Reproductive System - Dr. Par Mohammadian

PowerPoint® Lecture Slides prepared by Barbara Heard, Atlantic Cape Community College

CHAPTER

27

The Reproductive System: Modified by Dr. Par Mohammadian © Annie Leibovitz/Contact Press Images

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Reproductive System • Primary sex organs (gonads) - testes and ovaries – Produce gametes (sex cells ) – sperm & ova – Secrete steroid sex hormones • Androgens (males) • Estrogens and progesterone (females)

• Accessory reproductive organs - ducts, glands, and external genitalia

Reproductive System • Sex hormones play roles in – Development and function of reproductive organs – Sexual behavior and drives

– Growth and development of many other organs and tissues

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Figure 27.4A

Male Reproductive System Urinary bladder (excretory system)

Seminal vesicle (behind bladder)

Prostate gland Bulbourethral gland

Urethra

Erectile tissue of penis Vas deferens

Scrotum

Epididymis Testis

Glans of penis

Male Reproductive System • Testes (within scrotum) produce sperm • Sperm delivered to exterior through system of ducts – Epididymis  ductus deferens  ejaculatory duct  urethra

• Accessory sex glands – Seminal glands – Prostate – Bulbo-urethral glands – Empty secretions into ducts during ejaculation

Figure 27.1 Reproductive organs of the male, sagittal view.

Ureter Peritoneum Seminal gland (vesicle) Ampulla of ductus deferens Ejaculatory duct Rectum Prostate Bulbo-urethral gland Anus Bulb of penis Ductus (vas) deferens

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Epididymis Testis Scrotum

Urinary bladder Prostatic urethra Pubis Intermediate part of the urethra Urogenital diaphragm Corpus cavernosum Corpus spongiosum Spongy urethra Glans penis Prepuce (foreskin) External urethral orifice

The Scrotum • Sac of skin and superficial fascia – Hangs outside abdominopelvic cavity – Contains paired testes • 3C lower than core body temperature • Lower temperature necessary for sperm production

• Temperature kept constant by two sets of muscles: Dartos muscle & Cremaster muscles

Figure 27.2 Relationships of the testis to the scrotum and spermatic cord.

Urinary bladder

Superficial inguinal ring (end of inguinal canal) Spermatic cord

Penis Septum of scrotum Cremaster muscle External spermatic fascia Superficial fascia containing dartos Scrotum muscle Skin © 2013 Pearson Education, Inc.

Testicular artery Ductus (vas) deferens Autonomic nerve fibers Pampiniform venous plexus Epididymis Tunica vaginalis (from peritoneum) Tunica albuginea of testis Internal spermatic fascia

The Testes • Each surrounded by two tunics – Tunica vaginalis – outer layer derived from peritoneum – Tunica albuginea – inner layer; fibrous capsule

• Septa divide testis into ~250 lobules, each containing 1–4 seminiferous tubules site of sperm production; Produce androgens, e.g., testosterone – Secrete it into interstitial flui

Figure 27.3a Structure of the testis.

Spermatic cord Blood vessels and nerves

Ductus (vas) deferens Head of epididymis

Testis

Efferent ductule

Seminiferous tubule

Rete testis

Lobule Septum Tunica albuginea

Straight tubule Body of epididymis Duct of epididymis

Tunica vaginalis Cavity of tunica vaginalis

Tail of epididymis •

Sperm conveyed from Seminiferous tubules Straight tubule Rete testis Efferent ductules Epididymis

Figure 27.3b Structure of the testis.

