BIO202 - Unit 7 - Reproductive System - Ch 27-28

Gonads

reproductive organs

Male gonads

testes

Testes

produce = sperm

secrete = androgens (male sex hormones: example - testosterone)

Pathway of sperm

testis→ epididymis→ vas deferens→ seminal vesicles→ prostate gland→ bulbourethral glands→ urethra→ penis

Female gonads

ovaries

Ovaries

produce = eggs (also called ova or oocytes)

primary secretions: estrogen & progesterone

ovulation

process in which a mature egg is released from the ovary

Pathway of an egg (unfertilized)

ovary, fallopian tube, uterus, cervix, vagina

Where does fertilization take place?

fallopian tubes

Where does implantation/zygote development occur?

uterus (lining)

STI/STD: Gonorrhea

•caused by: Neisseria gonorrhoeae

•Bacterial infection of mucosae of reproductive & urinary tracts

•Spread by contact with genital, anal, and pharyngeal mucosae

•Males: Urethritis, painful urination, discharge of pus

•Females: Abdominal discomfort, vaginal discharge, abnormal uterine bleeding, or can result in pelvic inflammatory disease and sterility

•Treatment - antibiotics, but resistant strains becoming prevalent

STI/STD: Syphilis

•caused by: Treponema pallidum

•Bacterial infection transmitted sexually or contracted congenitally

•Infection asymptomatic for 2-3 weeks

•Painless chancre (ulcer) appears at site of infection; disappears in few weeks

•If untreated, secondary signs appear several weeks later for 3-12 weeks, then disappear

•Latent period may or may not progress to tertiary syphilis, characterized by gummas (lesions of CNS, blood vessels, bones, and skin)

•Treatment - penicillin

STI/STD: Chlamydia

•Most common bacterial STI in United States

•Responsible for 25-50% of all diagnosed cases of pelvic inflammatory disease

•Symptoms - urethritis; penile and vaginal discharges; abdominal, rectal, or testicular pain; painful intercourse; irregular menses

•Treatment - tetracycline

STI/STD: Trichomoniasis

•Parasitic infection; easily, inexpensively treated

•Most common curable STI in active young women in U.S.

•Yellow-green vaginal discharge with strong odor; some symptomless

Genital warts

•Caused by human papillomavirus (HPV)

•Second most common STI in United States

•Increased risk of cancers in infected body regions

-Linked to 80% cases of invasive cervical cancer; most strains do not cause cancer

Treatment difficult; controversial

HPV (human papilloma virus)

a group of viruses that can cause genital warts in males and females and can cause cervical cancer in females

vaccine available: Gardasil

Genital herpes

•Caused by herpes simplex virus 2

•Characterized by latent periods and flare-ups

•Congenital herpes can cause malformations of fetus

Treatment - acyclovir and other antiviral drugs

Cryptorchidism

failure of one or both testes to descend into the scrotum

Why are the testes located outside the body?

temperature regulation for sperm development

testicular cancer

•Rare; most common cancer in men 15-35

•Cryptorchidism is risk factor

•Sign - painless, solid mass in testis

•90% cured by surgical removal of testis and often radiation or chemotherapy

Pelvic inflammatory disease (PID)

•Spread of infection from reproductive tract to peritoneal cavity

May cause scar tissue àinfertility

Breast cancer - arises from?

•Usually arises from epithelial cells of smallest ducts; eventually metastasize

Breast cancer - risk factors

•Early onset of menstruation and late menopause

•No pregnancies

•First pregnancy late in life

•No or short periods of breast feeding

•Family history of breast cancer

-70% of women with breast cancer have no known risk factors

mammogram

radiographic image (x-ray) of the breast

Breast cancer - treatment

•Treatment depends upon characteristics of lesion

•Radiation; chemotherapy; surgery, often followed by radiation or chemotherapy to destroy stray cells

•Drugs for estrogen-responsive cancers

Mastectomy

surgical removal of a breast

Radical mastectomy

removal of an entire breast along with the underlying chest muscles and axillary lymph nodes

-complications that may occur:

Lymphedema: If lymph nodes are removed or damaged, lymphedema (swelling in the arm and hand due to fluid buildup) can develop.

