptured follicle after ovulation corpus albicans: If no pregnancy, corpus luteum degenerates into corpus albicans (scar) in 10 days granulosa cells: Stratified epithelium (granulosa cells) forms around oocyte *zona pellucida: forms around oocyte *corona radiata:
What is the function of the primary sex organs (gonads)? What are the primary sex organs in the male? Female?
*Produce gametes (sex cells ) - sperm & ova Male: Testes Secrete steroid sex hormones Androgens (males) Female: Ovaries Secrete steroid sex hormones Estrogens and progesterone (females)
Describe the physiology and hormonal control of lactation.
*Production of milk by mammary glands *Toward end of pregnancy >>>>Placental estrogens, progesterone, and human placental lactogen stimulate hypothalamus to release prolactin-releasing factors (PRFs) ---> >>>>Anterior pituitary releases prolactin ********2-3 days later true milk production begins *Colostrum >>>>Less lactose but more protein, vitamin A, minerals than true milk; almost no fat >>>>Yellowish secretion rich in IgA antibodies IgA resistant to digestion; may protect infant against bacterial infection; absorbed into bloodstream for immunity >>>>Released first 2-3 days >>>>Followed by true milk production *Prolactin release wanes after birth *Lactation sustained by mechanical stimulation of nipples - suckling >>>>Suckling causes afferent impulses to hypothalamus ---> prolactin ---> stimulates milk production for next feeding >>>>>Hypothalamus also ---> oxytocin from posterior pituitary ---> let-down reflex
Describe the effects of aging on the reproductive systems including: puberty, menarche, menopause, benign prostatic hyperplasia
*Puberty: releases GnRH in rhythmic pulse-like manner ---> FSH and LH release ---> ovarian hormone release *Menarche: If no fertilization Corpus luteum degenerates when LH levels fall ---> sharp decrease in estrogen and progesterone ---> ends blockage of FSH and LH secretion ---> Cycle starts anew **Menopause: Has occurred when menses have ceased for an entire year Declining estrogen levels ----> **Atrophy of reproductive organs and breasts **Irritability and depression in some **Hot flashes as skin blood vessels undergo intense vasodilation **Gradual thinning of skin and bone loss **Increased total blood cholesterol levels and falling HDL *Benign prostatic hyperplasia: May be age-related; distorts urethra; treated with surgery, microwaves, drugs, balloon compression, radio-frequency radiation
What is the function of the seminiferous tubules? Sertoli cells? Interstitial cells?
*Seminiferous tubules: -Sperm (spermatozoa) production. *Sertoli cells: Large supporting cells, -Provide nutrients and signals to dividing cells -Move cells along to lumen -Secrete testicular fluid into lumen for sperm transport -Phagocytize faulty germ cells and excess cytoplasm -Produce chemical mediators to regulate spermatogenesis. *Interstitial cells: -Produce androgens, e.g., testosterone & secrete it into interstitial fluid.
What is the perineum?
Diamond-shaped region between pubic arch and coccyx , bordered by ischial tuberosities laterally.
What is fertilization? How about capacitation?
Fertilization: Capactiation:
Describe the difference between fetal circulation and adult circulation. What structures exist in the fetus that are not in an adult?
Fetal circulation: Adult circulation: What structures exist in the fetus that are not in an adult?
Describe and recognize the phases of meiosis. What is the point of meiosis anyway? How does spermatogenesis differ from oogenesis?
Functions of meiosis -Number of chromosomes halved (from 2n to n) -Introduces genetic diversity PHASES slide 52 Spermatogenesis: Spermatids become sperm. Mitosis: Spermatogonia (stem cell) forms two spermatocytes Meiosis: Spermatocytes ---> secondary spermatocytes ---> spermatids Oogenesis: Production of female gametes, takes years to complete. =Oogonia (2n ovarian stem cells) multiply by mitosis and store nutrients -Primary oocytes develop in primordial follicles -Primary oocytes begin meiosis; stall in prophase I -One "selected" each month to resume meiosis I Result is two haploid cells of different sizes -Secondary oocyte - large cell with ~ all cytoplasm and organelles of original cell ****First polar body - small cell -Secondary oocyte arrests in metaphase II; ovulated ovum ****If not penetrated by sperm - deteriorates ****If penetrated by sperm second oocyte completes meiosis II, yielding ****Ovum (functional gamete) ****Second polar body
Describe the negative feedback loops in the connections in the male between GnRH, FSH, LH, testosterone, inhibin. What limits sperm production? What limits testosterone production?
