By Lauren and Jocelyn

The male reproductive system

The Male Reproductive System

Production of Sperm•http://highered.mcgraw-hill.com/sites/0072495855/student_view0/chapter28/animation__spermatogenesis__quiz_1_.

html

•Sperm have a head, body, and tail

•Have a flagellum for movement

•Inside the acrosome

are enzymes that

penetrate the

protective layer of the

egg

Development•S

eminiferous tubules begin to develop 43 to 50 days after conception

•After 9 to 10 weeks Leydig cells begin to secrete testosterone. This converts indifferent structures into male genitalia

•Shortly before birth the testes descend through the inguinal canal into the scrotum.

Structure and Function•S

eminiferous tubules-coiled inside the testis. Produce sperm

•Epididymis-long coiled tube. First place sperm travels after bring produced. Sperm has to stay here for 18 hours before mobile.

Structure and Function Cont.

•Vas deferens-long tube where sperm travels from the epididymis. Goes into the abdominal cavity.

•Seminal vesicles-glands producing a fructose rich fluid, 60% of the semen volume.

Structure and Function Cont.

•Prostate gland-located at the base of the urinary bladder. The size of a golf ball and spongy. Contributes to 30% of the semen volume.

•Urethra-inside the prostate gland. Merges with the ejaculatory duct. Carries semen out of the body through the penis

Structure and Function Cont.

•Bulbourethral glands-secretes a fluid lining the urethra and lubricates the of the penis before intercourse.

•Penis-contains two columns of erectile tissue, the corpora cavernosa and the

corpus spongiosum

Erections•C

aused by the release of nitric oxide, dilating the arterioles in the penis

•This increases pressure in the erectile tissue, which compresses the veins, causing blood to flow to the penis

•Some medicines promote the action

of the nitric oxide, prolonging

the erection (think Viagra!)

Ejaculation•R

esults from the erection•2

-5 milliliters of semen with an average of 300 million sperm are ejaculated from the penis

•Males with fewer than 20 million sperm per milliliter are generally considered sterile

Hormones•F

ollicle-stimulating hormone-stimulates spermatogenesis

•Luteinizing hormone-stimulates secretion of testosterone by Leydig cells

•Testosterone-stimulates development and maintenance of male secondary sexual characteristics, accessory sex organs, and spermatogenesis

Disorders•T

esticular trauma-injuries can occur when the testicles are either kicked, hit, crushed, or struck, usually during sports.

•Inguinal hernia-a part of the intestines pushes through an opening or weakening in the groin or scrotum.

•Ambiguous genitalia-this occurs

when a child is born with

genitals that aren't clearly

male or female

Why is it necessary?•I

t is necessary for reproduction. Without the male reproductive system, there would be no way to produce sperm. The egg would not be fertilized and we would have no babies.

Interdependency•T

he male reproductive system depends on the female reproductive system. If one of the systems are faulty, then the sperm and the egg will not meet to make babies. Without the female

reproductive system,

there would just be a

hole lot of sperm and

no eggs!!

Interdependency Cont.•T

hese same structures are also used in the expenditure of urine

•Also, works with the endocrine system-the testes secrete the male sex hormone testosterone

Simple Male Reproductive Systems

•Some reptiles and birds have a penis but most have a single opening for the reproductive, excretory, and digestive systems called a cloaca.

•In some types of reproduction, gametes are released into the water and they swim to the egg