Ch 23, 24, 25

Front 1

primary reproductive organs

Back 1

gonads:

testes

ovaries

Front 2

secondary/accessory reproductive organs

Back 2

internal ducts

exocrine glands

Front 3

gametes

Back 3

spermatozoa and ova

produced by meiosis

haploid - i.e. 1/2 # chromosomes as somatic cells (23 chromosomes each)

Front 4

zygote

Back 4

diploid

an ovum + sperm

Front 5

embryonic development

Back 5

at 5-6 weeks the sexes are undifferentiated

external genitals develop from the same embryonic structures

internal genital ducts develop from separate embryonic structures

wolffian ducts - male's rete testis, efferent ducts, epididymis, vas deferens, seminal vesicle & prostate

mullerian ducts - female's vagina, cervix, uterus, & fallopian tubes

Front 6

male reproductive system

Back 6

primary organ: testes

internal secondary:

ducts - epididymis, ductus/vas deferens, ejaculatory urethra

glands - seminal vesicles, prostate gland, bulbourethral glands

external secondary: scrotum & penis

Front 7

testes

Back 7

functions: sperm & testosterone production

Front 8

spermatic cord

Back 8

contains vas deferens/ductus deferens, blood vessels, lymphatic vessels, & nerves, and

a heat control system of veins which absorb heat from incoming arteries & radiates it away from the testes to help maintain the optimum temp. for sperm production (~ 3 ºC below body temp.)

Front 9

tunica albuginea

Back 9

fibrous capsule surrounding each testis
• capsule extensions (septa) divide the testis into lobules, each has 1-4 tightly coiled seminiferous tubules, the sperm forming factories

Front 10

cells of the seminiferous tubules

Back 10

interstitial/leydig cells: between the seminiferous tubules
• produce testosterone

spermatogonia: diploid germ cells lining the outside walls of the seminiferous tubules
• develop into mature spermatozoa

sertoli/sustentacular/nurse cells:

nourish & protect developing spermatocytes
• secrete a protein that binds testosterone in the
seminiferous tubules

Front 11

testosterone

Back 11

Produced by Interstitial/Leydig cells
 Main male androgen
 Steroid hormone derived from cholesterol

Front 12

testosterone functions

Back 12

1. Maintenance of male reproductive structures
2. Development of male secondary sexual characteristics (contributes to male sexual behavior & libido)
3. Development of spermatozoa
4. Stimulation of the descent of testes
5. Promotion of protein synthesis
6. May help prevent CVD
7. Benefits with mood, muscles & aiding blood sugar levels

Front 13

anabolic testosterone abuse

Back 13

Used to increase bone & muscle mass; misuse is associated
with:
• Males: dec production of one’s testosterone > testes shrink, dec sperm count, enlarged prostate, & impotence
• Females: dec breast size, menstrual problems, inc in facial & body
hair, and a deeper voice
• Both genders: dec BP, dec risk of CHD & CVD, liver and renal damage, sleep disorders, nausea & vomiting, severe acne, and baldness

Front 14

epididymis

Back 14

Coiled tube inside the scrotum
 Head, body & tail
 Stretches ~ 20 ft
 Site of sperm maturation
 Receives spermatozoa from the seminiferous tubules via the rete testes & efferent duct
 Tail extends upwards as the vas deferens

Front 15

The Vas/Ductus deferens

Back 15

Carries sperms away from testes
 Ends in an ampulla (a reservoir for sperms)
 Enters the body through the inguinal canal, loops around the bladder & joins the seminal vesicle duct > the ejaculatory duct

Front 16

urethra

Back 16

Prostatic urethra: surrounded by the prostate
 Membranous urethra: from prostatic urethra to the penis
 Spongy (penile) urethra: runs the length of the penis

Front 17

seminal vesicles

Back 17

Secrete seminal fluid, a viscous alkaline fluid
 ~ 65 % of semen volume
 Nourishes & activates sperms
 Contains: Fructose: energy source for sperms
• Prostaglandins: aid in sperm motility
• Semenogelin: a semen protein which causes the coagulation of semen after ejaculation
 Sperm + seminal fluid > urethra > ejaculation

Front 18

prostate gland

Back 18

Below the bladder, encircling the prostatic urethra
 Muscular tissue contracts to aid expulsion of semen
 Secretes an alkaline fluid
• ~ 25% of semen volume
• nourishes & enhances sperm motility
• neutralizes acidity in vaginal tract

