Male Reproduction System Structure and Function Male Reproductive

Male Reproduction System Structure and Function

Male Reproductive System - Index l Reproductive anatomy l Transport of sperm l Spermatogenesis l Hormonal control of reproduction l surgrical birth control l Common Cancers

Basic anatomy

Side View Vas deferens Ejaculatory duct Urinary bladder Pubic bone Prostate gland Penis Epididymis Urethra Testis Bulbourethral gland

Basic Function l Testes ¡site of sperm and testosterone production. l Epididymis ¡holds and matures sperm. l Vas deferens ¡transports sperm to the urethra. l Scrotum ¡regulates temperature for optimum sperm production.

Basic Function (cont. ) l Seminal Vesicles / Prostate / Cowper’s ¡glands that create semen. l Prostate Muscle ¡ forces semen and sperm out during ejaculation. l Ejaculatory duct ¡ regulates when sperm and semen enter the urethra. l Urethra ¡ transports sperm or urine out of the body. l Penis and erectile tissue ¡ ensure proper position for depositing sperm. ¡ Video

Male Anatomy - front

Semen l. Transports sperm to female l. Nourishes sperm l. Protects sperm

Fluid l Glands secrete it ¡seminal vesicles (4) ldrain into ejaculatory duct ¡prostate gland lejaculatory duct join urethra lsecretes fluid into urethra ¡bulbourethral gland (cowpers) Produce 95% of the ejaculate volume ldrains into urethra at the base of the prostate Video

Nutrients l Glands ¡seminal vesicle lfructose (energy) lprostaglandins (muscle contraction in female) ¡prostate gland lalkaline buffer (against acid in vagina – like tums) ¡bulbourethral gland (cowpers) lmucus (pre-cum, cleans urethra, aid movement)

Spermatogenesis creation of sperm

Occurs in Testes l Seminiferous tubules ¡ Sertoli Cells l Respond to FSH l Start sperm production, and nourish developing sperm Lumen seminiferous tubule Leydig cell Sertoli Cells Sperm Cross Section of Testis

Spermatogenesis – in tubules Video

Why males can produce for their lifetime. l Spermatogonia ¡ stem cells that are the precursors of sperm. ¡ divide by mitosis to produce more spermatogonia or ¡ differentiate into spermatocytes.

Reductional Division l Spermatocytes ¡ divide by meiosis to produce 4 haploid spermatids. l Spermatids ¡ differentiate into sperm, losing most of their cytoplasm.

Sperm - Structure l Head ¡ acrosome l enzymes allow penetration of ova ¡ nucleus l DNA, essential for new organism l Middle piece ¡ lots of mitochondria l Tail ¡ flagellum rotates like corkscrew

Testes also produce testosterone l Interstitial space ¡ Leydig cells l Respond to LH l Start testosterone production into blood Lumen seminiferous tubule Leydig cell Sertoli Cells Sperm Cross Section of Testis

Hormonal Control

Hormonal Control Hypothalamus Gn. RH - Anterior Pituitary FSH Stimulate Spermatogenesis (Androgen Binding Protein) Inhibin - LH Testes Sertoli Cell Leydig Cell Testosterone Accessory reproductive organs Secondary sex characteristics

Testosterone - secondary sex traits l hair distribution l growth of larynx l bone growth l protein synthesis l male pattern baldness l sex drive l aggressive behavior (? )

Surgical Birth Control

Vasectomy l cutting the vas deferens tubes and sealing them with stitches or heat. l done under local anaesthesia.

Common Cancers

Common Cancers l Testicular ¡Detect with self examination ¡Early l Prostate Gland ¡Detect at the doctors office ¡Later

Summary Video Crash Course