1. Male Reproductive System

2. Male Reproductive Anatomy
Prepuce (foreskin)
Penis
Scrotum

3. Supporting structures
Essential organs
testes (2) - one of the pair of male gonads that produce semen; suspended in the scrotum by the spermatic cords; descend at 7 months in utero into the scrotum accompanied by an evagination of muscular and connective tissue of the body wall that suspend the testes
Accessory Organs
Genital ducts – send sperm to outside of body
epididymis (2)
vasa deferens (2)
ejaculatory duct (2)
urethra
Accessory Glands – produce secretions that nourish, transport and mature sperm
seminal vesicles (2)
prostate
bulbourethral (2)
Supporting structures
scrotum
penis
spermatic cords (2)

5. Vas deferens
Vas deferens
Corpus cavernosum
Corpus spongiosum

6. Spermatogenesis Spermatogonia mitosis Primary spermatocytes meiosis
Secondary spermatocytes
meiosis
Spermatids
Spermatozoa (motile)
epididymis

7. Male Reproductive Cycle
Organ development in utero; testes descend into scrotum at 7 months in utero
Reproductive function at puberty
high hormone levels stimulate final stages of development
Sperm production
Spermatogenesis
mitosis meiosis
spermatogonia primary spermatocytes secondary spermatocytes
meiosis
spermatids spermatozoa (motile)
Sperm
Produced in seminiferous tubules when reach puberty
Spermatids mature to spermatozoa in epididymis
There are about million of those little guys in the average amount of semen produced each time a man ejaculates.
It takes 10 weeks for a single soldier to reach maturity.
Mature sperm can live up to 2 weeks in the epididymis
Healthy males produce about million sperm a day

8. Spermatozoa
Acrosome - resembles a toque which covers the upper portion of the head of the sperm. The covering contains enzymes that help the sperm penetrate the egg.
Head – contains the 23 chromosomes (genetic material) capable of merging with an egg to produce a new individual.
Midpiece – connects the head of the sperm to the tail. It contains many mitochondria that produce ATP. This ATP is used to move the microtubules in the tail and create propulsion for the sperm. Once in the female system, sperm will "swim" for up to 2 days looking for an egg.
Tail - flagellum with microtubules. The microtublues within the tail move past each other and move the tail in a whip-like motion. ATP provided by the midpiece is required for this movement.
Acrosome

9. Pathway of Sperm
Sperm travel from the testes
to the epididymis where they mature
During ejaculation sperm travel up into the abdomen from the epididymis in the vas deferens to the ejaculatory ducts.
The ejaculatory ducts move semen into the urethra. Once in the urethra, semen (sperm now is bathed in the seminal fluid released from the various other reproductive structures) moves through the
prostate gland and down to the urethral opening at the tip of the penis.
The seminal vesicles and bulbourethral glands are not included in the path of sperm as they contribute to seminal fluid but do not have sperm moving through them at any time.

10. Seminal Fluid (Semen) Semen Sperm – 10% Fluid – 90%
Semen only contains about 10% sperm - the rest consists of enzymes, vitamin C, calcium, protein, sodium, zinc, citric acid and fructose sugar.
Produced from 3 glands
Seminal vesicle – 60% of seminal fluid
yellowish fluid rich in nutrients (fructose)
Prostate – 30% of seminal fluid
spongy, secretes milk, alkaline fluid
Bulbourethral – 10% of seminal fluid
thin, clear mucus that neutralizes pH of urine and lubricates

11. Fertility Factors: Infertility sperm count sperm size sperm shape
sperm motility
Infertility
caused by antibodies some men make against own sperm
less than 20 million/mL of semen
Some things that may reduce sperm number and/or quality include:
alcohol, drugs, environmental toxins, including pesticides, smoking cigarettes, health problems, medicines, radiation treatment and chemotherapy for cancer, age

12. Male Reproductive Hormones
GnRH – gonadotropin releasing hormone
LH – leutinizing hormone
FSH – follicle stimulating hormone
Hypothalamus
GnRH
Pituitary
LH FSH
Testes
Testosterone Sperm
testosterone – secreted by Leydig cells
develop and maintain secondary sex characteristics
regulate metabolism; known as anabolic hormone
stimulates protein anabolism to promotes bone and muscle growth
early maturation leads to epiphyseal closure
late maturation, delayed epiphyseal closure
fluid and electrolyte metabolism
inhibits anterior pituitary secretion of gonadotropins (FSH and LH)