Front 19

bulbourethral/cowper glands

Back 19

A pair of pea-sized glands below the prostate
 Produce a thick, clear mucus into the penile urethra:
• lubricates the urethra & tip of penis prior to ejaculation
• cleanses urethra of acidic urine
• lubricant during sexual intercourse

pre-ejaculation fluid: secretions from the Cowper gland
• a small amount of sperm may enter the ejaculatory duct & mix with the secretions, i.e., pre-ejaculation fluid may contain sperm

Front 20

semen

Back 20

A sticky milky alkaline fluid (pH 7.2-7.8) composed of a mixture of sperms & various glandular secretions
 Average volume of an ejaculate 2- 6 ml
• 50-150 million sperms/ml (120 million/ml on average)
• a sperm count < 20 million/ml > infertility is most likely
 ~ 5 minutes after ejaculation, semenogelin causes semen to coagulate; then10-20 minutes later it re-liquefies (due to the action of enzymes produced by the prostate gland)

Front 21

functions of semen secretions

Back 21

Transport fluid for spermatozoa
 Prostaglandins, from seminal vesicles, enhance sperm motility
 Fructose, from seminal vesicles, provides energy to nourish the sperms
 Secretions neutralizes acidity in male urethra & female vaginal tract
 Lubricate reproductive tract during sexual intercourse
 Antibacterial enzymes & Abs prevent infections

Front 22

Pathway of Spermatozoa

Back 22

seminiferous tubules > rete testes > efferent duct > epididymis head > epididymis body > epididymis tail > ductus/vas deferens > ampulla > joins secretions from the seminal vesicle > ejaculatory duct > urethra > expulsion

Front 23

the penis

Back 23

Vascular spongy erectile tissue of 3 cylindrical masses (corpora)
• Corpora cavernosa: 2 masses dorsolateral to the corpus spongiosum
• Corpus spongiosum: a single mid-ventral mass, enlarges distally to form the glans penis; contains the urethra
 Glans Penis: tip of the penis, covered with the prepuce
• sensory receptors, & the external urethral orifice

Front 24

scrotum

Back 24

Hangs from the root of the penis, and contains the testes
 Regulates the testes’ temperature by the contraction of 2 muscles:
 Cremaster muscle: extension of the internal oblique muscle
 Dartos muscle: in the septum between the 2 testes

Front 25

spermatogenesis

Back 25

process of sperm formation
• starts at puberty & continues throughout a man’s life
• starts in seminiferous tubules > ends in epididymis
• completed via mitosis & meiosis

Front 26

spermiogenesis

Back 26

process of spermatid maturation
• occurs in the epididymis

Front 27

spermatozoon

Back 27

Head contains the nucleus
 Acrosome: covers the head & contains enzymes to penetrate the ovum
 Midpiece: contains the mitochondria
 Flagellum: propels the sperm to the ovum
 After puberty, sperms are manufactured continuously
 Sperms can be stored for many weeks inside the body, but survive only a 1-3 days after leaving the body

Front 28

Infertility

Back 28

a significantly lower than normal ability to reproduce

Front 29

oligospermia

Back 29

dec number of spermatozoa, may increase risk of infertility

Front 30

azoospermia

Back 30

complete lack of sperm in the ejaculate

treatment can restore fertility in some cases, as in blockage of a duct

Front 31

sterility

Back 31

complete inability to reproduce

Front 32

cryptorchidism

Back 32

failure of testes to descend into scrotum, if not corrected in childhood can lead to sterility

Front 33

torsion of testes

Back 33

twisting of the spermatic cord from the rotation of the testis; requires emergency surgery for correction or removal of testis

Front 34

orchitis

Back 34

inflammation of the testis
• secondary to a reproductive tract infection or UTI
• infection with mumps (a viral infection of the parotid gland) during or after puberty may result in orchitis > sterility

Front 35

orchiectomy

Back 35

• removal of the testis

Front 36

phimosis

Back 36

tightness of the prepuce (can’t be drawn back)
• remedied by circumcision

Front 37

STDs/STIs

Back 37

Clamydial & gonococcal infections: most common
• Genital herpes: a viral infection > fluid filled vesicles on & around the genital organs
• Syphilis (by Treponema pallidum, a spirochete) > systemic disorder

Front 38

epididymitis

Back 38

inflammation of the epididymis
• caused by spread of infection from the urethra or bladder

Front 39

prostatitis

Back 39

inflammation of the prostate gland
• due to a secondary bacterial infection from an ascending UTI

