Reproductive System (Genitalia)

Reproductive System (Genitalia) Not vital, but essential for producing offspring Primary sex organs: testis & ovary make gametes and secrete sex hormone Accessory sex organs: Male: Ducts: epididymis, ductus deferens, ejaculatory duct, urethra Glands: seminal vesicle, prostate gland, bulbourethral gl…. Others: penis, scrotum… Female: Ducts: oviduct (uterine tube), uterus, vagina Glands: uterine gl., bulb of vestibule, greater & lesser vestibular gl. Others: clitoris, labia major & minor, mammary gl…

The Male Reproductive System

The Male Reproductive System The scrotum skin and superficial fascia surrounding the testes Positioning provides an environment 3˚ C cooler than body temperature; muscles for elevating the testes Dartos muscle – layer of smooth muscle Cremaster muscle – bands of skeletal muscle surrounding the testes The spermatic cord consists of Ductus (vas) deferens Testicular a. & v. (pampiniform plexus for countercurrent heat exchange); varicocele Autonomic nerve fiber.

The Testis and Seminiferous Tubules Are enclosed in a serous sac – the tunica vaginalis Tunica albuginea fibrous capsule of the testes divides each testis into 250-300 lobules Lobules contain 1-4 coiled seminiferous tubules and epithelium consists of Spermatogenic cells – sperm-forming cells Columnar sustentacular cells – support cells (Sartoli cells) Spermatogenesis – sperm formation Begins at puberty – 400 million sperm per day

The Scrotum – Containing the Testes and Spermatic Cord

人類是少數會男女的生物 Spermiogenesis is controlled by ant. lobe of pituitary gl. →FSH Leydig cell → Testosterone Copyright © 2005 Pearson Education, Inc., publishing as Benjamin Cummings

The accessory ducts The Epididymis: About 6m long duct; store sperms Dominated by pseudostratified columnar epithelium with stereocilia (immotile, long microvilli ) Reabsorb testicular fluid Transfer nutrients and secretions to sperms 20-day journey for sperm to move through Gain the ability to swim and to fertilize an egg (maturation) The Ductus Deferens: about 45 cm; rapidly propel sperms Inner mucosa; middle muscularis; outer adventitia Joint with duct of seminal vesicle to form ejaculatory duct Vasectomy for sterility The Urethra: Consists of 3 parts: prostatic, membranous and spongy Urethral gl. lubricates urethra

Accessory Glands (I) The Seminal Vesicles Lie on the posterior surface of the urinary bladder Secretes about 60% of the volume of semen contains: Fructose: nourish sperm with autofloresces Other substances to enhance fertilization Prostaglandins: contraction of uterus Suppress immune response in female Substances enhance sperm motility Clot and liquefy semen in vagina (fornix) The Bulbourethral glands Pea-sized glands inferior to the prostate gland Produce mucus enters spongy urethra prior to ejaculation Cleanses urethra and enhances pH for fertilizations

The prostate gland Accessory Glands (II) Fibromuscular stroma encircles the prostatic urethra Consists of 20-30 compound tubuloalveolar glands secretes about 25-30% of semen from Contains substances that enhance sperm motility and clot & liquefy semen Benign prostatic hyperplasia (BPH) and prostate-specific antigen (PSA, prostatic cancer maker) Prostate cancer Slow-growing – arises from peripheral glands Risk factors Fatty diet Genetic predisposition

Prostate Glands BPH: benigh prostatic hyperplasia PSA: prostate-specific antigen Prostatitis

The Penis Circumcision Figure 24.8a, b

The Female Reproductive System Produces gametes (ova) oogenesis Prepares to support a developing embryo Ovulation and fertilization Implantation (pregnancy) and labor Undergoes changes according to the menstrual cycle (28 days) Ovarian cycle Uterine cycle

Female Internal Reproductive Organs

The Uterine Ducts and Ligaments Figure 24.11a Copyright © 2005 Pearson Education, Inc., publishing as Benjamin Cummings

Small, almond-shaped organs The Ovaries Small, almond-shaped organs Contain 400 million ova Ovarian cycle controlled by FSH and LH (ovulation) Held in place by ligaments and mesenteries Broad ligament Suspensory ligament – contains ovarian arteries Ovarian ligament

Ovulation occurs about halfway through each ovarian cycle The Ovarian Cycle Ovulation occurs about halfway through each ovarian cycle Controlled by LH Oocyte exits from one ovary Enters the peritoneal cavity, then is swept into the uterine tube Ectopic pregnancy Luteal Phase – occurs after ovulation Remaining follicle becomes a corpus luteum Secretes progesterone Acts to prepare for implantation of an embryo

Ovary

Includes chromosomal reduction division of meiosis Oogenesis Includes chromosomal reduction division of meiosis Takes many years to complete

The Female Reproductive System

The Uterus Anteverted U. Retroverted U. Prolapse U. Surrogate Mother

The Uterine Wall Functional layer Basal layer

Series of cyclic phases of the endometrium The Uterine Cycle Series of cyclic phases of the endometrium Phases coordinate with the ovarian cycle Endometrial phases directed by FSH and LH Phases of uterine cycle Menstrual phase – days 1-5 Stratum functionalis is shed Proliferative phase – days 6-14 Secretory phase – days 15-28

The Menstrual Cycle

Consists of three coats Adventitia – fibrous connective tissue The Vagina Consists of three coats Adventitia – fibrous connective tissue Muscularis – smooth muscle Mucosa – marked by transverse folds Consists of lamina propria and stratified squamous epithelium Cervical gland: anti-bacteria, anti-sperm Hymen: an incomplete diaphragm Fornix: recess formed at the superior part of the vagina Store semen Cervical cancer – slow-growing, arises from epithelium at the tip of the cervix Papanicolaou smear (Pap): cervicle smear test

The Vagina

The External Genitalia and Female Perineum Anal triangle Genital triangle

The Mammary Glands Breasts – modified sweat glands Glandular structure – undeveloped in non-pregnant women Milk production – starts after childbirth Breast cancer – mammogram, radical mastectomy or lumpectomy