GnRH indirectly stimulates testes via FSH & LH FSH & LH directly stimulate testes Testosterone & inhibin - negative feedback on hypothalamus and anterior pituitary Hypothalamus releases gonadotropin-releasing hormone (GnRH) ---> anterior pituitary to secrete FSH and LH FSH causes sustentocytes to release androgen-binding protein (ABP) ---> high concentration of testosterone near spermatogenic cells ---> spermatogenesis LH prods interstitial endocrine cells ---> testosterone ---> spermatogenesis Testosterone ---> sex organ maturation, development/maintenance secondary sex characteristics, libido Rising testosterone levels ---> feedback inhibition on hypothalamus to inhibit GnRH and on pituitary to inhibit gonadotropin release Inhibin (released when sperm count high) - inhibits GnRH and FSH release Three years to achieve balance, then testosterone and sperm production fairly stable throughout life Without GnRH and gonadotropins ---> testes atrophy; sperm and testosterone production cease
Describe the structure of the ovaries. How are they held in place?
Held in place by several ligaments Ovarian ligament - anchors ovary medially to uterus Suspensory ligament - anchors ovary laterally to pelvic wall Mesovarium - suspends ovary Suspensory ligament and mesovarium part of broad ligament - supports uterine tubes, uterus, and vagina Blood supply - ovarian arteries and ovarian branch of the uterine arteries Surrounded by fibrous tunica albuginea Germinal epithelium - outer layer Two poorly defined regions Outer cortex - houses forming gametes Inner medulla - large blood vessels and nerves
What components contribute to the placenta?
Maternal portion of placenta: Decidua basalis (stratum functionalis between chorionic villi and stratum basalis of endometrium) Fetal portion of placenta: Chorionic villi
Describe the development of the male and female reproductive systems including the mesonephric (Wolffian) and paramesonephric (Mullerian) ducts, the X and Y chromosomes, the SRY gene, Mullerian-inhibiting hormone (MIH), testosterone, DHT.
Paramesonephric (Müllerian) ducts (future female ducts) form lateral to mesonephric (Wolffian) ducts (future male ducts) *Sexually indifferent stage - embryo could develop into male or female X&Y CHROMOSOMES: Of 46 chromosomes in fertilized egg, two (one pair) are sex chromosomes Two sex chromosomes - X chromosome (large); Y chromosome (quite small) Females are XX; each ovum always has an X chromosome Males are XY, so ~50% of sperm contain X, ~50% contain X egg + X sperm ---> XX (female offspring) X egg + Y sperm ---> XY (male offspring) The SRY gene on Y chromosome initiates testes development and maleness ***********MIH: Testosterone: If absent, all embryos develop into females ***********DHT: Dihydrotestosterone in prostate
What is ejaculation and emission?
Propulsion of semen from male duct system **Ejaculatory event - climax (orgasm)
What are the mechanisms for genetic recombination?
Recombinant chromosomes: chromosomes have mixed contributions from each parent.
Describe the function of the scrotum as it relates to temperature control for sperm production.
Sac of skin and superficial fascia, hangs outside abdominopelvic cavity *Contains paired testes *3 degrees C lower than core body temperature ****Lower temperature necessary for sperm production.
Know the arrangement of the following: seminiferous tubules, straight tubules, rete testis, epididymis, vas deferens, ejaculatory duct, prostatic urethra, membranous urethra, penile urethra (hmmmm - maybe a short answer question - path of sperm from production to where it meets an oocyte).