Front 40

prostatic cancer

Back 40

May be benign or malignant
 Prostatic tumors cause pressure on the urethra  difficulty in urination > back pressure on kidneys > kidney tissue damage > urinary stasis > inc susceptibility to infection

Front 41

BPH

Back 41

benign prostatic hyperplasia

benign enlargement of the prostate
• may shrink in response to medication
• surgery to reduce the obstruction is performed if the urinary function is threatened

Front 42

malignant prostatic cancer

Back 42

Most common male cancer in the U.S.
 Risk factors include age (> 50), race, family history, red meat, and a high-fat diet
 Detected as a nodule during Digital Rectal Examination
 Screening & early detection of Prostatic-Specific Antigen (PSA) in the blood improves prognosis
 Treatment includes radiotherapy or surgery or hormones depending on the age of patient and nature of cancer

Front 43

testicular cancer

Back 43

Affects young to middle aged men (90% in 20-54 years)
 Most arise in the germ cells
 Widespread metastasis through the lymphatic system
 Early detection through Testicular Self Examination (TSE) improves effective treatment
 5 year survival is > 95%
 Fertility is often preserved
 Risk factors: undescended testis (cryptorchidism), age, family history, cancer of the other testis, & HIV

Front 44

Ovaries

Back 44

Layers of the ovaries:
• Germinal epithelium: a single layer of cuboidal epithelium
• Tunica albuginea: connective tissue capsule beneath the germinal epithelium
• Stroma: Cortex: contains the ovarian follicles & Medulla: contains blood vessels & nerves
 Functions: production of ova and production of female hormones

Front 45

follicles

Back 45

fluid filled cluster of cells in which oocytes at various stages of development exist

follicles msut mature before releasing the secondary oocyte

Front 46

4 stages of maturation

Back 46

primordial follicle

primary follicle

secondary follicle

graafian follicle (mature)

Front 47

ovulation

Back 47

release of a secondary oocyte from the ovary

ovulation is stimulated by a sure in LH

ruptured graafian follicle > corpus luteum

Front 48

corpus luteum

Back 48

Secretes mainly progesterone, with some estrogens & relaxin
 If fertilization DOES NOT occur
• hormone secretion stops within 14 days after ovulation
• Corpus Luteum degenerates  Corpus Albicans (a whitish scar tissue within the ovaries)
 If fertilization Occurs:
• hormone secretion continues for 2-3 month, until the placenta is ready to take over hormone production

Front 49

oviduct/uterine tube/ fallopian tube

Back 49

No direct connection with the ovary
 Infundibulum: funnel shaped open end of uterine tube
 Fimbriae: finger-like projections at the end of oviduct; produce currents to draw the secondary oocyte into the fallopian tube
 Action of cilia in the tube’s lining & peristalsis push ovum towards the uterus

Front 50

oviduct/uterine tube/ fallopian tube

Back 50

The ovum is usually fertilized in the upper 1/3 of the tube
 Fertilization can occur up to 24 hours after ovulation
 If the ovum is fertilized, it reaches the uterus in 5-7 days, to be implanted in the endometrium

Front 51

Uterus

Back 51

Inverted pear shaped muscular organ
 Supported mainly by the broad ligament (contains the blood vessels
supplying the uterus)
 Divided into:
• Corpus (body): wider upper region of the uterus,
• Fundus: area where the uterine tube enters the uterus, and
• Cervix (neck): narrow outlet that protrudes into the vagina
 Layer of the Uterine Wall
• Endometrium: site of implantation of fertilized ovum; highly vascular
mucosa; sheds during menstruation
• Myometrium: bulk of the uterus, contracts under the influence of
oxytocin during labor
• Perimetrium: part of the visceral peritoneum

Front 52

vagina

Back 52

~ 3 in. muscular tube from the cervix to the exterior
 Behind the bladder & in front of rectum
 Lining has rugae
 Hymen: a membrane fold partially closing the vaginal opening

Front 53

fornix

Back 53

a circular recess where the cervix dips into the
posterior portion of the vagina
• posterior fornix: deepest area of fornix, behind the cervix

Front 54

cul-de-sac/rectouterine pouch/pouch of douglas

Back 54

an extension of the peritoneal cavity between the rectum & the back wall of the uterus
• a thin layer of tissue separates the posterior fornix from the culde-sac, such that tumors in the peritoneal cavity may be detected by a vaginal examination

