The Reproductive System

Secreted steroid sex hormones:

• androgens (males)

• estrogens and progesterone (females)

The Scrotum

• sac of skin and superficial fascia

• paired testes below body temp. for sperm production

• Dartos muscle: smooth muscle, pulls Scrotum close to body

• cremaster muscles: skeletal muscle - elevate

The Testes

• membranes: tunica vaginalis & albuginea

• septa: divide testes into lobules

  • seminiferous tubules: site of sperm production

    • myoid cells: squeeze sperm and testicular fluids out of testes

Sperm Formation

• acrosome: contains enzymes for digesting through the egg’s protective coat

• head: contains chromosomes

• middle piece: has mitochondria for energy release

• tail: for movement

Testicular Cancer

Rare, but most common cancer in men age 15-35

• having mumps that lead to orchitis (inflammation of testis) could be a risk factor

• cryptorchidism is most common risk factor (non descent of testes)

• failure of the testis to make their normal decent is also a risk factor

sign: painless, solid mass in testis

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

Prostate Cnacer

• second most common cause of cancer death in males

• digital exam screening, PSA levels: biopsy if abnormal

• treated with surgery and sometimes radiation, castration, drugs

• in clinical trails: cryosurgery, chemotherapy, ultrasound, proton beam therapy

Seminal Glands

• smooth muscle contracts during ejeculation

• viscous alkaline seminal fluid

• duct joints ductus deferens to form ejaculatory duct

Prostate

• encircles urethra inferior to bladder

• smooth muscle that contracts during ejeculation

• secretes milky, slightly acid fluid

• plays a role in sperm activation

Bulbourethral Glands

• pea size glands inferior to prostate

• thick, clear mucus during sexual arousal

• neutralize traces of acidic urine in urethra

• lubricate glands penis

Semen

• sperm and accessory gland secretions

• contains fructose of ATP production, protects & activates sperm, and facilitates sperm movements

• alkaline fluid

Secreted female sex hormones

• estrogen (estradiol, estrogen, estriol): induce secondary sex characteristics, promote oogenesis & follicle growth in ovary, and metabolic effects

• progesterone: establish & regulate uterine cycle

Ovulation

ejection of oocyte from ripening follicle

Male Duct System

• Epididymis: contracts, expel sperm into ductus deferens, stores sperm cells

• Ductus deferens: join duct of seminal vesicle to form ejaculatory duct

• Ejaculatory duct

• Urethra: transports urine and semen

Female Duct System

• Uterine tubes: receives ovulated oocyte & usual site of fertilization

• Uterus: receive, retain, and nourish fertilized ovum

• Vagina: birth canal, passageway for menstrual flow, copulation

Ectopic Pregnancy

oocyte is fertilized in peritoneal cavity or distal uterine tubes and begins developing there

• normally aborted naturally with substantial bleeding

Uterine Tubes

Pelvic inflammatory disease (PID)

spread of infection from reproductive tract to peritoneal cavity

• may cause scar tissue and lead to infertility

Uterine Tubes

Cervical Cancer

• Risk: frequent cervical inflammation; STIs, including HPV, or multiple pregnancies

• Papanicolaou (Pap) smear for detection

Uterus

Prolapse of the uterus

• An unsupported uterus may sink inferiorly, until tip of cervix protrudes through the external vaginal opening

• causes: overstretching & tearing muscles during childbirth

Mammary Glands

main function is milk production to nourish newborn

Breast Cancer

• usually arises from epithelial cells of smallest ducts that eventually metastasize

• risks factors:

  • early onset of menstruation and late menopause

  • no pregnancies or first pregnancy lat ein life

  • no or short periods of breast feeding

  • family history of breast cancer

• diagnosis: self-examination, mammography

• treatment: radiation, chemotherapy, sorgery

Follicle- Stimulating Hormone (FSH)

Females: triggers the growth of eggs in the ovaries and gets the eggs ready for ovulation

Males: stimulate sperm production

Luteinizing Hormone (LH)

• sexual development in children and fertility in adults

Females: helps control the menstrual cycle; triggers the release of an egg from the ovary (ovulation)

Males: causes the Leydig cells of the testes to produce testosterone

Testosterone

stimulates male secondary sex characteristics (muscle mass, deeper voice, facial hair, increases bone density)

Estrogen

Females: secondary sex characteristics (breasts growth, public hair), start menstrual cycles, regulate menstrual cycle

Males: erectile function

Progesterone

Females: maintenance of embryo and uterus during early pregnancy, stays at high levels during pregnancy to stop menstrual cycles

Males: builds bone mass

GnRH

controls the release of the anterior pituitary(FSH & LH release)

Egg Production: What is D?

corpus luteum

Egg Production: What is C?

mature follicle

Egg Production: What is E?

ovulation

Egg Production: What is A?

primordial follicle

Sperm Production: What is E?

early spermatids

Sperm Production: What is A?

spermatagonia

Sperm Production: What is B?

primary spermatocyte

Fallopian Tubes

receives the ovulated oocyte, providing a site for fertilization

Pathway of Sperm

1. seminiferous tubules

2. epididymis

3. vas deferens

4. urethra

Order of the Layers of the Uterine Wall (inner→outer)

1. endometrium

2. myometrium

3. perimetrium

Blood supply

• arteries from abdominal aorta

• veins form pampiniform venous plexus surrounding arteries - absorb heat from testicular arteries, keep testes cool

Spermatic Cord

encloses nerve fibers, blood vessels and lymphatics that supply testes

Spermatogenesis

production of sperm (spermatozoa) in seminiferous tubules

• most body cell shave 46 chromosomes:

  • two sets (23 pairs) of chromosomes

    • one maternal, one paternal: homologous chromosomes

    • referred to as diploid chromosomal number (2n)

  • gametes have only 23 chromosomes: haploid chromosomal number (n)

    • only one member of the homologous pair