1. Sexual Reproduction

2. Male Reproductive System

3. Gonads
Testis:
Seminiferous tubules: coiled ducts (~ long), where (male sex cell) made (several 100 million/day)
Intestitial cells (Leydig cells): between tubules & secrete
Scrotum: sac that holds testis outside , which provides lower temperature ( °C) needed for sperm production

4. Duct System Epididymis:
coiled tubes in sac (~6m long), where sperm mature over days & stored for weeks
Ductus deferens (Vas Deferens):
tube that sperm from testes to by peristalsis during ejaculation
curves around & empties into urethra

5. Accessory Organs Seminal Vesicles:
produces thick, secretion into vas deferens that:
has pH (basic): protects sperm from low pH (acidic) in vagina
contains : provides energy for sperm
contains : causes uterine contractions, which sperm towards egg
located at of urinary bladder

6. produces thin, white secretion into deferens that:
Prostate Gland:
produces thin, white secretion into deferens that:
has alkaline pH to:
neutralize pH in vagina
increases pH to activate sperm ( at pH 7.5)
helps sperm
located below urinary bladder & top of urethra

7. Cowper’s gland (bulbourethral gland)
produces secretion into urethra that:
has alkaline to protect sperm from urine (acidic) in urethra
provides during sexual intercourse
pea–sized located below prostate
NOTE: sperm become motile (capable of ) after maturing in epididymis, but not active exposed to secretions from seminal vesicles & prostate gland in vas

8. Penis external structure that delivers sperm into
erectile tissue: sponge–like with many that fill with blood by constricting veins during
glans penis: head that contains many endings for sexual excitement
force of ejaculation provided by of smooth muscle in vas deferens, then skeletal in pelvis

9. SPERM:
head: contains
acrosome: enzymes to help sperm penetrate egg
midpiece: contains mitochondria to provide energy for tail
tail: flagellum for movement
continuously made in seminiferous of testes through

10. Spermogensis
spermatogonia (46 chromosomes) → meiosis & differentiation → sperm cell (23 chromosomes)

11. Route of Sperm
during , 200–500 million sperm ejaculated in 3–4mL of seminal
sphincter at of bladder before ejaculation

12. SEMINAL FLUID (SEMEN)
fluid expelled from penis that secretions from , seminal vesicles, prostate gland, & Cowper’s gland
sperm in fluid survive only 24–48 h
Functions
provides medium for of sperm
provides for sperm
activates sperm by alkaline pH
neutralizes urine in urethra
neutralizes acidic environment of vagina
provides which cause uterus to contract (sperm to egg)
provides lubrication intercourse

13. Testosterone: male sex hormone
produced by testes in males & adrenal medulla in females (in lower conc.)
Functions in males:
before puberty, development of penis & testes (sex organs)
at puberty, stimulates:
spermatogenesis
sex drive
development of male sex characteristics,
facial, , & pubic hair
products from oil & sweat glands in skin, which causes acne
enlargement of larynx, which causes voice
increased strength
aggression
baldness (if gene present)
Function in females:
body (muscle & bone), sex drive, & pubic hair growth

14. leutenizing hormone (LH): stimulates secretion of
follicle hormone (FSH): stimulates spermatogenesis
NOTE: testosterone also required for spermatogenesis
secretion from pituitary gland stimulated by secretion of gonadotropin hormone (GnRH) from hypothalamus
secretions from hypothalamus & anterior gland regulated by testosterone in blood plasma through negative
NOTE: LH, FSH, & testosterone secreted into blood plasma

15. By the End of this Section You should be able to :
identify and give functions for each of the following:
– testes (seminiferous tubules and interstitial cells)
– scrotum
– epididymis
– ductus (vas) deferens
– prostate gland
– Cowper’s glands
– seminal vesicles
– penis
– urethra
describe the path of sperm from the seminiferous tubules to the urethral opening
List the components seminal fluid (as contributed by the Cowper’s glands, prostate gland, and seminal vesicles), and describe the functions of each component
identify the tail (flagellum), midpiece, head, and acrosome of a mature sperm and state their functions
describe the functions of testosterone
describe the homeostatic regulation of testosterone levels by the hypothalamus, anterior pituitary, and testes