Front 55

greater vestibular/bartholin glands

Back 55

On either side of the vaginal opening
 Homologous to the male’ s Bulbourethral glands
 Secrete lubricating mucus during sexual stimulation
 Not palpable except in the presence of an infection

Front 56

vulva

Back 56

Mons pubis: adipose tissue cushioning the pubic symphysis
• Labia majora: skin folds analogous to the scrotum
• Labia minora: skin folds with blood vessels & oil glands
• Clitoris: a small projectile between the labia minora, analogous to the glans penis
• Vestibule: area enclosed by the labia minora
• includes the vaginal & urethral openings
• the greater vestibular (Bartholin’s) glands secrete their lubrication into the vestibule

Front 57

estrogens

Back 57

produced by the ovarian follicles
• estradiol is the most active estrogen
• release is controlled by FSH
• estrogens stimulate the growth, development & maintenance of female reproductive organs, the breasts, & the secondary female sex characteristics
• Reduces the risk of heart disease and CVD among women of childbearing years, by raising high density lipoprotein (HDL) cholesterol levels
 HDL tends to decrease with the loss of estrogen, and LDL tends to
increase, which raises the risk of heart disease

Front 58

progesterone

Back 58

produced by the corpus luteum before pregnancy, & the placenta during pregnancy
• release is controlled by LH
• works with estrogen to prepare the endometrium for implantation of the fertilized ovum
• helps maintain pregnancy
• stimulates the mammary glands for milk production

Front 59

FSH

Back 59

Follicle stimulating hormone

Stimulates the development of ovarian follicles
• Initiates secretion of estrogens by the ovarian follicles
 as follicles mature they produce more estrogens

Front 60

LSH

Back 60

Luteinizing Hormone

Stimulates the weakening of the Graafian follicle & ovary walls > ovulation
• Triggers the secretion of progesterone by the corpus luteum

Front 61

Phases of reproductive cycle - menstrual cycle

Back 61

in the uterus

prepares the uterus to receive the fertilized ovum

1. menstrual phase

2. proliferative phase

3. secretary phase

ovulation occurs b/w proliferative & secretory phases

Front 62

ovarian cycle

Back 62

in the ovaries

maturation & release of an ovum

1. follicular phase

2. luteal phase

ovulation occurs b/w the 2 phases

Front 63

Phases of Uterine Cycle

Back 63

Menstrual Phase (1-5 days)

dec. in blood levels of estrogen & progesterone >endometrial cells die &
are sloughed off > menses/bleeding
• dec. estrogen levels > release FSH (via -ve feedback) > start of ovarian
follicle maturation > start of inc. in estrogen levels

Proliferative Phase (6-13 days)

Most variable in duration
• Estrogen levels increasing (due to growing ovarian follicles)
• inc. estrogen > endometrial thickening & vascularization

Secretory phase (after ovulation, 14-28 days)

Most constant in duration
• Corpus luteum secretes more progesterone, which causes
inc. in endometrial vascularization
inc. in tissue fluids containing nutrients

Front 64

Phases in ovarian cycle

Back 64

Follicular phase: days 1-13 (between menses & ovulation)
• Most variable in length (accounts for the longer/shorter cycles)
• FSH > maturation of a # of ovarian follicles > follicles start to enlarge > inc. estrogen levels
• A dominant follicle develops into a Graafian follicle
• Dominant follicle secretes more estrogen & inhibin > inhibit FSH
> inhibits the development of the other follicles causing them to
degenerate
• If 2 follicles achieve co-dominance, both may be ovulated > fraternal twins

Front 65

ovulation

Back 65

1 day before ovulation, when estrogen levels are at their highest, the high levels of estrogen trigger the hypothalamus > a surge in LH (surge lasts ~ 36 hours) > weakening & rupture of Graafian follicle & ovary walls > ovum release
 Many birth control pills work by blocking the LH surge, thus inhibiting the release of the ovum

Front 66

Luteal phase

Back 66

after ovulation

collapsed Graafian follicle > corpus luteum
• LH > stimulates the corpus luteum > inc. progesterone
 the rise in progesterone > slight inc. in basal temp. for a couple of days, indicating that the next 24-48 hrs. are the most likely time for fertilization
• The ovum is now moving towards the uterus
• Rising levels of estrogen & progesterone feedback to inhibit the release of FSH & LH from the anterior pituitary

Front 67

if fertilization does not occur

Back 67

ovum disintegrates within 2-3 days
• corpus luteum > corpus albicans
• progesterone & estrogens secretions decline, which causes:
 endometrium degeneration > menstrual flow
 hypothalamus > GnRH > anterior pituitary > FSH > maturation of
ovarian follicles > the cycle repeats

