Male reproductive - Tutorial 6

• Location: A hairy sac of skin and connective tissue that hangs outside the pelvic cavity at the root of the penis Function: The scrotum helps regulate the temperature of the testes, by contraction of the cremaster muscle to either pull the scrotum closer to the body in cold weather or to hang more loosely in warm weather

In cold conditions the testes are pulled closer to the pelvic floor and the warmth of the body by the cremaster muscle and dartos muscle

• Control release of sperm into lumen of the seminiferous tubule • Produce testicular fluid for transport of sperm • Supports and provide nutrients for 70 days while the cells undergo meiosis and develop into sperm -Sometimes called a “nurse cell” because of it’s role in nurturing the developing sperm cells

• Acrosome: is a cap-like vesicle containing enzymes to help the sperm penetrate the secondary oocyte for fertilization • Tail: propels the sperm • Mitochondria: is contained in the midpiece of the sperm, provides energy so that the tail can propel the sperm through the female reproductive tract

• GnRH • LH • FSH

• Controls the growth, development, functioning and maintenance of sex organs • Stimulates sperm maturation, bone growth and protein synthesis • Stimulates development of male secondary sex characterises during puberty

• Site for sperm to mature and gain mobility over 14 days • Stores sperm • Propels sperm into ductus (vas) deferens by peristalsis during sexual arousal

• Transports sperm from the epididymis to the urethra by peristalsis • Can store sperm for several months

• Testicular blood vessels • Autonomic nerves • Lymphatic vessels • Ductus (vas) deferens • Cremaster muscle

• Location: The ductus (vas) deferens leads to the short ejaculatory duct, the duct runs through the superior aspect of the prostate gland Function: The ejaculatory duct ejects sperm and seminal vesicle secretions into urethra just before ejaculation

• Location: A golf-sized gland that encircles the urethra just inferior to the urinary bladder • Function: During ejaculation smooth muscles contracts squeezing glandular secretions into the urethra via several ducts

• Location: Small glands located inferiorly to the prostate gland at the root of the penis Function: Produce a thick, clear, alkaline mucus which drains into the urethra and lubricates the male urethra during sexual excitement. Neutralises acidic urine

It carries urine out of the bladder and propels semen along the length of the penis for discharge during ejaculation

During ejaculation a smooth muscle sphincter at the base of the urinary bladder closes (involuntary/reflex action), preventing urine from entering the urethra and preventing semen entering the urinary bladder

• At 55 yrs decreased testosterone results in decreased muscular strength, fewer viable sperm (amount is not affected) and decreased sexual desire • Benign prostatic hypertrophy (hyperplasia) can cause frequent urination, decreased force of urine stream, sensation of incomplete emptying of the bladder (this is not cancerous but often requires treatment)

Onset of puberty at 12 - 14 yrs. Pulses of GnRH stimulate production of LH and FSH