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Infertility. Infertility is defined as the inability to conceive a pregnancy after 12 months of unprotected sexual intercourse. Human Reproduction. Reproduction. The process of forming new organisms from existing organisms. Why?. Main functions. Reproduction Includes
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Infertility • Infertility is defined as the inability to conceive a pregnancy after 12 months of unprotected sexual intercourse.
Reproduction The process of forming new organisms from existing organisms. Why?
Main functions Reproduction Includes • producing sperm and testosterone • male characteristics • transport of sperm • deposit sperm into the female
Side view – male reproductive system bladder Sperm duct Seminal vesicle Prostate Ejaculatory duct rectum Urethra epididymis Penis testis Scrotum
Major Components • scrotum • testes & epididymis • duct system • accessory glands • penis
1. Scrotum • Keeps the temperature just right for sperm development (2 -3°C) below core body temp
2 Testes – male gonads 2 major functions • produce sperm • Produce testosterone • Sperm formation begins here at puberty. lobule septae Seminiferous tubules
4. Epididymis • stores and protects sperm • sperm mature here • Sperm may be stored here for several months.
5. Sperm duct (vas deferens) • Connects epididymis to urethra
6. Urinary bladder • Stores and expels urine from the body. • Valve at the base of the bladder closes during ejaculation.
7. Urethra • extends from the bladder to the urethral opening • transports both urine and semen to the outside through the urethral opening
8. Penis • contains spongy erectile tissue that becomes filled with blood during sexual excitement → an erection.
Passage of sperm (TESUP) Testis Epididymis Sperm duct (vas deferens) Urethra Penis
7. Accessory glands • Prostate • Seminal vesicles • Bulbo-urethral glands (Cowper’s glands)
a. Prostate gland • ~ 40% of seminal fluid • Milky alkaline fluid • Acts as a pump during ejaculation
b. Seminal vesicle • ~ 60% of semen • Has fructose an energy source for sperm
c. Bulbo-urethral glands (cowper’s glands) • Fluid neutralises any urine residue in the urethra,
Semen Semen = seminal fluid + sperm Functions • nourish sperm • neutralise acidity of female • fluid in which sperm can swim. 99% 1%
Side view – male reproductive system Pubic bone Seminal vesicle urethra Erectile tissue Prostate gland Sperm duct (vas deferens) penis Urethral opening epididymis Bulbo-urethral gland scrotum
Asexual One parent Offspring and parent – identical genetic make-up (clone). → no genetic variation in offspring Without sex - does not involve the union of two sex cells. Common in bacteria, protists, fungi, plants and some simple animals. Sexual Involves union of a male and female sex cell – fertilisation. Usually two parents. Offspring combination of genes from both parents → genetic variation in offspring. Common in plants and animals Reproduction Many simple organisms can reproduce both sexually and asexually.