Front 68

dysmenorrhea

Back 68

painful & difficult menstruation, may be due to:
 Immaturity of the uterus in young women
 May be relieved by drugs that block prostaglandins
 Sufficient rest, well balanced diet & exercise help

Front 69

amenorrhea

Back 69

absence of menstrual flow; may be due to
 insufficient hormone secretion
 a congenital abnormality of the reproductive organs,
 stress due to psychological factors,
 very low body weight and/or very low % of body fat (due to reduction in estrogen synthesis)

Front 70

premenstrual syndrome/premenstrual tension

Back 70

fluid retention in various tissues, including the brain
• may cause nervousness, irritability & depression preceding menses
• low salt diet & right meds 2 weeks before menses may reduce symptoms

Front 71

abnormal uterine bleeding

Back 71

excessive or frequent menstruation bleeding > anemia
• non-menstrual bleeding may indicate a tumor

Front 72

menopause

Back 72

Ovaries no longer produce mature follicles > no menses
 Occurs gradually between 45-55 years
 Causes a decline in ovarian function > dec. in estrogen levels > anxiety, insomnia & “hot flashes”
 The uterus, oviducts, vagina & vulva become somewhat atrophied
 Vaginal mucosa become thinner, dryer & more sensitive

Front 73

HRT

Back 73

hormone replacement theory

Estrogen + Progestin (a synthetic progesterone)
• progestin prevents the overgrowth of the endometrium & reduces the risk of endometrial cancer
• Prescribed to relieve discomforts of menopause, however:
 HRT > inc. risk of breast cancer, thrombosis & embolism
 risk associated with HRT inc. with the duration of therapy, i.e., should be given for a short time & at the lowest effective dose

Front 74

the mammary glands

Back 74

Modified exocrine sweat glands
• Areola
• Nipple
• Lobes: internal structures that
radiate around the nipple
 Produce, secrete & eject milk

Front 75

alveolar glands

Back 75

milk producing glands within the lobules
• surrounded by myoepithelial cells which contract to eject the milk

Front 76

lactiferous ducts

Back 76

connect alveolar glands to the nipple

Milk passes from the alveolar glands > alveolar ducts > lactiferous ducts > nipple > ejected outside
 Hormonal Effects:
 Prolactin > milk production
 Oxytocin > milk ejection

Front 77

risk factors of BC

Back 77

Being a female and > 40 years
• Family history of BC: mutations in BRCA1 & BRCA2 genes account for 8% of cases
• Early menses (<12 years) & late menopause (>50 years)
• Late or no pregnancies
• Long-term hormone replacement therapy (HRT)
• Obesity
• Diets high in saturated fat
• Moderate alcohol intake (> 2 per day)

Front 78

breast cancer

Back 78

Regular BSE greatly improves treatment outcomes
 Mammogram: a radiographic study of the breast tissue
 Lumpectomy: surgical removal of a breast lump
 Modified radical mastectomy: removal of the entire breast & the lymph nodes in the respective axilla
• treatment is based on how much metastasis has occurred
 Chemotherapy after mastectomy is common

Front 79

fibroids

Back 79

 Smooth muscle uterine tumors
 1 in 4 women have fibroids
 Small growths with no symptoms, but may interfere with pregnancy
 Pressure from large fibroids on adjacent blood vessels may cause hemorrhages
 Hysterectomy for serious cases

Front 80

endometrial cancer

Back 80

Most common cancer of the female reproductive tract
• Affects women during or after menopause
• Highest in women with few pregnancies, abnormal bleeding or missed menstrual cycles
• Symptoms include abnormal discharge or irregular bleeding
• Surgery, radiation & chemotherapy may be effective

Front 81

ovarian cancer

Back 81

Leading cause of cancer deaths in women
• 2nd most common of the female reproductive tract
• Occurs in women between the ages of 40 – 65
• Surgery, radiation & chemotherapy may be effective

Front 82

cervical cancer

Back 82

3rd most common of the female reproductive tract
• Frequent in women aged 30-50 years
• Risk factors cited in research include first sexual intercourse at early age; many sexual partners & STI

Front 83

PAP smear

Back 83

Examination of cervical cells
• Responsible for  of death rate from cervical cancer
• Every sexually active female (no matter what age) should havean annual pap smear