Spermatic cord

Ductus deferens Epididymis Testis

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The Penis • External genitalia - scrotum and penis • Penis - male copulatory organ • Penis consists of – Root and shaft that ends in glans penis – Prepuce, or foreskin—cuff of loose skin covering glans • •

Circumcision: Surgical removal of foreskin 60% newborn boys in US circumcised – 15% in other parts of world – Some claim medically unnecessary – Studies show • 60% reduction in HIV risk • Reduced risk for other reproductive system infections

The Penis: Internally

Ureter Urinary bladder

•

Spongy urethra and three cylindrical bodies of erectile tissue (spongy network of connective tissue and smooth muscle with vascular spaces) – Corpus spongiosum surrounds urethra and expands to form glans and bulb – Corpora cavernosa paired dorsal erectile bodies

•

Erection - erectile tissue fills with blood, causing penis to enlarge and become rigid

Ampulla of ductus deferens Seminal gland Prostate Prostatic urethra

Ejaculatory duct

Orifices of prostatic ducts Intermediate part of the urethra (membranous urethra)

Urogenital diaphragm

Root of penis

Crus of penis

Bulbo-urethral gland and duct

Bulb of penis

Bulbo-urethral duct opening Ductus deferens Corpora cavernosa Epididymis Body (shaft) of penis

Corpus spongiosum Testis Section of (b) Spongy urethra

Glans penis

Prepuce (foreskin) External urethral orifice

Dorsal vessels and nerves

Corpora cavernosa Urethra

Skin Tunica albuginea of erectile bodies Deep arteries Corpus spongiosum

The Male Duct System • Ducts carry sperm from testes to body exterior – Epididymis – Ductus deferens

– Ejaculatory duct – Urethra

Vasectomy!

The Male Accessory Glands • • • •

Paired seminal glands (seminal vesicles) Paired bulbo-urethral glands Prostate Produce bulk of semen – Remainder - sperm from testes

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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; protects and activates sperm; facilitates sperm movement • Alkaline  neutralizes acidity of male urethra and female vagina  enhanced motility © 2013 Pearson Education, Inc.

Female Reproductive Anatomy • Internal genitalia – in pelvic cavity – Ovaries – Uterine tubes – Uterus

– Vagina

• External genitalia – External sex organs

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Figure 27.3A

Female Reproductive system Ovaries

Oviduct

Follicles

Corpus luteum

Uterus

Wall of uterus Endometrium (lining of uterus)

Vagina

Cervix (“neck” of uterus)

Figure 27.12 Internal organs of the female reproductive system, midsagittal section.

Peritoneum Uterosacral ligament Perimetrium Rectouterine pouch Rectum Posterior fornix Cervix Anterior fornix Vagina Anus Urogenital diaphragm Greater vestibular gland

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Suspensory ligament of ovary Infundibulum Uterine tube Ovary Fimbriae Uterus Round ligament Vesicouterine pouch Urinary bladder Pubic symphysis Mons pubis

Urethra Clitoris External urethral orifice Hymen Labium minus Labium majus

Figure 27.14 Internal reproductive organs of a female, posterior view.

Suspensory ligament of ovary Ovarian blood vessels Broad ligament • Mesosalpinx • Mesovarium • Mesometrium

Uterine (fallopian) tube

Ovarian ligament Body of uterus Ureter Uterine blood vessels Isthmus Uterosacral ligament Cardinal (lateral cervical) ligament Lateral fornix Cervix

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Fundus Lumen (cavity) of uterus of uterus Ovary

Uterine tube • Ampulla • Isthmus • Infundibulum • Fimbriae

Round ligament of uterus Wall of uterus • Endometrium • Myometrium • Perimetrium • Internal os • Cervical canal • External os

Vagina

Uterine Wall • Three layers – Perimetrium - serous layer (visceral peritoneum) – Myometrium - interlacing layers of smooth muscle – Endometrium - mucosal lining

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Uterine Vascular Supply • Uterine arteries arise from internal iliacs; branch into • Arcuate arteries in myometrium; branch into • Radial arteries in endometrium; branch into

• Straight arteries  stratum basalis • Spiral arteries  stratum functionalis – Degenerate and regenerate; spasms  shedding of functionalis layer during menstruation

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Figure 27.15b The endometrium and its blood supply.

Lumen of uterus Epithelium Capillaries Uterine glands

Venous sinusoids Lamina propria of connective tissue Spiral (coiled) artery Straight artery

Endometrial vein Radial artery Smooth muscle fibers Arcuate artery Uterine artery © 2013 Pearson Education, Inc.