HUMAN REPRODUCTION
STRUCTURE AND FUNCTION OF MALE REPRODUCTIVE SYSTEM
- The male sex organ = testes
- Ducts and tubules – seminiferous tubules, epididymis, vas deferens and the urethra
- Accessory glands – prostate gland, Cowper’s gland and seminal vesicles
- External genitalia – penis
Organ Structure function
Testes Pair of organs containing seminiferous Seminiferous tubules: spermatogenesis
tubules and germinal epithelium cells GE: produces testosterone under pituitary LH.
scrotum Sac of skin and muscle fibers that enclose the maintains their temperature at ~34 °C, essential
testes for effective spermatogenesis.
Epididymis Coiled duct lined with ciliated epithelium Site of sperm maturation (1–10 days); stores
and smooth muscle sperm up to 4 weeks before reabsorption:
Sperm duct Muscular tube (sperm duct) capable of Stores sperm for up to several months; propels
(vas deferens) peristalsis. Site of vasectomy them to the urethra during ejaculation.
Penis spongy erectile tissue and the glans; covered Delivers sperm to the cervix; erection of spongy
(in uncircumcised males) by the prepuce tissue; glans rich in sensory cells essential for
(foreskin) erection reflex
Prostate gland Glandular tissue secreting an alkaline fluid Contributes alkaline fluid to semen, neutralizing
vaginal acidity to maintain sperm
Seminal vesicle Glandular sac producing seminal volume; provide sperm with a respiratory substrate and
fluid rich in fructose and alkaline bulk of semen.
Cowper gland On either side of the urethra Secretes yellow fluid, cleans urethra
, Semen is the fluid ejaculated from the urethra during sexual excitation.
- Sperm (250 million per ejaculation)
>Prostate gland secretions: alkaline fluid that contributes to semen, helps to neutralize the acidic
>Cowper’s gland secretions: antacid fluid and mucus that lubricates and neutralizes acidity.
>Seminal vesicle secretions: alkaline, fructose-rich fluid forming the bulk of semen volume
The alkaline secretions neutralize the acidic environment of the female vagina
Sperm Semen
Definition Male gametes - cells carrying paternal DNA Fluid mixture ejaculated + secretions
Function Carry genetic material Transport medium, neutralize vaginal
acidity, nutrients and activate sperm
Composition Individual cells 1 % sperm + 99 % secretions
Storage location Produced in seminiferous tubules Stored collectively in reproductive tract
Mature in epididymis ducts and glands until ejaculation
Erection Ejaculation
Definition stiffening of penis due to blood filling spongy Forceful expulsion of semen from the urethra
erectile tissues
Trigger Sexual arousal Peak of sexual stimulation
Mechanism Dilation penile arteries → increased blood Constriction of arteries follows erection
MALE CIRCUMCISION IN SOUTH AFRICA
- Ritual circumcision in Xhosa culture is initiation marking a boy’s transition to manhood
- Epidemiological research shows circumcised men have a lower HIV risk
ISSUES:
Traditional surgeon’s training: Inadequately trained may use poor technique or operate under the influence of
alcohol. Instrumentation sterility
- Use of blunt or reused spreads infections
- Prevalent STDs: Earlier sexual activity and unsterilized equipment.
- Tight thong bandages = tissue loss.
- Dehydration: Drinking is taboo post-circumcision; poor wound healing.
STRUCTURE AND FUNCTION OF MALE REPRODUCTIVE SYSTEM
- The male sex organ = testes
- Ducts and tubules – seminiferous tubules, epididymis, vas deferens and the urethra
- Accessory glands – prostate gland, Cowper’s gland and seminal vesicles
- External genitalia – penis
Organ Structure function
Testes Pair of organs containing seminiferous Seminiferous tubules: spermatogenesis
tubules and germinal epithelium cells GE: produces testosterone under pituitary LH.
scrotum Sac of skin and muscle fibers that enclose the maintains their temperature at ~34 °C, essential
testes for effective spermatogenesis.
Epididymis Coiled duct lined with ciliated epithelium Site of sperm maturation (1–10 days); stores
and smooth muscle sperm up to 4 weeks before reabsorption:
Sperm duct Muscular tube (sperm duct) capable of Stores sperm for up to several months; propels
(vas deferens) peristalsis. Site of vasectomy them to the urethra during ejaculation.
Penis spongy erectile tissue and the glans; covered Delivers sperm to the cervix; erection of spongy
(in uncircumcised males) by the prepuce tissue; glans rich in sensory cells essential for
(foreskin) erection reflex
Prostate gland Glandular tissue secreting an alkaline fluid Contributes alkaline fluid to semen, neutralizing
vaginal acidity to maintain sperm
Seminal vesicle Glandular sac producing seminal volume; provide sperm with a respiratory substrate and
fluid rich in fructose and alkaline bulk of semen.
Cowper gland On either side of the urethra Secretes yellow fluid, cleans urethra
, Semen is the fluid ejaculated from the urethra during sexual excitation.
- Sperm (250 million per ejaculation)
>Prostate gland secretions: alkaline fluid that contributes to semen, helps to neutralize the acidic
>Cowper’s gland secretions: antacid fluid and mucus that lubricates and neutralizes acidity.
>Seminal vesicle secretions: alkaline, fructose-rich fluid forming the bulk of semen volume
The alkaline secretions neutralize the acidic environment of the female vagina
Sperm Semen
Definition Male gametes - cells carrying paternal DNA Fluid mixture ejaculated + secretions
Function Carry genetic material Transport medium, neutralize vaginal
acidity, nutrients and activate sperm
Composition Individual cells 1 % sperm + 99 % secretions
Storage location Produced in seminiferous tubules Stored collectively in reproductive tract
Mature in epididymis ducts and glands until ejaculation
Erection Ejaculation
Definition stiffening of penis due to blood filling spongy Forceful expulsion of semen from the urethra
erectile tissues
Trigger Sexual arousal Peak of sexual stimulation
Mechanism Dilation penile arteries → increased blood Constriction of arteries follows erection
MALE CIRCUMCISION IN SOUTH AFRICA
- Ritual circumcision in Xhosa culture is initiation marking a boy’s transition to manhood
- Epidemiological research shows circumcised men have a lower HIV risk
ISSUES:
Traditional surgeon’s training: Inadequately trained may use poor technique or operate under the influence of
alcohol. Instrumentation sterility
- Use of blunt or reused spreads infections
- Prevalent STDs: Earlier sexual activity and unsterilized equipment.
- Tight thong bandages = tissue loss.
- Dehydration: Drinking is taboo post-circumcision; poor wound healing.