Front 84

genital warts

Back 84

caused by HPV

linked to cervical cancer

Front 85

salpingitis

Back 85

inflammation of fallopian tube

may be due to clamydial or gonococcal infections

may cause sterility through obstruction of tube

Front 86

PID

Back 86

pelvic inflammatory disease

the spread of infection into pelvic cavity

Front 87

infertility

Back 87

more difficult to diagnose and evaluate in females

may be due to

infections
• endocrine disorders
• psychogenic factors
• abnormalities in structure & function of reproductive organs

Front 88

stages of pregnancy

Back 88

fertilization

embryonic development

fetal development

childbirthd

Front 89

fertilization

Back 89

Usually takes place in the upper 1/3 of the uterine tube
 1-2 hr. for sperm to reach the upper 1/3 of uterine tube
 It requires the combined action of many sperms to allow 1 sperm to penetrate the ovum

Sperms remain viable up to 72 hours within the female reproductive tract, and an ovum can be fertilized 12 - 24 hours after ovulation, thus...
• there is a 3 day “window” for intercourse to result in fertilization (2 days before to 1 day after ovulation)
 Gestation: the 38-week period from zygote > fetus

Front 90

capacitation

Back 90

a functional change that sperms undergo in the
female tract; the membrane around the acrosome becomes fragile
& its enzymes are released

Front 91

dizygotic v monozygotic twins

Back 91

Fraternal/Dizygotic twins: 2 secondary oocytes are ovulated; each is fertilized by a separate sperm; twins may be of different or the same
sexes
• Identical/Monozygotic twins: dividing cells of a fertilized ovum break into 2 groups > 2 individuals; genetically identical

Front 92

cleavage division

Back 92

rapid mitotic cell division without a cell size increase from a zygote > morula > blastocyst > implantation

Front 93

ectopic pregnancy

Back 93

implantation of the blastocyst anywhere outside the uterus
• implantation of the blastocyst may occur in the oviducts or in the abdominal cavity
 growth inside the uterine tube > rupture of tube > severe bleeding & threat to the mother’s life

Front 94

blastocyst

Back 94

tropho blast: outer layer of cells
• trophoblast projections invade the endometrium & maternal blood channels to form  the chorion, which gives rise to the fetal part of the placenta
 Chorionic villi connect the fetal circulation to the placenta

inner cell mass - embryonic Stem cells

self-renewing, pluripotent & theoretically immortal

Front 95

hCG hormone

Back 95

human chorionic gonadotropin hormone

8-12 days after fertilization, trophoblasts produce human Chorionic Gonadotropin (hCG) hormone, which:
• prevents menstruation, and
• keeps the corpus luteum active until the placenta can produce estrogens & progesterone
• Presence of hCG in urine or serum is the basis for the pregnancy tests

Front 96

amnion

Back 96

inner membrane filled with amniotic fluid for protection and space for growth

Front 97

chorion

Back 97

outer membrane

embryonic part of the placenta

Front 98

yolk sac

Back 98

produces the embryo's first blood vessels & bloods cells

Front 99

embryo development

Back 99

Embryo: from fertilization up to 8th week of gestation
 Fetus: after the 8th week through delivery
 The heart & brain are the first organs to develop
• by the 4th week, the heart is beating
 By the 4th month, rudiments of all organs are formed
 The 2nd trimester (4-6) is the most rapid growth period
 Vernix caseosa: a cheese-like material which protects the skin of the fetus

Front 100

quickening

Back 100

first fetal movement felt by mother usually during 4-5 months

Front 101

placenta

Back 101

by the end of the 3rd month, the placenta is
functioning & hormone secretion is shifted from the corpus luteum to the placenta
• miscarriages usually occur during this time of hormonal shifting

Front 102

functions of placenta

Back 102

Forms a placenta-blood barrier between the mother & the embryo/fetus, however…
• alcohol, steroids, narcotics, anesthetics, some antibiotics & some organisms can cross the placenta-blood-barrier
 Delivers nutrients & oxygen to the embryo/fetus
 Removes waste & CO2 from embryonic blood
 Becomes an endocrine organ & takes over hormone production from the Corpus Luteum

Front 103

ductus venosus

Back 103

connects the umbilical vein to the
inferior vena cava
• carries oxygen-rich blood

Front 104

aductus arteriosus

Back 104

shunts blood from the pulmonary
artery > aorta
• protects the fetal lungs against
circulatory overload
• carries medium oxygenated blood

