Reproductive System

1. Reproductive System Objectives: 12.0 Identify structures and functions of the reproductive system 12.1 Differentiating between male and female reproductive systems 12.3 Identifying disorders of the reproductive systemExamples: endometriosis, sexually transmitted diseases, prostate cancer

2. Preassessment Quiz What is a male sex cell called? What is the male primary sex organ? What do the primary sex organs do? Name 2 internal male accessory organs. Name 2 external male accessory organs. What is a female sex cell called? What is the female primary sex organ? Name 2 internal female accessory organs. Name 2 external female accessory organs.

3. Organs of the Male Reproductive System • Label and color Figure 19.1

4. 1.Testes • Enclosed in a tough, white, fibrous capsule (tunica albuginea) within the scrotum(2.) • Connective tissue thickens along inferior border of capsule and projects into testis, dividing it into 250 lobules • Each lobule contains 1-4 highly convoluted seminiferous tubules.

5. Testes, continued….. • Seminiferous tubules join in a complex network called the rete testis. • Ducts branching off the rete testis join a single, convoluted tube called the epididymis (3.) • Once the epididymis straightens, it becomes the vas deferens (4.)

6. Structure of the Testes, continued….. • What does spermatogenicmean? • Inside the seminiferous tubules: • Spermatogenic cells (specialized epithelial cells) line the walls. • They form sperm cells that collect in the lumen of the tubule. • Between the tubules are interstitial cells (“cells of Leydig”), which produce male sex hormones.

8. Testicular Cancer • Arises from the epithelial cells of the seminiferous tubules. (What are the names of these cells?) • Signs: • Painless swelling of the testis • Scrotal mass attached to the testis • Treatments: • Surgical removal of testis • Radiation and/or chemotherapy

9. Formation of Sperm Cells Where are they formed??? Males produce sperm cells continually throughout their reproductive lives. They collect in the lumen and pass to the epididymis, where they mature and accumulate.

10. Formation of Sperm Cells, continued….. • 3 main parts: • Head • Mainly a nucleus containing 23 chromosomes • Acrosome – a projection at the end of the head that contains enzymes to assist in penetrating an egg • Midpiece - contains many mitochondria • Tail - flagella; function????

11. Male Internal Accessory Organs • Epididymis • Vas deferens • Seminal vesicle • Prostate gland • Bulbourethral glands • Semen (*)

12. 3. Epididymis Convoluted tube that is connected to ducts within the testis, emerges from the top of the testis, descends along the posterior surface of the testis, and ascends to become the vas deferens. Immature, nonmotile sperm mature as they are moved through the epididymis.

13. 4. Vas deferens Travels from epididymis to just behind the bladder Unites with the duct of a seminal vesicle(5) to form an ejaculatory duct (6) Ejaculatory duct passes through the prostate gland (7) and empties into the urethra (8)

14. 5. Seminal vesicle • Convoluted sac-like structure attached to the vas deferens near the base of the urinary bladder • Secretes: • a slightly alkaline fluid to regulate pH of tubular contents • fructose to provide energy to sperm cells • prostaglandins to stimulate muscular contractions in female reproductive organs to help move sperm cells

15. 7. Prostate Gland • Chestnut-shaped structure that surrounds proximal portion of urethra • Ducts open into urethra • Secretes thin, milky, alkaline fluid • Neutralizes acidic fluid containing sperm cells • Neutralizes acidic vaginal secretions • Enhances motility of sperm cells

16. 10. Bulbourethral Glands AKA, Cowper’s glands Located inferiorly to the prostate gland, within muscle fibers of external urethral sphincter Secretes mucuslike fluid to lubricate the end of the penis for sexual intercourse (As always, females do most of the work of producing lubricating fluid. :)

17. Semen • The fluid the male urethra releases during ejaculation • Consists of: • Sperm cells • Secretions of the seminal vesicles, prostate gland, and bulbourethral glands • About 120 million sperm cells/mL semen • 2-5 mL semen released at a time

18. Enlarged Prostate Gland • Where is the prostate gland located??? • So, what would happen if the prostate gland became enlarged? • Testing for prostate cancer: • Rectal exam • PSA (prostate-specific antigen) blood test to check for a cell surface protein found on prostate cells • Ultrasound

19. Treatment Options for Enlarged Prostate Gland Surgical removal of prostate Radiation Microwave energy delivered through a probe inserted into the urethra or rectum Freeze tumor with liquid nitrogen delivered by a probe through the skin Others

20. Male External Accessory Organs Scrotum Penis

21. 2. Scrotum 1.Pouch of skin that houses the testes 2. Medial septum divides it into 2 chambers 3. Protects and aids in temperature regulation of the testes

22. 11. Penis Conveys urine and semen through the urethra to the outside The body (shaft) has 3 columns of erectile tissue: A pair of dorsally located corpora cavernosa (12) A single, ventralcorpus spongiosum (13)

23. 11. Penis, continued….. Corpus spongiosum: Urethra passes through it Enlarges at distal end to form the glans penis (14) Glans penis Covers the ends of the corpora cavernosa Bears urethral opening (orifice) Contains sensory receptors Prepuce (15)– fold of skin that covers the glans penis; removed in circumcision