Seminiferous tubules > Straight tubule > Rete testis > Efferent ductules > Head of epididymis > Body of epididymis > Tail of epididymis > Vas deferens > Ejaculatory duct > Prostatic urethra > membranous urethra > Spongy urethra > External urethra orifice > Vagina > External os > Cervical canal > Internal os > Uterus > Isthmus of uterine tube > Ampulla of uterine tube > Ovum
What are the 3 stages of labor? What happens in each?
Stages of Labor: Dilation Stage - *From labor's onset to fully dilated cervix (10 cm) *Longest stage of labor - 6-12 hours or more *Initial weak contractions: >>>>15-30 minutes apart, 10-30 seconds long >>>>Become more vigorous and rapid *Cervix effaces and dilates fully to 10 cm *Amnion ruptures, releasing amniotic fluid *Engagement occurs - head enters true pelvis Stages of Labor: Expulsion Stage - *From full dilation to delivery of infant *Strong contractions every 2-3 minutes, about 1 minute long *Urge to push increases (in absence of local anesthesia) *Crowning occurs when largest dimension of head distends vulva >>>>Episiotomy may be done to reduce tearing *Vertex position - head-first >>>>Skull dilates cervix; early suctioning allows breathing prior to complete delivery *Breech position - buttock-first >>>>Delivery more difficult; often forceps required, or C- section (delivery through abdominal and uterine wall incision) Stages of Labor: Placental Stage - *Strong contractions continue, causing detachment of placenta and compression of uterine blood vessels >>>>Limit bleeding; cause placental detachment *Delivery of afterbirth (placenta and membranes) occurs ~30 minutes after birth *All placenta fragments must be removed to prevent postpartum bleeding
Describe the structure of the uterine (Fallopian) tubes including: the tube itself, infundibulum, fimbriae, epithelial lining, layers of the wall.
The tube itself: Infundibulum: Fimbriae: Epithelial lining: Layers of the wall:
Describe the structure of the vagina.
Thin-walled tube 8-10 cm in length Birth canal and organ of copulation Extends between bladder and rectum from cervix to exterior Urethra parallels course anteriorly; embedded in anterior wall Layers of wall Fibroelastic adventitia Smooth muscle muscularis Stratified squamous mucosa with rugae Dendritic cells in mucosa may provide route for HIV transmission Mucosa near vaginal orifice forms incomplete partition called hymen - ruptures with intercourse Vaginal fornix - upper end of vagina surrounding cervix
Review birth control methods and failure rates.
Vasectomy - cutting and ligating ductus deferens; nearly 100% effective form of birth control ***********
What is done in a vasectomy?
Vasectomy - cutting and ligating ductus deferens; nearly 100% effective form of birth control.
What glands/structures in the male are the following female structures homologous to: clitoris, prepuce, paraurethral glands, greater vestibular glands, bulb of the vestibule, ovaries, ovum, labia majora, labia minora.
clitoris - penis prepuce - prepuce paraurethral glands - greater vestibular glands - bulbo-urethral glands bulb of the vestibule - bulb of the penis ovaries - testes ovum - sperm labia majora - male scrotum labia minora - spongy urethra of male
CHAPTER 29 -HEREDITY In genetics, define the following terms: dominant, recessive, genotype, phenotype.
dominant: Dominant-one allele masks (suppresses) its recessive partner ****Dominant denoted by capital letter ****Dominant expressed if one or both alleles dominant recessive: Recessive expressed only if both alleles recessive ****recessive by same letter in lower case genotype: Genetic makeup ****predicts possible gene combinations resulting from mating of parents of known phenotype: Expression of genotype ****only probability of particular genotype
Describe the structure of the uterus including: fundus, body, cervix, uterine cavity, perimetrium, myometrium, endometrium. Where is the vesicouterine pouch? The rectouterine pouch?
fundus: rounded superior region body: major portion cervix: narrow neck, or outlet; projects into vagina uterine cavity: perimetrium: serous layer (visceral peritoneum) - of uterine wall myometrium: interlacing layers of smooth muscle - of uterine wall endometrium: mucosal lining - of uterine wall Where is the vesicouterine pouch? The rectouterine pouch?