Front 105

foramen ovale

Back 105

• a small hole that shunts blood from
the RA to LA

Front 106

anatomical changes of mother

Back 106

Enlargements of the uterus & breasts
 Accentuated lumbar curvature
 Relaxin causes the softening & lengthening of the cervix & the pubic symphysis ( where the pubic bones join)

Front 107

physiological changes of mother

Back 107

Gastrointestinal System
• morning sickness; organ crowding > heartburn
• dec. motility of digestive tract > constipation
 Urinary System
• additional fetal wastes > more urine
• uterus compresses bladder > inc. in voiding frequency
 Respiratory System
• inc. in rate & depth of respiration > inc. O2 blood levels
 Cardiovascular System
• inc. water volume > inc. blood volume by 25 - 40 %
• inc. BP & heart rate

Front 108

childbirth

Back 108

Prostaglandins stimulate uterine muscles promoting uterine contractions
 Uterine muscles become increasingly sensitive to oxytocin
 After labor begins, vaginal & cervical secretions of oxytocin positively feeds back to the posterior pituitary > inc. oxytocin > inc.uterine contractions

Front 109

Stage 1

Back 109

onset of uterine contractions cause the cervix to thin out & dilate & the amniotic sac to rupture
• lasts 6 -24 hrs depending on the # of previous deliveries

Front 110

stage 2

Back 110

period from maximal cervical dilation through delivery
• contractions become more intense & more frequent
• lasts minutes to an hour

Front 111

stage 3

Back 111

ends with the expulsion of the after-birth (placenta, amniotic sac & the umbilical cord)
• usually occurs from 5-60 min. after birth

Front 112

stage 4

Back 112

control of bleeding
• contraction of uterine muscles close off blood vessels leading to the placental site

Front 113

episiotomy

Back 113

a clean surgical cut in the mother’s obstetrical
perineum to prevent tearing of the pelvic floor tissues during delivery

Front 114

cesarean section

Back 114

incision made in the abdominal & uterine walls for delivering the baby, due to medical complications, such as:
• abnormalities of the placenta or fetal position, or
• a disproportion between baby’s head & mother’s pelvis

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placenta previa

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Placenta attaches at or near the internal opening of the cervix
• Later in the pregnancy, cervical dilation separates part of the placenta from its attachment > painless bleeding that may
interfere with the fetal oxygen supply

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placental abruption

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Premature separation of the placenta from the uterine wall
• Occurs more often in women who have had multiple pregnancies, and > 35 years
• Causes bleeding during second trimester of pregnancy
• May require termination of pregnancy to save mother’s life

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PIH

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pregnancy-induced hypertension/pre-eclampsia

Symptoms: hypertension, proteinuria, edema, & sudden weight gain, all mainly due to kidney malfunction
• Develops in the 2nd trimester in women with poor nutritional diets, & little or no health care during pregnancy
• Untreated may lead to eclampsia (severe hypertension) resulting> seizures, coma, & may cause death to mother & fetus

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genes

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segments of DNA w/i the chromosomes

govern the cell by controlling manufacturing of proteins

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allele

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each member of a gene pair on the same locus
• humans have 2 alleles for each trait
• some alleles are dominant over others

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dominant gene

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the trait is always expressed;
represented by capital letters

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recessive gene

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the trait is masked unless the other allele is also recessive; represented by small letters

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inheritance

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Multifactorial inheritance: i.e., trait is determined by more than one pair of genes (accounts for the wide variations within populations)
 Hereditary/Genetic: any trait that is genetically transmitted
 Congenital: any trait/condition present at birth
• a birth defect may be a problem (e.g. congenital heart defects) or not (e.g. third nipple, sacral dimples)
• Teratogen: any substance that causes birth defects
• A trait/condition may be congenital & hereditary, or congenital & non-hereditary

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congenital disorders/birth defects

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May be caused by genetics, chromosomal problems, environmental hazards, lack of certain nutrients, alcohol or drug abuse, infections or diseases.
• Most common birth defects include:
• cleft lip and/or cleft palate,
• neural tube defects such as spina bifida,
• heart defects, and
• cerebral palsy.