Scar tissue formation, especially in the armpit, can lead to cording (tight, rope-like structures) and limited movement.

Endometriosis

a condition in which patches of endometrial tissue escape the uterus and become attached to other structures in the pelvic cavity & responds like the uterine lining during menstrual cycle which can cause pain, irregular periods and infertility.

Enlarged prostate

Benign prostatic hyperplasia (BPH)

a common condition in men where the prostate gland grows larger than normal, but not due to cancer. This enlargement can put pressure on the urethra, causing urination problems like difficulty starting or stopping urination, a weak urine stream, and the feeling of not fully emptying the bladder.

Cervical cancer

Malignant cell growth in the cervix; can be caused by HPV virus

•Risks - frequent cervical inflammations, STIs, multiple pregnancies

•Papanicolaou (Pap) smear for detection

Nondisjunction

the failure of one or more pairs of homologous chromosomes or sister chromatids to separate normally during nuclear division, usually resulting in an abnormal distribution of chromosomes in the daughter nuclei.

Klinefelter's Syndrome

a chromosomal trisomy in which males have an extra X chromosome resulting in an XXy condition; affected individuals typically have reduced fertility

Turner's Syndrome

A genetic defect in which affected women have only one X chromosome, causing developmental abnormalities and infertility.

Three stages of labor

1. Dilation

2. Expulsion

3. Placental stage

Dilation stage of labor

from the onset of labor to complete dilation of the cervix, cervix dilates to 10 cm in diameter, amniotic fluid is expelled "water breaks" amniotic sac ruptures or is manually ruptured average 6-12 HOURS, pressure from fetal head stimulates dilation

fully dilated cervix

10 cm

Expulsion stage of labor

actually giving birth to the baby

Vertex position

a birth in which the infant is delivered head first

Breech position

turned so that the buttocks or feet would be delivered first

Placental stage of labor

Delivery of afterbirth (placenta and membranes) occurs within 30 minutes after birth

Strong contractions continue, causing detachment of placenta and compression of uterine blood vessels

Contractions limit bleeding and shear placental from uterine wall, causing detachment

All placenta fragments must be removed to prevent postpartum bleeding

Physiological changes of pregnancy - urinary system

•Increased urine production due to increased maternal metabolism and fetal wastes

•Increase of up to 30% more urine volume

•Frequent, urgent urination; stress incontinence may occur as bladder compressed

Physiological changes of pregnancy - GI tract

•Morning sickness (all day sickness) believed due to elevated levels of hCG (identified by pregnancy test), estrogen and progesterone

•Heartburn and constipation are common

Physiological changes of pregnancy - cardiovascular system

•Blood volume increases 25-40%

•Safeguards against blood loss during childbirth

•Cardiac output rises as much as 35-40%

•Propels greater volume around body

•Venous return from lower limbs may be impaired, resulting in varicose veins

Fetal waste products are disposed of by the

placenta

-then via urinary system

Fetal metabolic needs (nutrition & oxygen) are provided by the

endometrium (nutrition) and placenta (nutrition & oxygen)

Braxton Hicks contractions

intermittent weak contractions of the uterus occurring during pregnancy due to increased hormone levels. They can start as early as 20 weeks and last through 32 weeks or until real labor begins.

Relaxin

hormone produced by the placenta that causes pelvic ligaments and pubic symphysis to relax to ease birth passage

Chloasma

pigmentation of facial skin may increase causing patches of darker skin; pregnancy mask

Ectopic pregnancy

pregnancy occurring outside the uterus, commonly in the fallopian tubes (but may also happen in the cervix, on an ovary or in the abdomen)

Extra calories per day needed during pregnancy

300 calories (not eating for two!)

Vitamins/minerals necessary for proper fetal development

folic acid (to reduce risk of spina bifida, anencephaly)

vitamin D (necessary for adequate calcium for fetal bone mineralization)

calcium

iron

teratogen

any agent that can disturb embryonic development and cause a birth defect. Classes of teratogens include: radiation, maternal infections, chemicals, alcohol & drugs

fetal alcohol syndrome

Physical and mental damage in a child due to alcohol exposure while in the womb.