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german measles/rubella

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a normally mild contagious viral infection, however, if maternal infection occurs during the 2nd trimester of pregnancy the fetus has a 40% chance of developing cataracts, deafness, and brain & heart defects
• may be prevented by the appropriate immunizations

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FAS

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fetal alcohol syndrome

mental retardation & physical defects such as deformed facial features, abnormal joints & limbs, poor coordination, problems with learning, & short memories
• those who give birth to FAS children are more often alcoholics, smoke, use illegal drugs, malnourished, & rarely receive medical care during pregnancy

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meningocele

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the meninges protrude through the vertebrae in a sac, the "meningocele”, but the spinal cord
remains intact
 repaired with little or no damage to the
nerve pathways

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myelomeningocele

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the most severe form; a portion of the spinal cord protrudes through the back
 spinal cord ends at the point of the defect,
affecting the function below that point

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chromosomal disorders

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can be hereditary or can develop after fertilization as embryo splits during development

i.e. downs syndrome, sickle cell anemia, tay-sachs, PKU

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Downs Syndrome

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trisomy 21

An extra copy of chromosome 21 is inherited
• the extra chromosome may be present in the sperm or in the egg, or occurs in the first cellular division
 Distinctive facial features include round face,close-set eyes, small head, flat nose, & large tongue
 Poor muscle tone, lowered immunity, and prone to heart disease, leukemia and Alzheimer's
 Linked to maternal age not to hereditary genetic factors
• the risk of having a child with Down’s syndrome increases dramatically in woman > 35 years

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Autosomal dominant inheritance

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Only one copy of the dominant allele is needed for a person to exhibit the trait, i.e., no carriers
 People exhibiting the trait may be homozygous (AA) or heterozygous (Aa)
 Males & females can be affected and can transmit it
 Transmission stops when a generation arises in which no family member is affected
 Examples: Huntington's disease & Marfan syndrome

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huntington's disease

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a neural degenerative disorder
• rapid involuntary muscle activity & mental deterioration
• appears around 40 years
• death usually occurs within 15 years
• no cure
• can be identified via genetic testing

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marfan syndrome

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a connective tissue disease
• affects skeletal system, cardiovascular system, eyes & skin
• affected people are usually tall with long, thin arms and legs, and spider-like fingers, a condition called arachnodactyly
• some also have heart defects

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autosomal recessive inheritance

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Most inherited diseases are autosomal recessive
 2 copies of the recessive allele are needed for a person to exhibit the trait
 If 1 copy is present, the person is a carrier
 Males and females are affected
 Affected males & females can transmit the trait
 The trait expression can “skip” generations
• i.e. only carriers are present in that generation

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PKU

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phenylketonuria

a genetic disorder that affects children whose parents carry the PKU genetic defect.
• affects how the body processes protein; if left untreated, it can lead to severe developmental and physical delays, including mild to moderate mental retardation.
• About 1 in 10,000 children are born with this disease every year in the U.S.

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cystic fibrosis

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Chronic lung disease among children and young adults, which may result in early death.
 thick, sticky mucus builds up in the lungs, intestine, & pancreatic ducts > obstruction of the organs
• One of the most common & frequently inherited disease in Whites
• Symptoms: frequent respiratory infections, intestinal fats loss, fat soluble vitamins loss, (A, D, E & K) & massive loss of salts
• Treatment includes oral administration of pancreatic enzymes and special pulmonary exercises

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tay-sachs disease

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A fatal (by age 4) genetic lipid storage disorder  lipid build up in tissues (e.g. retina) & nervous tissue, due to lack of the enzyme that catalyzes the breakdown of this lipid> as nerve cells become distended with fatty material > deterioration of mental & physical abilities > blindness, deafness, inability to swallow; muscles begin to atrophy > paralysis sets in
• Mainly in Eastern European Jews
• No cure

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albinism

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Altered genes do not make the usual amounts of melanin > skin & hair color are strikingly white
• Associated with vision problems (main test for albinism is an eye examination)
• Albinos are susceptible to myopia & photophobia & skin cance

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OI

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osteogenesis imperfecta

Brittle bones disease
• Heritable disorder of connective tissue
• Affected people are susceptible to multiple fractures

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sex-linked (x-linked) genes

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Most sex-linked genes are X-linked genes
• the X chromosome is longer & thus carries more traits than the Y chromosome
 Most X-linked traits are recessive, therefore
• X-linked traits appear almost exclusively in males
• e.g. hemophilia & red-green colorblindness

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x-linked recessive inheritance

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Males always express the trait
 Affected females (homozygous recessive) have an affected father & a mother who is either affected or a carrier
 Heterozygous females are always carriers
• their sons have a 50/50 chance of being affected
• their daughters have a 50/50 chance of being carriers
 The trait can “skip” generations (i.e. only female carriers & unaffected males are born)